Sense of awareness of self and of the environment.
Organic mental disorders in which there is impairment of the ability to maintain awareness of self and environment and to respond to environmental stimuli. Dysfunction of the cerebral hemispheres or brain stem RETICULAR FORMATION may result in this condition.
Loss of the ability to maintain awareness of self and environment combined with markedly reduced responsiveness to environmental stimuli. (From Adams et al., Principles of Neurology, 6th ed, pp344-5)
Vegetative state refers to the neurocognitive status of individuals with severe brain damage, in whom physiologic functions (sleep-wake cycles, autonomic control, and breathing) persist, but awareness (including all cognitive function and emotion) is abolished.
A profound state of unconsciousness associated with depressed cerebral activity from which the individual cannot be aroused. Coma generally occurs when there is dysfunction or injury involving both cerebral hemispheres or the brain stem RETICULAR FORMATION.
An intravenous anesthetic agent which has the advantage of a very rapid onset after infusion or bolus injection plus a very short recovery period of a couple of minutes. (From Smith and Reynard, Textbook of Pharmacology, 1992, 1st ed, p206). Propofol has been used as ANTICONVULSANTS and ANTIEMETICS.
Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.
Ultrashort-acting anesthetics that are used for induction. Loss of consciousness is rapid and induction is pleasant, but there is no muscle relaxation and reflexes frequently are not reduced adequately. Repeated administration results in accumulation and prolongs the recovery time. Since these agents have little if any analgesic activity, they are seldom used alone except in brief minor procedures. (From AMA Drug Evaluations Annual, 1994, p174)
Devices used to assess the level of consciousness especially during anesthesia. They measure brain activity level based on the EEG.
The act of "taking account" of an object or state of affairs. It does not imply assessment of, nor attention to the qualities or nature of the object.
A love or pursuit of wisdom. A search for the underlying causes and principles of reality. (Webster, 3d ed)
A scale that assesses the response to stimuli in patients with craniocerebral injuries. The parameters are eye opening, motor response, and verbal response.
The major of two hallucinogenic components of Teonanacatl, the sacred mushroom of Mexico, the other component being psilocin. (From Merck Index, 11th ed)
Those forces and content of the mind which are not ordinarily available to conscious awareness or to immediate recall.
Continuous sequential changes which occur in the physiological and psychological functions during the life-time of an individual.
A transient loss of consciousness and postural tone caused by diminished blood flow to the brain (i.e., BRAIN ISCHEMIA). Presyncope refers to the sensation of lightheadedness and loss of strength that precedes a syncopal event or accompanies an incomplete syncope. (From Adams et al., Principles of Neurology, 6th ed, pp367-9)
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Procedure in which patients are induced into an unconscious state through use of various medications so that they do not feel pain during surgery.
Medical philosophy is a branch of philosophy that deals with the concepts, values, and nature of medicine, including its ethical implications, epistemological foundations, and societal impact, aimed at informing and improving medical practice, research, and education.
Drugs used to induce drowsiness or sleep or to reduce psychological excitement or anxiety.
Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.
Traumatic injuries involving the cranium and intracranial structures (i.e., BRAIN; CRANIAL NERVES; MENINGES; and other structures). Injuries may be classified by whether or not the skull is penetrated (i.e., penetrating vs. nonpenetrating) or whether there is an associated hemorrhage.
Clinical or subclinical disturbances of cortical function due to a sudden, abnormal, excessive, and disorganized discharge of brain cells. Clinical manifestations include abnormal motor, sensory and psychic phenomena. Recurrent seizures are usually referred to as EPILEPSY or "seizure disorder."
The constant checking on the state or condition of a patient during the course of a surgical operation (e.g., checking of vital signs).
Paired bodies containing mostly GRAY MATTER and forming part of the lateral wall of the THIRD VENTRICLE of the brain.
A generalized seizure disorder characterized by recurrent major motor seizures. The initial brief tonic phase is marked by trunk flexion followed by diffuse extension of the trunk and extremities. The clonic phase features rhythmic flexor contractions of the trunk and limbs, pupillary dilation, elevations of blood pressure and pulse, urinary incontinence, and tongue biting. This is followed by a profound state of depressed consciousness (post-ictal state) which gradually improves over minutes to hours. The disorder may be cryptogenic, familial, or symptomatic (caused by an identified disease process). (From Adams et al., Principles of Neurology, 6th ed, p329)
Process of administering an anesthetic through injection directly into the bloodstream.
A disorder characterized by recurrent partial seizures marked by impairment of cognition. During the seizure the individual may experience a wide variety of psychic phenomenon including formed hallucinations, illusions, deja vu, intense emotional feelings, confusion, and spatial disorientation. Focal motor activity, sensory alterations and AUTOMATISM may also occur. Complex partial seizures often originate from foci in one or both temporal lobes. The etiology may be idiopathic (cryptogenic partial complex epilepsy) or occur as a secondary manifestation of a focal cortical lesion (symptomatic partial complex epilepsy). (From Adams et al., Principles of Neurology, 6th ed, pp317-8)
Acute and chronic (see also BRAIN INJURIES, CHRONIC) injuries to the brain, including the cerebral hemispheres, CEREBELLUM, and BRAIN STEM. Clinical manifestations depend on the nature of injury. Diffuse trauma to the brain is frequently associated with DIFFUSE AXONAL INJURY or COMA, POST-TRAUMATIC. Localized injuries may be associated with NEUROBEHAVIORAL MANIFESTATIONS; HEMIPARESIS, or other focal neurologic deficits.
A series of thoughts, images, or emotions occurring during sleep which are dissociated from the usual stream of consciousness of the waking state.
Prolonged unconsciousness from which the individual cannot be aroused, associated with traumatic injuries to the BRAIN. This may be defined as unconsciousness persisting for 6 hours or longer. Coma results from injury to both cerebral hemispheres or the RETICULAR FORMATION of the BRAIN STEM. Contributing mechanisms include DIFFUSE AXONAL INJURY and BRAIN EDEMA. (From J Neurotrauma 1997 Oct;14(10):699-713)
A drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions are required to maintain a patent airway. (From: American Society of Anesthesiologists Practice Guidelines)
A state in which there is an enhanced potential for sensitivity and an efficient responsiveness to external stimuli.
Philosophy based on the analysis of the individual's existence in the world which holds that human existence cannot be completely described in scientific terms. Existentialism also stresses the freedom and responsibility of the individual as well as the uniqueness of religious and ethical experiences and the analysis of subjective phenomena such as anxiety, guilt, and suffering. (APA, Thesaurus of Psychological Index Terms, 8th ed.)
Tomography using x-ray transmission and a computer algorithm to reconstruct the image.
Gases or volatile liquids that vary in the rate at which they induce anesthesia; potency; the degree of circulation, respiratory, or neuromuscular depression they produce; and analgesic effects. Inhalation anesthetics have advantages over intravenous agents in that the depth of anesthesia can be changed rapidly by altering the inhaled concentration. Because of their rapid elimination, any postoperative respiratory depression is of relatively short duration. (From AMA Drug Evaluations Annual, 1994, p173)
A group of compounds that contain the general formula R-OCH3.
Loss of consciousness due to a reduction in blood pressure that is associated with an increase in vagal tone and peripheral vasodilation.
Drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposely following repeated painful stimulation. The ability to independently maintain ventilatory function may be impaired. (From: American Society of Anesthesiologists Practice Guidelines)
Bleeding into one or both CEREBRAL HEMISPHERES including the BASAL GANGLIA and the CEREBRAL CORTEX. It is often associated with HYPERTENSION and CRANIOCEREBRAL TRAUMA.
The symptom of PAIN in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of HEADACHE DISORDERS.
A nonspecific term used to describe transient alterations or loss of consciousness following closed head injuries. The duration of UNCONSCIOUSNESS generally lasts a few seconds, but may persist for several hours. Concussions may be classified as mild, intermediate, and severe. Prolonged periods of unconsciousness (often defined as greater than 6 hours in duration) may be referred to as post-traumatic coma (COMA, POST-HEAD INJURY). (From Rowland, Merritt's Textbook of Neurology, 9th ed, p418)
The period of emergence from general anesthesia, where different elements of consciousness return at different rates.
A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures.
A short-acting hypnotic-sedative drug with anxiolytic and amnestic properties. It is used in dentistry, cardiac surgery, endoscopic procedures, as preanesthetic medication, and as an adjunct to local anesthesia. The short duration and cardiorespiratory stability makes it useful in poor-risk, elderly, and cardiac patients. It is water-soluble at pH less than 4 and lipid-soluble at physiological pH.
The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.
Pathologic partial or complete loss of the ability to recall past experiences (AMNESIA, RETROGRADE) or to form new memories (AMNESIA, ANTEROGRADE). This condition may be of organic or psychologic origin. Organic forms of amnesia are usually associated with dysfunction of the DIENCEPHALON or HIPPOCAMPUS. (From Adams et al., Principles of Neurology, 6th ed, pp426-7)
Automatic, mechanical, and apparently undirected behavior which is outside of conscious control.
Bleeding into the intracranial or spinal SUBARACHNOID SPACE, most resulting from INTRACRANIAL ANEURYSM rupture. It can occur after traumatic injuries (SUBARACHNOID HEMORRHAGE, TRAUMATIC). Clinical features include HEADACHE; NAUSEA; VOMITING, nuchal rigidity, variable neurological deficits and reduced mental status.
Conditions characterized by recurrent paroxysmal neuronal discharges which arise from a focal region of the brain. Partial seizures are divided into simple and complex, depending on whether consciousness is unaltered (simple partial seizure) or disturbed (complex partial seizure). Both types may feature a wide variety of motor, sensory, and autonomic symptoms. Partial seizures may be classified by associated clinical features or anatomic location of the seizure focus. A secondary generalized seizure refers to a partial seizure that spreads to involve the brain diffusely. (From Adams et al., Principles of Neurology, 6th ed, pp317)
An interdisciplinary study dealing with the transmission of messages or signals, or the communication of information. Information theory does not directly deal with meaning or content, but with physical representations that have meaning or content. It overlaps considerably with communication theory and CYBERNETICS.
The study of the structure, growth, activities, and functions of NEURONS and the NERVOUS SYSTEM.
The scientific disciplines concerned with the embryology, anatomy, physiology, biochemistry, pharmacology, etc., of the nervous system.
Excision of part of the skull. This procedure is used to treat elevated intracranial pressure that is unresponsive to conventional treatment.
A disorder characterized by recurrent episodes of paroxysmal brain dysfunction due to a sudden, disorderly, and excessive neuronal discharge. Epilepsy classification systems are generally based upon: (1) clinical features of the seizure episodes (e.g., motor seizure), (2) etiology (e.g., post-traumatic), (3) anatomic site of seizure origin (e.g., frontal lobe seizure), (4) tendency to spread to other structures in the brain, and (5) temporal patterns (e.g., nocturnal epilepsy). (From Adams et al., Principles of Neurology, 6th ed, p313)
Health as viewed from the perspective that humans and other organisms function as complete, integrated units rather than as aggregates of separate parts.
Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.
Agents that induce various degrees of analgesia; depression of consciousness, circulation, and respiration; relaxation of skeletal muscle; reduction of reflex activity; and amnesia. There are two types of general anesthetics, inhalation and intravenous. With either type, the arterial concentration of drug required to induce anesthesia varies with the condition of the patient, the desired depth of anesthesia, and the concomitant use of other drugs. (From AMA Drug Evaluations Annual, 1994, p.173)
Accumulation of blood in the SUBDURAL SPACE between the DURA MATER and the arachnoidal layer of the MENINGES. This condition primarily occurs over the surface of a CEREBRAL HEMISPHERE, but may develop in the spinal canal (HEMATOMA, SUBDURAL, SPINAL). Subdural hematoma can be classified as the acute or the chronic form, with immediate or delayed symptom onset, respectively. Symptoms may include loss of consciousness, severe HEADACHE, and deteriorating mental status.
Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, INTRACRANIAL HYPERTENSION; HEADACHE; lethargy; URINARY INCONTINENCE; and ATAXIA.
Elements of limited time intervals, contributing to particular results or situations.
The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.
A standard and widely accepted diagnostic test used to identify patients who have a vasodepressive and/or cardioinhibitory response as a cause of syncope. (From Braunwald, Heart Disease, 7th ed)
Severe or complete loss of motor function in all four limbs which may result from BRAIN DISEASES; SPINAL CORD DISEASES; PERIPHERAL NERVOUS SYSTEM DISEASES; NEUROMUSCULAR DISEASES; or rarely MUSCULAR DISEASES. The locked-in syndrome is characterized by quadriplegia in combination with cranial muscle paralysis. Consciousness is spared and the only retained voluntary motor activity may be limited eye movements. This condition is usually caused by a lesion in the upper BRAIN STEM which injures the descending cortico-spinal and cortico-bulbar tracts.
A dental specialty concerned with the diagnosis and surgical treatment of disease, injuries, and defects of the human oral and maxillofacial region.
Agents that are capable of inducing a total or partial loss of sensation, especially tactile sensation and pain. They may act to induce general ANESTHESIA, in which an unconscious state is achieved, or may act locally to induce numbness or lack of sensation at a targeted site.
Fractures of the skull which may result from penetrating or nonpenetrating head injuries or rarely BONE DISEASES (see also FRACTURES, SPONTANEOUS). Skull fractures may be classified by location (e.g., SKULL FRACTURE, BASILAR), radiographic appearance (e.g., linear), or based upon cranial integrity (e.g., SKULL FRACTURE, DEPRESSED).
A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.
Bacterial infections of the leptomeninges and subarachnoid space, frequently involving the cerebral cortex, cranial nerves, cerebral blood vessels, spinal cord, and nerve roots.
Pathologic conditions affecting the BRAIN, which is composed of the intracranial components of the CENTRAL NERVOUS SYSTEM. This includes (but is not limited to) the CEREBRAL CORTEX; intracranial white matter; BASAL GANGLIA; THALAMUS; HYPOTHALAMUS; BRAIN STEM; and CEREBELLUM.
An acute neurological disorder characterized by the triad of ophthalmoplegia, ataxia, and disturbances of mental activity or consciousness. Eye movement abnormalities include nystagmus, external rectus palsies, and reduced conjugate gaze. THIAMINE DEFICIENCY and chronic ALCOHOLISM are associated conditions. Pathologic features include periventricular petechial hemorrhages and neuropil breakdown in the diencephalon and brainstem. Chronic thiamine deficiency may lead to KORSAKOFF SYNDROME. (Adams et al., Principles of Neurology, 6th ed, pp1139-42; Davis & Robertson, Textbook of Neuropathology, 2nd ed, pp452-3)
The selecting and organizing of visual stimuli based on the individual's past experience.
Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.
Study of the anatomy of the nervous system as a specialty or discipline.
Traumatic injuries to the cranium where the integrity of the skull is not compromised and no bone fragments or other objects penetrate the skull and dura mater. This frequently results in mechanical injury being transmitted to intracranial structures which may produce traumatic brain injuries, hemorrhage, or cranial nerve injury. (From Rowland, Merritt's Textbook of Neurology, 9th ed, p417)
Assessment of sensory and motor responses and reflexes that is used to determine impairment of the nervous system.
Brain waves characterized by a relatively high voltage or amplitude and a frequency of 8-13 Hz. They constitute the majority of waves recorded by EEG registering the activity of the parietal and occipital lobes when the individual is awake, but relaxed with the eyes closed.
An acute or subacute inflammatory process of the CENTRAL NERVOUS SYSTEM characterized histologically by multiple foci of perivascular demyelination. Symptom onset usually occurs several days after an acute viral infection or immunization, but it may coincide with the onset of infection or rarely no antecedent event can be identified. Clinical manifestations include CONFUSION, somnolence, FEVER, nuchal rigidity, and involuntary movements. The illness may progress to COMA and eventually be fatal. (Adams et al., Principles of Neurology, 6th ed, p921)
A state of reduced sensibility and response to stimuli which is distinguished from COMA in that the person can be aroused by vigorous and repeated stimulation. The person is still conscious and can make voluntary movements. It can be induced by CENTRAL NERVOUS SYSTEM AGENTS. The word derives from Latin stupere and is related to stunned, stupid, dazed or LETHARGY.
A barbiturate that is administered intravenously for the induction of general anesthesia or for the production of complete anesthesia of short duration.
Brain waves seen on EEG characterized by a high amplitude and a frequency of 4 Hz and below. They are considered the "deep sleep waves" observed during sleep in dreamless states, infancy, and in some brain disorders.
The cognitive and affective processes which constitute an internalized moral governor over an individual's moral conduct.
An intravenous anesthetic with a short duration of action that may be used for induction of anesthesia.
Surgical creation of an opening in a cerebral ventricle.
A potentially fatal syndrome associated primarily with the use of neuroleptic agents (see ANTIPSYCHOTIC AGENTS) which are in turn associated with dopaminergic receptor blockade (see RECEPTORS, DOPAMINE) in the BASAL GANGLIA and HYPOTHALAMUS, and sympathetic dysregulation. Clinical features include diffuse MUSCLE RIGIDITY; TREMOR; high FEVER; diaphoresis; labile blood pressure; cognitive dysfunction; and autonomic disturbances. Serum CPK level elevation and a leukocytosis may also be present. (From Adams et al., Principles of Neurology, 6th ed, p1199; Psychiatr Serv 1998 Sep;49(9):1163-72)
The state that distinguishes organisms from inorganic matter, manifested by growth, metabolism, reproduction, and adaptation. It includes the course of existence, the sum of experiences, the mode of existing, or the fact of being. Over the centuries inquiries into the nature of life have crossed the boundaries from philosophy to biology, forensic medicine, anthropology, etc., in creative as well as scientific literature. (Random House Unabridged Dictionary, 2d ed; Dr. James H. Cassedy, NLM History of Medicine Division)
The observable response of a man or animal to a situation.
A syndrome characterized by central nervous system dysfunction in association with LIVER FAILURE, including portal-systemic shunts. Clinical features include lethargy and CONFUSION (frequently progressing to COMA); ASTERIXIS; NYSTAGMUS, PATHOLOGIC; brisk oculovestibular reflexes; decorticate and decerebrate posturing; MUSCLE SPASTICITY; and bilateral extensor plantar reflexes (see REFLEX, BABINSKI). ELECTROENCEPHALOGRAPHY may demonstrate triphasic waves. (From Adams et al., Principles of Neurology, 6th ed, pp1117-20; Plum & Posner, Diagnosis of Stupor and Coma, 3rd ed, p222-5)
Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
A medical specialty concerned with the study of the structures, functions, and diseases of the nervous system.
Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.
Any operation on the cranium or incision into the cranium. (Dorland, 28th ed)
Historical term for a chronic, but fluctuating, disorder beginning in early life and characterized by recurrent and multiple somatic complaints not apparently due to physical illness. This diagnosis is not used in contemporary practice.
Neural tracts connecting one part of the nervous system with another.
The continuous measurement of physiological processes, blood pressure, heart rate, renal output, reflexes, respiration, etc., in a patient or experimental animal; includes pharmacologic monitoring, the measurement of administered drugs or their metabolites in the blood, tissues, or urine.
Cortical vigilance or readiness of tone, presumed to be in response to sensory stimulation via the reticular activating system.
Upper central part of the cerebral hemisphere. It is located posterior to central sulcus, anterior to the OCCIPITAL LOBE, and superior to the TEMPORAL LOBES.
Continuation of visual impression after cessation of stimuli causing the original image.
A childhood seizure disorder characterized by rhythmic electrical brain discharges of generalized onset. Clinical features include a sudden cessation of ongoing activity usually without loss of postural tone. Rhythmic blinking of the eyelids or lip smacking frequently accompanies the SEIZURES. The usual duration is 5-10 seconds, and multiple episodes may occur daily. Juvenile absence epilepsy is characterized by the juvenile onset of absence seizures and an increased incidence of myoclonus and tonic-clonic seizures. (Menkes, Textbook of Child Neurology, 5th ed, p736)
The use of two or more chemicals simultaneously or sequentially to induce anesthesia. The drugs need not be in the same dosage form.
The organic and psychogenic disturbances observed after closed head injuries (HEAD INJURIES, CLOSED). Post-concussion syndrome includes subjective physical complaints (i.e. headache, dizziness), cognitive, emotional, and behavioral changes. These disturbances can be chronic, permanent, or late emerging.
A short-acting opioid anesthetic and analgesic derivative of FENTANYL. It produces an early peak analgesic effect and fast recovery of consciousness. Alfentanil is effective as an anesthetic during surgery, for supplementation of analgesia during surgical procedures, and as an analgesic for critically ill patients.
A drive stemming from a physiological need for WATER.
The instinctive tendency (or ability) to assume a normal position of the body in space when it has been displaced.
Sudden temporary alterations in the normally integrative functions of consciousness.
Elevated level of AMMONIA in the blood. It is a sign of defective CATABOLISM of AMINO ACIDS or ammonia to UREA.
A branch of psychology which investigates the correlation between experience or behavior and the basic neurophysiological processes. The term neuropsychology stresses the dominant role of the nervous system. It is a more narrowly defined field than physiological psychology or psychophysiology.
The measure of that part of the heat or energy of a system which is not available to perform work. Entropy increases in all natural (spontaneous and irreversible) processes. (From Dorland, 28th ed)
The removal of a circular disk of the cranium.
The use of mind to cure disease, particularly physical illness.
A disorder characterized by CONFUSION; inattentiveness; disorientation; ILLUSIONS; HALLUCINATIONS; agitation; and in some instances autonomic nervous system overactivity. It may result from toxic/metabolic conditions or structural brain lesions. (From Adams et al., Principles of Neurology, 6th ed, pp411-2)
The formation of an area of NECROSIS in the CEREBRUM caused by an insufficiency of arterial or venous blood flow. Infarcts of the cerebrum are generally classified by hemisphere (i.e., left vs. right), lobe (e.g., frontal lobe infarction), arterial distribution (e.g., INFARCTION, ANTERIOR CEREBRAL ARTERY), and etiology (e.g., embolic infarction).
The chemical processes, enzymatic activities, and pathways of living things and related temporal, dimensional, qualitative, and quantitative concepts.
A prolonged seizure or seizures repeated frequently enough to prevent recovery between episodes occurring over a period of 20-30 minutes. The most common subtype is generalized tonic-clonic status epilepticus, a potentially fatal condition associated with neuronal injury and respiratory and metabolic dysfunction. Nonconvulsive forms include petit mal status and complex partial status, which may manifest as behavioral disturbances. Simple partial status epilepticus consists of persistent motor, sensory, or autonomic seizures that do not impair cognition (see also EPILEPSIA PARTIALIS CONTINUA). Subclinical status epilepticus generally refers to seizures occurring in an unresponsive or comatose individual in the absence of overt signs of seizure activity. (From N Engl J Med 1998 Apr 2;338(14):970-6; Neurologia 1997 Dec;12 Suppl 6:25-30)
Systems for assessing, classifying, and coding injuries. These systems are used in medical records, surveillance systems, and state and national registries to aid in the collection and reporting of trauma.
Imidazole derivative anesthetic and hypnotic with little effect on blood gases, ventilation, or the cardiovascular system. It has been proposed as an induction anesthetic.
A state of prolonged irreversible cessation of all brain activity, including lower brain stem function with the complete absence of voluntary movements, responses to stimuli, brain stem reflexes, and spontaneous respirations. Reversible conditions which mimic this clinical state (e.g., sedative overdose, hypothermia, etc.) are excluded prior to making the determination of brain death. (From Adams et al., Principles of Neurology, 6th ed, pp348-9)
Condition wherein the force of gravity is greater than or is increased above that on the surface of the earth. This is expressed as being greater than 1 g.
Conceptual functions or thinking in all its forms.
Inflammation of the BRAIN due to infection, autoimmune processes, toxins, and other conditions. Viral infections (see ENCEPHALITIS, VIRAL) are a relatively frequent cause of this condition.
EEG phase synchronization of the cortical brain region (CEREBRAL CORTEX).
Disease having a short and relatively severe course.
Anesthesia caused by the breathing of anesthetic gases or vapors or by insufflating anesthetic gases or vapors into the respiratory tract.
That branch of medicine dealing with the studies and effects of flight through the atmosphere or in space upon the human body and with the prevention or cure of physiological or psychological malfunctions arising from these effects. (from NASA Thesaurus)
The killing of animals for reasons of mercy, to control disease transmission or maintain the health of animal populations, or for experimental purposes (ANIMAL EXPERIMENTATION).
Surgical creation of a communication between a cerebral ventricle and the peritoneum by means of a plastic tube to permit drainage of cerebrospinal fluid for relief of hydrocephalus. (From Dorland, 28th ed)
Bleeding within the SKULL, including hemorrhages in the brain and the three membranes of MENINGES. The escape of blood often leads to the formation of HEMATOMA in the cranial epidural, subdural, and subarachnoid spaces.
A syndrome characterized by a silent and inert state without voluntary motor activity despite preserved sensorimotor pathways and vigilance. Bilateral FRONTAL LOBE dysfunction involving the anterior cingulate gyrus and related brain injuries are associated with this condition. This may result in impaired abilities to communicate and initiate motor activities. (From Adams et al., Principles of Neurology, 6th ed, p348; Fortschr Neurol Psychiatr 1995 Feb;63(2):59-67)
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
Stimulation at an intensity below that where a differentiated response can be elicited.
Radiography of the ventricular system of the brain after injection of air or other contrast medium directly into the cerebral ventricles. It is used also for x-ray computed tomography of the cerebral ventricles.
Deficiency of sodium in the blood; salt depletion. (Dorland, 27th ed)
Severe HYPOGLYCEMIA induced by a large dose of exogenous INSULIN resulting in a COMA or profound state of unconsciousness from which the individual cannot be aroused.
Accumulation of blood in the SUBDURAL SPACE with delayed onset of neurological symptoms. Symptoms may include loss of consciousness, severe HEADACHE, and deteriorating mental status.
A mental state characterized by bewilderment, emotional disturbance, lack of clear thinking, and perceptual disorientation.
A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.
The relation between the mind and the body in a religious, social, spiritual, behavioral, and metaphysical context. This concept is significant in the field of alternative medicine. It differs from the relationship between physiologic processes and behavior where the emphasis is on the body's physiology ( = PSYCHOPHYSIOLOGY).
A stable, non-explosive inhalation anesthetic, relatively free from significant side effects.
Radiography of the vascular system of the brain after injection of a contrast medium.
A collection of blood outside the BLOOD VESSELS. Hematoma can be localized in an organ, space, or tissue.
Infarctions that occur in the BRAIN STEM which is comprised of the MIDBRAIN; PONS; and MEDULLA OBLONGATA. There are several named syndromes characterized by their distinctive clinical manifestations and specific sites of ischemic injury.
A dangerous life-threatening hypermetabolic condition characterized by high FEVER and dysfunction of the cardiovascular, the nervous, and the gastrointestinal systems.
Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory.
Recurrent seizures causally related to CRANIOCEREBRAL TRAUMA. Seizure onset may be immediate but is typically delayed for several days after the injury and may not occur for up to two years. The majority of seizures have a focal onset that correlates clinically with the site of brain injury. Cerebral cortex injuries caused by a penetrating foreign object (CRANIOCEREBRAL TRAUMA, PENETRATING) are more likely than closed head injuries (HEAD INJURIES, CLOSED) to be associated with epilepsy. Concussive convulsions are nonepileptic phenomena that occur immediately after head injury and are characterized by tonic and clonic movements. (From Rev Neurol 1998 Feb;26(150):256-261; Sports Med 1998 Feb;25(2):131-6)
Accumulation of blood in the EPIDURAL SPACE between the SKULL and the DURA MATER, often as a result of bleeding from the MENINGEAL ARTERIES associated with a temporal or parietal bone fracture. Epidural hematoma tends to expand rapidly, compressing the dura and underlying brain. Clinical features may include HEADACHE; VOMITING; HEMIPARESIS; and impaired mental function.
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.
Withholding or withdrawal of a particular treatment or treatments, often (but not necessarily) life-prolonging treatment, from a patient or from a research subject as part of a research protocol. The concept is differentiated from REFUSAL TO TREAT, where the emphasis is on the health professional's or health facility's refusal to treat a patient or group of patients when the patient or the patient's representative requests treatment. Withholding of life-prolonging treatment is usually indexed only with EUTHANASIA, PASSIVE, unless the distinction between withholding and withdrawing treatment, or the issue of withholding palliative rather than curative treatment, is discussed.
Mental activity, not predominantly perceptual, by which one apprehends some aspect of an object or situation based on past learning and experience.
A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility.
Tapping fluid from the subarachnoid space in the lumbar region, usually between the third and fourth lumbar vertebrae.
Abnormal outpouching in the wall of intracranial blood vessels. Most common are the saccular (berry) aneurysms located at branch points in CIRCLE OF WILLIS at the base of the brain. Vessel rupture results in SUBARACHNOID HEMORRHAGE or INTRACRANIAL HEMORRHAGES. Giant aneurysms (>2.5 cm in diameter) may compress adjacent structures, including the OCULOMOTOR NERVE. (From Adams et al., Principles of Neurology, 6th ed, p841)
Wave-like oscillations of electric potential between parts of the brain recorded by EEG.
The inability to generate oral-verbal expression, despite normal comprehension of speech. This may be associated with BRAIN DISEASES or MENTAL DISORDERS. Organic mutism may be associated with damage to the FRONTAL LOBE; BRAIN STEM; THALAMUS; and CEREBELLUM. Selective mutism is a psychological condition that usually affects children characterized by continuous refusal to speak in social situations by a child who is able and willing to speak to selected persons. Kussmal aphasia refers to mutism in psychosis. (From Fortschr Neurol Psychiatr 1994; 62(9):337-44)
A reduction in brain oxygen supply due to ANOXEMIA (a reduced amount of oxygen being carried in the blood by HEMOGLOBIN), or to a restriction of the blood supply to the brain, or both. Severe hypoxia is referred to as anoxia, and is a relatively common cause of injury to the central nervous system. Prolonged brain anoxia may lead to BRAIN DEATH or a PERSISTENT VEGETATIVE STATE. Histologically, this condition is characterized by neuronal loss which is most prominent in the HIPPOCAMPUS; GLOBUS PALLIDUS; CEREBELLUM; and inferior olives.
Recurrent conditions characterized by epileptic seizures which arise diffusely and simultaneously from both hemispheres of the brain. Classification is generally based upon motor manifestations of the seizure (e.g., convulsive, nonconvulsive, akinetic, atonic, etc.) or etiology (e.g., idiopathic, cryptogenic, and symptomatic). (From Mayo Clin Proc, 1996 Apr;71(4):405-14)
A group of diseases related to a deficiency of the enzyme ARGININOSUCCINATE SYNTHASE which causes an elevation of serum levels of CITRULLINE. In neonates, clinical manifestations include lethargy, hypotonia, and SEIZURES. Milder forms also occur. Childhood and adult forms may present with recurrent episodes of intermittent weakness, lethargy, ATAXIA, behavioral changes, and DYSARTHRIA. (From Menkes, Textbook of Child Neurology, 5th ed, p49)
Intellectual or mental process whereby an organism obtains knowledge.
A type of lung inflammation resulting from the aspiration of food, liquid, or gastric contents into the upper RESPIRATORY TRACT.
Medical procedure involving the emptying of contents in the stomach through the use of a tube inserted through the nose or mouth. It is performed to remove poisons or relieve pressure due to intestinal blockages or during surgery.
A syndrome of abnormally low BLOOD GLUCOSE level. Clinical hypoglycemia has diverse etiologies. Severe hypoglycemia eventually lead to glucose deprivation of the CENTRAL NERVOUS SYSTEM resulting in HUNGER; SWEATING; PARESTHESIA; impaired mental function; SEIZURES; COMA; and even DEATH.
Puncture of a vein to draw blood for therapeutic purposes. Bloodletting therapy has been used in Talmudic and Indian medicine since the medieval time, and was still practiced widely in the 18th and 19th centuries. Its modern counterpart is PHLEBOTOMY.
Accumulation of blood in the SUBDURAL SPACE with acute onset of neurological symptoms. Symptoms may include loss of consciousness, severe HEADACHE, and deteriorating mental status.
A condition when the SELLA TURCICA is not filled with pituitary tissue. The pituitary gland is either compressed, atrophied, or removed. There are two types: (1) primary empty sella is due a defect in the sella diaphragm leading to arachnoid herniation into the sellar space; (2) secondary empty sella is associated with the removal or treatment of PITUITARY NEOPLASMS.
A spectrum of pathological conditions of impaired blood flow in the brain. They can involve vessels (ARTERIES or VEINS) in the CEREBRUM, the CEREBELLUM, and the BRAIN STEM. Major categories include INTRACRANIAL ARTERIOVENOUS MALFORMATIONS; BRAIN ISCHEMIA; CEREBRAL HEMORRHAGE; and others.
A false belief regarding the self or persons or objects outside the self that persists despite the facts, and is not considered tenable by one's associates.
A condition or physical state produced by the ingestion, injection, inhalation of or exposure to a deleterious agent.
The part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.
Presence of air or gas within the intracranial cavity (e.g., epidural space, subdural space, intracerebral, etc.) which may result from traumatic injuries, fistulous tract formation, erosions of the skull from NEOPLASMS or infection, NEUROSURGICAL PROCEDURES, and other conditions.

Vision: modular analysis--or not? (1/1219)

It has commonly been assumed that the many separate areas of the visual system perform modular analyses, each restricted to a single attribute of the image. A recent paper advocates a radically different approach, where all areas in the hierarchy analyse all attributes of the image to extract perceptually relevant decisions.  (+info)

Effect of the cannabinoid receptor agonist WIN55212-2 on sympathetic cardiovascular regulation. (2/1219)

1. The aim of the present study was to analyse the cardiovascular actions of the synthetic CB1/CB2 cannabinoid receptor agonist WIN55212-2, and specifically to determine its sites of action on sympathetic cardiovascular regulation. 2. Pithed rabbits in which the sympathetic outflow was continuously stimulated electrically or which received a pressor infusion of noradrenaline were used to study peripheral prejunctional and direct vascular effects, respectively. For studying effects on brain stem cardiovascular regulatory centres, drugs were administered into the cisterna cerebellomedullaris in conscious rabbits. Overall cardiovascular effects of the cannabinoid were studied in conscious rabbits with intravenous drug administration. 3. In pithed rabbits in which the sympathetic outflow was continuously electrically stimulated, intravenous injection of WIN55212-2 (5, 50 and 500 microg kg(-1)) markedly reduced blood pressure, the spillover of noradrenaline into plasma and the plasma noradrenaline concentration, and these effects were antagonized by the CB1 cannabinoid receptor-selective antagonist SR141716A. The hypotensive and the sympathoinhibitory effect of WIN55212-2 was shared by CP55940, another mixed CB1/CB2 cannabinoid receptor agonist, but not by WIN55212-3, the enantiomer of WIN55212-2, which lacks affinity for cannabinoid binding sites. WIN55212-2 had no effect on vascular tone established by infusion of noradrenaline in pithed rabbits. 4. Intracisternal application of WIN55212-2 (0.1, 1 and 10 microg kg(-1)) in conscious rabbits increased blood pressure and the plasma noradrenaline concentration and elicited bradycardia; this latter effect was antagonized by atropine. 5. In conscious animals, intravenous injection of WIN55212-2 (5 and 50 microg kg(-1)) caused bradycardia, slight hypotension, no change in the plasma noradrenaline concentration, and an increase in renal sympathetic nerve firing. The highest dose of WIN55212-2 (500 microg kg(-1)) elicited hypotension and tachycardia, and sympathetic nerve activity and the plasma noradrenaline concentration declined. 6. The results obtained in pithed rabbits indicate that activation of CB1 cannabinoid receptors leads to marked peripheral prejunctional inhibition of noradrenaline release from postganglionic sympathetic axons. Intracisternal application of WIN55212-2 uncovered two effects on brain stem cardiovascular centres: sympathoexcitation and activation of cardiac vagal fibres. The highest dose of systemically administered WIN55212-2 produced central sympathoinhibition; the primary site of this action is not known.  (+info)

ATP-sensitive potassium channels regulate in vivo dopamine release in rat striatum. (3/1219)

ATP-sensitive K+ channels (K(ATP)) are distributed in a variety of tissues including smooth muscle, cardiac and skeletal muscle, pancreatic beta-cells and neurons. Since K(ATP) channels are present in the nigrostriatal dopamine (DA) pathway, the effect of potassium-channel modulators on the release of DA in the striatum of conscious, freely-moving rats was investigated. The extracellular concentration of DA was significantly decreased by the K(ATP)-channel opener (-)-cromakalim but not by diazoxide. (-)-Cromakalim was effective at 100 and 1000 microM concentrations, and the maximum decrease was 54% below baseline. d-Amphetamine significantly increased extracellular DA levels at the doses of 0.75 and 1.5 mg/kg, s.c. with a 770% maximum increase. (-)-Cromakalim had no effect on d-amphetamine-induced DA release, while glyburide, a K(ATP) blocker, significantly potentiated the effects of a low dose of d-amphetamine. These data indicate that K+ channels present in the nigrostriatal dopaminergic terminals modulate basal release as well as evoked release of DA.  (+info)

Stroke units in their natural habitat: can results of randomized trials be reproduced in routine clinical practice? Riks-Stroke Collaboration. (4/1219)

BACKGROUND AND PURPOSE: Meta-analyses of randomized controlled trials of acute stroke care have shown care in stroke units (SUs) to be superior to that in conventional general medical, neurological, or geriatric wards, with reductions in early case fatality, functional outcome, and the need for long-term institutionalization. This study examined whether these results can be reproduced in clinical practice. METHODS: A multicenter observational study of procedures and outcomes in acute stroke patients admitted to designated SUs or general medical or neurological wards (GWs), the study included patients of all ages with acute stroke excluding those with subarachnoid hemorrhage, who were entered into the Riks-Stroke (Swedish national quality assessment) database during 1996 (14 308 patients in 80 hospitals). RESULTS: Patients admitted to SUs who had lived independently and who were fully conscious on admission to the hospital had a lower case fatality than those cared for in GWs (relative risk [RR] for death, 0.87; 95% confidence interval [CI], 0.79 to 0.96) and at 3 months (RR, 0.91; 95% CI, 0.85 to 0.98). A greater proportion of patients cared for in an SU could be discharged home (RR, 1.06; 95% CI, 1.03 to 1.10), and fewer were in long-term institutional care 3 months after the stroke (RR, 0.94; 95% CI, 0.89 to 0.99). No difference was seen in outcome in patients cared for in SUs or GWs if they had impaired consciousness on admission. CONCLUSIONS: The improvement in outcomes after stroke care in SUs compared with care in GWs can be reproduced in the routine clinical setting, but the magnitude of the benefit appears smaller than that reported from meta-analyses.  (+info)

Assessment of the effects of endothelin-1 and magnesium sulphate on regional blood flows in conscious rats, by the coloured microsphere reference technique. (5/1219)

There is evidence to suggest that magnesium (Mg2+) is beneficial in the treatment of a number of conditions, including pre-eclampsia and acute myocardial infarction. The mode of action of Mg2+ in these conditions is not clear, although the vasodilator properties of Mg2+ are well documented both in vitro and in vivo. Previously, we demonstrated that i.v. infusion of magnesium sulphate (MgSO4) alone, or in the presence of vasoconstrictors, caused increases in flow and conductance in the common carotid, internal carotid and hindquarters vascular beds, in conscious rats. Therefore, the objective of the present study was to investigate the regional and subregional changes in haemodynamics in response to the vasoconstrictor peptide endothelin-1 (ET-1) and MgSO4 in more detail, using the coloured microsphere reference technique. Infusion of ET-1 and MgSO4 had similar effects on heart rate and mean arterial pressure as in our previous study. Infusion of ET-1 caused a rise in mean arterial pressure and a fall in heart rate, and infusion of MgSO4 returned mean arterial pressure to control levels with no effect on heart rate. The responses to MgSO4 in the presence of ET-1 showed considerable regional heterogeneity with blood flow increasing (e.g. skeletal muscle), decreasing (e.g. stomach) or not changing (e.g. kidney). Of particular interest was the finding that MgSO4 caused increases in flow in the cerebral and coronary vascular beds. This, and our previous studies, have shown that MgSO4 can reverse vasoconstriction in a number of vascular beds, and indicate that this compound may have therapeutic benefit in conditions associated with vasospasm.  (+info)

Propofol infusion for induction and maintenance of anaesthesia in patients with end-stage renal disease. (6/1219)

We have investigated the pharmacokinetics and pharmacodynamics of propofol in 11 patients with end-stage renal disease (ESRD) compared with nine healthy patients during and after a manually controlled three-stage infusion of propofol 21, 12 and 6 mg kg-1 h-1 lasting a minimum of 2 h. Mean total body clearance was not reduced significantly in the ESRD group (30.66 (SD 8.47) ml kg-1 min-1) compared with the control group (33.75 (7.8) ml kg-1 min-1). ESRD patients exhibited a greater, but not statistically significant, volume of distribution at steady state compared with patients in the control group (11.25 (8.86) vs 5.79 (2.14) litre kg-1, respectively). Elimination half-life values were unchanged by renal failure. Mean times to induction of anaesthesia were similar in both groups: 177 (SD 57) and 167 (58) s for the ESRD and control groups, respectively. Waking time after cessation of propofol infusion was significantly shorter in the ESRD group (474 (156) s) compared with the control group (714 (240) s) (P < 0.05). Mean plasma concentrations on waking were similar. We conclude that the pharmacokinetic and pharmacodynamic profiles of propofol after infusion were not markedly affected by renal failure.  (+info)

Cardiovascular effects of rilmenidine, moxonidine and clonidine in conscious wild-type and D79N alpha2A-adrenoceptor transgenic mice. (7/1219)

1. We investigated the cardiovascular effects of rilmenidine, moxonidine and clonidine in conscious wild-type and D79N alpha2A-adrenoceptor mice. The in vitro pharmacology of these agonists was determined at recombinant (human) alpha2-adrenoceptors and at endogenous (dog) alpha2A-adrenoceptors. 2. In wild-type mice, rilmenidine, moxonidine (100, 300 and 1000 microg kg(-1), i.v.) and clonidine (30, 100 and 300 microg kg(-1), i.v.) dose-dependently decreased blood pressure and heart rate. 3. In D79N alpha2A-adrenoceptor mice, responses to rilmenidine and moxonidine did not differ from vehicle control. Clonidine-induced hypotension was absent, but dose-dependent hypertension and bradycardia were observed. 4. In wild-type mice, responses to moxonidine (1 mg kg(-1), i.v.) were antagonized by the non-selective, non-imidazoline alpha2-adrenoceptor antagonist, RS-79948-197 (1 mg kg(-1), i.v.). 5. Affinity estimates (pKi) at human alpha2A-, alpha2B- and alpha2C-adrenoceptors, respectively, were: rilmenidine (5.80, 5.76 and 5.33), moxonidine (5.37, <5 and <5) and clonidine (7.21, 7.16 and 6.87). In a [35S]-GTPgammaS incorporation assay, moxonidine and clonidine were alpha2A-adrenoceptor agonists (pEC50/intrinsic activity relative to noradrenaline): moxonidine (5.74/0.85) and clonidine (7.57/0.32). 6. In dog saphenous vein, concentration-dependent contractions were observed (pEC50/intrinsic activity relative to noradrenaline): rilmenidine (5.83/0.70), moxonidine (6.48/0.98) and clonidine (7.22/0.83). Agonist-independent affinities were obtained with RS-79948-197. 7. Thus, expression of alpha2A-adrenoceptors is a prerequisite for the cardiovascular effects of moxonidine and rilmenidine in conscious mice. There was no evidence of I1-imidazoline receptor-mediated effects. The ability of these compounds to act as alpha2A-adrenoceptor agonists in vitro supports this conclusion.  (+info)

Neuroimaging of genesis and satiation of thirst and an interoceptor-driven theory of origins of primary consciousness. (8/1219)

There are defined hypothalamic functions in the genesis of thirst, but little is known of the cortical processes subserving consciousness of thirst notwithstanding the medical disorders that occur in psychiatric illness, addiction, and the attested decline of thirst with aging. In 10 adult males, positron emission tomography scans were made (i) during genesis of moderate thirst by infusion of i.v. hypertonic saline 0.51 M, (ii) after irrigation of the mouth with water to remove the sensation of dryness, and (iii) 3, 14, 45, and 60 minutes after drinking water to fully satiate thirst. The correlation of regional cerebral blood flow with thirst score showed the major activation to be in the posterior cingulate. Maximum thirst sensation evoked 13 highly significant activations and 9 deactivations in cingulate and parahippocampal gyri, insula, thalamus, amygdala, and mesencephalon. It is possible that cingulate sites (Brodmann's areas 32, 24, and 31) that persisted with wet mouth but disappeared immediately after drinking to satiation may have an important role in the consciousness of thirst. Consciousness of thirst, a primal vegetative emotion, and satiation of thirst appear to be subserved by phylogenetically ancient brain regions. This is salient to current discussion on evolutionary emergence of primary consciousness.  (+info)

Consciousness is a complex and multifaceted concept that is difficult to define succinctly, but in a medical or neurological context, it generally refers to an individual's state of awareness and responsiveness to their surroundings. Consciousness involves a range of cognitive processes, including perception, thinking, memory, and attention, and it requires the integration of sensory information, language, and higher-order cognitive functions.

In medical terms, consciousness is often assessed using measures such as the Glasgow Coma Scale, which evaluates an individual's ability to open their eyes, speak, and move in response to stimuli. A coma is a state of deep unconsciousness where an individual is unable to respond to stimuli or communicate, while a vegetative state is a condition where an individual may have sleep-wake cycles and some automatic responses but lacks any meaningful awareness or cognitive function.

Disorders of consciousness can result from brain injury, trauma, infection, or other medical conditions that affect the functioning of the brainstem or cerebral cortex. The study of consciousness is a rapidly evolving field that involves researchers from various disciplines, including neuroscience, psychology, philosophy, and artificial intelligence.

Consciousness disorders, also known as altered consciousness, refer to conditions that affect a person's awareness or perception of their surroundings, themselves, or their current state. These disorders can range from mild to severe and can be caused by various factors such as brain injury, illness, or the use of certain medications.

There are several types of consciousness disorders, including:

1. Coma: A state of deep unconsciousness in which a person is unable to respond to stimuli or communicate.
2. Vegetative State: A condition in which a person may have sleep-wake cycles and some automatic responses, but lacks awareness or the ability to interact with their environment.
3. Minimally Conscious State: A condition in which a person has some degree of awareness and may be able to respond to stimuli, but is unable to communicate or consistently interact with their environment.
4. Delirium: A state of confusion and altered consciousness that can occur suddenly and fluctuate over time. It is often caused by an underlying medical condition or the use of certain medications.
5. Locked-in Syndrome: A rare condition in which a person is fully conscious but unable to move or communicate due to complete paralysis of all voluntary muscles except for those that control eye movement.

Treatment for consciousness disorders depends on the underlying cause and may include medication, therapy, or surgery. In some cases, recovery may be possible with appropriate treatment and rehabilitation. However, in other cases, the disorder may be permanent or result in long-term disability.

Unconsciousness is a state of complete awareness where a person is not responsive to stimuli and cannot be awakened. It is often caused by severe trauma, illness, or lack of oxygen supply to the brain. In medical terms, it is defined as a lack of response to verbal commands, pain, or other stimuli, indicating that the person's brain is not functioning at a level necessary to maintain wakefulness and awareness.

Unconsciousness can be described as having different levels, ranging from drowsiness to deep coma. The causes of unconsciousness can vary widely, including head injury, seizure, stroke, infection, drug overdose, or lack of oxygen supply to the brain. Depending on the cause and severity, unconsciousness may last for a few seconds or continue for an extended period, requiring medical intervention and treatment.

Persistent vegetative state (PVS) is a medical condition characterized by a prolonged disorder of consciousness. It's not the same as a coma. In PVS, a person may open their eyes, appear to be awake and have periods of sleep and wakefulness, but they do not show signs of awareness or cognition. They do not respond to stimuli, cannot communicate, and do not have any purposeful behaviors.

This condition can occur after a severe brain injury, such as from trauma, stroke, or lack of oxygen supply. The chance of recovery from PVS is very low, and if some recovery does occur, it's usually incomplete.

It's important to note that the term "persistent vegetative state" has been replaced in some clinical settings with "unresponsive wakefulness syndrome" due to the negative connotations associated with the term "vegetative".

A coma is a deep state of unconsciousness in which an individual cannot be awakened, cannot respond to stimuli, and does not exhibit any sleep-wake cycles. It is typically caused by severe brain injury, illness, or toxic exposure that impairs the function of the brainstem and cerebral cortex.

In a coma, the person may appear to be asleep, but they are not aware of their surroundings or able to communicate or respond to stimuli. Comas can last for varying lengths of time, from days to weeks or even months, and some people may emerge from a coma with varying degrees of brain function and disability.

Medical professionals use various diagnostic tools and assessments to evaluate the level of consciousness and brain function in individuals who are in a coma, including the Glasgow Coma Scale (GCS), which measures eye opening, verbal response, and motor response. Treatment for coma typically involves supportive care to maintain vital functions, manage any underlying medical conditions, and prevent further complications.

Propofol is a short-acting medication that is primarily used for the induction and maintenance of general anesthesia during procedures such as surgery. It belongs to a class of drugs called hypnotics or sedatives, which work by depressing the central nervous system to produce a calming effect. Propofol can also be used for sedation in mechanically ventilated patients in intensive care units and for procedural sedation in various diagnostic and therapeutic procedures outside the operating room.

The medical definition of Propofol is:
A rapid-onset, short-duration intravenous anesthetic agent that produces a hypnotic effect and is used for induction and maintenance of general anesthesia, sedation in mechanically ventilated patients, and procedural sedation. It acts by enhancing the inhibitory effects of gamma-aminobutyric acid (GABA) in the brain, leading to a decrease in neuronal activity and a reduction in consciousness. Propofol has a rapid clearance and distribution, allowing for quick recovery after discontinuation of its administration.

Electroencephalography (EEG) is a medical procedure that records electrical activity in the brain. It uses small, metal discs called electrodes, which are attached to the scalp with paste or a specialized cap. These electrodes detect tiny electrical charges that result from the activity of brain cells, and the EEG machine then amplifies and records these signals.

EEG is used to diagnose various conditions related to the brain, such as seizures, sleep disorders, head injuries, infections, and degenerative diseases like Alzheimer's or Parkinson's. It can also be used during surgery to monitor brain activity and ensure that surgical procedures do not interfere with vital functions.

EEG is a safe and non-invasive procedure that typically takes about 30 minutes to an hour to complete, although longer recordings may be necessary in some cases. Patients are usually asked to relax and remain still during the test, as movement can affect the quality of the recording.

Intravenous anesthetics are a type of medication that is administered directly into a vein to cause a loss of consciousness and provide analgesia (pain relief) during medical procedures. They work by depressing the central nervous system, inhibiting nerve impulse transmission and ultimately preventing the patient from feeling pain or discomfort during surgery or other invasive procedures.

There are several different types of intravenous anesthetics, each with its own specific properties and uses. Some common examples include propofol, etomidate, ketamine, and barbiturates. These drugs may be used alone or in combination with other medications to provide a safe and effective level of anesthesia for the patient.

The choice of intravenous anesthetic depends on several factors, including the patient's medical history, the type and duration of the procedure, and the desired depth and duration of anesthesia. Anesthesiologists must carefully consider these factors when selecting an appropriate medication regimen for each individual patient.

While intravenous anesthetics are generally safe and effective, they can have side effects and risks, such as respiratory depression, hypotension, and allergic reactions. Anesthesia providers must closely monitor patients during and after the administration of these medications to ensure their safety and well-being.

I'm not aware of a specific medical definition for "consciousness monitors." The term "consciousness" generally refers to an individual's state of being awake and aware of their surroundings and experiences. In a medical context, healthcare professionals may monitor a person's level of consciousness as part of their overall assessment of the patient's neurological status.

There are several tools and scales that healthcare providers use to assess a person's level of consciousness, including:

1. The Glasgow Coma Scale (GCS): This is a widely used tool for assessing level of consciousness in patients with traumatic brain injury or other conditions that may affect consciousness. The GCS evaluates a patient's ability to open their eyes, speak, and move in response to stimuli.
2. The Alert, Voice, Pain, Unresponsive (AVPU) scale: This is another tool used to assess level of consciousness. It evaluates whether a patient is alert, responds to voice, responds to pain, or is unresponsive.
3. Pupillary response: Healthcare providers may also monitor the size and reactivity of a person's pupils as an indicator of their level of consciousness. Changes in pupil size or reactivity can be a sign of brainstem dysfunction or increased intracranial pressure.

It's important to note that while healthcare professionals may monitor a patient's level of consciousness, there is no single device or tool that can directly measure "consciousness" itself. Instead, these tools and assessments provide valuable information about a person's neurological status and help healthcare providers make informed decisions about their care.

In a medical context, awareness generally refers to the state of being conscious or cognizant of something. This can include being aware of one's own thoughts, feelings, and experiences, as well as being aware of external events or sensations.

For example, a person who is awake and alert is said to have full awareness, while someone who is in a coma or under general anesthesia may be described as having reduced or absent awareness. Similarly, a person with dementia or Alzheimer's disease may have impaired awareness of their surroundings or of their own memory and cognitive abilities.

In some cases, awareness may also refer to the process of becoming informed or educated about a particular health condition or medical treatment. For example, a patient may be encouraged to increase their awareness of heart disease risk factors or of the potential side effects of a medication. Overall, awareness involves a deep understanding and perception of oneself and one's environment.

I'm sorry for any confusion, but "philosophy" is not a medical term. It is a branch of study that deals with fundamental questions about existence, knowledge, ethics, and reality. In contrast, medical terms typically refer to concepts within the field of medicine, such as diseases, treatments, or anatomical structures. If you have any questions related to medical terminology or concepts, I would be happy to try and help answer those for you!

The Glasgow Coma Scale (GCS) is a standardized tool used by healthcare professionals to assess the level of consciousness and neurological response in a person who has suffered a brain injury or illness. It evaluates three aspects of a patient's responsiveness: eye opening, verbal response, and motor response. The scores from these three categories are then added together to provide an overall GCS score, which can range from 3 (indicating deep unconsciousness) to 15 (indicating a normal level of consciousness). This scale helps medical professionals to quickly and consistently communicate the severity of a patient's condition and monitor their progress over time.

Psilocybin is defined as a naturally occurring psychedelic compound found in certain species of mushrooms, also known as "magic mushrooms." It is classified as a tryptamine and is structurally similar to the neurotransmitter serotonin. When ingested, psilocybin is converted into psilocin, which acts as a serotonin receptor agonist in the brain, leading to altered consciousness, perception, and thought. Its effects can vary widely depending on the individual, the dose, and the setting in which it is taken.

Human development in a medical context often refers to the process of physical, cognitive, and emotional growth and development that occurs from conception through adulthood. This includes the development of organs, organ systems, and bodily functions, as well as the acquisition of skills, knowledge, and social-emotional capabilities.

The medical community may also use the term "human development" to refer to the study of how genetic and environmental factors influence this growth and development over time. This field draws on insights from a range of disciplines, including genetics, neuroscience, psychology, sociology, and anthropology, among others.

It's important to note that human development is a complex and dynamic process that can be influenced by a wide range of factors, including genetics, nutrition, physical activity, stress, social support, and cultural context, among others. Understanding the many factors that contribute to healthy human development is an important goal for researchers, clinicians, and policymakers alike.

Syncope is a medical term defined as a transient, temporary loss of consciousness and postural tone due to reduced blood flow to the brain. It's often caused by a drop in blood pressure, which can be brought on by various factors such as dehydration, emotional stress, prolonged standing, or certain medical conditions like heart diseases, arrhythmias, or neurological disorders.

During a syncope episode, an individual may experience warning signs such as lightheadedness, dizziness, blurred vision, or nausea before losing consciousness. These episodes usually last only a few minutes and are followed by a rapid, full recovery. However, if left untreated or undiagnosed, recurrent syncope can lead to severe injuries from falls or even life-threatening conditions related to the underlying cause.

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

General anesthesia is a state of controlled unconsciousness, induced by administering various medications, that eliminates awareness, movement, and pain sensation during medical procedures. It involves the use of a combination of intravenous and inhaled drugs to produce a reversible loss of consciousness, allowing patients to undergo surgical or diagnostic interventions safely and comfortably. The depth and duration of anesthesia are carefully monitored and adjusted throughout the procedure by an anesthesiologist or certified registered nurse anesthetist (CRNA) to ensure patient safety and optimize recovery. General anesthesia is typically used for more extensive surgical procedures, such as open-heart surgery, major orthopedic surgeries, and neurosurgery.

Medical philosophy is a branch of philosophy that deals with the concepts, issues, and arguments specific to medicine and healthcare. It involves the application of philosophical inquiry and reasoning to various aspects of medicine, such as:

1. Ethics: Examining moral principles and values that guide medical practice, including patient autonomy, beneficence, non-maleficence, and justice. This includes issues related to end-of-life care, informed consent, research ethics, and resource allocation.
2. Epistemology: Exploring the nature of knowledge in medicine, including how medical knowledge is acquired, validated, and disseminated. It also involves examining the limitations and uncertainties of medical knowledge.
3. Metaphysics: Examining the fundamental nature of reality as it relates to medicine, such as the nature of disease, health, and the human body. This includes exploring questions about the mind-body relationship and the role of emergent properties in understanding health and illness.
4. Logic and Rationality: Applying logical reasoning and critical thinking skills to medical decision making, including the evaluation of evidence, the assessment of risks and benefits, and the formulation of clinical guidelines.
5. Aesthetics: Exploring the role of values and subjective experience in medicine, such as the importance of empathy, compassion, and communication in the patient-physician relationship. This also includes examining the ethical implications of medical aesthetics, such as cosmetic surgery and enhancement technologies.

Medical philosophy is an interdisciplinary field that draws on insights from a variety of disciplines, including philosophy, medicine, ethics, law, psychology, and sociology. It seeks to provide a deeper understanding of the complex issues that arise in medical practice and to inform the development of evidence-based, ethical, and compassionate healthcare policies and practices.

Hypnotics and sedatives are classes of medications that have depressant effects on the central nervous system, leading to sedation (calming or inducing sleep), reduction in anxiety, and in some cases, decreased awareness or memory. These agents work by affecting the neurotransmitter GABA (gamma-aminobutyric acid) in the brain, which results in inhibitory effects on neuronal activity.

Hypnotics are primarily used for the treatment of insomnia and other sleep disorders, while sedatives are often prescribed to manage anxiety or to produce a calming effect before medical procedures. Some medications can function as both hypnotics and sedatives, depending on the dosage and specific formulation. Common examples of these medications include benzodiazepines (such as diazepam and lorazepam), non-benzodiazepine hypnotics (such as zolpidem and eszopiclone), barbiturates, and certain antihistamines.

It is essential to use these medications under the guidance of a healthcare professional, as they can have potential side effects, such as drowsiness, dizziness, confusion, and impaired coordination. Additionally, long-term use or high doses may lead to tolerance, dependence, and withdrawal symptoms upon discontinuation.

Medical Definition:

Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic imaging technique that uses a strong magnetic field and radio waves to create detailed cross-sectional or three-dimensional images of the internal structures of the body. The patient lies within a large, cylindrical magnet, and the scanner detects changes in the direction of the magnetic field caused by protons in the body. These changes are then converted into detailed images that help medical professionals to diagnose and monitor various medical conditions, such as tumors, injuries, or diseases affecting the brain, spinal cord, heart, blood vessels, joints, and other internal organs. MRI does not use radiation like computed tomography (CT) scans.

Craniocerebral trauma, also known as traumatic brain injury (TBI), is a type of injury that occurs to the head and brain. It can result from a variety of causes, including motor vehicle accidents, falls, sports injuries, violence, or other types of trauma. Craniocerebral trauma can range in severity from mild concussions to severe injuries that cause permanent disability or death.

The injury typically occurs when there is a sudden impact to the head, causing the brain to move within the skull and collide with the inside of the skull. This can result in bruising, bleeding, swelling, or tearing of brain tissue, as well as damage to blood vessels and nerves. In severe cases, the skull may be fractured or penetrated, leading to direct injury to the brain.

Symptoms of craniocerebral trauma can vary widely depending on the severity and location of the injury. They may include headache, dizziness, confusion, memory loss, difficulty speaking or understanding speech, changes in vision or hearing, weakness or numbness in the limbs, balance problems, and behavioral or emotional changes. In severe cases, the person may lose consciousness or fall into a coma.

Treatment for craniocerebral trauma depends on the severity of the injury. Mild injuries may be treated with rest, pain medication, and close monitoring, while more severe injuries may require surgery, intensive care, and rehabilitation. Prevention is key to reducing the incidence of craniocerebral trauma, including measures such as wearing seat belts and helmets, preventing falls, and avoiding violent situations.

A seizure is an uncontrolled, abnormal firing of neurons (brain cells) that can cause various symptoms such as convulsions, loss of consciousness, altered awareness, or changes in behavior. Seizures can be caused by a variety of factors including epilepsy, brain injury, infection, toxic substances, or genetic disorders. They can also occur without any identifiable cause, known as idiopathic seizures. Seizures are a medical emergency and require immediate attention.

Intraoperative monitoring (IOM) is the practice of using specialized techniques to monitor physiological functions or neural structures in real-time during surgical procedures. The primary goal of IOM is to provide continuous information about the patient's status and the effects of surgery on neurological function, allowing surgeons to make informed decisions and minimize potential risks.

IOM can involve various methods such as:

1. Electrophysiological monitoring: This includes techniques like somatosensory evoked potentials (SSEP), motor evoked potentials (MEP), and electroencephalography (EEG) to assess the integrity of neural pathways and brain function during surgery.
2. Neuromonitoring: Direct electrical stimulation of nerves or spinal cord structures can help identify critical neuroanatomical structures, evaluate their functional status, and guide surgical interventions.
3. Hemodynamic monitoring: Measuring blood pressure, heart rate, cardiac output, and oxygen saturation helps assess the patient's overall physiological status during surgery.
4. Imaging modalities: Intraoperative imaging techniques like ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI) can provide real-time visualization of anatomical structures and surgical progress.

The specific IOM methods employed depend on the type of surgery, patient characteristics, and potential risks involved. Intraoperative monitoring is particularly crucial in procedures where there is a risk of neurological injury, such as spinal cord or brain surgeries, vascular interventions, or tumor resections near critical neural structures.

The thalamus is a large, paired structure in the brain that serves as a relay station for sensory and motor signals to the cerebral cortex. It is located in the dorsal part of the diencephalon and is made up of two symmetrical halves, each connected to the corresponding cerebral hemisphere.

The thalamus receives inputs from almost all senses, except for the olfactory system, and processes them before sending them to specific areas in the cortex. It also plays a role in regulating consciousness, sleep, and alertness. Additionally, the thalamus is involved in motor control by relaying information between the cerebellum and the motor cortex.

The thalamus is divided into several nuclei, each with distinct connections and functions. Some of these nuclei are involved in sensory processing, while others are involved in motor function or regulation of emotions and cognition. Overall, the thalamus plays a critical role in integrating information from various brain regions and modulating cognitive and emotional processes.

Tonic-clonic epilepsy, also known as grand mal epilepsy, is a type of generalized seizure that affects the entire brain. This type of epilepsy is characterized by two distinct phases: the tonic phase and the clonic phase.

During the tonic phase, which usually lasts for about 10-20 seconds, the person loses consciousness and their muscles stiffen, causing them to fall to the ground. This can result in injuries if the person falls unexpectedly or hits an object on the way down.

The clonic phase follows immediately after the tonic phase and is characterized by rhythmic jerking movements of the limbs, face, and neck. These movements are caused by alternating contractions and relaxations of the muscles and can last for several minutes. The person may also lose bladder or bowel control during this phase.

After the seizure, the person may feel tired, confused, and disoriented. They may also have a headache, sore muscles, and difficulty remembering what happened during the seizure.

Tonic-clonic epilepsy can be caused by a variety of factors, including genetics, brain injury, infection, or stroke. It is typically diagnosed through a combination of medical history, physical examination, and diagnostic tests such as an electroencephalogram (EEG) or imaging studies. Treatment may include medication, surgery, or dietary changes, depending on the underlying cause and severity of the seizures.

Intravenous anesthesia, also known as IV anesthesia, is a type of anesthesia that involves the administration of one or more drugs into a patient's vein to achieve a state of unconsciousness and analgesia (pain relief) during medical procedures. The drugs used in intravenous anesthesia can include sedatives, hypnotics, analgesics, and muscle relaxants, which are carefully selected and dosed based on the patient's medical history, physical status, and the type and duration of the procedure.

The administration of IV anesthesia is typically performed by a trained anesthesiologist or nurse anesthetist, who monitors the patient's vital signs and adjusts the dosage of the drugs as needed to ensure the patient's safety and comfort throughout the procedure. The onset of action for IV anesthesia is relatively rapid, usually within minutes, and the depth and duration of anesthesia can be easily titrated to meet the needs of the individual patient.

Compared to general anesthesia, which involves the administration of inhaled gases or vapors to achieve a state of unconsciousness, intravenous anesthesia is associated with fewer adverse effects on respiratory and cardiovascular function, and may be preferred for certain types of procedures or patients. However, like all forms of anesthesia, IV anesthesia carries risks and potential complications, including allergic reactions, infection, bleeding, and respiratory depression, and requires careful monitoring and management by trained medical professionals.

Complex partial epilepsy, also known as temporal lobe epilepsy or focal impaired awareness epilepsy, is a type of epilepsy characterized by recurrent, unprovoked seizures that originate in the temporal lobe or other localized areas of the brain. These seizures typically involve alterations in consciousness or awareness, and may include automatisms (involuntary, repetitive movements), such as lip smacking, fidgeting, or picking at clothes. Complex partial seizures can last from a few seconds to several minutes and may be followed by a post-ictal period of confusion or fatigue.

Complex partial epilepsy is often associated with structural abnormalities in the brain, such as hippocampal sclerosis, tumors, or malformations. It can also be caused by infectious or inflammatory processes, vascular disorders, or genetic factors. The diagnosis of complex partial epilepsy typically involves a thorough neurological evaluation, including a detailed history of seizure symptoms, neuroimaging studies (such as MRI or CT scans), and electroencephalography (EEG) to record brain activity during and between seizures.

Treatment for complex partial epilepsy usually involves medication therapy with antiepileptic drugs (AEDs). In some cases, surgery may be recommended if medications are not effective in controlling seizures or if there is a structural lesion that can be safely removed. Other treatment options may include dietary modifications, such as the ketogenic diet, or vagus nerve stimulation.

A brain injury is defined as damage to the brain that occurs following an external force or trauma, such as a blow to the head, a fall, or a motor vehicle accident. Brain injuries can also result from internal conditions, such as lack of oxygen or a stroke. There are two main types of brain injuries: traumatic and acquired.

Traumatic brain injury (TBI) is caused by an external force that results in the brain moving within the skull or the skull being fractured. Mild TBIs may result in temporary symptoms such as headaches, confusion, and memory loss, while severe TBIs can cause long-term complications, including physical, cognitive, and emotional impairments.

Acquired brain injury (ABI) is any injury to the brain that occurs after birth and is not hereditary, congenital, or degenerative. ABIs are often caused by medical conditions such as strokes, tumors, anoxia (lack of oxygen), or infections.

Both TBIs and ABIs can range from mild to severe and may result in a variety of physical, cognitive, and emotional symptoms that can impact a person's ability to perform daily activities and function independently. Treatment for brain injuries typically involves a multidisciplinary approach, including medical management, rehabilitation, and supportive care.

Dreams are a series of thoughts, images, and sensations occurring in a person's mind during sleep. They can be vivid or vague, positive or negative, and may involve memories, emotions, and fears. The scientific study of dreams is called oneirology. While the exact purpose and function of dreams remain a topic of debate among researchers, some theories suggest that dreaming may help with memory consolidation, problem-solving, emotional processing, and learning.

Dreams usually occur during the rapid eye movement (REM) stage of sleep, although they can also happen in non-REM stages. They are typically associated with complex brain activities, involving areas such as the amygdala, hippocampus, and the neocortex. The content of dreams can be influenced by various factors, including a person's thoughts, experiences, emotions, physical state, and environmental conditions.

It is important to note that dreaming is a natural and universal human experience, and understanding dreams can provide insights into our cognitive processes, emotional well-being, and mental health.

A post-head injury coma is a state of deep unconsciousness that occurs following a traumatic brain injury to the head. This condition is characterized by a complete loss of awareness and inability to respond to external stimuli or communicate. The individual is unable to move or speak, and there is no sleep-wake cycle.

The duration of a post-head injury coma can vary widely, from a few days to several weeks or even months, depending on the severity of the brain injury. Factors that influence the prognosis include the cause and location of the injury, the patient's age and overall health status, and the promptness and effectiveness of medical treatment.

Post-head injury coma is a serious medical emergency that requires immediate evaluation and management by a team of healthcare professionals, including neurosurgeons, neurologists, critical care specialists, and rehabilitation therapists. The goal of treatment is to minimize secondary brain damage, prevent complications, and promote recovery.

Conscious sedation, also known as procedural sedation and analgesia, is a minimally depressed level of consciousness that retains the patient's ability to maintain airway spontaneously and respond appropriately to physical stimulation and verbal commands. It is typically achieved through the administration of sedative and/or analgesic medications and is commonly used in medical procedures that do not require general anesthesia. The goal of conscious sedation is to provide a comfortable and anxiety-free experience for the patient while ensuring their safety throughout the procedure.

Wakefulness is a state of consciousness in which an individual is alert and aware of their surroundings. It is characterized by the ability to perceive, process, and respond to stimuli in a purposeful manner. In a medical context, wakefulness is often assessed using measures such as the electroencephalogram (EEG) to evaluate brain activity patterns associated with consciousness.

Wakefulness is regulated by several interconnected neural networks that promote arousal and attention. These networks include the ascending reticular activating system (ARAS), which consists of a group of neurons located in the brainstem that project to the thalamus and cerebral cortex, as well as other regions involved in regulating arousal and attention, such as the basal forebrain and hypothalamus.

Disorders of wakefulness can result from various underlying conditions, including neurological disorders, sleep disorders, medication side effects, or other medical conditions that affect brain function. Examples of such disorders include narcolepsy, insomnia, hypersomnia, and various forms of encephalopathy or brain injury.

Existentialism is a philosophical movement that emphasizes individual existence, freedom, and choice. It is not a medical term, but rather a concept in philosophy that deals with the nature of human existence, particularly the feeling of disorientation and confusion in the face of an apparently meaningless or absurd world. Existentialists hold that people must create their own meaning in life, as there is no God-given purpose or inherent meaning to be found. This concept can have implications for mental health and psychotherapy, particularly in the areas of anxiety, depression, and identity formation. Some existentialist thinkers include Søren Kierkegaard, Friedrich Nietzsche, Martin Heidegger, and Jean-Paul Sartre.

X-ray computed tomography (CT or CAT scan) is a medical imaging method that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of the body. These cross-sectional images can then be used to display detailed internal views of organs, bones, and soft tissues in the body.

The term "computed tomography" is used instead of "CT scan" or "CAT scan" because the machines take a series of X-ray measurements from different angles around the body and then use a computer to process these data to create detailed images of internal structures within the body.

CT scanning is a noninvasive, painless medical test that helps physicians diagnose and treat medical conditions. CT imaging provides detailed information about many types of tissue including lung, bone, soft tissue and blood vessels. CT examinations can be performed on every part of the body for a variety of reasons including diagnosis, surgical planning, and monitoring of therapeutic responses.

In computed tomography (CT), an X-ray source and detector rotate around the patient, measuring the X-ray attenuation at many different angles. A computer uses this data to construct a cross-sectional image by the process of reconstruction. This technique is called "tomography". The term "computed" refers to the use of a computer to reconstruct the images.

CT has become an important tool in medical imaging and diagnosis, allowing radiologists and other physicians to view detailed internal images of the body. It can help identify many different medical conditions including cancer, heart disease, lung nodules, liver tumors, and internal injuries from trauma. CT is also commonly used for guiding biopsies and other minimally invasive procedures.

In summary, X-ray computed tomography (CT or CAT scan) is a medical imaging technique that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional images of the body. It provides detailed internal views of organs, bones, and soft tissues in the body, allowing physicians to diagnose and treat medical conditions.

Inhalational anesthetics are a type of general anesthetic that is administered through the person's respiratory system. They are typically delivered in the form of vapor or gas, which is inhaled through a mask or breathing tube. Commonly used inhalational anesthetics include sevoflurane, desflurane, isoflurane, and nitrous oxide. These agents work by depressing the central nervous system, leading to a loss of consciousness and an inability to feel pain. They are often used for their rapid onset and offset of action, making them useful for both induction and maintenance of anesthesia during surgical procedures.

Methyl ethers are a type of organic compound where a methyl group (CH3-) is attached to an oxygen atom, which in turn is connected to another carbon atom. They are formed by the process of methylation, where a methyl group replaces a hydrogen atom in another molecule.

Methyl ethers can be found in various natural and synthetic substances. For example, dimethyl ether (CH3-O-CH3) is a common fuel used in refrigeration systems and as a propellant in aerosol sprays. Anisole (CH3-O-C6H5), another methyl ether, is found in anise oil and is used as a flavoring agent and solvent.

It's worth noting that some methyl ethers have been associated with potential health risks, particularly when they are volatile and can be inhaled or ingested. For example, exposure to high levels of dimethyl ether can cause respiratory irritation, headaches, and dizziness. Therefore, it's important to handle these substances with care and follow appropriate safety guidelines.

Vasovagal syncope is a type of fainting (syncope) that occurs when the body overreacts to certain triggers, such as the sight of blood or extreme emotional distress. This reaction causes the heart rate and blood pressure to drop, leading to reduced blood flow to the brain and loss of consciousness. Vasovagal syncope is usually not a cause for concern and does not typically indicate a serious underlying medical condition. However, it can be dangerous if it occurs during activities such as driving or operating heavy machinery. If you experience frequent episodes of vasovagal syncope, it is important to speak with a healthcare provider for evaluation and treatment options.

Deep sedation, also known as general anesthesia, is a drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation. It is characterized by the loss of protective reflexes such as cough and gag, and the ability to ventilate spontaneously may be impaired. Patients may require assistance in maintaining a patent airway, and positive pressure ventilation may be required.

Deep sedation/general anesthesia is typically used for surgical procedures or other medical interventions that require patients to be completely unaware and immobile, and it is administered by trained anesthesia professionals who monitor and manage the patient's vital signs and level of consciousness throughout the procedure.

A cerebral hemorrhage, also known as an intracranial hemorrhage or intracerebral hemorrhage, is a type of stroke that results from bleeding within the brain tissue. It occurs when a weakened blood vessel bursts and causes localized bleeding in the brain. This bleeding can increase pressure in the skull, damage nearby brain cells, and release toxic substances that further harm brain tissues.

Cerebral hemorrhages are often caused by chronic conditions like hypertension (high blood pressure) or cerebral amyloid angiopathy, which weakens the walls of blood vessels over time. Other potential causes include trauma, aneurysms, arteriovenous malformations, illicit drug use, and brain tumors. Symptoms may include sudden headache, weakness, numbness, difficulty speaking or understanding speech, vision problems, loss of balance, and altered level of consciousness. Immediate medical attention is required to diagnose and manage cerebral hemorrhage through imaging techniques, supportive care, and possible surgical interventions.

A headache is defined as pain or discomfort in the head, scalp, or neck. It can be a symptom of various underlying conditions such as stress, sinus congestion, migraine, or more serious issues like meningitis or concussion. Headaches can vary in intensity, ranging from mild to severe, and may be accompanied by other symptoms such as nausea, vomiting, or sensitivity to light and sound. There are over 150 different types of headaches, including tension headaches, cluster headaches, and sinus headaches, each with their own specific characteristics and causes.

A brain concussion is a type of traumatic brain injury that is typically caused by a blow to the head or a violent shaking of the head and body. A concussion can also occur from a fall or accident that causes the head to suddenly jerk forward or backward.

The impact or forceful movement causes the brain to move back and forth inside the skull, which can result in stretching and damaging of brain cells, as well as disrupting the normal functioning of the brain. Concussions can range from mild to severe and may cause a variety of symptoms, including:

* Headache or a feeling of pressure in the head
* Temporary loss of consciousness
* Confusion or fogginess
* Amnesia surrounding the traumatic event
* Dizziness or "seeing stars"
* Ringing in the ears
* Nausea or vomiting
* Slurred speech
* Fatigue

In some cases, concussions may also cause more serious symptoms, such as seizures, difficulty walking, loss of balance, and changes in behavior or mood. It is important to seek medical attention immediately if you suspect that you or someone else has a brain concussion. A healthcare professional can evaluate the severity of the injury and provide appropriate treatment and follow-up care.

The anesthesia recovery period, also known as the post-anesthetic care unit (PACU) or recovery room stay, is the time immediately following anesthesia and surgery during which a patient's vital signs are closely monitored as they emerge from the effects of anesthesia.

During this period, the patient is typically observed for adequate ventilation, oxygenation, circulation, level of consciousness, pain control, and any potential complications. The length of stay in the recovery room can vary depending on the type of surgery, the anesthetic used, and the individual patient's needs.

The anesthesia recovery period is a critical time for ensuring patient safety and comfort as they transition from the surgical setting to full recovery. Nurses and other healthcare providers in the recovery room are specially trained to monitor and manage patients during this vulnerable period.

Anesthesia is a medical term that refers to the loss of sensation or awareness, usually induced by the administration of various drugs. It is commonly used during surgical procedures to prevent pain and discomfort. There are several types of anesthesia, including:

1. General anesthesia: This type of anesthesia causes a complete loss of consciousness and is typically used for major surgeries.
2. Regional anesthesia: This type of anesthesia numbs a specific area of the body, such as an arm or leg, while the patient remains conscious.
3. Local anesthesia: This type of anesthesia numbs a small area of the body, such as a cut or wound, and is typically used for minor procedures.

Anesthesia can be administered through various routes, including injection, inhalation, or topical application. The choice of anesthesia depends on several factors, including the type and duration of the procedure, the patient's medical history, and their overall health. Anesthesiologists are medical professionals who specialize in administering anesthesia and monitoring patients during surgical procedures to ensure their safety and comfort.

Midazolam is a medication from the class of drugs known as benzodiazepines. It works by enhancing the effect of a neurotransmitter called gamma-aminobutyric acid (GABA), which has a calming effect on the brain and nervous system. Midazolam is often used for its sedative, hypnotic, anxiolytic, anticonvulsant, and muscle relaxant properties.

Medically, midazolam is used for various purposes, including:

1. Preoperative medication (sedation before surgery)
2. Procedural sedation (for minor surgical or diagnostic procedures)
3. Treatment of seizures (status epilepticus)
4. Sedation in critically ill patients
5. As an adjunct to anesthesia during surgeries
6. Treatment of alcohol withdrawal symptoms
7. To induce amnesia for certain medical or dental procedures

Midazolam is available in various forms, such as tablets, intravenous (IV) solutions, and intranasal sprays. It has a rapid onset of action and a short duration, making it suitable for brief, intermittent procedures. However, midazolam can cause side effects like drowsiness, confusion, respiratory depression, and memory impairment. Therefore, its use should be carefully monitored by healthcare professionals.

Auditory evoked potentials (AEP) are medical tests that measure the electrical activity in the brain in response to sound stimuli. These tests are often used to assess hearing function and neural processing in individuals, particularly those who cannot perform traditional behavioral hearing tests.

There are several types of AEP tests, including:

1. Brainstem Auditory Evoked Response (BAER) or Brainstem Auditory Evoked Potentials (BAEP): This test measures the electrical activity generated by the brainstem in response to a click or tone stimulus. It is often used to assess the integrity of the auditory nerve and brainstem pathways, and can help diagnose conditions such as auditory neuropathy and retrocochlear lesions.
2. Middle Latency Auditory Evoked Potentials (MLAEP): This test measures the electrical activity generated by the cortical auditory areas of the brain in response to a click or tone stimulus. It is often used to assess higher-level auditory processing, and can help diagnose conditions such as auditory processing disorders and central auditory dysfunction.
3. Long Latency Auditory Evoked Potentials (LLAEP): This test measures the electrical activity generated by the cortical auditory areas of the brain in response to a complex stimulus, such as speech. It is often used to assess language processing and cognitive function, and can help diagnose conditions such as learning disabilities and dementia.

Overall, AEP tests are valuable tools for assessing hearing and neural function in individuals who cannot perform traditional behavioral hearing tests or who have complex neurological conditions.

Amnesia is a condition characterized by memory loss, which can be temporary or permanent. It may result from brain damage or disease, and it can affect various aspects of memory, such as the ability to recall past events (retrograde amnesia), the ability to form new memories (anterograde amnesia), or both. Amnesia can also affect a person's sense of identity and their ability to learn new skills.

There are several types of amnesia, including:

1. Anterograde amnesia: This type of amnesia affects the ability to form new memories after an injury or trauma. People with anterograde amnesia may have difficulty learning new information and remembering recent events.
2. Retrograde amnesia: Retrograde amnesia affects the ability to recall memories that were formed before an injury or trauma. People with retrograde amnesia may have trouble remembering events, people, or facts from their past.
3. Transient global amnesia: This is a temporary form of amnesia that usually lasts for less than 24 hours. It is often caused by a lack of blood flow to the brain, and it can be triggered by emotional stress, physical exertion, or other factors.
4. Korsakoff's syndrome: This is a type of amnesia that is caused by alcohol abuse and malnutrition. It is characterized by severe memory loss, confusion, and disorientation.
5. Dissociative amnesia: This type of amnesia is caused by psychological factors, such as trauma or stress. People with dissociative amnesia may have trouble remembering important personal information or events that are emotionally charged.

The treatment for amnesia depends on the underlying cause. In some cases, memory may improve over time, while in other cases, it may be permanent. Treatment may involve medication, therapy, or rehabilitation to help people with amnesia cope with their memory loss and develop new skills to compensate for their memory impairments.

Automatism is a medical and legal term that refers to unconscious or involuntary behavior or actions that are performed without conscious awareness or control. In medicine, automatisms can occur in various neurological or psychiatric conditions, such as epilepsy, sleepwalking, or certain mental disorders. During an automatism episode, a person may appear to be awake and functioning, but they are not fully aware of their actions and may not remember them later.

In the legal context, automatism is often used as a defense in criminal cases, where it is argued that the defendant was not mentally responsible for their actions due to an involuntary automatism episode. However, the definition and application of automatism as a legal defense can vary depending on the jurisdiction and the specific circumstances of the case.

A subarachnoid hemorrhage is a type of stroke that results from bleeding into the space surrounding the brain, specifically within the subarachnoid space which contains cerebrospinal fluid (CSF). This space is located between the arachnoid membrane and the pia mater, two of the three layers that make up the meninges, the protective covering of the brain and spinal cord.

The bleeding typically originates from a ruptured aneurysm, a weakened area in the wall of a cerebral artery, or less commonly from arteriovenous malformations (AVMs) or head trauma. The sudden influx of blood into the CSF-filled space can cause increased intracranial pressure, irritation to the brain, and vasospasms, leading to further ischemia and potential additional neurological damage.

Symptoms of a subarachnoid hemorrhage may include sudden onset of severe headache (often described as "the worst headache of my life"), neck stiffness, altered mental status, nausea, vomiting, photophobia, and focal neurological deficits. Rapid diagnosis and treatment are crucial to prevent further complications and improve the chances of recovery.

Epilepsy, partial is a type of epilepsy characterized by recurrent, unprovoked seizures that originate in a specific, localized area of the brain. These seizures are also known as focal seizures and can vary in severity and symptoms depending on the location of the abnormal electrical activity in the brain.

Partial epilepsies can be further classified into two main categories: simple partial seizures and complex partial seizures. Simple partial seizures do not involve a loss of consciousness, while complex partial seizures are associated with impaired awareness or responsiveness during the seizure.

The causes of partial epilepsies can include brain injury, infection, stroke, tumors, genetic factors, or an unknown cause. Treatment typically involves anti-seizure medications, and in some cases, surgery may be recommended to remove the specific area of the brain responsible for the seizures.

I'm sorry for any confusion, but "Information Theory" is not a term that has a specific medical definition. Information theory is a branch of mathematics and electrical engineering that deals with the quantification, storage, and communication of information. It was developed by Claude Shannon in 1948 and has found applications in various fields such as computer science, telecommunications, and cognitive science.

In a broader context, information theory concepts might be used in medical research or healthcare settings to analyze and manage complex data sets, optimize communication systems for telemedicine, or study the neural coding of sensory information in the brain. However, there is no specific medical definition associated with "Information Theory" itself.

Neurobiology is not strictly a medical term, but rather a field of study that investigates the interconnections between the nervous system and living organisms' biological processes. It is a multidisciplinary area that combines neuroscience, biology, chemistry, and physics to understand how the brain and nervous system function at molecular, cellular, and systems levels.

In medical contexts, neurobiological concepts are often applied to understand the underlying mechanisms of various neurological and psychiatric disorders, develop diagnostic tools, and design treatment strategies. For instance, research in neurobiology may explore how genetic factors contribute to neurodevelopmental disorders like autism or how molecular changes in the brain lead to neurodegenerative diseases such as Alzheimer's and Parkinson's.

In summary, neurobiology is a scientific discipline concerned with understanding the biological basis of nervous system function, which has significant implications for medical research and practice.

Neurosciences is a multidisciplinary field of study that focuses on the structure, function, development, and disorders of the nervous system, which includes the brain, spinal cord, and peripheral nerves. It incorporates various scientific disciplines such as biology, chemistry, physics, mathematics, engineering, and computer science to understand the complexities of the nervous system at different levels, from molecular and cellular mechanisms to systems and behavior.

The field encompasses both basic research and clinical applications, with the aim of advancing our knowledge of the nervous system and developing effective treatments for neurological and psychiatric disorders. Specialties within neurosciences include neuroanatomy, neurophysiology, neurochemistry, neuropharmacology, neurobiology, neuroimmunology, behavioral neuroscience, cognitive neuroscience, clinical neuroscience, and computational neuroscience, among others.

A decompressive craniectomy is a neurosurgical procedure in which a portion of the skull is removed to allow the swollen brain to expand and reduce intracranial pressure. This surgical intervention is typically performed as a last resort in cases where other treatments for increased intracranial pressure, such as hyperosmolar therapy or drainage of cerebrospinal fluid, have been unsuccessful.

During the procedure, the surgeon creates an opening in the skull (craniectomy) and removes a piece of bone (bone flap). This exposes the brain and creates additional space for it to expand without being compressed by the rigid skull. The dura mater, the outermost protective layer surrounding the brain, may also be opened to provide further room for brain swelling.

Once the swelling has subsided, a second procedure known as cranioplasty is performed to replace the removed bone flap or use an artificial implant to restore the skull's integrity and protect the underlying brain tissue. The timing of cranioplasty can vary depending on individual patient factors and clinical conditions.

Decompressive craniectomy is most commonly used in the management of traumatic brain injuries, stroke-induced malignant cerebral edema, and intracranial hypertension due to various causes, such as infection or inflammation. While this procedure can be lifesaving in some cases, it may also lead to complications like seizures, hydrocephalus, or neurological deficits. Therefore, the decision to perform a decompressive craniectomy should be made carefully and on an individual basis, considering both the potential benefits and risks.

Epilepsy is a chronic neurological disorder characterized by recurrent, unprovoked seizures. These seizures are caused by abnormal electrical activity in the brain, which can result in a wide range of symptoms, including convulsions, loss of consciousness, and altered sensations or behaviors. Epilepsy can have many different causes, including genetic factors, brain injury, infection, or stroke. In some cases, the cause may be unknown.

There are many different types of seizures that can occur in people with epilepsy, and the specific type of seizure will depend on the location and extent of the abnormal electrical activity in the brain. Some people may experience only one type of seizure, while others may have several different types. Seizures can vary in frequency, from a few per year to dozens or even hundreds per day.

Epilepsy is typically diagnosed based on the patient's history of recurrent seizures and the results of an electroencephalogram (EEG), which measures the electrical activity in the brain. Imaging tests such as MRI or CT scans may also be used to help identify any structural abnormalities in the brain that may be contributing to the seizures.

While there is no cure for epilepsy, it can often be effectively managed with medication. In some cases, surgery may be recommended to remove the area of the brain responsible for the seizures. With proper treatment and management, many people with epilepsy are able to lead normal, productive lives.

Holistic health is a concept in medicine that considers the whole person, including their physical, mental, emotional, social, and spiritual well-being, in the prevention, diagnosis, and treatment of illness. It emphasizes the importance of these different aspects of an individual's life in maintaining optimal health and preventing disease.

The goal of holistic health is to achieve a state of balance and harmony within the body, mind, and spirit, and to empower individuals to take responsibility for their own health and well-being. Holistic healthcare practitioners may use a variety of treatments, including conventional medical therapies, complementary and alternative medicine (CAM) approaches, lifestyle modifications, and self-care techniques, to help patients achieve this balance and improve their overall quality of life.

It's important to note that while the concept of holistic health is gaining popularity, it is not a substitute for conventional medical care and should be used in conjunction with, not instead of, evidence-based medical treatments.

A fatal outcome is a term used in medical context to describe a situation where a disease, injury, or illness results in the death of an individual. It is the most severe and unfortunate possible outcome of any medical condition, and is often used as a measure of the severity and prognosis of various diseases and injuries. In clinical trials and research, fatal outcome may be used as an endpoint to evaluate the effectiveness and safety of different treatments or interventions.

General anesthetics are a type of medication used to render a person unconscious and insensible to pain during surgical procedures. They work by depressing the central nervous system, affecting the brain's ability to process information and transmit signals, including those related to pain and muscle movement. General anesthesia involves a combination of intravenous (IV) drugs and inhaled gases that produce a state of controlled unconsciousness, amnesia, analgesia, and immobility.

General anesthetics can be classified into several categories based on their chemical structure and mechanism of action, including:

1. Inhalation anesthetics: These are volatile liquids or gases that are vaporized and inhaled through a breathing circuit. Examples include sevoflurane, desflurane, isoflurane, and nitrous oxide.
2. Intravenous anesthetics: These are drugs that are administered directly into the bloodstream through an IV line. Examples include propofol, etomidate, and ketamine.
3. Dissociative anesthetics: These are drugs that produce a state of dissociation between the thalamus and the cerebral cortex, resulting in altered consciousness, analgesia, and amnesia. Ketamine is a commonly used example.
4. Neurodegenerative anesthetics: These are drugs that cause degeneration of neurons in specific areas of the brain, leading to loss of consciousness. Examples include barbiturates such as thiopental and methohexital.

The choice of general anesthetic depends on several factors, including the patient's medical history, the type and duration of surgery, and the anesthesiologist's preference. The administration of general anesthetics requires careful monitoring and management by a trained anesthesia provider to ensure the patient's safety and comfort throughout the procedure.

A subdural hematoma is a type of hematoma (a collection of blood) that occurs between the dura mater, which is the outermost protective covering of the brain, and the brain itself. It is usually caused by bleeding from the veins located in this potential space, often as a result of a head injury or trauma.

Subdural hematomas can be classified as acute, subacute, or chronic based on their rate of symptom progression and the time course of their appearance on imaging studies. Acute subdural hematomas typically develop and cause symptoms rapidly, often within hours of the head injury. Subacute subdural hematomas have a more gradual onset of symptoms, which can occur over several days to a week after the trauma. Chronic subdural hematomas may take weeks to months to develop and are often seen in older adults or individuals with chronic alcohol abuse, even after minor head injuries.

Symptoms of a subdural hematoma can vary widely depending on the size and location of the hematoma, as well as the patient's age and overall health. Common symptoms include headache, altered mental status, confusion, memory loss, weakness or numbness, seizures, and in severe cases, coma or even death. Treatment typically involves surgical evacuation of the hematoma, along with management of any underlying conditions that may have contributed to its development.

Hydrocephalus is a medical condition characterized by an abnormal accumulation of cerebrospinal fluid (CSF) within the brain, leading to an increase in intracranial pressure and potentially causing damage to the brain tissues. This excessive buildup of CSF can result from either overproduction or impaired absorption of the fluid, which typically causes the ventricles (fluid-filled spaces) inside the brain to expand and put pressure on surrounding brain structures.

The condition can be congenital, present at birth due to genetic factors or abnormalities during fetal development, or acquired later in life as a result of injuries, infections, tumors, or other disorders affecting the brain's ability to regulate CSF flow and absorption. Symptoms may vary depending on age, severity, and duration but often include headaches, vomiting, balance problems, vision issues, cognitive impairment, and changes in behavior or personality.

Treatment for hydrocephalus typically involves surgically implanting a shunt system that diverts the excess CSF from the brain to another part of the body where it can be absorbed, such as the abdominal cavity. In some cases, endoscopic third ventriculostomy (ETV) might be an alternative treatment option, creating a new pathway for CSF flow within the brain. Regular follow-ups with neurosurgeons and other healthcare professionals are essential to monitor the condition and make any necessary adjustments to the treatment plan.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

The cerebral cortex is the outermost layer of the brain, characterized by its intricate folded structure and wrinkled appearance. It is a region of great importance as it plays a key role in higher cognitive functions such as perception, consciousness, thought, memory, language, and attention. The cerebral cortex is divided into two hemispheres, each containing four lobes: the frontal, parietal, temporal, and occipital lobes. These areas are responsible for different functions, with some regions specializing in sensory processing while others are involved in motor control or associative functions. The cerebral cortex is composed of gray matter, which contains neuronal cell bodies, and is covered by a layer of white matter that consists mainly of myelinated nerve fibers.

A tilt-table test is a diagnostic procedure used to evaluate symptoms of syncope (fainting) or near-syncope. It measures your body's cardiovascular response to changes in position. During the test, you lie on a table that can be tilted to change the angle of your body from horizontal to upright. This simulates what happens when you stand up from a lying down position.

The test monitors heart rate, blood pressure, and oxygen levels while you're in different positions. If you experience symptoms like dizziness or fainting during the test, these can provide clues about the cause of your symptoms. The test is used to diagnose conditions like orthostatic hypotension (a sudden drop in blood pressure when standing), vasovagal syncope (fainting due to an overactive vagus nerve), and other heart rhythm disorders.

Quadriplegia, also known as tetraplegia, is a medical condition characterized by paralysis affecting all four limbs and the trunk of the body. It results from damage to the cervical spinal cord, typically at levels C1-C8, which controls signals to the muscles in the arms, hands, trunk, legs, and pelvic organs. The extent of quadriplegia can vary widely, ranging from weakness to complete loss of movement and sensation below the level of injury. Other symptoms may include difficulty breathing, bowel and bladder dysfunction, and sexual dysfunction. The severity and prognosis depend on the location and extent of the spinal cord injury.

Oral surgery is a specialized branch of dentistry that focuses on the diagnosis and surgical treatment of various conditions related to the mouth, teeth, jaws, and facial structures. Some of the common procedures performed by oral surgeons include:

1. Tooth extractions: Removal of severely decayed, damaged, or impacted teeth, such as wisdom teeth.
2. Dental implant placement: Surgical insertion of titanium posts that serve as artificial tooth roots to support dental restorations like crowns, bridges, or dentures.
3. Jaw surgery (orthognathic surgery): Corrective procedures for misaligned jaws, uneven bite, or sleep apnea caused by structural jaw abnormalities.
4. Oral pathology: Diagnosis and treatment of benign and malignant growths or lesions in the oral cavity, including biopsies and removal of tumors.
5. Temporomandibular joint (TMJ) disorders: Surgical intervention for issues related to the joint that connects the jawbone to the skull, such as arthroscopy, open joint surgery, or total joint replacement.
6. Facial trauma reconstruction: Repair of fractured facial bones, soft tissue injuries, and lacerations resulting from accidents, sports injuries, or interpersonal violence.
7. Cleft lip and palate repair: Surgical correction of congenital deformities affecting the upper lip and hard/soft palate.
8. Sleep apnea treatment: Surgical reduction or removal of excess tissue in the throat to alleviate airway obstruction and improve breathing during sleep.
9. Cosmetic procedures: Enhancement of facial aesthetics through various techniques, such as chin or cheekbone augmentation, lip reshaping, or scar revision.

Oral surgeons typically complete a four-year dental school program followed by an additional four to six years of specialized surgical training in a hospital-based residency program. They are qualified to administer general anesthesia and often perform procedures in a hospital setting or outpatient surgical center.

Anesthetics are medications that are used to block or reduce feelings of pain and sensation, either locally in a specific area of the body or generally throughout the body. They work by depressing the nervous system, interrupting the communication between nerves and the brain. Anesthetics can be administered through various routes such as injection, inhalation, or topical application, depending on the type and the desired effect. There are several classes of anesthetics, including:

1. Local anesthetics: These numb a specific area of the body and are commonly used during minor surgical procedures, dental work, or to relieve pain from injuries. Examples include lidocaine, prilocaine, and bupivacaine.
2. Regional anesthetics: These block nerve impulses in a larger area of the body, such as an arm or leg, and can be used for more extensive surgical procedures. They are often administered through a catheter to provide continuous pain relief over a longer period. Examples include spinal anesthesia, epidural anesthesia, and peripheral nerve blocks.
3. General anesthetics: These cause a state of unconsciousness and are used for major surgical procedures or when the patient needs to be completely immobile during a procedure. They can be administered through inhalation or injection and affect the entire body. Examples include propofol, sevoflurane, and isoflurane.

Anesthetics are typically safe when used appropriately and under medical supervision. However, they can have side effects such as drowsiness, nausea, and respiratory depression. Proper dosing and monitoring by a healthcare professional are essential to minimize the risks associated with anesthesia.

A skull fracture is a break in one or more of the bones that form the skull. It can occur from a direct blow to the head, penetrating injuries like gunshot wounds, or from strong rotational forces during an accident. There are several types of skull fractures, including:

1. Linear Skull Fracture: This is the most common type, where there's a simple break in the bone without any splintering, depression, or displacement. It often doesn't require treatment unless it's near a sensitive area like an eye or ear.

2. Depressed Skull Fracture: In this type, a piece of the skull is pushed inward toward the brain. Surgery may be needed to relieve pressure on the brain and repair the fracture.

3. Diastatic Skull Fracture: This occurs along the suture lines (the fibrous joints between the skull bones) that haven't fused yet, often seen in infants and young children.

4. Basilar Skull Fracture: This involves fractures at the base of the skull. It can be serious due to potential injury to the cranial nerves and blood vessels located in this area.

5. Comminuted Skull Fracture: In this severe type, the bone is shattered into many pieces. These fractures usually require extensive surgical repair.

Symptoms of a skull fracture can include pain, swelling, bruising, bleeding (if there's an open wound), and in some cases, clear fluid draining from the ears or nose (cerebrospinal fluid leak). Severe fractures may cause brain injury, leading to symptoms like confusion, loss of consciousness, seizures, or neurological deficits. Immediate medical attention is necessary for any suspected skull fracture.

A nerve net, also known as a neural net or neuronal network, is not a medical term per se, but rather a concept in neuroscience and artificial intelligence (AI). It refers to a complex network of interconnected neurons that process and transmit information. In the context of the human body, the nervous system can be thought of as a type of nerve net, with the brain and spinal cord serving as the central processing unit and peripheral nerves carrying signals to and from various parts of the body.

In the field of AI, artificial neural networks are computational models inspired by the structure and function of biological nerve nets. These models consist of interconnected nodes or "neurons" that process information and learn patterns through a process of training and adaptation. They have been used in a variety of applications, including image recognition, natural language processing, and machine learning.

Bacterial meningitis is a serious infection that causes the membranes (meninges) surrounding the brain and spinal cord to become inflamed. It's caused by various types of bacteria, such as Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b.

The infection can develop quickly, over a few hours or days, and is considered a medical emergency. Symptoms may include sudden high fever, severe headache, stiff neck, nausea, vomiting, confusion, and sensitivity to light. In some cases, a rash may also be present.

Bacterial meningitis can lead to serious complications such as brain damage, hearing loss, learning disabilities, and even death if not treated promptly with appropriate antibiotics and supportive care. It is important to seek immediate medical attention if you suspect bacterial meningitis. Vaccines are available to prevent certain types of bacterial meningitis.

Brain diseases, also known as neurological disorders, refer to a wide range of conditions that affect the brain and nervous system. These diseases can be caused by various factors such as genetics, infections, injuries, degeneration, or structural abnormalities. They can affect different parts of the brain, leading to a variety of symptoms and complications.

Some examples of brain diseases include:

1. Alzheimer's disease - a progressive degenerative disorder that affects memory and cognitive function.
2. Parkinson's disease - a movement disorder characterized by tremors, stiffness, and difficulty with coordination and balance.
3. Multiple sclerosis - a chronic autoimmune disease that affects the nervous system and can cause a range of symptoms such as vision loss, muscle weakness, and cognitive impairment.
4. Epilepsy - a neurological disorder characterized by recurrent seizures.
5. Brain tumors - abnormal growths in the brain that can be benign or malignant.
6. Stroke - a sudden interruption of blood flow to the brain, which can cause paralysis, speech difficulties, and other neurological symptoms.
7. Meningitis - an infection of the membranes surrounding the brain and spinal cord.
8. Encephalitis - an inflammation of the brain that can be caused by viruses, bacteria, or autoimmune disorders.
9. Huntington's disease - a genetic disorder that affects muscle coordination, cognitive function, and mental health.
10. Migraine - a neurological condition characterized by severe headaches, often accompanied by nausea, vomiting, and sensitivity to light and sound.

Brain diseases can range from mild to severe and may be treatable or incurable. They can affect people of all ages and backgrounds, and early diagnosis and treatment are essential for improving outcomes and quality of life.

Wernicke Encephalopathy is a neuropsychiatric disorder that is caused by a deficiency of thiamine (vitamin B1). It is characterized by a classic triad of symptoms: confusion, oculomotor dysfunction (such as nystagmus and ophthalmoplegia), and gait ataxia. Other symptoms can include memory loss, apathy, and hypothermia.

Wernicke Encephalopathy is most commonly seen in alcoholics due to poor nutrition, but it can also occur in people with conditions that cause malabsorption or increased thiamine requirements, such as AIDS, cancer, and chronic diarrhea. Immediate treatment with thiamine replacement therapy is necessary to prevent progression of the disease and potential permanent neurological damage. If left untreated, Wernicke Encephalopathy can lead to Korsakoff's syndrome, a chronic memory disorder.

Visual perception refers to the ability to interpret and organize information that comes from our eyes to recognize and understand what we are seeing. It involves several cognitive processes such as pattern recognition, size estimation, movement detection, and depth perception. Visual perception allows us to identify objects, navigate through space, and interact with our environment. Deficits in visual perception can lead to learning difficulties and disabilities.

Brain mapping is a broad term that refers to the techniques used to understand the structure and function of the brain. It involves creating maps of the various cognitive, emotional, and behavioral processes in the brain by correlating these processes with physical locations or activities within the nervous system. Brain mapping can be accomplished through a variety of methods, including functional magnetic resonance imaging (fMRI), positron emission tomography (PET) scans, electroencephalography (EEG), and others. These techniques allow researchers to observe which areas of the brain are active during different tasks or thoughts, helping to shed light on how the brain processes information and contributes to our experiences and behaviors. Brain mapping is an important area of research in neuroscience, with potential applications in the diagnosis and treatment of neurological and psychiatric disorders.

Neuroanatomy is the branch of anatomy that deals with the study of the structure, organization, and relationships of the nervous system, including the brain, spinal cord, and peripheral nerves. It involves understanding the complex arrangement of neurons, neural pathways, and support structures that make up the nervous system, as well as how these components work together to enable various functions such as sensation, movement, cognition, and emotion. Neuroanatomy is a fundamental area of study in neuroscience, medicine, and psychology, providing critical knowledge for understanding brain function and dysfunction, developing treatments for neurological disorders, and advancing our overall understanding of the human body.

A closed head injury is a type of traumatic brain injury (TBI) that occurs when there is no penetration or breakage of the skull. The brain is encased in the skull and protected by cerebrospinal fluid, but when the head experiences a sudden impact or jolt, the brain can move back and forth within the skull, causing it to bruise, tear blood vessels, or even cause nerve damage. This type of injury can result from various incidents such as car accidents, sports injuries, falls, or any other event that causes the head to suddenly stop or change direction quickly.

Closed head injuries can range from mild (concussion) to severe (diffuse axonal injury, epidural hematoma, subdural hematoma), and symptoms may not always be immediately apparent. They can include headache, dizziness, nausea, vomiting, confusion, memory loss, difficulty concentrating, mood changes, sleep disturbances, and in severe cases, loss of consciousness, seizures, or even coma. It is essential to seek medical attention immediately if you suspect a closed head injury, as prompt diagnosis and treatment can significantly improve the outcome.

A neurological examination is a series of tests used to evaluate the functioning of the nervous system, including both the central nervous system (the brain and spinal cord) and peripheral nervous system (the nerves that extend from the brain and spinal cord to the rest of the body). It is typically performed by a healthcare professional such as a neurologist or a primary care physician with specialized training in neurology.

During a neurological examination, the healthcare provider will assess various aspects of neurological function, including:

1. Mental status: This involves evaluating a person's level of consciousness, orientation, memory, and cognitive abilities.
2. Cranial nerves: There are 12 cranial nerves that control functions such as vision, hearing, smell, taste, and movement of the face and neck. The healthcare provider will test each of these nerves to ensure they are functioning properly.
3. Motor function: This involves assessing muscle strength, tone, coordination, and reflexes. The healthcare provider may ask the person to perform certain movements or tasks to evaluate these functions.
4. Sensory function: The healthcare provider will test a person's ability to feel different types of sensations, such as touch, pain, temperature, vibration, and proprioception (the sense of where your body is in space).
5. Coordination and balance: The healthcare provider may assess a person's ability to perform coordinated movements, such as touching their finger to their nose or walking heel-to-toe.
6. Reflexes: The healthcare provider will test various reflexes throughout the body using a reflex hammer.

The results of a neurological examination can help healthcare providers diagnose and monitor conditions that affect the nervous system, such as stroke, multiple sclerosis, Parkinson's disease, or peripheral neuropathy.

Alpha rhythm is a type of brain wave that is typically observed in the electroencephalogram (EEG) of normal, awake individuals when they have their eyes closed. It is characterized by sinusoidal waves with a frequency range of 8-13 Hz and is most prominent over the occipital region of the head, which is located at the back of the skull above the brain's visual cortex.

Alpha rhythm is typically associated with relaxed wakefulness, and its presence may indicate that an individual is awake but not engaged in any mentally demanding tasks. It can be blocked or suppressed by various stimuli, such as opening one's eyes, hearing a loud noise, or engaging in mental activity.

Disruptions in alpha rhythm have been observed in various neurological and psychiatric conditions, including epilepsy, dementia, depression, and anxiety disorders. However, more research is needed to fully understand the clinical significance of these abnormalities.

Acute disseminated encephalomyelitis (ADEM) is a rare inflammatory demyelinating disease of the central nervous system, characterized by a sudden onset of widespread inflammation and damage to the brain and spinal cord. It typically follows a viral infection or, less commonly, vaccination and is more prevalent in children than adults.

The condition involves the rapid development of multiple inflammatory lesions throughout the white matter of the brain and spinal cord. These lesions lead to demyelination, which means the loss of the protective myelin sheath surrounding nerve fibers, disrupting communication between neurons. This results in various neurological symptoms such as:

1. Encephalopathy (changes in consciousness, behavior, or mental status)
2. Weakness or paralysis of limbs
3. Visual disturbances
4. Speech and language problems
5. Seizures
6. Ataxia (loss of coordination and balance)
7. Sensory changes
8. Autonomic nervous system dysfunction (e.g., temperature regulation, blood pressure, heart rate)

The diagnosis of ADEM is based on clinical presentation, radiological findings, and laboratory tests to exclude other possible causes. Magnetic resonance imaging (MRI) typically shows multiple, large, bilateral lesions in the white matter of the brain and spinal cord. Cerebrospinal fluid analysis may reveal an elevated white blood cell count and increased protein levels.

Treatment for ADEM generally includes high-dose corticosteroids to reduce inflammation and improve outcomes. Intravenous immunoglobulin (IVIG) or plasma exchange (plasmapheresis) may be used if there is no response to steroid therapy. Most patients with ADEM recover completely or have significant improvement within several months, although some may experience residual neurological deficits.

Stupor, in medical terms, is a state of impaired consciousness and responsiveness. A person in a stupor is unresponsive to most or all stimuli, but can be aroused briefly by strong stimulation such as sharp pain or loud noise. However, they quickly return to their unresponsive state once the stimulus is removed. It's a condition that lies between lethargy and coma on the spectrum of decreased levels of consciousness. Prolonged stupor may indicate serious underlying conditions like brain injury, infection, or severe metabolic disturbances.

Thiopental, also known as Thiopentone, is a rapid-onset, ultrashort-acting barbiturate derivative. It is primarily used for the induction of anesthesia due to its ability to cause unconsciousness quickly and its short duration of action. Thiopental can also be used for sedation in critically ill patients, though this use has become less common due to the development of safer alternatives.

The drug works by enhancing the inhibitory effects of gamma-aminobutyric acid (GABA), a neurotransmitter in the brain that produces a calming effect. This results in the depression of the central nervous system, leading to sedation, hypnosis, and ultimately, anesthesia.

It is worth noting that Thiopental has been largely replaced by newer drugs in many clinical settings due to its potential for serious adverse effects, such as cardiovascular and respiratory depression, as well as the risk of anaphylaxis. Additionally, it has been used in controversial procedures like capital punishment in some jurisdictions.

A "delta rhythm" is a term used in electroencephalography (EEG) to describe a pattern of brain waves that are typically seen in the delta frequency range (0.5-4 Hz) and are maximal over the posterior regions of the head. This rhythm is often observed during deep sleep stages, specifically stage 3 and stage 4 of non-rapid eye movement (NREM) sleep, also known as slow-wave sleep.

Delta waves are characterized by their high amplitude and slow frequency, making them easily distinguishable from other brain wave patterns. The presence of a robust delta rhythm during sleep is thought to reflect the restorative processes that occur during this stage of sleep, including memory consolidation and physical restoration.

However, it's important to note that abnormal delta rhythms can also be observed in certain neurological conditions, such as epilepsy or encephalopathy, where they may indicate underlying brain dysfunction or injury. In these cases, the presence of delta rhythm may have different clinical implications and require further evaluation by a medical professional.

Conscience is not a medical term, but it is a concept that is often discussed in the context of ethics, psychology, and philosophy. In general, conscience refers to an individual's sense of right and wrong, which guides their behavior and decision-making. It is sometimes described as an inner voice or a moral compass that helps people distinguish between right and wrong actions.

While conscience is not a medical term, there are medical conditions that can affect a person's ability to distinguish between right and wrong or to make ethical decisions. For example, certain neurological conditions, such as frontotemporal dementia, can impair a person's moral judgment and decision-making abilities. Similarly, some mental health disorders, such as psychopathy, may be associated with reduced moral reasoning and empathy, which can affect a person's conscience.

It is worth noting that the concept of conscience is complex and multifaceted, and there is ongoing debate among philosophers, psychologists, and neuroscientists about its nature and origins. Some theories suggest that conscience is a product of socialization and cultural influences, while others propose that it has a more fundamental basis in human biology and evolution.

Methohexital is a rapidly acting barbiturate sedative-hypnotic agent primarily used for the induction of anesthesia. It is a short-acting drug, with an onset of action of approximately one minute and a duration of action of about 5 to 10 minutes. Methohexital is highly lipid soluble, which allows it to rapidly cross the blood-brain barrier and produce a rapid and profound sedative effect.

Methohexital is administered intravenously and works by depressing the central nervous system (CNS), producing a range of effects from mild sedation to general anesthesia. At lower doses, it can cause drowsiness, confusion, and amnesia, while at higher doses, it can lead to unconsciousness and suppression of respiratory function.

Methohexital is also used for diagnostic procedures that require sedation, such as electroconvulsive therapy (ECT) and cerebral angiography. It is not commonly used outside of hospital or clinical settings due to its potential for serious adverse effects, including respiratory depression, cardiovascular instability, and anaphylaxis.

It's important to note that Methohexital should only be administered by trained medical professionals under close supervision, as it requires careful titration to achieve the desired level of sedation while minimizing the risk of adverse effects.

A ventriculostomy is a medical procedure in which an opening is made into one of the cerebral ventricles, the fluid-filled spaces within the brain, to relieve pressure or to obtain cerebrospinal fluid (CSF) for diagnostic testing. This is typically performed using a catheter known as an external ventricular drain (EVD). The EVD is inserted through a burr hole in the skull and into the ventricle, allowing CSF to drain out and be measured or tested. Ventriculostomy may be necessary in the management of various conditions that can cause increased intracranial pressure, such as hydrocephalus, brain tumors, or traumatic brain injuries.

Neuroleptic Malignant Syndrome (NMS) is a rare but potentially life-threatening condition characterized by a group of symptoms that may occur together in individuals taking antipsychotic medications, or in some cases, after the abrupt discontinuation of dopamine agonists.

The four primary features of NMS are:

1. High fever (temperature greater than 38°C/100.4°F)
2. Muscle rigidity or stiffness
3. Altered mental status, which can range from confusion and agitation to a coma
4. Autonomic instability, which can cause symptoms such as irregular pulse or blood pressure, rapid heartbeat, sweating, and unstable body temperature.

Other possible symptoms of NMS may include:

- Tremors or involuntary movements (dyskinesias)
- Labored breathing (dyspnea)
- Changes in heart rate and rhythm (arrhythmias)
- Elevated white blood cell count (leukocytosis)
- Metabolic abnormalities, such as increased creatine phosphokinase levels, elevated liver enzymes, and myoglobinuria.

NMS is a medical emergency that requires immediate treatment, typically involving the discontinuation of the offending medication, supportive care (such as hydration, temperature control, and management of autonomic instability), and sometimes medications to reduce muscle rigidity and lower fever. The exact cause of NMS remains unclear, but it is thought to be related to a dysregulation in dopamine receptors in the brain.

Defining "life" is a complex question that has been debated by philosophers, scientists, and theologians for centuries. From a biological or medical perspective, life can be defined as a characteristic that distinguishes physical entities that do have biological processes, such as growth, reproduction, and response to stimuli, from those that do not, either because such functions have ceased (death), or because they never had such functions and are classified as inanimate.

The National Institutes of Health (NIH) defines life as "the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death."

It's important to note that there is no one universally accepted definition of life, and different fields and disciplines may have slightly different definitions or criteria.

'Behavior' is a term used in the medical and scientific community to describe the actions or reactions of an individual in response to internal or external stimuli. It can be observed and measured, and it involves all the responses of a person, including motor responses, emotional responses, and cognitive responses. Behaviors can be voluntary or involuntary, adaptive or maladaptive, and normal or abnormal. They can also be influenced by genetic, physiological, environmental, and social factors. In a medical context, the study of behavior is often relevant to understanding and treating various mental health conditions, such as anxiety disorders, mood disorders, and personality disorders.

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome associated with liver dysfunction and/or portosystemic shunting. It results from the accumulation of toxic substances, such as ammonia and inflammatory mediators, which are normally metabolized by the liver. HE can present with a wide range of symptoms, including changes in sleep-wake cycle, altered mental status, confusion, disorientation, asterixis (flapping tremor), and in severe cases, coma. The diagnosis is based on clinical evaluation, neuropsychological testing, and exclusion of other causes of cognitive impairment. Treatment typically involves addressing the underlying liver dysfunction, reducing ammonia production through dietary modifications and medications, and preventing further episodes with lactulose or rifaximin therapy.

Neurological models are simplified representations or simulations of various aspects of the nervous system, including its structure, function, and processes. These models can be theoretical, computational, or physical and are used to understand, explain, and predict neurological phenomena. They may focus on specific neurological diseases, disorders, or functions, such as memory, learning, or movement. The goal of these models is to provide insights into the complex workings of the nervous system that cannot be easily observed or understood through direct examination alone.

Neurology is a branch of medicine that deals with the study and treatment of diseases and disorders of the nervous system, which includes the brain, spinal cord, peripheral nerves, muscles, and autonomic nervous system. Neurologists are medical doctors who specialize in this field, diagnosing and treating conditions such as stroke, Alzheimer's disease, epilepsy, Parkinson's disease, multiple sclerosis, and various types of headaches and pain disorders. They use a variety of diagnostic tests, including imaging studies like MRI and CT scans, electrophysiological tests like EEG and EMG, and laboratory tests to evaluate nerve function and identify any underlying conditions or abnormalities. Treatment options may include medication, surgery, rehabilitation, or lifestyle modifications.

Prospective studies, also known as longitudinal studies, are a type of cohort study in which data is collected forward in time, following a group of individuals who share a common characteristic or exposure over a period of time. The researchers clearly define the study population and exposure of interest at the beginning of the study and follow up with the participants to determine the outcomes that develop over time. This type of study design allows for the investigation of causal relationships between exposures and outcomes, as well as the identification of risk factors and the estimation of disease incidence rates. Prospective studies are particularly useful in epidemiology and medical research when studying diseases with long latency periods or rare outcomes.

A craniotomy is a surgical procedure where a bone flap is temporarily removed from the skull to access the brain. This procedure is typically performed to treat various neurological conditions, such as brain tumors, aneurysms, arteriovenous malformations, or traumatic brain injuries. After the underlying brain condition is addressed, the bone flap is usually replaced and secured back in place with plates and screws. The purpose of a craniotomy is to provide access to the brain for diagnostic or therapeutic interventions while minimizing potential damage to surrounding tissues.

The term "hysteria" is an outdated and discredited concept in medicine, particularly in psychiatry and psychology. Originally, it was used to describe a condition characterized by dramatic, excessive emotional reactions and physical symptoms that couldn't be explained by a medical condition. These symptoms often included things like paralysis, blindness, or fits, which would sometimes be "hysterical" in nature - that is, they seemed to have no physical cause.

However, the concept of hysteria has been largely abandoned due to its lack of scientific basis and its use as a catch-all diagnosis for symptoms that doctors couldn't explain. Today, many of the symptoms once attributed to hysteria are now understood as manifestations of other medical or psychological conditions, such as conversion disorder, panic attacks, or malingering. It's important to note that using outdated and stigmatizing terms like "hysteria" can be harmful and misleading, so it's best to avoid them in favor of more precise and respectful language.

Neural pathways, also known as nerve tracts or fasciculi, refer to the highly organized and specialized routes through which nerve impulses travel within the nervous system. These pathways are formed by groups of neurons (nerve cells) that are connected in a series, creating a continuous communication network for electrical signals to transmit information between different regions of the brain, spinal cord, and peripheral nerves.

Neural pathways can be classified into two main types: sensory (afferent) and motor (efferent). Sensory neural pathways carry sensory information from various receptors in the body (such as those for touch, temperature, pain, and vision) to the brain for processing. Motor neural pathways, on the other hand, transmit signals from the brain to the muscles and glands, controlling movements and other effector functions.

The formation of these neural pathways is crucial for normal nervous system function, as it enables efficient communication between different parts of the body and allows for complex behaviors, cognitive processes, and adaptive responses to internal and external stimuli.

Physiological monitoring is the continuous or intermittent observation and measurement of various body functions or parameters in a patient, with the aim of evaluating their health status, identifying any abnormalities or changes, and guiding clinical decision-making and treatment. This may involve the use of specialized medical equipment, such as cardiac monitors, pulse oximeters, blood pressure monitors, and capnographs, among others. The data collected through physiological monitoring can help healthcare professionals assess the effectiveness of treatments, detect complications early, and make timely adjustments to patient care plans.

In a medical or physiological context, "arousal" refers to the state of being awake and responsive to stimuli. It involves the activation of the nervous system, particularly the autonomic nervous system, which prepares the body for action. Arousal levels can vary from low (such as during sleep) to high (such as during states of excitement or stress). In clinical settings, changes in arousal may be assessed to help diagnose conditions such as coma, brain injury, or sleep disorders. It is also used in the context of sexual response, where it refers to the level of physical and mental awareness and readiness for sexual activity.

The parietal lobe is a region of the brain that is located in the posterior part of the cerebral cortex, covering the upper and rear portions of the brain. It is involved in processing sensory information from the body, such as touch, temperature, and pain, as well as spatial awareness and perception, visual-spatial cognition, and the integration of different senses.

The parietal lobe can be divided into several functional areas, including the primary somatosensory cortex (which receives tactile information from the body), the secondary somatosensory cortex (which processes more complex tactile information), and the posterior parietal cortex (which is involved in spatial attention, perception, and motor planning).

Damage to the parietal lobe can result in various neurological symptoms, such as neglect of one side of the body, difficulty with spatial orientation, problems with hand-eye coordination, and impaired mathematical and language abilities.

An afterimage is a visual phenomenon that occurs when the eye's retina continues to send signals to the brain even after exposure to a stimulus has ended. This can result in the perception of a lingering image, often in complementary colors to the original stimulus. Afterimages can be either positive or negative, with a positive afterimage appearing as the same color as the original stimulus and a negative afterimage appearing as its complementary color.

Afterimages are typically caused by exposure to bright or intense light sources, such as a camera flash or the sun. They can also occur after prolonged exposure to a particular color or pattern. The phenomenon is thought to be related to the adaptation of photoreceptor cells in the retina, which become less responsive to stimuli after prolonged exposure.

Afterimages are generally harmless and temporary, lasting only a few seconds to several minutes. However, they can sometimes be used as a tool for visual perception experiments or to study the mechanisms of visual processing in the brain.

Absence epilepsy is a type of epilepsy characterized by recurrent brief episodes of "absences," or staring spells, that can last from a few seconds to several minutes. These episodes are often accompanied by subtle body movements such as lip smacking or eyelid flutters. Absence epilepsy is most commonly diagnosed in children and adolescents, and it is more common in girls than boys.

The seizures in absence epilepsy are caused by abnormal electrical activity in the brain, specifically in a part of the brain called the cortex. These abnormal electrical discharges occur in a pattern that involves both sides of the brain simultaneously. This differs from other types of epilepsy, which may involve only one side of the brain or specific areas within a single hemisphere.

Absence seizures are typically brief and do not cause confusion or disorientation after they end. However, if they occur frequently, they can interfere with learning and social development. In some cases, absence epilepsy may be associated with other types of seizures, such as generalized tonic-clonic (grand mal) seizures or myoclonic jerks.

The diagnosis of absence epilepsy is usually made based on the characteristic symptoms and the results of an electroencephalogram (EEG), which can detect the abnormal electrical activity in the brain during a seizure. Treatment typically involves medication to control the seizures, such as ethosuximide or valproic acid. In some cases, a ketogenic diet may also be recommended as an alternative treatment option.

Combined anesthetics refer to the use of two or more types of anesthetic agents together during a medical procedure to produce a desired level of sedation, amnesia, analgesia, and muscle relaxation. This approach can allow for lower doses of individual anesthetic drugs, which may reduce the risk of adverse effects associated with each drug. Common combinations include using a general anesthetic in combination with a regional or local anesthetic technique. The specific choice of combined anesthetics depends on various factors such as the type and duration of the procedure, patient characteristics, and the desired outcomes.

Post-concussion syndrome (PCS) is not strictly defined by the medical community using a specific set of symptoms or diagnostic tests. Instead, it is generally characterized as a complex disorder in which various symptoms persist for weeks to months after a concussion or mild traumatic brain injury (mTBI). These symptoms can include headaches, dizziness, memory and concentration problems, irritability, depression, anxiety, sleep disturbances, and intolerance to noise and light.

The diagnosis of PCS is typically made based on the patient's history, reported symptoms, and the exclusion of other possible causes for these symptoms. It's important to note that not everyone who experiences a concussion will develop PCS, and the severity and duration of symptoms can vary widely from person to person. Proper management, rest, and a gradual return to normal activities are crucial in the treatment and recovery of PCS.

Alfentanil is a synthetic opioid analgesic drug that is chemically related to fentanyl. It is used for the provision of sedation and pain relief, particularly in critical care settings and during surgical procedures.

The medical definition of Alfentanil is as follows:

Alfentanil is a potent, short-acting opioid analgesic with a rapid onset of action. It is approximately 10 times more potent than morphine and has a rapid clearance rate due to its short elimination half-life of 1-2 hours. Alfentanil is used for the induction and maintenance of anesthesia, as well as for sedation and pain relief in critically ill patients. It works by binding to opioid receptors in the brain and spinal cord, which inhibits the transmission of pain signals and produces analgesia, sedation, and respiratory depression.

Like all opioids, Alfentanil carries a risk of dependence, tolerance, and respiratory depression, and should be used with caution in patients with respiratory or cardiovascular disease. It is typically administered by healthcare professionals in a controlled setting due to its potency and potential for adverse effects.

Thirst, also known as dry mouth or polydipsia, is a physiological need or desire to drink fluids to maintain fluid balance and hydration in the body. It is primarily regulated by the hypothalamus in response to changes in osmolality and volume of bodily fluids, particularly blood. Thirst can be triggered by various factors such as dehydration, excessive sweating, diarrhea, vomiting, fever, burns, certain medications, and medical conditions affecting the kidneys, adrenal glands, or other organs. It is a vital homeostatic mechanism to ensure adequate hydration and proper functioning of various bodily systems.

A righting reflex is a type of involuntary response that helps to maintain the body's position and orientation in space. These reflexes are critical for maintaining balance and preventing falls, especially during movement.

Righting reflexes involve a complex network of sensory receptors, including those in the inner ear, muscles, joints, and skin, which detect changes in the body's position or orientation. When these receptors detect a change, they send signals to the brainstem, which rapidly activates specific muscle groups to restore balance and maintain an upright posture.

Examples of righting reflexes include:

* The labyrinthine righting reflex, which helps to keep the head in a stable position relative to the body, even when the body is moving or changing position.
* The tonic neck reflex, which causes the arms and legs to extend when the head is turned to one side.
* The asymmetrical tonic neck reflex, which causes the arm and leg on the same side as the head turn to bend, while the opposite limbs extend.

Righting reflexes are present from birth and are critical for normal motor development. However, they can also be affected by brainstem or cerebellar injuries, leading to balance and coordination problems.

Dissociative disorders are a group of mental health conditions characterized by disruptions or dysfunctions in memory, consciousness, identity, or perception. These disturbances can be sudden or ongoing and can interfere significantly with a person's ability to function in daily life. The main types of dissociative disorders include:

1. Dissociative Amnesia: This disorder is characterized by an inability to recall important personal information, usually due to trauma or stress.
2. Dissociative Identity Disorder (formerly known as Multiple Personality Disorder): In this disorder, a person exhibits two or more distinct identities or personalities that recurrently take control of their behavior.
3. Depersonalization/Derealization Disorder: This disorder involves persistent or recurring feelings of detachment from one's self (depersonalization) or the environment (derealization).
4. Other Specified Dissociative Disorder and Unspecified Dissociative Disorder: These categories are used for disorders that do not meet the criteria for any of the specific dissociative disorders but still cause significant distress or impairment.

Dissociative disorders often develop as a way to cope with trauma, stress, or other overwhelming life experiences. Treatment typically involves psychotherapy, including cognitive-behavioral therapy (CBT) and dialectical behavior therapy (DBT), as well as medication for co-occurring conditions such as anxiety or depression.

Hyperammonemia is a medical condition characterized by an excessively high level of ammonia (a toxic byproduct of protein metabolism) in the blood. This can lead to serious neurological symptoms and complications, as ammonia is highly toxic to the brain. Hyperammonemia can be caused by various underlying conditions, including liver disease, genetic disorders that affect ammonia metabolism, certain medications, and infections. It is important to diagnose and treat hyperammonemia promptly to prevent long-term neurological damage or even death. Treatment typically involves addressing the underlying cause of the condition, as well as providing supportive care such as administering medications that help remove ammonia from the blood.

Neuropsychology is a branch of psychology that deals with the study of the structure and function of the brain as they relate to cognitive and behavioral processes. It involves understanding how damage to different parts of the brain can affect various mental abilities such as memory, attention, language, perception, and problem-solving.

Neuropsychologists often work with patients who have neurological conditions like Alzheimer's disease, Parkinson's disease, traumatic brain injury, stroke, or epilepsy to evaluate their cognitive and behavioral strengths and weaknesses. They use various assessment tools and techniques, including neuropsychological tests, interviews, and observations, to make these evaluations.

The findings from a neuropsychological evaluation can help in several ways, such as:

1. Diagnosing neurological conditions or monitoring the progression of a known condition.
2. Developing treatment plans that take into account the individual's cognitive and behavioral strengths and weaknesses.
3. Providing recommendations for rehabilitation or accommodations in daily life, education, or work settings.
4. Monitoring changes in cognitive function over time to assess the effectiveness of treatments or the progression of a condition.
5. Conducting research to better understand the relationship between brain structure and function and behavior.

Entropy, in the context of thermodynamics, is a measure of the number of specific ways in which a system may be arranged, often taken to be a measure of disorder or randomness. The entropy of a system increases as the number of possible arrangements of its particles increases. It is usually denoted by the letter S and measured in units of joules per kelvin (J/K).

However, I must clarify that 'Entropy' is not a medical term. It is a concept from the field of thermodynamics, which is a branch of physics. Entropy has been applied to various fields including information theory and statistical mechanics but it does not have a specific medical definition.

Trephination, also known as trepanation or burr hole surgery, is a surgical procedure that involves making a circular hole in the skull. This ancient medical practice was used in various cultures throughout history for various purposes, such as relieving pressure on the brain, treating mental disorders, or releasing evil spirits. In modern medicine, it is rarely performed and usually reserved for severe conditions like subdural hematomas or infection inside the skull.

"Mental healing" is not a term that is widely used in modern medicine or psychiatry. However, it generally refers to the process of addressing and resolving psychological issues or emotional distress through non-pharmacological means, such as talk therapy, psychotherapy, or mindfulness practices.

In a broader sense, mental healing can also refer to the improvement of one's mental and emotional well-being through various holistic approaches, including self-care, stress management techniques, social support, and spiritual practices. These methods aim to help individuals develop coping skills, build resilience, and improve their overall quality of life.

It is important to note that while these approaches can be helpful in managing mental health symptoms, they should not replace evidence-based treatments for mental health conditions, such as medication or therapy with a licensed mental health professional.

Delirium is a serious disturbance in mental abilities that results in confused thinking and reduced awareness of the environment, which can cause people to be easily distracted and unable to focus on any one topic for very long. It can also lead to rapid changes in emotions, perception, behavior, sleep-wake cycle, and hallucinations. Delirium is caused by various underlying medical conditions, such as infection, illness, or medication side effects, and it can be a symptom of severe illness or brain disorder. It can develop quickly, often over the course of hours or days, and it may come and go.

Delirium is different from dementia, which is a chronic and progressive decline in cognitive abilities, although delirium can occur in people with dementia. Delirium is also different from a mental illness such as schizophrenia, which involves persistent disturbances in thinking and perception that are not caused by a medical condition or medication.

Delirium is a serious medical condition that requires immediate evaluation and treatment. If you suspect someone may have delirium, it's important to seek medical attention right away.

Cerebral infarction, also known as a "stroke" or "brain attack," is the sudden death of brain cells caused by the interruption of their blood supply. It is most commonly caused by a blockage in one of the blood vessels supplying the brain (an ischemic stroke), but can also result from a hemorrhage in or around the brain (a hemorrhagic stroke).

Ischemic strokes occur when a blood clot or other particle blocks a cerebral artery, cutting off blood flow to a part of the brain. The lack of oxygen and nutrients causes nearby brain cells to die. Hemorrhagic strokes occur when a weakened blood vessel ruptures, causing bleeding within or around the brain. This bleeding can put pressure on surrounding brain tissues, leading to cell death.

Symptoms of cerebral infarction depend on the location and extent of the affected brain tissue but may include sudden weakness or numbness in the face, arm, or leg; difficulty speaking or understanding speech; vision problems; loss of balance or coordination; and severe headache with no known cause. Immediate medical attention is crucial for proper diagnosis and treatment to minimize potential long-term damage or disability.

Biochemical phenomena refer to the chemical processes and reactions that occur within living organisms. These phenomena are essential for the structure, function, and regulation of all cells and tissues in the body. They involve a wide range of molecular interactions, including enzyme-catalyzed reactions, signal transduction pathways, and gene expression regulatory mechanisms.

Biochemical phenomena can be studied at various levels, from individual molecules to complex biological systems. They are critical for understanding the underlying mechanisms of many physiological processes, as well as the basis of various diseases and medical conditions.

Examples of biochemical phenomena include:

1. Metabolism: the chemical reactions that occur within cells to maintain life, including the breakdown of nutrients to produce energy and the synthesis of new molecules.
2. Protein folding: the process by which a protein molecule assumes its three-dimensional structure, which is critical for its function.
3. Signal transduction: the molecular mechanisms by which cells respond to external signals, such as hormones or neurotransmitters, and convert them into intracellular responses.
4. Gene expression regulation: the complex network of molecular interactions that control the production of proteins from DNA, including transcription, RNA processing, and translation.
5. Cell-cell communication: the mechanisms by which cells communicate with each other to coordinate their functions and maintain tissue homeostasis.
6. Apoptosis: the programmed cell death pathway that eliminates damaged or unnecessary cells.
7. DNA repair: the molecular mechanisms that detect and correct damage to DNA, preventing mutations and maintaining genomic stability.

Status epilepticus is a serious and life-threatening medical condition characterized by an ongoing seizure activity or a series of seizures without full recovery of consciousness between them, lasting for 30 minutes or more. It is a neurological emergency that requires immediate medical attention to prevent potential complications such as brain damage, respiratory failure, or even death.

The condition can occur in people with a history of epilepsy or seizure disorders, as well as those without any prior history of seizures. The underlying causes of status epilepticus can vary and may include infection, trauma, stroke, metabolic imbalances, toxins, or other medical conditions that affect the brain's normal functioning. Prompt diagnosis and treatment are crucial to prevent long-term neurological damage and improve outcomes in patients with this condition.

"Trauma severity indices" refer to various scoring systems used by healthcare professionals to evaluate the severity of injuries in trauma patients. These tools help standardize the assessment and communication of injury severity among different members of the healthcare team, allowing for more effective and consistent treatment planning, resource allocation, and prognosis estimation.

There are several commonly used trauma severity indices, including:

1. Injury Severity Score (ISS): ISS is an anatomical scoring system that evaluates the severity of injuries based on the Abbreviated Injury Scale (AIS). The body is divided into six regions, and the square of the highest AIS score in each region is summed to calculate the ISS. Scores range from 0 to 75, with higher scores indicating more severe injuries.
2. New Injury Severity Score (NISS): NISS is a modification of the ISS that focuses on the three most severely injured body regions, regardless of their anatomical location. The three highest AIS scores are squared and summed to calculate the NISS. This scoring system tends to correlate better with mortality than the ISS in some studies.
3. Revised Trauma Score (RTS): RTS is a physiological scoring system that evaluates the patient's respiratory, cardiovascular, and neurological status upon arrival at the hospital. It uses variables such as Glasgow Coma Scale (GCS), systolic blood pressure, and respiratory rate to calculate a score between 0 and 7.84, with lower scores indicating more severe injuries.
4. Trauma and Injury Severity Score (TRISS): TRISS is a combined anatomical and physiological scoring system that estimates the probability of survival based on ISS or NISS, RTS, age, and mechanism of injury (blunt or penetrating). It uses logistic regression equations to calculate the predicted probability of survival.
5. Pediatric Trauma Score (PTS): PTS is a physiological scoring system specifically designed for children under 14 years old. It evaluates six variables, including respiratory rate, oxygen saturation, systolic blood pressure, capillary refill time, GCS, and temperature to calculate a score between -6 and +12, with lower scores indicating more severe injuries.

These scoring systems help healthcare professionals assess the severity of trauma, predict outcomes, allocate resources, and compare patient populations in research settings. However, they should not replace clinical judgment or individualized care for each patient.

Etomidate is a intravenous anesthetic medication used for the induction of general anesthesia. It provides a rapid and smooth induction with minimal cardiovascular effects, making it a popular choice in patients with hemodynamic instability. Etomidate also has antiseizure properties. However, its use is associated with adrenal suppression, which can lead to complications such as hypotension and impaired stress response. Therefore, its use is generally avoided in critically ill or septic patients.

The medical definition of 'Etomidate' is:

A carboxylated imidazole derivative that is used as an intravenous anesthetic for the induction of general anesthesia. It has a rapid onset of action and minimal cardiovascular effects, making it useful in patients with hemodynamic instability. Etomidate also has antiseizure properties. However, its use is associated with adrenal suppression, which can lead to complications such as hypotension and impaired stress response. Therefore, its use is generally avoided in critically ill or septic patients.

Brain death is a legal and medical determination that an individual has died because their brain has irreversibly lost all functions necessary for life. It is characterized by the absence of brainstem reflexes, unresponsiveness to stimuli, and the inability to breathe without mechanical support. Brain death is different from a vegetative state or coma, where there may still be some brain activity.

The determination of brain death involves a series of tests and examinations to confirm the absence of brain function. These tests are typically performed by trained medical professionals and may include clinical assessments, imaging studies, and electroencephalograms (EEGs) to confirm the absence of electrical activity in the brain.

Brain death is an important concept in medicine because it allows for the organ donation process to proceed, potentially saving the lives of others. In many jurisdictions, brain death is legally equivalent to cardiopulmonary death, which means that once a person has been declared brain dead, they are considered deceased and their organs can be removed for transplantation.

Hypergravity is a term used to describe an environment where the force of gravity is greater than that which we normally experience on Earth's surface (1G). This can occur in various situations such as high-speed aircraft rides, space travel, or in certain laboratory settings. It leads to increased gravitational load and force on the body, which can have various physiological effects, including cardiovascular changes, muscle tension, and altered body positioning. Prolonged exposure to hypergravity can lead to physical fatigue and discomfort.

Mental processes, also referred to as cognitive processes, are the ways in which our minds perceive, process, and understand information from the world around us. These processes include:

1. Attention: The ability to focus on specific stimuli while ignoring others.
2. Perception: The way in which we interpret and organize sensory information.
3. Memory: The storage and retrieval of information.
4. Learning: The process of acquiring new knowledge or skills.
5. Language: The ability to understand, produce and communicate using words and symbols.
6. Thinking: The process of processing information, reasoning, problem-solving, and decision making.
7. Intelligence: The capacity to understand, learn, and adapt to new situations.
8. Emotion: The ability to experience and respond to different feelings.
9. Consciousness: The state of being aware of and able to think and perceive one's surroundings, thoughts, and feelings.

These mental processes are interconnected and influence each other in complex ways. They allow us to interact with our environment, make decisions, and communicate with others. Disorders in these mental processes can lead to various neurological and psychiatric conditions.

Encephalitis is defined as inflammation of the brain parenchyma, which is often caused by viral infections but can also be due to bacterial, fungal, or parasitic infections, autoimmune disorders, or exposure to toxins. The infection or inflammation can cause various symptoms such as headache, fever, confusion, seizures, and altered consciousness, ranging from mild symptoms to severe cases that can lead to brain damage, long-term disabilities, or even death.

The diagnosis of encephalitis typically involves a combination of clinical evaluation, imaging studies (such as MRI or CT scans), and laboratory tests (such as cerebrospinal fluid analysis). Treatment may include antiviral medications, corticosteroids, immunoglobulins, and supportive care to manage symptoms and prevent complications.

Cortical synchronization refers to the phenomenon of coordinated neural activity in the cerebral cortex, the brain region responsible for higher cognitive functions. It is characterized by the synchronized firing of neurons in various cortical areas, leading to the generation of rhythmic electrical patterns. These rhythms can be observed using electroencephalography (EEG) and other neuroimaging techniques.

Cortical synchronization plays a crucial role in various cognitive processes, such as attention, perception, memory, and consciousness. It is also involved in the pathophysiology of several neurological and psychiatric disorders, including epilepsy, schizophrenia, and Parkinson's disease.

The degree of cortical synchronization can be modulated by various factors, such as sensory stimulation, attention, arousal, and cognitive load. The precise mechanisms underlying cortical synchronization are still not fully understood but are thought to involve complex interactions between excitatory and inhibitory neurons, as well as the modulation of synaptic strength and connectivity.

An acute disease is a medical condition that has a rapid onset, develops quickly, and tends to be short in duration. Acute diseases can range from minor illnesses such as a common cold or flu, to more severe conditions such as pneumonia, meningitis, or a heart attack. These types of diseases often have clear symptoms that are easy to identify, and they may require immediate medical attention or treatment.

Acute diseases are typically caused by an external agent or factor, such as a bacterial or viral infection, a toxin, or an injury. They can also be the result of a sudden worsening of an existing chronic condition. In general, acute diseases are distinct from chronic diseases, which are long-term medical conditions that develop slowly over time and may require ongoing management and treatment.

Examples of acute diseases include:

* Acute bronchitis: a sudden inflammation of the airways in the lungs, often caused by a viral infection.
* Appendicitis: an inflammation of the appendix that can cause severe pain and requires surgical removal.
* Gastroenteritis: an inflammation of the stomach and intestines, often caused by a viral or bacterial infection.
* Migraine headaches: intense headaches that can last for hours or days, and are often accompanied by nausea, vomiting, and sensitivity to light and sound.
* Myocardial infarction (heart attack): a sudden blockage of blood flow to the heart muscle, often caused by a buildup of plaque in the coronary arteries.
* Pneumonia: an infection of the lungs that can cause coughing, chest pain, and difficulty breathing.
* Sinusitis: an inflammation of the sinuses, often caused by a viral or bacterial infection.

It's important to note that while some acute diseases may resolve on their own with rest and supportive care, others may require medical intervention or treatment to prevent complications and promote recovery. If you are experiencing symptoms of an acute disease, it is always best to seek medical attention to ensure proper diagnosis and treatment.

Inhalational anesthesia is a type of general anesthesia that is induced by the inhalation of gases or vapors. It is administered through a breathing system, which delivers the anesthetic agents to the patient via a face mask, laryngeal mask airway, or endotracheal tube.

The most commonly used inhalational anesthetics include nitrous oxide, sevoflurane, isoflurane, and desflurane. These agents work by depressing the central nervous system, causing a reversible loss of consciousness, amnesia, analgesia, and muscle relaxation.

The depth of anesthesia can be easily adjusted during the procedure by changing the concentration of the anesthetic agent. Once the procedure is complete, the anesthetic agents are eliminated from the body through exhalation, allowing for a rapid recovery.

Inhalational anesthesia is commonly used in a wide range of surgical procedures due to its ease of administration, quick onset and offset of action, and ability to rapidly adjust the depth of anesthesia. However, it requires careful monitoring and management by trained anesthesia providers to ensure patient safety and optimize outcomes.

Aerospace medicine is a branch of medicine that deals with the health and safety of pilots, astronauts, and passengers during space travel or aircraft flight. It involves studying the effects of various factors such as altitude, weightlessness, radiation, noise, vibration, and temperature extremes on the human body, and developing measures to prevent or mitigate any adverse effects.

Aerospace medicine also encompasses the diagnosis and treatment of medical conditions that occur during space travel or aircraft flight, as well as the development of medical standards and guidelines for pilot and astronaut selection, training, and fitness for duty. Additionally, it includes research into the physiological and psychological challenges of long-duration space missions and the development of countermeasures to maintain crew health and performance during such missions.

Euthanasia, when used in the context of animals, refers to the act of intentionally causing the death of an animal in a humane and peaceful manner to alleviate suffering from incurable illness or injury. It is also commonly referred to as "putting an animal to sleep" or "mercy killing." The goal of euthanasia in animals is to minimize pain and distress, and it is typically carried out by a veterinarian using approved medications and techniques. Euthanasia may be considered when an animal's quality of life has become significantly compromised and there are no reasonable treatment options available to alleviate its suffering.

A Ventriculoperitoneal (VP) shunt is a surgical procedure that involves the insertion of a long, flexible tube (shunt) into the cerebral ventricles of the brain to drain excess cerebrospinal fluid (CSF). The other end of the shunt is directed into the peritoneal cavity, where the CSF can be absorbed.

The VP shunt is typically used to treat hydrocephalus, a condition characterized by an abnormal accumulation of CSF within the ventricles of the brain, which can cause increased intracranial pressure and damage to the brain. By diverting the excess CSF from the ventricles into the peritoneal cavity, the VP shunt helps to relieve the symptoms of hydrocephalus and prevent further neurological damage.

The shunt system consists of several components, including a ventricular catheter that is placed in the ventricle, a one-way valve that regulates the flow of CSF, and a distal catheter that is directed into the peritoneal cavity. The valve helps to prevent backflow of CSF into the brain and ensures that the fluid flows in only one direction, from the ventricles to the peritoneal cavity.

VP shunts are generally safe and effective, but they can be associated with complications such as infection, obstruction, or malfunction of the shunt system. Regular follow-up with a healthcare provider is necessary to monitor the function of the shunt and ensure that any potential issues are addressed promptly.

Intracranial hemorrhage (ICH) is a type of stroke caused by bleeding within the brain or its surrounding tissues. It's a serious medical emergency that requires immediate attention and treatment. The bleeding can occur in various locations:

1. Epidural hematoma: Bleeding between the dura mater (the outermost protective covering of the brain) and the skull. This is often caused by trauma, such as a head injury.
2. Subdural hematoma: Bleeding between the dura mater and the brain's surface, which can also be caused by trauma.
3. Subarachnoid hemorrhage: Bleeding in the subarachnoid space, which is filled with cerebrospinal fluid (CSF) and surrounds the brain. This type of ICH is commonly caused by the rupture of an intracranial aneurysm or arteriovenous malformation.
4. Intraparenchymal hemorrhage: Bleeding within the brain tissue itself, which can be caused by hypertension (high blood pressure), amyloid angiopathy, or trauma.
5. Intraventricular hemorrhage: Bleeding into the brain's ventricular system, which contains CSF and communicates with the subarachnoid space. This type of ICH is often seen in premature infants but can also be caused by head trauma or aneurysm rupture in adults.

Symptoms of intracranial hemorrhage may include sudden severe headache, vomiting, altered consciousness, confusion, seizures, weakness, numbness, or paralysis on one side of the body, vision changes, or difficulty speaking or understanding speech. Rapid diagnosis and treatment are crucial to prevent further brain damage and potential long-term disabilities or death.

Akinetic mutism is a neurological condition characterized by a severe decrease in initiating and sustaining voluntary movements and speech, along with a decreased level of responsiveness to the environment. It is often caused by damage to the frontal lobe of the brain, particularly to the anterior cingulate cortex and its connections to other parts of the brain.

People with akinetic mutism may appear awake and have their eyes open, but they are generally unresponsive to external stimuli and do not initiate voluntary movements or speech on their own. They may occasionally respond to direct questions or commands, but their responses are often limited and delayed. The condition can be caused by various factors, including brain injury, stroke, tumors, infections, or degenerative diseases such as Parkinson's disease.

Akinetic mutism is distinct from a vegetative state, which is characterized by the absence of both awareness and sleep-wake cycles. In contrast, people with akinetic mutism may retain some degree of awareness and have sleep-wake cycles, although their level of responsiveness is significantly reduced.

Treatment outcome is a term used to describe the result or effect of medical treatment on a patient's health status. It can be measured in various ways, such as through symptoms improvement, disease remission, reduced disability, improved quality of life, or survival rates. The treatment outcome helps healthcare providers evaluate the effectiveness of a particular treatment plan and make informed decisions about future care. It is also used in clinical research to compare the efficacy of different treatments and improve patient care.

Subliminal stimulation refers to the presentation of stimuli (such as visual, auditory, or tactile) below the threshold of conscious perception. The term "subliminal" means "below the limen," with "limen" being the smallest intensity level at which a stimulus can be perceived and recognized.

In subliminal stimulation, the individual is unaware of the presence of the stimuli and cannot consciously identify or respond to them. However, research suggests that such stimuli may still have an impact on cognitive processes, emotions, and behaviors, as they can influence brain activity and activate unconscious mental processes.

It's important to note that subliminal stimulation has been a subject of controversy, particularly in the context of its application in advertising and entertainment. While some studies suggest that subliminal messages may have subtle effects on behavior, other research has failed to replicate these findings or found them to be minimal at best. Additionally, ethical concerns surround the use of subliminal stimulation, as it involves manipulating individuals without their knowledge or consent.

Cerebral ventriculography is a medical imaging technique that involves the injection of a contrast material into the cerebral ventricles, which are fluid-filled spaces within the brain. The purpose of this procedure is to produce detailed images of the ventricular system and the surrounding structures in order to diagnose and evaluate various neurological conditions, such as hydrocephalus (excessive accumulation of cerebrospinal fluid in the ventricles), tumors, or other abnormalities that may be causing obstruction or compression of the ventricular system.

The procedure typically involves inserting a thin, flexible tube called a catheter into the lateral ventricle of the brain through a small hole drilled in the skull. The contrast material is then injected through the catheter and X-ray images are taken as the contrast material flows through the ventricular system. These images can help to identify any abnormalities or blockages that may be present.

Cerebral ventriculography has largely been replaced by non-invasive imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), which provide similar information without the need for invasive procedures. However, cerebral ventriculography may still be used in certain cases where these other methods are not sufficient to make a definitive diagnosis.

Hyponatremia is a condition characterized by abnormally low sodium levels in the blood, specifically levels less than 135 mEq/L. Sodium is an essential electrolyte that helps regulate water balance in and around your cells and plays a crucial role in nerve and muscle function. Hyponatremia can occur due to various reasons, including certain medical conditions, medications, or excessive water intake leading to dilution of sodium in the body. Symptoms may range from mild, such as nausea, confusion, and headache, to severe, like seizures, coma, or even death in extreme cases. It's essential to seek medical attention if you suspect hyponatremia, as prompt diagnosis and treatment are vital for a favorable outcome.

An Insulin Coma is not a formal medical term, but it has been used in the past to describe a deliberate medical procedure known as Insulin Shock Therapy. This was a treatment for mental illness that involved administering large doses of insulin to induce hypoglycemia (low blood sugar), which could lead to a coma.

The idea behind this therapy, which was popular in the mid-20th century, was that the induced coma and subsequent recovery could have therapeutic effects on the brain and help alleviate symptoms of mental illnesses like schizophrenia. However, this treatment fell out of favor due to its significant risks and the development of more effective and safer treatments.

It's important to note that in current medical practice, inducing a coma with insulin is not a standard or recommended procedure due to the potential for severe harm, including brain damage and death.

A subdural hematoma (SDH) is a type of intracranial hemorrhage that occurs between the dura mater and the brain. When it becomes chronic, it means that the bleeding has occurred slowly over time, often over the course of several weeks or months. The blood gradually collects in the potential space between the dura and the arachnoid membrane, forming a clot.

A chronic subdural hematoma (CSDH) is typically characterized by the presence of liquefied blood, which can form a loculated collection that may exert mass effect on the underlying brain tissue. This can lead to symptoms such as headache, confusion, weakness, or even seizures, depending on the size and location of the hematoma.

CSDHs are often associated with underlying brain atrophy, which can create a larger potential space for blood to collect. They may also be seen in patients who are taking anticoagulant medications or have a bleeding disorder. Treatment typically involves surgical evacuation of the hematoma, although smaller CSDHs may be managed conservatively with close monitoring and repeat imaging.

Confusion is a state of bewilderment or disorientation in which a person has difficulty processing information, understanding their surroundings, and making clear decisions. It can be caused by various medical conditions such as infections, brain injury, stroke, dementia, alcohol or drug intoxication or withdrawal, and certain medications. Confusion can also occur in older adults due to age-related changes in the brain.

In medical terms, confusion is often referred to as "acute confusional state" or "delirium." It is characterized by symptoms such as difficulty paying attention, memory loss, disorientation, hallucinations, and delusions. Confusion can be a serious medical condition that requires immediate evaluation and treatment by a healthcare professional.

Prognosis is a medical term that refers to the prediction of the likely outcome or course of a disease, including the chances of recovery or recurrence, based on the patient's symptoms, medical history, physical examination, and diagnostic tests. It is an important aspect of clinical decision-making and patient communication, as it helps doctors and patients make informed decisions about treatment options, set realistic expectations, and plan for future care.

Prognosis can be expressed in various ways, such as percentages, categories (e.g., good, fair, poor), or survival rates, depending on the nature of the disease and the available evidence. However, it is important to note that prognosis is not an exact science and may vary depending on individual factors, such as age, overall health status, and response to treatment. Therefore, it should be used as a guide rather than a definitive forecast.

I'm happy to help! However, I would like to clarify that the term "Metaphysical" in this context might be misleading. Mind-body relations is a well-established field within psychology, neuroscience, and medicine, while "metaphysical" generally refers to philosophical questions beyond the physical world or the realm of scientific inquiry. Therefore, I will provide a definition for "Mind-Body Relations" without the metaphysical aspect.

Mind-Body Relations:
Mind-body relations is an interdisciplinary field that investigates the connection and interaction between mental processes (thoughts, emotions, beliefs, attitudes) and physical health or bodily functions. It explores how psychological factors can influence physiological responses and contribute to health outcomes, as well as how physical conditions can impact mental states.

Some key concepts within mind-body relations include:

1. Psychoneuroimmunology (PNI): The study of the interaction between psychological processes, the nervous system, and the immune system, examining how stress and emotions affect immunity and susceptibility to illness.
2. Placebo effects: Positive therapeutic outcomes resulting from patients' beliefs or expectations in a treatment, even when the treatment itself has no active ingredients or specific mechanisms of action.
3. Biofeedback: A technique that uses electronic monitoring of bodily functions (e.g., heart rate, skin temperature, brain waves) to train individuals to consciously control these processes, often used to manage stress and improve health outcomes.
4. Mindfulness-based interventions: Practices derived from meditation and yoga that aim to cultivate non-judgmental awareness of the present moment, which have been shown to reduce stress, anxiety, and depression while improving overall well-being.

While there is a metaphysical aspect to mind-body relations in some philosophical or spiritual contexts (e.g., mind-body dualism, holistic approaches), these perspectives are not typically considered part of the medical definition.

Isoflurane is a volatile halogenated ether used for induction and maintenance of general anesthesia. It is a colorless liquid with a pungent, sweet odor. Isoflurane is an agonist at the gamma-aminobutyric acid type A (GABAA) receptor and inhibits excitatory neurotransmission in the brain, leading to unconsciousness and immobility. It has a rapid onset and offset of action due to its low blood solubility, allowing for quick adjustments in anesthetic depth during surgery. Isoflurane is also known for its bronchodilator effects, making it useful in patients with reactive airway disease. However, it can cause dose-dependent decreases in heart rate and blood pressure, so careful hemodynamic monitoring is required during its use.

Cerebral angiography is a medical procedure that involves taking X-ray images of the blood vessels in the brain after injecting a contrast dye into them. This procedure helps doctors to diagnose and treat various conditions affecting the blood vessels in the brain, such as aneurysms, arteriovenous malformations, and stenosis (narrowing of the blood vessels).

During the procedure, a catheter is inserted into an artery in the leg and threaded through the body to the blood vessels in the neck or brain. The contrast dye is then injected through the catheter, and X-ray images are taken to visualize the blood flow through the brain's blood vessels.

Cerebral angiography provides detailed images of the blood vessels in the brain, allowing doctors to identify any abnormalities or blockages that may be causing symptoms or increasing the risk of stroke. Based on the results of the cerebral angiography, doctors can develop a treatment plan to address these issues and prevent further complications.

A hematoma is defined as a localized accumulation of blood in a tissue, organ, or body space caused by a break in the wall of a blood vessel. This can result from various causes such as trauma, surgery, or certain medical conditions that affect coagulation. The severity and size of a hematoma may vary depending on the location and extent of the bleeding. Symptoms can include swelling, pain, bruising, and decreased mobility in the affected area. Treatment options depend on the size and location of the hematoma but may include observation, compression, ice, elevation, or in some cases, surgical intervention.

Brainstem infarctions refer to the damage or death of brain tissue in the brainstem due to lack of blood supply, resulting in a localized injury known as an infarction. The brainstem is a critical region that controls essential functions such as breathing, heart rate, and consciousness. Infarctions in this area can result in various symptoms depending on the location and extent of damage, which may include:

1. Hemiparesis or paralysis on one side of the body
2. Cranial nerve dysfunction, leading to double vision, slurred speech, or facial weakness
3. Difficulty swallowing or speaking
4. Unstable blood pressure and heart rate
5. Altered level of consciousness, ranging from confusion to coma
6. Abnormal muscle tone and reflexes
7. Respiratory disturbances, such as irregular breathing patterns or apnea (cessation of breathing)

Brainstem infarctions can be caused by various conditions, including atherosclerosis, embolism, vasospasm, or small vessel disease. Prompt diagnosis and treatment are crucial to minimize the risk of long-term disability or death.

A thyroid crisis, also known as thyrotoxic crisis or storm, is a rare but life-threatening condition characterized by an exaggerated response to the excess production of thyroid hormones (thyrotoxicosis). This condition can lead to severe hypermetabolic state, multi-organ dysfunction, and cardiovascular collapse if not promptly diagnosed and treated.

Thyroid crisis is often triggered by a stressful event, infection, or surgery in individuals with uncontrolled or poorly managed hyperthyroidism, particularly those with Graves' disease. The symptoms of thyroid crisis include high fever, tachycardia (rapid heart rate), hypertension (high blood pressure), agitation, confusion, delirium, vomiting, diarrhea, and sometimes coma.

The diagnosis of thyroid crisis is based on the clinical presentation, laboratory tests, and imaging studies. Treatment typically involves hospitalization in an intensive care unit, administration of medications to block the production and release of thyroid hormones, control heart rate and rhythm, correct electrolyte imbalances, and provide supportive care until the patient's condition stabilizes.

In the context of medical and clinical neuroscience, memory is defined as the brain's ability to encode, store, retain, and recall information or experiences. Memory is a complex cognitive process that involves several interconnected regions of the brain and can be categorized into different types based on various factors such as duration and the nature of the information being remembered.

The major types of memory include:

1. Sensory memory: The shortest form of memory, responsible for holding incoming sensory information for a brief period (less than a second to several seconds) before it is either transferred to short-term memory or discarded.
2. Short-term memory (also called working memory): A temporary storage system that allows the brain to hold and manipulate information for approximately 20-30 seconds, although this duration can be extended through rehearsal strategies. Short-term memory has a limited capacity, typically thought to be around 7±2 items.
3. Long-term memory: The memory system responsible for storing large amounts of information over extended periods, ranging from minutes to a lifetime. Long-term memory has a much larger capacity compared to short-term memory and is divided into two main categories: explicit (declarative) memory and implicit (non-declarative) memory.

Explicit (declarative) memory can be further divided into episodic memory, which involves the recollection of specific events or episodes, including their temporal and spatial contexts, and semantic memory, which refers to the storage and retrieval of general knowledge, facts, concepts, and vocabulary, independent of personal experience or context.

Implicit (non-declarative) memory encompasses various forms of learning that do not require conscious awareness or intention, such as procedural memory (skills and habits), priming (facilitated processing of related stimuli), classical conditioning (associative learning), and habituation (reduced responsiveness to repeated stimuli).

Memory is a crucial aspect of human cognition and plays a significant role in various aspects of daily life, including learning, problem-solving, decision-making, social interactions, and personal identity. Memory dysfunction can result from various neurological and psychiatric conditions, such as dementia, Alzheimer's disease, stroke, traumatic brain injury, and depression.

Post-traumatic epilepsy (PTE) is a type of epilepsy that is caused by brain injury or trauma. The head injury can be either traumatic (such as from a car accident, fall, or physical assault) or non-traumatic (such as stroke, infection, or brain tumor).

In PTE, the first seizure occurs within one week to one year after the initial injury. The seizures may be immediate (within the first 24 hours of the injury) or delayed (occurring more than one week after the injury).

PTE is characterized by recurrent seizures that are caused by abnormal electrical activity in the brain. These seizures can vary in severity and frequency, and may cause a range of symptoms such as convulsions, loss of consciousness, and altered sensations or emotions.

The diagnosis of PTE is typically made based on the patient's history of head trauma, along with the results of an electroencephalogram (EEG) and neuroimaging studies such as MRI or CT scans. Treatment for PTE may include medication to control seizures, as well as surgery or other interventions in some cases.

An epidural cranial hematoma is a specific type of hematoma, which is defined as an abnormal accumulation of blood in a restricted space, occurring between the dura mater (the outermost layer of the meninges that covers the brain and spinal cord) and the skull in the cranial region. This condition is often caused by trauma or head injury, which results in the rupture of blood vessels, allowing blood to collect in the epidural space. The accumulation of blood can compress the brain tissue and cause various neurological symptoms, potentially leading to serious complications if not promptly diagnosed and treated.

Retrospective studies, also known as retrospective research or looking back studies, are a type of observational study that examines data from the past to draw conclusions about possible causal relationships between risk factors and outcomes. In these studies, researchers analyze existing records, medical charts, or previously collected data to test a hypothesis or answer a specific research question.

Retrospective studies can be useful for generating hypotheses and identifying trends, but they have limitations compared to prospective studies, which follow participants forward in time from exposure to outcome. Retrospective studies are subject to biases such as recall bias, selection bias, and information bias, which can affect the validity of the results. Therefore, retrospective studies should be interpreted with caution and used primarily to generate hypotheses for further testing in prospective studies.

"Withholding treatment" in a medical context refers to the deliberate decision not to provide or initiate certain medical treatments, interventions, or procedures for a patient. This decision is typically made after considering various factors such as the patient's wishes, their overall prognosis, the potential benefits and burdens of the treatment, and the patient's quality of life.

The reasons for withholding treatment can vary widely, but some common reasons include:

* The treatment is unlikely to be effective in improving the patient's condition or extending their life.
* The treatment may cause unnecessary discomfort, pain, or suffering for the patient.
* The patient has expressed a desire not to receive certain treatments, particularly if they are deemed to be burdensome or of little benefit.
* The cost of the treatment is prohibitive and not covered by insurance, and the patient cannot afford to pay out-of-pocket.

It's important to note that withholding treatment does not mean abandoning the patient or providing substandard care. Rather, it involves making thoughtful and informed decisions about the most appropriate course of action for a given situation, taking into account the patient's individual needs and preferences.

I'm sorry for any confusion, but "thinking" is not a term that has a specific medical definition. It is a cognitive process, which is a general term used to describe various mental activities related to perception, reasoning, memory, attention, language use, learning, and problem-solving. These processes are studied across many fields, including psychology, neuroscience, philosophy, and linguistics.

If you're looking for medical definitions of cognitive processes or conditions that affect cognition, I'd be happy to help! Please provide more details.

Sleep is a complex physiological process characterized by altered consciousness, relatively inhibited sensory activity, reduced voluntary muscle activity, and decreased interaction with the environment. It's typically associated with specific stages that can be identified through electroencephalography (EEG) patterns. These stages include rapid eye movement (REM) sleep, associated with dreaming, and non-rapid eye movement (NREM) sleep, which is further divided into three stages.

Sleep serves a variety of functions, including restoration and strengthening of the immune system, support for growth and development in children and adolescents, consolidation of memory, learning, and emotional regulation. The lack of sufficient sleep or poor quality sleep can lead to significant health problems, such as obesity, diabetes, cardiovascular disease, and even cognitive decline.

The American Academy of Sleep Medicine (AASM) defines sleep as "a period of daily recurring natural rest during which consciousness is suspended and metabolic processes are reduced." However, it's important to note that the exact mechanisms and purposes of sleep are still being researched and debated among scientists.

A spinal puncture, also known as a lumbar puncture or a spinal tap, is a medical procedure in which a thin, hollow needle is inserted between two vertebrae in the lower back to extract cerebrospinal fluid (CSF) from the subarachnoid space. This procedure is typically performed to diagnose conditions affecting the central nervous system, such as meningitis, encephalitis, or subarachnoid hemorrhage, by analyzing the CSF for cells, chemicals, bacteria, or viruses. Additionally, spinal punctures can be used to administer medications or anesthetics directly into the CSF space, such as in the case of epidural anesthesia during childbirth.

The medical definition of a spinal puncture is: "A diagnostic and therapeutic procedure that involves introducing a thin needle into the subarachnoid space, typically at the lumbar level, to collect cerebrospinal fluid or administer medications."

An intracranial aneurysm is a localized, blood-filled dilation or bulging in the wall of a cerebral artery within the skull (intracranial). These aneurysms typically occur at weak points in the arterial walls, often at branching points where the vessel divides into smaller branches. Over time, the repeated pressure from blood flow can cause the vessel wall to weaken and balloon out, forming a sac-like structure. Intracranial aneurysms can vary in size, ranging from a few millimeters to several centimeters in diameter.

There are three main types of intracranial aneurysms:

1. Saccular (berry) aneurysm: This is the most common type, characterized by a round or oval shape with a narrow neck and a bulging sac. They usually develop at branching points in the arteries due to congenital weaknesses in the vessel wall.
2. Fusiform aneurysm: These aneurysms have a dilated segment along the length of the artery, forming a cigar-shaped or spindle-like structure. They are often caused by atherosclerosis and can affect any part of the cerebral arteries.
3. Dissecting aneurysm: This type occurs when there is a tear in the inner lining (intima) of the artery, allowing blood to flow between the layers of the vessel wall. It can lead to narrowing or complete blockage of the affected artery and may cause subarachnoid hemorrhage if it ruptures.

Intracranial aneurysms can be asymptomatic and discovered incidentally during imaging studies for other conditions. However, when they grow larger or rupture, they can lead to severe complications such as subarachnoid hemorrhage, stroke, or even death. Treatment options include surgical clipping, endovascular coiling, or flow diversion techniques to prevent further growth and potential rupture of the aneurysm.

Brain waves, also known as electroencephalography (EEG) waves, are the rhythmic electrical activity produced by the brain's neurons. These waves are detected by placing electrodes on the scalp and can be visualized using an EEG machine. Brain waves are typically categorized into different frequency bands, including:

1. Delta waves (0.5-4 Hz): Slow waves that are typically seen during deep sleep or in pathological states such as coma.
2. Theta waves (4-8 Hz): Slower waves that are associated with drowsiness, meditation, and creative thinking.
3. Alpha waves (8-13 Hz): These waves are present during relaxed wakefulness and can be seen during eyes-closed rest.
4. Beta waves (13-30 Hz): Faster waves that are associated with active thinking, focus, and alertness.
5. Gamma waves (30-100 Hz): The fastest waves, which are associated with higher cognitive functions such as attention, perception, and problem-solving.

Abnormalities in brain wave patterns can be indicative of various neurological conditions, including epilepsy, sleep disorders, brain injuries, and neurodegenerative diseases.

1. Mutism (also known as Selective Mutism) is a psychological disorder where a person becomes unable to speak in specific situations or around certain people, despite having normal language skills. It's most commonly diagnosed in children and can lead to significant distress and impairment in social communication and academic performance. The exact cause of mutism isn't well understood, but it's believed to be related to anxiety and social phobias.
2. In a medical context, Mutism may also refer to a symptom characterized by the loss of speech due to neurological or psychological conditions, such as after a stroke or head injury, or in response to severe emotional trauma. This is different from Selective Mutism, which is a specific anxiety disorder that occurs in certain situations and not others.

Brain hypoxia is a medical condition characterized by a reduced supply of oxygen to the brain. The brain requires a continuous supply of oxygen to function properly, and even a brief period of hypoxia can cause significant damage to brain cells.

Hypoxia can result from various conditions, such as cardiac arrest, respiratory failure, carbon monoxide poisoning, or high altitude exposure. When the brain is deprived of oxygen, it can lead to a range of symptoms, including confusion, disorientation, seizures, loss of consciousness, and ultimately, brain death.

Brain hypoxia is a medical emergency that requires immediate treatment to prevent long-term neurological damage or death. Treatment typically involves addressing the underlying cause of hypoxia, such as administering oxygen therapy, resuscitating the heart, or treating respiratory failure. In some cases, more invasive treatments, such as therapeutic hypothermia or mechanical ventilation, may be necessary to prevent further brain damage.

Generalized epilepsy is a type of epilepsy characterized by seizures that involve both halves of the brain (generalized onset) from the beginning of the seizure. These types of seizures include tonic-clonic (grand mal) seizures, absence (petit mal) seizures, and myoclonic seizures. Generalized epilepsy can be caused by genetic factors or brain abnormalities, and it is typically treated with medication. People with generalized epilepsy may experience difficulties with learning, memory, and behavior, and they may have a higher risk of injury during a seizure. It's important for individuals with generalized epilepsy to work closely with their healthcare team to manage their condition and reduce the frequency and severity of seizures.

Citrullinemia is a rare inherited metabolic disorder characterized by the body's inability to properly process and eliminate certain toxic byproducts that are generated during the breakdown of proteins. This condition results from a deficiency of the enzyme argininosuccinate synthetase, which is required for the normal functioning of the urea cycle. The urea cycle is a series of biochemical reactions that occur in the liver and help to convert ammonia, a toxic substance, into urea, which can then be excreted by the kidneys.

There are two main types of citrullinemia: type I (also known as classic citrullinemia) and type II (also known as citrullinemia type II or adult-onset citrullinemia). Type I is typically more severe and can present in newborns with symptoms such as poor feeding, vomiting, seizures, and developmental delays. If left untreated, it can lead to serious complications, including intellectual disability, coma, and even death.

Type II citrullinemia, on the other hand, tends to present later in life, often in adulthood, and may cause symptoms such as confusion, seizures, and neurological problems. It is important to note that some individuals with type II citrullinemia may never develop any symptoms at all.

Treatment for citrullinemia typically involves a combination of dietary restrictions, supplements, and medications to help manage the buildup of toxic byproducts in the body. In severe cases, liver transplantation may be considered as a last resort.

Cognition refers to the mental processes involved in acquiring, processing, and utilizing information. These processes include perception, attention, memory, language, problem-solving, and decision-making. Cognitive functions allow us to interact with our environment, understand and respond to stimuli, learn new skills, and remember experiences.

In a medical context, cognitive function is often assessed as part of a neurological or psychiatric evaluation. Impairments in cognition can be caused by various factors, such as brain injury, neurodegenerative diseases (e.g., Alzheimer's disease), infections, toxins, and mental health conditions. Assessing cognitive function helps healthcare professionals diagnose conditions, monitor disease progression, and develop treatment plans.

Aspiration pneumonia is a type of pneumonia that occurs when foreign materials such as food, liquid, or vomit enter the lungs, resulting in inflammation or infection. It typically happens when a person inhales these materials involuntarily due to impaired swallowing mechanisms, which can be caused by various conditions such as stroke, dementia, Parkinson's disease, or general anesthesia. The inhalation of foreign materials can cause bacterial growth in the lungs, leading to symptoms like cough, chest pain, fever, and difficulty breathing. Aspiration pneumonia can be a serious medical condition, particularly in older adults or individuals with weakened immune systems, and may require hospitalization and antibiotic treatment.

Gastric lavage, also known as stomach pumping, is a medical procedure where the stomach's contents are emptied using a tube that is inserted through the mouth or nose and into the stomach. The tube is then connected to suction, which helps remove the stomach contents. This procedure is often used in emergency situations to treat poisonings or overdoses by removing the toxic substance before it gets absorbed into the bloodstream. It can also be used to empty the stomach before certain surgeries or procedures.

Hypoglycemia is a medical condition characterized by an abnormally low level of glucose (sugar) in the blood. Generally, hypoglycemia is defined as a blood glucose level below 70 mg/dL (3.9 mmol/L), although symptoms may not occur until the blood sugar level falls below 55 mg/dL (3.0 mmol/L).

Hypoglycemia can occur in people with diabetes who are taking insulin or medications that increase insulin production, as well as those with certain medical conditions such as hormone deficiencies, severe liver illnesses, or disorders of the adrenal glands. Symptoms of hypoglycemia include sweating, shaking, confusion, rapid heartbeat, and in severe cases, loss of consciousness or seizures.

Hypoglycemia is typically treated by consuming fast-acting carbohydrates such as fruit juice, candy, or glucose tablets to rapidly raise blood sugar levels. If left untreated, hypoglycemia can lead to serious complications, including brain damage and even death.

Bloodletting is a medical procedure that was commonly used in the past to balance the four humors of the body, which were believed to be blood, phlegm, black bile, and yellow bile. The procedure involved withdrawing blood from a patient through various methods such as venesection (making an incision in a vein), leeches, or cupping.

The theory behind bloodletting was that if one humor became overabundant, it could cause disease or illness. By removing some of the excess humor, practitioners believed they could restore balance and promote healing. Bloodletting was used to treat a wide variety of conditions, including fever, inflammation, and pain.

While bloodletting is no longer practiced in modern medicine, it was once a common treatment for many different ailments. The practice dates back to ancient times and was used by various cultures throughout history, including the Greeks, Romans, Egyptians, and Chinese. However, its effectiveness as a medical treatment has been called into question, and it is now considered an outdated and potentially harmful procedure.

A subdural hematoma is a type of brain injury in which blood accumulates between the dura mater (the outermost layer of the meninges, the protective coverings of the brain and spinal cord) and the brain. In the case of an acute subdural hematoma, the bleeding occurs suddenly and rapidly as a result of trauma, such as a severe head injury from a fall, motor vehicle accident, or assault. The accumulation of blood puts pressure on the brain, which can lead to serious complications, including brain damage or death, if not promptly diagnosed and treated. Acute subdural hematomas are considered medical emergencies and require immediate neurosurgical intervention.

Empty Sella Syndrome is a condition characterized by the absence or near-absence of the pituitary gland in the sella turcica, a bony structure at the base of the skull that houses the pituitary gland. This can occur due to the herniation of the arachnoid membrane, which surrounds the brain and spinal cord, into the sella turcica, compressing or replacing the pituitary gland.

In some cases, Empty Sella Syndrome may be asymptomatic and discovered incidentally on imaging studies. However, in other cases, it can lead to hormonal imbalances due to the disruption of the pituitary gland's function. Symptoms may include headaches, vision changes, menstrual irregularities, fatigue, and decreased libido. Treatment typically involves addressing any underlying hormonal deficiencies with medication or hormone replacement therapy.

Cerebrovascular disorders are a group of medical conditions that affect the blood vessels of the brain. These disorders can be caused by narrowing, blockage, or rupture of the blood vessels, leading to decreased blood flow and oxygen supply to the brain. The most common types of cerebrovascular disorders include:

1. Stroke: A stroke occurs when a blood vessel in the brain becomes blocked or bursts, causing a lack of oxygen and nutrients to reach brain cells. This can lead to permanent damage or death of brain tissue.
2. Transient ischemic attack (TIA): Also known as a "mini-stroke," a TIA occurs when blood flow to the brain is temporarily blocked, often by a blood clot. Symptoms may last only a few minutes to a few hours and typically resolve on their own. However, a TIA is a serious warning sign that a full-blown stroke may occur in the future.
3. Aneurysm: An aneurysm is a weakened or bulging area in the wall of a blood vessel. If left untreated, an aneurysm can rupture and cause bleeding in the brain.
4. Arteriovenous malformation (AVM): An AVM is a tangled mass of abnormal blood vessels that connect arteries and veins. This can lead to bleeding in the brain or stroke.
5. Carotid stenosis: Carotid stenosis occurs when the carotid arteries, which supply blood to the brain, become narrowed or blocked due to plaque buildup. This can increase the risk of stroke.
6. Vertebrobasilar insufficiency: This condition occurs when the vertebral and basilar arteries, which supply blood to the back of the brain, become narrowed or blocked. This can lead to symptoms such as dizziness, vertigo, and difficulty swallowing.

Cerebrovascular disorders are a leading cause of disability and death worldwide. Risk factors for these conditions include age, high blood pressure, smoking, diabetes, high cholesterol, and family history. Treatment may involve medications, surgery, or lifestyle changes to reduce the risk of further complications.

A delusion is a fixed, false belief that is firmly held despite evidence to the contrary and is not shared by others who hold similar cultural or religious beliefs. Delusions are a key symptom of certain psychiatric disorders, such as schizophrenia and delusional disorder. They can also be seen in other medical conditions, such as dementia, brain injury, or substance abuse.

Delusions can take many forms, but some common types include:

* Persecutory delusions: the belief that one is being targeted or harmed by others
* Grandiose delusions: the belief that one has special powers, talents, or importance
* Erotomanic delusions: the belief that someone, often of higher social status, is in love with the individual
* Somatic delusions: the belief that one's body is abnormal or has been altered in some way
* Religious or spiritual delusions: the belief that one has a special relationship with a deity or religious figure

Delusions should not be confused with overvalued ideas, which are strongly held beliefs based on subjective interpretation of experiences or evidence. Overvalued ideas may be shared by others and can sometimes develop into delusions if they become fixed and firmly held despite contradictory evidence.

Poisoning is defined medically as the harmful, sometimes fatal, effect produced by a substance when it is introduced into or absorbed by living tissue. This can occur through various routes such as ingestion, inhalation, injection, or absorption through the skin. The severity of poisoning depends on the type and amount of toxin involved, the route of exposure, and the individual's age, health status, and susceptibility. Symptoms can range from mild irritation to serious conditions affecting multiple organs, and may include nausea, vomiting, diarrhea, abdominal pain, difficulty breathing, seizures, or unconsciousness. Immediate medical attention is required in cases of poisoning to prevent severe health consequences or death.

The frontal lobe is the largest lobes of the human brain, located at the front part of each cerebral hemisphere and situated in front of the parietal and temporal lobes. It plays a crucial role in higher cognitive functions such as decision making, problem solving, planning, parts of social behavior, emotional expressions, physical reactions, and motor function. The frontal lobe is also responsible for what's known as "executive functions," which include the ability to focus attention, understand rules, switch focus, plan actions, and inhibit inappropriate behaviors. It is divided into five areas, each with its own specific functions: the primary motor cortex, premotor cortex, Broca's area, prefrontal cortex, and orbitofrontal cortex. Damage to the frontal lobe can result in a wide range of impairments, depending on the location and extent of the injury.

Pneumocephalus is a medical condition characterized by the presence of air or gas within the intracranial cavity, specifically within the cranial vault (the space enclosed by the skull and containing the brain). This can occur due to various reasons such as trauma, neurosurgical procedures, tumors, or infection. The accumulation of air in the cranium can lead to symptoms like headache, altered mental status, nausea, vomiting, and neurological deficits. It is essential to diagnose and treat pneumocephalus promptly to prevent further complications, such as meningitis or brain abscess. Treatment options may include surgery, bed rest with head elevation, or administration of oxygen to facilitate the reabsorption of air.

... state/event consciousness; reportability; introspective consciousness; subjective consciousness; self-consciousness)-and that ... Max Velmans (2009). "How to define consciousness-and how not to define consciousness". Journal of Consciousness Studies. 16: ... Wikimedia Commons has media related to Consciousness. The dictionary definition of consciousness at Wiktionary Consciousness ... Medicine portal Philosophy portal Chaitanya (consciousness): Pure consciousness in Hindu philosophy. Models of consciousness: ...
... is the idea that human beings are members of a planetary society of Earth as much as they are members ... Key planetary consciousness events of the 20th century include the creation of the League of Nations, the signing of Kellogg- ... Bummel describes planetary consciousness as integral, insofar as it does not conflict with other levels of social identity, but ... Author Shashi Tharoor argues that an Earth Anthem sung by people across the world can inspire planetary consciousness and ...
The Consciousness Party, also translated as the Awareness Party, is a political party in Egypt founded in 2011. The party was ...
Michael Gazzaniga, while working on the model of dual consciousness, came to the conclusion that simple dual consciousness (i.e ... Revonsuo stated that it seemed that one consciousness saw the flower and another consciousness saw the rabbit independently ... Dual consciousness is a theoretical concept in neuroscience. It is proposed that it is possible that a person may develop two ... The theory of a division of consciousness was touched upon by Carl Jung in 1935 when he stated, "The so-called unity of ...
"The paradox of consciousness", The Lancet, Vol 357, Issue 9249, 6 January 2001. "The Blackwell Companion to Consciousness: ... Reductionism, for example, attempts to reduce consciousness to being a state of the brain; thus consciousness is nothing more ... functionalism and consciousness in machines. Part 2 gives a new analysis of consciousness, grounded in its everyday ... Understanding Consciousness (2000) is a book by Max Velmans, Emeritus Professor of Psychology at Goldsmiths, University of ...
"Class Consciousness and Working Class Emancipation". 2021. Archived from the original on 2021-03-02. "Class Consciousness 101 ... "Understanding Karl Marx's Class Consciousness and False Consciousness". Archived from the original on 2017-10-14. 'Marxism, ... In Marxism, class consciousness is the set of beliefs that a person holds regarding their social class or economic rank in ... Philosophy portal False consciousness Psychology of social class Wright, Erik Olin (2006). "Class". In Beckert, Jens; ...
The consciousness industry is a term coined by author and theorist Hans Magnus Enzensberger, which identifies the mechanisms ... Hans Haacke elaborates on the consciousness industry as it applies to the arts in a wider system of production, distribution, ... Haacke, H. (1983/2006). "Museums: Managers of consciousness," in Hans Haacke : For real : Works 1959-2006. M. Flügge & R. Fleck ... The Consciousness Industry: On Literature, Politics and the Media. New York: Continuum Books/ Seabury Press. Michael Roloff, ...
... may refer to: Black Consciousness Movement, an anti-apartheid movement in the 1960s in South Africa Black ... Consciousness Day, or Black Awareness Day, a day celebrated every November 20 in Brazil This disambiguation page lists articles ... associated with the title Black consciousness. If an internal link led you here, you may wish to change the link to point ...
Knowing the brain basis of consciousness reduces the Hard problem of consciousness in a significant way while the provision of ... Journal of Consciousness Studies 21, 6-32. Hobson, J.A. (2015). Psychodynamic Neurology: Dreams, Consciousness, and Virtual ... Dream consciousness is a term defined by the theorist of dreaming science J. Allan Hobson, M.D. as the memory of subjective ... Hence, Hobson argues, consciousness may thus be no more and no less than the simultaneous combination of all of these ...
... may refer to: Collective consciousness, the set of shared beliefs, ideas and moral attitudes which operate ... Group consciousness (political science) Vijnanakaya, one of the seven Sarvāstivāda Abhidharma Buddhist scriptures. This ... disambiguation page lists articles associated with the title Group consciousness. If an internal link led you here, you may ...
The rule consciousness as one of the primary factors of personality out of sixteen as categorized by Raymond Cattell, 1946 as ... A theory also associates rule consciousness as the "original apperception", which is a Kantian concept of a mental state in ... Jean Piaget also studied rule consciousness between boys and girls in the context of games. Hausenblas, Heather; Rhodes, Ryan ( ... The descriptors of low level rule consciousness are expedient, nonconforming, disregards rules, self-indulgent or having a low ...
The legal consciousness evaluates the existing law and also bears in mind an image of the desired or ideal law. Consciousness ... Legal consciousness is a form of social consciousness. Legal ideology, the system of legal views based on certain social and ... Legal consciousness is a state of being, legal socialisation is the process to Legal consciousness; where as legal awareness & ... legal consciousness narratives Before the law With the law Against the law Law Consciousness Natural law Legal positivism Legal ...
... (AC), also known as machine consciousness (MC), synthetic consciousness or digital consciousness, is ... Memory and consciousness. Canadian Psychology 26:1-12 Franklin, Stan, et al. "The role of consciousness in memory." Brains, ... Characters with artificial consciousness (or at least with personalities that imply they have consciousness), from works of ... Access consciousness concerns those aspects of experience that can be apprehended, while phenomenal consciousness concerns ...
... can refer to a multitude of different individual forms of consciousness coalescing into a greater ... Part 1: Collective Consciousness and its Socio-Cultural Foundations, Journal of Consciousness Studies, 5 (1) p 72. Tsoukalas, I ... Cognitive materialism is based on a kind of collective consciousness of the mind. This consciousness can be used, with ... "Collective consciousness and the social brain". Journal of Consciousness Studies. 15: 264-276.{{cite journal}}: CS1 maint: ...
Consciousness is the state or quality of awareness. Consciousness may also refer to: Consciousness (Hill book), 2009 book by ... 1970 Consciousness (Pat Martino album), 1974 Consciousness (Smile Empty Soul album), 2009 Conscious (disambiguation) ... Look up consciousness in Wiktionary, the free dictionary. ... page lists articles associated with the title Consciousness. If ... a 2000 book by biologists Gerald Maurice Edelman and Giulio Tononi Consciousness! (Eric Kloss album), ...
Dennett's views set out in Consciousness Explained put him at odds with thinkers who say that consciousness can be described ... What neurology tells us about the biological functions of consciousness, qualia and the self." Journal of consciousness studies ... Detractors have provided the alternative titles of Consciousness Ignored and Consciousness Explained Away. According to Galen ... Frankish, Keith (2016). "Illusionism as a Theory of Consciousness". Journal of Consciousness Studies. 23: 11-39. Graziano, ...
This form of consciousness is also sometimes called "sensory consciousness". Put another way, primary consciousness is the ... Consciousness has not yet become a scientific term that can be defined in this way. Currently we all use the term consciousness ... Consciousness in a Cockroach Discover, 10 January 2007. Do insects Feel pain? Animal consciousness at the Stanford Encyclopedia ... Phenomenal consciousness is usually consciousness of something or about something, a property known as intentionality in ...
Gerald Edelman distinguishes higher consciousness or "secondary consciousness" from "primary consciousness", defined as simple ... "God-consciousness", is a higher form of consciousness. This consciousness is not "God himself", since God would then no longer ... consciousness. In his book The Spectrum of Consciousness Wilber describes consciousness as a spectrum with ordinary awareness ... Higher consciousness (also called expanded consciousness) is a term that has been used in various ways to label particular ...
... "cosmic consciousness" to be a collective consciousness, a "larger reservoir of consciousness", which manifests itself in the ... In Cosmic Consciousness, Bucke stated that he discerned three forms, or degrees, of consciousness: Simple consciousness, ... brutish self-awareness Sensual consciousness Higher self-consciousness In Schleiermacher's theology, higher consciousness "is ... According to Ervin László, cosmic consciousness corresponds to Jean Gebser's integral consciousness and to Don Edward Beck and ...
... is consciousness which is incorrect and misaligned from reality. In a Marxist worldview, false ... In the letter, Engels uses the term false consciousness interchangeably with the term ideology. "Consciousness", in this ... Society portal Capitalist realism Character mask Class consciousness Cognitive dissonance Consciousness raising Cultural ... Engels dubs this consciousness "false" because the class is asserting itself towards goals that do not benefit it. ...
... is a term coined by Ernest Hilgard to define a psychological state in which one's consciousness is split ... the separation of phenomenal experience from reflexive consciousness and the non-unity of reflexive consciousness. Reflexive ... Reflexive consciousness is operative only when we attend to our own states. When we are involved in the world, reflexivity ... With regard to theory, he does state that it is useful to assign two modes of consciousness, a receptive mode and an active ...
Critical consciousness Class consciousness Consciousness raising Double consciousness History of Consciousness, an ... For Marx, consciousness describes a person's political sense of self. That is, consciousness describes a person's awareness of ... In these uses of the term "consciousness" is truth or destiny. These uses of political consciousness are often politically ... Many social movements have loosely followed Marx's thinking on consciousness. Attaining consciousness, many believe, means ...
Chapter 14: Cit-Shakti (The Consciousness Aspect of the Universe) v t e v t e (Use dmy dates from August 2019, Articles ... Chit (Sanskrit: चित् or Cit) is a Sanskrit word meaning consciousness. It is a core principle in all ancient spiritual ... Gupta, Bina (2003), CIT consciousness, Oxford University Press Arthur Avalon, Shakti and Shâkta. ...
In his books Pedagogy of the Oppressed and Education for Critical Consciousness, Freire explains critical consciousness as a ... Adult education Adult literacy Class consciousness Critical pedagogy Consciousness Raising Identity politics Liberation ... "consciousness raising" and "critical consciousness". The term was popularized by Brazilian educator, activist, and theorist ... and from the fratricidal violence that results therefrom is a major goal of critical consciousness. Critical consciousness is a ...
... social consciousness, and polity Theology and the social consciousness: a study of the relations of the social consciousness to ... Society portal Civic intelligence Class consciousness Collective consciousness Collective intelligence Consciousness raising ... Social consciousness or social awareness, is collective consciousness shared by individuals within a society. Social ... Awakening to Race: Individualism and Social Consciousness in America Children's Social Consciousness and the Development of ...
"Alice Coltrane: Universal Consciousness". AllMusic. Retrieved October 28, 2022. "Alice Coltrane - Universal Consciousness". ... Universal Consciousness is the fifth solo album by Alice Coltrane. It was recorded from April to June, 1971, in New York City ... Universal Consciousness was recorded shortly after Coltrane returned from a trip to India, and was the first album on which she ... "Alice Coltrane - Universal Consciousness/Lord of Lords". Jazz Music Archives. Retrieved October 28, 2022. Cook, Richard; Morton ...
... is the human ability to mentally place oneself in the past and future (i.e. mental time travel) or in ... Autonoetic consciousness is important in our formation of our "self" identity. What we have done in the past becomes a part of ... Autonoetic consciousness is thought to emerge by retrieval of memory of personally experienced events (episodic memory). ... Hills, Thomas T.; Butterfill, Stephen (2015). "From Foraging to Autonoetic Consciousness: The Primal Self as a Consequence of ...
... is a theory stating that equality under the law is insufficient to address racial inequalities in society. ... This contrasts with modern notions of positive color consciousness, through such endeavors as affirmative action, to bolster ... ISBN 978-1-84467-126-7. Ansell, Amy Elizabeth (2013). "Color-Consciousness". Race and Ethnicity: The Key Concepts. Routledge. ... This distinction between free black and white wage workers shows a kind of negative color consciousness, in which the white " ...
Consciousness Lucid dream Primary consciousness Neural Darwinism Edelman, G. M. (2003). Naturalizing consciousness: a ... can occur independently of consciousness of consciousness. Using lucid dreaming as a model of secondary consciousness. Some ... Research on animal consciousness Many researchers of consciousness have looked upon such types of research in animals as ... The current problem consciousness researchers face involves explaining how and why consciousness arises from neural computation ...
Raising consciousness meant helping oneself and helping others to become politically conscious. Consciousness raising groups ... Yu, Nilan (2018), "Consciousness-raising and critical practice", Consciousness-Raising, Routledge, pp. 1-13, doi:10.4324/ ... What really counts in consciousness-raising are not methods, but results. The only 'methods' of consciousness raising are ... Historically, poetry has been used as a consciousness-raising tactic by consciousness-raising groups. Activist and writer Audre ...

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