The compartment containing the anterior extremities and half the inferior surface of the temporal lobes (TEMPORAL LOBE) of the cerebral hemispheres. Lying posterior and inferior to the anterior cranial fossa (CRANIAL FOSSA, ANTERIOR), it is formed by part of the TEMPORAL BONE and SPHENOID BONE. It is separated from the posterior cranial fossa (CRANIAL FOSSA, POSTERIOR) by crests formed by the superior borders of the petrous parts of the temporal bones.
The compartment containing the inferior part and anterior extremities of the frontal lobes (FRONTAL LOBE) of the cerebral hemispheres. It is formed mainly by orbital parts of the FRONTAL BONE and the lesser wings of the SPHENOID BONE.
The infratentorial compartment that contains the CEREBELLUM and BRAIN STEM. It is formed by the posterior third of the superior surface of the body of the sphenoid (SPHENOID BONE), by the occipital, the petrous, and mastoid portions of the TEMPORAL BONE, and the posterior inferior angle of the PARIETAL BONE.
The inferior region of the skull consisting of an internal (cerebral), and an external (basilar) surface.
Intracranial or spinal cavities containing a cerebrospinal-like fluid, the wall of which is composed of arachnoidal cells. They are most often developmental or related to trauma. Intracranial arachnoid cysts usually occur adjacent to arachnoidal cistern and may present with HYDROCEPHALUS; HEADACHE; SEIZURES; and focal neurologic signs. (From Joynt, Clinical Neurology, 1994, Ch44, pp105-115)
Surgery performed on the external, middle, or internal ear.
Benign and malignant neoplasms that arise from one or more of the twelve cranial nerves.
Diseases of the trigeminal nerve or its nuclei, which are located in the pons and medulla. The nerve is composed of three divisions: ophthalmic, maxillary, and mandibular, which provide sensory innervation to structures of the face, sinuses, and portions of the cranial vault. The mandibular nerve also innervates muscles of mastication. Clinical features include loss of facial and intra-oral sensation and weakness of jaw closure. Common conditions affecting the nerve include brain stem ischemia, INFRATENTORIAL NEOPLASMS, and TRIGEMINAL NEURALGIA.
Any operation on the cranium or incision into the cranium. (Dorland, 28th ed)
Either of a pair of compound bones forming the lateral (left and right) surfaces and base of the skull which contains the organs of hearing. It is a large bone formed by the fusion of parts: the squamous (the flattened anterior-superior part), the tympanic (the curved anterior-inferior part), the mastoid (the irregular posterior portion), and the petrous (the part at the base of the skull).
Neoplasms of the base of the skull specifically, differentiated from neoplasms of unspecified sites or bones of the skull (SKULL NEOPLASMS).
Diseases of the facial nerve or nuclei. Pontine disorders may affect the facial nuclei or nerve fascicle. The nerve may be involved intracranially, along its course through the petrous portion of the temporal bone, or along its extracranial course. Clinical manifestations include facial muscle weakness, loss of taste from the anterior tongue, hyperacusis, and decreased lacrimation.
The outermost of the three MENINGES, a fibrous membrane of connective tissue that covers the brain and the spinal cord.
Junction between the cerebellum and the pons.
A group of congenital malformations involving the brainstem, cerebellum, upper spinal cord, and surrounding bony structures. Type II is the most common, and features compression of the medulla and cerebellar tonsils into the upper cervical spinal canal and an associated MENINGOMYELOCELE. Type I features similar, but less severe malformations and is without an associated meningomyelocele. Type III has the features of type II with an additional herniation of the entire cerebellum through the bony defect involving the foramen magnum, forming an ENCEPHALOCELE. Type IV is a form a cerebellar hypoplasia. Clinical manifestations of types I-III include TORTICOLLIS; opisthotonus; HEADACHE; VERTIGO; VOCAL CORD PARALYSIS; APNEA; NYSTAGMUS, CONGENITAL; swallowing difficulties; and ATAXIA. (From Menkes, Textbook of Child Neurology, 5th ed, p261; Davis, Textbook of Neuropathology, 2nd ed, pp236-46)
Congenital, inherited, or acquired abnormalities involving ARTERIES; VEINS; or venous sinuses in the BRAIN; SPINAL CORD; and MENINGES.
A light and spongy (pneumatized) bone that lies between the orbital part of FRONTAL BONE and the anterior of SPHENOID BONE. Ethmoid bone separates the ORBIT from the ETHMOID SINUS. It consists of a horizontal plate, a perpendicular plate, and two lateral labyrinths.
Pathological processes of the ear, the hearing, and the equilibrium system of the body.
A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). (From Dorland, 27th ed)
The numerous (6-12) small thin-walled spaces or air cells in the ETHMOID BONE located between the eyes. These air cells form an ethmoidal labyrinth.
Intracranial tumors originating in the region of the brain inferior to the tentorium cerebelli, which contains the cerebellum, fourth ventricle, cerebellopontine angle, brain stem, and related structures. Primary tumors of this region are more frequent in children, and may present with ATAXIA; CRANIAL NERVE DISEASES; vomiting; HEADACHE; HYDROCEPHALUS; or other signs of neurologic dysfunction. Relatively frequent histologic subtypes include TERATOMA; MEDULLOBLASTOMA; GLIOBLASTOMA; ASTROCYTOMA; EPENDYMOMA; CRANIOPHARYNGIOMA; and choroid plexus papilloma (PAPILLOMA, CHOROID PLEXUS).
Tomography using x-ray transmission and a computer algorithm to reconstruct the image.
An irregular unpaired bone situated at the SKULL BASE and wedged between the frontal, temporal, and occipital bones (FRONTAL BONE; TEMPORAL BONE; OCCIPITAL BONE). Sphenoid bone consists of a median body and three pairs of processes resembling a bat with spread wings. The body is hollowed out in its inferior to form two large cavities (SPHENOID SINUS).
The dense rock-like part of temporal bone that contains the INNER EAR. Petrous bone is located at the base of the skull. Sometimes it is combined with the MASTOID PROCESS and called petromastoid part of temporal bone.
The posterior part of the temporal bone. It is a projection of the petrous bone.
A retention cyst of the salivary gland, lacrimal sac, paranasal sinuses, appendix, or gallbladder. (Stedman, 26th ed)
A neoplasm that arises from SCHWANN CELLS of the cranial, peripheral, and autonomic nerves. Clinically, these tumors may present as a cranial neuropathy, abdominal or soft tissue mass, intracranial lesion, or with spinal cord compression. Histologically, these tumors are encapsulated, highly vascular, and composed of a homogenous pattern of biphasic fusiform-shaped cells that may have a palisaded appearance. (From DeVita Jr et al., Cancer: Principles and Practice of Oncology, 5th ed, pp964-5)
Either of a pair of bones that form the prominent part of the CHEEK and contribute to the ORBIT on each side of the SKULL.
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.
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.
Veins draining the cerebrum.
Part of the back and base of the CRANIUM that encloses the FORAMEN MAGNUM.
Rare, benign, chronic, progressive metaplasia in which cartilage is formed in the synovial membranes of joints, tendon sheaths, or bursae. Some of the metaplastic foci can become detached producing loose bodies. When the loose bodies undergo secondary calcification, the condition is called synovial osteochondromatosis.
Accumulation of blood in the SUBDURAL SPACE over the CEREBRAL HEMISPHERE.
Leakage and accumulation of CEREBROSPINAL FLUID in the subdural space which may be associated with an infectious process; CRANIOCEREBRAL TRAUMA; BRAIN NEOPLASMS; INTRACRANIAL HYPOTENSION; and other conditions.
A delicate membrane enveloping the brain and spinal cord. It lies between the PIA MATER and the DURA MATER. It is separated from the pia mater by the subarachnoid cavity which is filled with CEREBROSPINAL FLUID.
One of the paired, but seldom symmetrical, air spaces located between the inner and outer compact layers of the FRONTAL BONE in the forehead.
Neoplasms of the bony part of the skull.
Benign and malignant neoplastic processes that arise from or secondarily involve the meningeal coverings of the brain and spinal cord.
Severe or complete loss of facial muscle motor function. This condition may result from central or peripheral lesions. Damage to CNS motor pathways from the cerebral cortex to the facial nuclei in the pons leads to facial weakness that generally spares the forehead muscles. FACIAL NERVE DISEASES generally results in generalized hemifacial weakness. NEUROMUSCULAR JUNCTION DISEASES and MUSCULAR DISEASES may also cause facial paralysis or paresis.
Tumors or cancer of the PARANASAL SINUSES.
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.
Surgery performed on the nervous system or its parts.
One of the paired air spaces located in the body of the SPHENOID BONE behind the ETHMOID BONE in the middle of the skull. Sphenoid sinus communicates with the posterosuperior part of NASAL CAVITY on the same side.
A small space in the skull between the MAXILLA and the SPHENOID BONE, medial to the pterygomaxillary fissure, and connecting to the NASAL CAVITY via the sphenopalatine foramen.
An abnormal direct communication between an artery and a vein without passing through the CAPILLARIES. An A-V fistula usually leads to the formation of a dilated sac-like connection, arteriovenous aneurysm. The locations and size of the shunts determine the degree of effects on the cardiovascular functions such as BLOOD PRESSURE and HEART RATE.
The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.
Diseases of the bony orbit and contents except the eyeball.
The space and structures directly internal to the TYMPANIC MEMBRANE and external to the inner ear (LABYRINTH). Its major components include the AUDITORY OSSICLES and the EUSTACHIAN TUBE that connects the cavity of middle ear (tympanic cavity) to the upper part of the throat.
An irregularly shaped venous space in the dura mater at either side of the sphenoid bone.
Neoplasms of the bony orbit and contents except the eyeball.
Radiography of the vascular system of the brain after injection of a contrast medium.
The process of generating three-dimensional images by electronic, photographic, or other methods. For example, three-dimensional images can be generated by assembling multiple tomographic images with the aid of a computer, while photographic 3-D images (HOLOGRAPHY) can be made by exposing film to the interference pattern created when two laser light sources shine on an object.
A congenital abnormality of the central nervous system marked by failure of the midline structures of the cerebellum to develop, dilation of the fourth ventricle, and upward displacement of the transverse sinuses, tentorium, and torcula. Clinical features include occipital bossing, progressive head enlargement, bulging of anterior fontanelle, papilledema, ataxia, gait disturbances, nystagmus, and intellectual compromise. (From Menkes, Textbook of Child Neurology, 5th ed, pp294-5)
Artery formed by the bifurcation of the BASILAR ARTERY. Branches of the posterior cerebral artery supply portions of the OCCIPITAL LOBE; PARIETAL LOBE; inferior temporal gyrus, brainstem, and CHOROID PLEXUS.
A strong ligament of the knee that originates from the anterolateral surface of the medial condyle of the femur, passes posteriorly and inferiorly between the condyles, and attaches to the posterior intercondylar area of the tibia.
Primary or metastatic neoplasms of the CEREBELLUM. Tumors in this location frequently present with ATAXIA or signs of INTRACRANIAL HYPERTENSION due to obstruction of the fourth ventricle. Common primary cerebellar tumors include fibrillary ASTROCYTOMA and cerebellar HEMANGIOBLASTOMA. The cerebellum is a relatively common site for tumor metastases from the lung, breast, and other distant organs. (From Okazaki & Scheithauer, Atlas of Neuropathology, 1988, p86 and p141)
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.
Inflammation of the choroid as well as the retina and vitreous body. Some form of visual disturbance is usually present. The most important characteristics of posterior uveitis are vitreous opacities, choroiditis, and chorioretinitis.
Diseases that affect the structure or function of the cerebellum. Cardinal manifestations of cerebellar dysfunction include dysmetria, GAIT ATAXIA, and MUSCLE HYPOTONIA.
The part of the hypothalamus posterior to the middle region consisting of several nuclei including the medial maxillary nucleus, lateral mammillary nucleus, and posterior hypothalamic nucleus (posterior hypothalamic area). The posterior hypothalamic area is concerned with control of sympathetic responses and is sensitive to conditions of decreasing temperature and controls the mechanisms for the conservation and increased production of heat.
An irregularly shaped cavity in the RHOMBENCEPHALON, located between the MEDULLA OBLONGATA; the PONS; and the isthmus in front, and the CEREBELLUM behind. It is continuous with the central canal of the cord below and with the CEREBRAL AQUEDUCT above, and through its lateral and median apertures it communicates with the SUBARACHNOID SPACE.
A calcification of the posterior longitudinal ligament of the spinal column, usually at the level of the cervical spine. It is often associated with anterior ankylosing hyperostosis.
The posterior process on the ramus of the mandible composed of two parts: a superior part, the articular portion, and an inferior part, the condylar neck.

Cerebellar infarct caused by spontaneous thrombosis of a developmental venous anomaly of the posterior fossa. (1/258)

Spontaneous thrombosis of a posterior fossa developmental venous anomaly (DVA) caused a nonhemorrhagic cerebellar infarct in a 31-year-old man who also harbored a midbrain cavernous angioma. DVA thrombosis was well depicted on CT and MR studies and was proved at angiography by the demonstration of an endoluminal clot.  (+info)

Abnormal prenatal sonographic findings in the posterior cranial fossa: a case of Joubert's syndrome. (2/258)

Joubert's syndrome is a well-documented but rare disorder characterized by a variable combination of central nervous system, respiratory, renal and eye anomalies. The most significant and constant neuropathological finding is partial or complete agenesis of the cerebellar vermis. The syndrome was first described by Joubert and colleagues as a familial agenesis of the cerebellar vermis and appears to be inherited as an autosomal recessive trait. A case of Joubert's syndrome is described in which second-trimester ultrasonography demonstrated abnormal findings in the fetal posterior fossa with associated renal abnormalities. However, postnatal sonography of the posterior fossa could not confirm the prenatal findings, and the diagnosis of Joubert's syndrome was only later established by computed tomography of the neonatal brain in the knowledge of the characteristic clinical picture.  (+info)

Posterior fossa epithelial cyst: case report and review of the literature. (3/258)

A 49-year old woman with progressive cranial nerve signs and hemiparesis was found at MR imaging and at surgery to have a cyst at the foramen magnum. Immunohistochemistry and electron microscopy showed an epithelial cyst of endodermal origin. MR findings were of an extraaxial mass, with short T1 and T2 times. Unless immunohistochemistry and electron microscopy are used in the final diagnosis of such cysts, all posterior fossa cysts lined by a single layer of epithelium should be described simply as epithelial cysts.  (+info)

Magnetic resonance imaging supplements ultrasonographic imaging of the posterior fossa, pharynx and neck in malformed fetuses. (4/258)

OBJECTIVE: The objective of this study was to compare antepartum ultrasonography and magnetic resonance imaging (MRI) in the diagnosis and exclusion of malformations of the fetal neck, pharynx, skull base and posterior fossa in late pregnancy. MATERIALS AND METHODS: The study involved 26 women and 27 fetuses with ultrasonographically or clinically suspected abnormalities of the fetal neck, pharynx or central nervous system (CNS). Findings obtained by ultrasound were compared with those obtained by MRI (1.5 T) in the last trimester. RESULTS: In cases with CNS malformation (n = 19), MRI provided additional information on the anatomy of the foramen magnum and posterior fossa in nine cases (47%). When antepartum ultrasonography indicated malformation of the soft tissues of the neck or pharynx (n = 8), MRI provided additional information on diagnosis or exclusion of the abnormality in six cases (75%). The imaging capacity of the anatomy of the naso-, oro- and hypopharynx, trachea, esophagus and cervical skin outlines was better with MRI. CONCLUSIONS: MRI proved to be a valuable supplementary method to ultrasound in obtaining accurate information from the fetal neck, pharynx and posterior fossa, particularly when acoustic shadowing by bony structures or adjacent malformation impaired the quality of the ultrasonographic examination.  (+info)

Midline cerebellar cystic schwannoma : a case report. (5/258)

An extremely unusual case of a cystic schwannoma in the region of the inferior vermis and posterior to the fourth ventricle in a fifteen year old boy is reported. The cystic tumour caused partial obstruction to the outflow of cerebrospinal fluid from fourth ventricle and resulted in development of supratentorial hydrocephalus. On investigations, the schwannoma simulated a Dandy-Walker cyst. The boy presented with symptoms of increased intracranial pressure. On surgery, the lesion was not arising from any cranial nerve, nor was it attached to brain parenchyma, blood vessel or to the dura. The possible histogenesis of the cystic schwannoma in a rare location is discussed.  (+info)

Avulsion fracture of the anterior half of the foramen magnum involving the bilateral occipital condyles and the inferior clivus--case report. (6/258)

A 38-year-old male presented with an avulsion fracture of the anterior half of the foramen magnum due to a traffic accident. He had palsy of the bilateral VI, left IX, and left X cranial nerves, weakness of his left upper extremity, and crossed sensory loss. He was treated conservatively and placed in a halo brace for 16 weeks. After immobilization, swallowing, hoarseness, and left upper extremity weakness improved. Hyperextension with a rotatory component probably resulted in strain in the tectorial membrane and alar ligaments, resulting in avulsion fracture at the sites of attachment, the bilateral occipital condyles and the inferior portion of the clivus. Conservative treatment is probably optimum even for this unusual and severe type of occipital condyle fracture.  (+info)

Neurodevelopmental outcome after antenatal diagnosis of posterior fossa abnormalities. (7/258)

Posterior fossa abnormalities are sonographically diagnosable in the fetus. Anomalies of this region include Dandy-Walker malformation, enlarged cisterna magna, and arachnoid cyst. Despite prenatal diagnosis, the uncertainties related to natural history and neurodevelopmental outcome in survivors make patient counseling difficult. The purposes of this study were to determine the accuracy of prenatal diagnosis of these lesions and elucidate long-term neurodevelopmental outcome in survivors in prenatally diagnosed posterior fossa abnormalities. Fifteen cases of posterior fossa abnormalities were reviewed. Antenatal diagnoses of Dandy-Walker malformation was made in 13 of these cases, arachnoid cyst in one case, and enlarged cisterna magna in one case. Hydrocephalus was present in 66% of patients. The sonographic diagnosis was concordant with the pathologic or neonatal radiologic diagnosis in 13 of 15 cases. Seven fetuses (47%) exhibited additional cranial or extracranial anomalies. A karyotypic abnormality (trisomy 18) was found in one of 15 cases of posterior fossa abnormalities. Neurodevelopmental delay was present in 80% of survivors with follow-up study to 4 years of age. Prenatal diagnosis of posterior fossa abnormalities is highly accurate, yet the differential diagnosis can be challenging. Cognitive and psychomotor developmental delays remain commonplace despite early diagnosis and treatment. The approach with families in cases of prenatal diagnosis of posterior fossa abnormalities should include a search for additional central nervous system and extra-central nervous system anomalies in the fetus and counseling of parents regarding potential adverse outcome for survivors.  (+info)

Tumour type and size are high risk factors for the syndrome of "cerebellar" mutism and subsequent dysarthria. (8/258)

OBJECTIVE: "Cerebellar mutis" and subsequent dysarthria (MSD) is a documented complication of posterior fossa surgery in children. In this prospective study the following risk factors for MSD were assessed: type, size and site of the tumour; hydrocephalus at presentation and after surgery, cerebellar incision site, postoperative infection, and cerebellar swelling. METHODS: In a consecutive series of 42 children with a cerebellar tumour, speech and neuroradiological studies (CT and MRI) were systematically analysed preoperatively and postoperatively. Speech was assessed using the Mayo Clinic lists and the severity of dysarthria using the Michigan rating scale. RESULTS: Twelve children (29%) developed MSD postoperatively. The type of tumour, midline localisation, and vermal incision were significant single independent risk factors. In addition, an interdependency of possible risk factors (tumour>5 cm, medulloblastoma) was found. CONCLUSION: MSD often occurs after paediatric cerebellar tumour removal and is most likely after removal of a medulloblastoma with a maximum lesion diameter>5 cm.  (+info)

The middle cranial fossa is a depression or hollow in the skull that forms the upper and central portion of the cranial cavity. It is located between the anterior cranial fossa (which lies anteriorly) and the posterior cranial fossa (which lies posteriorly). The middle cranial fossa contains several important structures, including the temporal lobes of the brain, the pituitary gland, the optic chiasm, and the cavernous sinuses. It is also where many of the cranial nerves pass through on their way to the brain.

The middle cranial fossa can be further divided into two parts: the anterior and posterior fossae. The anterior fossa contains the optic chiasm and the pituitary gland, while the posterior fossa contains the temporal lobes of the brain and the cavernous sinuses.

The middle cranial fossa is formed by several bones of the skull, including the sphenoid bone, the temporal bone, and the parietal bone. The shape and size of the middle cranial fossa can vary from person to person, and abnormalities in its structure can be associated with various medical conditions, such as pituitary tumors or aneurysms.

The anterior cranial fossa is a term used in anatomy to refer to the portion of the skull that forms the upper part of the orbits (eye sockets) and the roof of the nasal cavity. It is located at the front of the skull, and is formed by several bones including the frontal bone, sphenoid bone, and ethmoid bone.

The anterior cranial fossa contains several important structures, including the olfactory bulbs (which are responsible for our sense of smell), as well as the optic nerves and parts of the pituitary gland. This region of the skull also provides protection for the brain, particularly the frontal lobes, which are involved in higher cognitive functions such as decision-making, problem-solving, and emotional regulation.

Abnormalities or injuries to the anterior cranial fossa can have serious consequences, including damage to the olfactory bulbs, optic nerves, and pituitary gland, as well as potential injury to the frontal lobes of the brain.

The posterior cranial fossa is a term used in anatomy to refer to the portion of the skull that forms the lower, back part of the cranial cavity. It is located between the occipital bone and the temporal bones, and it contains several important structures including the cerebellum, pons, medulla oblongata, and the lower cranial nerves (IX-XII). The posterior fossa also contains the foramen magnum, which is a large opening through which the spinal cord connects to the brainstem. This region of the skull is protected by the occipital bone, which forms the base of the skull and provides attachment for several neck muscles.

The skull base is the lower part of the skull that forms the floor of the cranial cavity and the roof of the facial skeleton. It is a complex anatomical region composed of several bones, including the frontal, sphenoid, temporal, occipital, and ethmoid bones. The skull base supports the brain and contains openings for blood vessels and nerves that travel between the brain and the face or neck. The skull base can be divided into three regions: the anterior cranial fossa, middle cranial fossa, and posterior cranial fossa, which house different parts of the brain.

An Arachnoid cyst is a type of abnormal fluid-filled sac that develops between the brain or spinal cord and the arachnoid membrane, which is one of the three layers that cover and protect the central nervous system. These cysts are filled with cerebrospinal fluid (CSF), which is the same fluid that surrounds and cushions the brain and spinal cord.

Arachnoid cysts can vary in size and may be present at birth or develop later in life due to trauma, infection, or other factors. While many arachnoid cysts are asymptomatic and do not cause any problems, larger cysts or those that grow or shift over time can put pressure on the brain or spinal cord, leading to a range of neurological symptoms such as headaches, seizures, hearing or vision changes, balance or coordination difficulties, and cognitive impairments.

Treatment for arachnoid cysts depends on their size, location, and associated symptoms. In some cases, observation and monitoring may be sufficient, while in others, surgical intervention may be necessary to drain the cyst or create a connection between it and the surrounding CSF space to relieve pressure.

Otologic surgical procedures refer to a range of surgeries performed on the ear or its related structures. These procedures are typically conducted by otologists, who are specialists trained in diagnosing and treating conditions that affect the ears, balance system, and related nerves. The goal of otologic surgery can vary from repairing damaged bones in the middle ear to managing hearing loss, tumors, or chronic infections. Some common otologic surgical procedures include:

1. Stapedectomy/Stapedotomy: These are procedures used to treat otosclerosis, a condition where the stapes bone in the middle ear becomes fixed and causes conductive hearing loss. The surgeon creates an opening in the stapes footplate (stapedotomy) or removes the entire stapes bone (stapedectomy) and replaces it with a prosthetic device to improve sound conduction.
2. Myringoplasty/Tympanoplasty: These are surgeries aimed at repairing damaged eardrums (tympanic membrane). A myringoplasty involves grafting a piece of tissue over the perforation in the eardrum, while a tympanoplasty includes both eardrum repair and reconstruction of the middle ear bones if necessary.
3. Mastoidectomy: This procedure involves removing the mastoid air cells, which are located in the bony prominence behind the ear. A mastoidectomy is often performed to treat chronic mastoiditis, cholesteatoma, or complications from middle ear infections.
4. Ossiculoplasty: This procedure aims to reconstruct and improve the function of the ossicles (middle ear bones) when they are damaged due to various reasons such as infection, trauma, or congenital conditions. The surgeon uses prosthetic devices made from plastic, metal, or even bone to replace or support the damaged ossicles.
5. Cochlear implantation: This is a surgical procedure that involves placing an electronic device inside the inner ear to help individuals with severe to profound hearing loss. The implant consists of an external processor and internal components that directly stimulate the auditory nerve, bypassing the damaged hair cells in the cochlea.
6. Labyrinthectomy: This procedure involves removing the balance-sensing structures (vestibular system) inside the inner ear to treat severe vertigo or dizziness caused by conditions like Meniere's disease when other treatments have failed.
7. Acoustic neuroma removal: An acoustic neuroma is a benign tumor that grows on the vestibulocochlear nerve, which connects the inner ear to the brain. Surgical removal of the tumor is necessary to prevent hearing loss, balance problems, and potential neurological complications.

These are just a few examples of the various surgical procedures performed by otolaryngologists (ear, nose, and throat specialists) to treat conditions affecting the ear and surrounding structures. Each procedure has its specific indications, benefits, risks, and postoperative care requirements. Patients should consult with their healthcare providers to discuss the most appropriate treatment options for their individual needs.

Cranial nerve neoplasms refer to abnormal growths or tumors that develop within or near the cranial nerves. These nerves are responsible for transmitting sensory and motor information between the brain and various parts of the head, neck, and trunk. There are 12 pairs of cranial nerves, each with a specific function and location in the skull.

Cranial nerve neoplasms can be benign or malignant and may arise from the nerve itself (schwannoma, neurofibroma) or from surrounding tissues that invade the nerve (meningioma, epidermoid cyst). The growth of these tumors can cause various symptoms depending on their size, location, and rate of growth. Common symptoms include:

* Facial weakness or numbness
* Double vision or other visual disturbances
* Hearing loss or tinnitus (ringing in the ears)
* Difficulty swallowing or speaking
* Loss of smell or taste
* Uncontrollable eye movements or drooping eyelids

Treatment for cranial nerve neoplasms depends on several factors, including the type, size, location, and extent of the tumor, as well as the patient's overall health. Treatment options may include surgery, radiation therapy, chemotherapy, or a combination of these approaches. Regular follow-up care is essential to monitor for recurrence or complications.

Trigeminal nerve diseases refer to conditions that affect the trigeminal nerve, which is one of the cranial nerves responsible for sensations in the face and motor functions such as biting and chewing. The trigeminal nerve has three branches: ophthalmic, maxillary, and mandibular, which innervate different parts of the face and head.

Trigeminal nerve diseases can cause various symptoms, including facial pain, numbness, tingling, or weakness. Some common trigeminal nerve diseases include:

1. Trigeminal neuralgia: A chronic pain condition that affects the trigeminal nerve, causing intense, stabbing, or electric shock-like pain in the face.
2. Hemifacial spasm: A neuromuscular disorder that causes involuntary muscle spasms on one side of the face, often affecting the muscles around the eye and mouth.
3. Trigeminal neuropathy: Damage or injury to the trigeminal nerve, which can result in numbness, tingling, or weakness in the face.
4. Herpes zoster oticus (Ramsay Hunt syndrome): A viral infection that affects the facial nerve and geniculate ganglion of the trigeminal nerve, causing facial paralysis, ear pain, and a rash around the ear.
5. Microvascular compression: Compression of the trigeminal nerve by a blood vessel, which can cause symptoms similar to trigeminal neuralgia.

Treatment for trigeminal nerve diseases depends on the specific condition and its severity. Treatment options may include medication, surgery, or radiation therapy.

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 temporal bone is a paired bone that is located on each side of the skull, forming part of the lateral and inferior walls of the cranial cavity. It is one of the most complex bones in the human body and has several important structures associated with it. The main functions of the temporal bone include protecting the middle and inner ear, providing attachment for various muscles of the head and neck, and forming part of the base of the skull.

The temporal bone is divided into several parts, including the squamous part, the petrous part, the tympanic part, and the styloid process. The squamous part forms the lateral portion of the temporal bone and articulates with the parietal bone. The petrous part is the most medial and superior portion of the temporal bone and contains the inner ear and the semicircular canals. The tympanic part forms the lower and anterior portions of the temporal bone and includes the external auditory meatus or ear canal. The styloid process is a long, slender projection that extends downward from the inferior aspect of the temporal bone and serves as an attachment site for various muscles and ligaments.

The temporal bone plays a crucial role in hearing and balance, as it contains the structures of the middle and inner ear, including the oval window, round window, cochlea, vestibule, and semicircular canals. The stapes bone, one of the three bones in the middle ear, is entirely encased within the petrous portion of the temporal bone. Additionally, the temporal bone contains important structures for facial expression and sensation, including the facial nerve, which exits the skull through the stylomastoid foramen, a small opening in the temporal bone.

Skull base neoplasms refer to abnormal growths or tumors located in the skull base, which is the region where the skull meets the spine and where the brain connects with the blood vessels and nerves that supply the head and neck. These neoplasms can be benign (non-cancerous) or malignant (cancerous), and they can arise from various types of cells in this area, including bone, nerve, glandular, and vascular tissue.

Skull base neoplasms can cause a range of symptoms depending on their size, location, and growth rate. Some common symptoms include headaches, vision changes, hearing loss, facial numbness or weakness, difficulty swallowing, and balance problems. Treatment options for skull base neoplasms may include surgery, radiation therapy, chemotherapy, or a combination of these approaches. The specific treatment plan will depend on the type, size, location, and stage of the tumor, as well as the patient's overall health and medical history.

Facial nerve diseases refer to a group of medical conditions that affect the function of the facial nerve, also known as the seventh cranial nerve. This nerve is responsible for controlling the muscles of facial expression, and it also carries sensory information from the taste buds in the front two-thirds of the tongue, and regulates saliva flow and tear production.

Facial nerve diseases can cause a variety of symptoms, depending on the specific location and extent of the nerve damage. Common symptoms include:

* Facial weakness or paralysis on one or both sides of the face
* Drooping of the eyelid and corner of the mouth
* Difficulty closing the eye or keeping it closed
* Changes in taste sensation or dryness of the mouth and eyes
* Abnormal sensitivity to sound (hyperacusis)
* Twitching or spasms of the facial muscles

Facial nerve diseases can be caused by a variety of factors, including:

* Infections such as Bell's palsy, Ramsay Hunt syndrome, and Lyme disease
* Trauma or injury to the face or skull
* Tumors that compress or invade the facial nerve
* Neurological conditions such as multiple sclerosis or Guillain-Barre syndrome
* Genetic disorders such as Moebius syndrome or hemifacial microsomia

Treatment for facial nerve diseases depends on the underlying cause and severity of the symptoms. In some cases, medication, physical therapy, or surgery may be necessary to restore function and relieve symptoms.

Dura Mater is the thickest and outermost of the three membranes (meninges) that cover the brain and spinal cord. It provides protection and support to these delicate structures. The other two layers are called the Arachnoid Mater and the Pia Mater, which are thinner and more delicate than the Dura Mater. Together, these three layers form a protective barrier around the central nervous system.

The cerebellopontine angle (CPA) is a narrow space located at the junction of the brainstem and the cerebellum, where the pons and cerebellum meet. This region is filled with several important nerves, blood vessels, and membranous coverings called meninges. The CPA is a common site for various neurological disorders because it contains critical structures such as:

1. Cerebellum: A part of the brain responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
2. Pons: A portion of the brainstem that plays a role in several vital functions, including facial movements, taste sensation, sleep regulation, and respiration.
3. Cranial nerves: The CPA is home to the following cranial nerves:
* Vestibulocochlear nerve (CN VIII): This nerve has two components - cochlear and vestibular. The cochlear part is responsible for hearing, while the vestibular part contributes to balance and eye movement.
* Facial nerve (CN VII): This nerve controls facial expressions, taste sensation in the anterior two-thirds of the tongue, salivary gland function, and lacrimation (tear production).
4. Blood vessels: The CPA contains critical blood vessels like the anterior inferior cerebellar artery (AICA), which supplies blood to various parts of the brainstem, cerebellum, and cranial nerves.
5. Meninges: These are protective membranes surrounding the brain and spinal cord. In the CPA, the meninges include the dura mater, arachnoid mater, and pia mater.

Disorders that can affect the structures in the cerebellopontine angle include acoustic neuromas (vestibular schwannomas), meningiomas, epidermoids, and arteriovenous malformations. These conditions may cause symptoms such as hearing loss, tinnitus (ringing in the ears), vertigo (dizziness), facial weakness or numbness, difficulty swallowing, and imbalance.

Arnold-Chiari malformation is a structural abnormality of the brain and skull base, specifically the cerebellum and brainstem. It is characterized by the descent of the cerebellar tonsils and sometimes parts of the brainstem through the foramen magnum (the opening at the base of the skull) into the upper spinal canal. This can cause pressure on the brainstem and cerebellum, potentially leading to a range of symptoms such as headaches, neck pain, unsteady gait, swallowing difficulties, hearing or balance problems, and in severe cases, neurological deficits. There are four types of Arnold-Chiari malformations, with type I being the most common and least severe form. Types II, III, and IV are progressively more severe and involve varying degrees of hindbrain herniation and associated neural tissue damage. Surgical intervention is often required to alleviate symptoms and prevent further neurological deterioration.

Central nervous system (CNS) vascular malformations are abnormal tangles or masses of blood vessels in the brain or spinal cord. These malformations can be congenital (present at birth) or acquired (develop later in life). They can vary in size, location, and symptoms, which may include headaches, seizures, weakness, numbness, difficulty speaking or understanding speech, and vision problems.

There are several types of CNS vascular malformations, including:

1. Arteriovenous malformations (AVMs): These are tangles of arteries and veins with a direct connection between them, bypassing the capillary network. AVMs can cause bleeding in the brain or spinal cord, leading to stroke or neurological deficits.
2. Cavernous malformations: These are clusters of dilated, thin-walled blood vessels that form a sac-like structure. They can rupture and bleed, causing symptoms such as seizures, headaches, or neurological deficits.
3. Developmental venous anomalies (DVAs): These are benign vascular malformations characterized by an abnormal pattern of veins that drain blood from the brain. DVAs are usually asymptomatic but can be associated with other vascular malformations.
4. Capillary telangiectasias: These are small clusters of dilated capillaries in the brain or spinal cord. They are usually asymptomatic and found incidentally during imaging studies.
5. Moyamoya disease: This is a rare, progressive cerebrovascular disorder characterized by the narrowing or blockage of the internal carotid arteries and their branches. This can lead to decreased blood flow to the brain, causing symptoms such as headaches, seizures, and strokes.

The diagnosis of CNS vascular malformations typically involves imaging studies such as MRI or CT scans, and sometimes angiography. Treatment options may include observation, medication, surgery, or endovascular procedures, depending on the type, location, and severity of the malformation.

The ethmoid bone is a paired, thin, and lightweight bone that forms part of the skull's anterior cranial fossa and contributes to the formation of the orbit and nasal cavity. It is located between the frontal bone above and the maxilla and palatine bones below. The ethmoid bone has several important features:

1. Cribriform plate: This is the horizontal, sieve-like portion that forms part of the anterior cranial fossa and serves as the roof of the nasal cavity. It contains small openings (foramina) through which olfactory nerves pass.
2. Perpendicular plate: The perpendicular plate is a vertical structure that projects downward from the cribriform plate, forming part of the nasal septum and separating the left and right nasal cavities.
3. Superior and middle nasal conchae: These are curved bony projections within the lateral walls of the nasal cavity that help to warm, humidify, and filter incoming air.
4. Lacrimal bone: The ethmoid bone articulates with the lacrimal bone, forming part of the medial wall of the orbit.
5. Frontal process: This is a thin, vertical plate that articulates with the frontal bone above the orbit.
6. Sphenoidal process: The sphenoidal process connects the ethmoid bone to the sphenoid bone posteriorly.

The ethmoid bone plays a crucial role in protecting the brain and providing structural support for the eyes, as well as facilitating respiration by warming, humidifying, and filtering incoming air.

Ear diseases are medical conditions that affect the ear and its various components, including the outer ear, middle ear, and inner ear. These diseases can cause a range of symptoms, such as hearing loss, tinnitus (ringing in the ears), vertigo (dizziness), ear pain, and discharge. Some common ear diseases include:

1. Otitis externa (swimmer's ear) - an infection or inflammation of the outer ear and ear canal.
2. Otitis media - an infection or inflammation of the middle ear, often caused by a cold or flu.
3. Cholesteatoma - a skin growth that develops in the middle ear behind the eardrum.
4. Meniere's disease - a disorder of the inner ear that can cause vertigo, hearing loss, and tinnitus.
5. Temporomandibular joint (TMJ) disorders - problems with the joint that connects the jawbone to the skull, which can cause ear pain and other symptoms.
6. Acoustic neuroma - a noncancerous tumor that grows on the nerve that connects the inner ear to the brain.
7. Presbycusis - age-related hearing loss.

Treatment for ear diseases varies depending on the specific condition and its severity. It may include medication, surgery, or other therapies. If you are experiencing symptoms of an ear disease, it is important to seek medical attention from a healthcare professional, such as an otolaryngologist (ear, nose, and throat specialist).

Osteoma is a benign (noncancerous) tumor that is made up of mature bone tissue. It usually grows slowly over a period of years and is most commonly found in the skull or jaw, although it can occur in other bones of the body as well. Osteomas are typically small, but they can grow to be several centimeters in size. They may cause symptoms if they press on nearby tissues or structures, such as nerves or blood vessels. In some cases, osteomas may not cause any symptoms and may only be discovered during routine imaging studies. Treatment for osteoma is typically not necessary unless it is causing problems or growing rapidly. If treatment is needed, it may involve surgical removal of the tumor.

The ethmoid sinuses are a pair of air-filled spaces located in the ethmoid bone, which is a part of the skull that forms the upper portion of the nasal cavity and the inner eye socket. These sinuses are divided into anterior and posterior groups and are present in adults, but not at birth. They continue to grow and develop until early adulthood.

The ethmoid sinuses are lined with mucous membrane, which helps to warm, humidify, and filter the air we breathe. They are surrounded by a network of blood vessels and nerves, making them susceptible to inflammation and infection. Inflammation of the ethmoid sinuses can lead to conditions such as sinusitis, which can cause symptoms such as nasal congestion, headache, and facial pain.

Infratentorial neoplasms refer to tumors that originate in the region of the brain called the posterior fossa, which is located below the tentorium cerebelli (a membranous structure that separates the cerebrum from the cerebellum). This area contains several important structures such as the cerebellum, pons, medulla oblongata, and fourth ventricle. Infratentorial neoplasms can be benign or malignant and can arise from various cell types including nerve cells, glial cells, or supportive tissues. They can cause a variety of symptoms depending on their location and size, such as headache, vomiting, unsteady gait, weakness, numbness, vision changes, hearing loss, and difficulty swallowing or speaking. Treatment options may include surgery, radiation therapy, and chemotherapy.

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.

The sphenoid bone is a complex, irregularly shaped bone located in the middle cranial fossa and forms part of the base of the skull. It articulates with several other bones, including the frontal, parietal, temporal, ethmoid, palatine, and zygomatic bones. The sphenoid bone has two main parts: the body and the wings.

The body of the sphenoid bone is roughly cuboid in shape and contains several important structures, such as the sella turcica, which houses the pituitary gland, and the sphenoid sinuses, which are air-filled cavities within the bone. The greater wings of the sphenoid bone extend laterally from the body and form part of the skull's lateral walls. They contain the superior orbital fissure, through which important nerves and blood vessels pass between the cranial cavity and the orbit of the eye.

The lesser wings of the sphenoid bone are thin, blade-like structures that extend anteriorly from the body and form part of the floor of the anterior cranial fossa. They contain the optic canal, which transmits the optic nerve and ophthalmic artery between the brain and the orbit of the eye.

Overall, the sphenoid bone plays a crucial role in protecting several important structures within the skull, including the pituitary gland, optic nerves, and ophthalmic arteries.

The petrous bone is a part of the temporal bone, one of the 22 bones in the human skull. It is a thick and irregularly shaped bone located at the base of the skull and forms part of the ear and the cranial cavity. The petrous bone contains the cochlea, vestibule, and semicircular canals of the inner ear, which are responsible for hearing and balance. It also helps protect the brain from injury by forming part of the bony structure surrounding the brain.

The term "petrous" comes from the Latin word "petrosus," meaning "stony" or "rock-like," which describes the hard and dense nature of this bone. The petrous bone is one of the densest bones in the human body, making it highly resistant to fractures and other forms of damage.

In medical terminology, the term "petrous" may also be used to describe any structure that resembles a rock or is hard and dense, such as the petrous apex, which refers to the portion of the petrous bone that points towards the sphenoid bone.

The mastoid is a term used in anatomy and refers to the bony prominence located at the base of the skull, posterior to the ear. More specifically, it's part of the temporal bone, one of the bones that forms the side and base of the skull. The mastoid process provides attachment for various muscles involved in chewing and moving the head.

In a medical context, "mastoid" can also refer to conditions or procedures related to this area. For example, mastoiditis is an infection of the mastoid process, while a mastoidectomy is a surgical procedure that involves removing part or all of the mastoid process.

A mucocele is a mucus-containing cystic lesion that results from the accumulation of mucin within a damaged minor salivary gland duct or mucous gland. It is typically caused by trauma, injury, or blockage of the duct. Mucocele appears as a round, dome-shaped, fluid-filled swelling, which may be bluish or clear in color. They are most commonly found on the lower lip but can also occur on other areas of the oral cavity. Mucocele is generally painless unless it becomes secondarily infected; however, it can cause discomfort during speaking, chewing, or swallowing, and may affect aesthetics. Treatment usually involves surgical excision of the mucocele to prevent recurrence.

A neurilemmoma, also known as schwannoma or peripheral nerve sheath tumor, is a benign, slow-growing tumor that arises from the Schwann cells, which produce the myelin sheath that surrounds and insulates peripheral nerves. These tumors can occur anywhere along the course of a peripheral nerve, but they most commonly affect the acoustic nerve (vestibulocochlear nerve), leading to a type of tumor called vestibular schwannoma or acoustic neuroma. Neurilemmomas are typically encapsulated and do not invade the surrounding tissue, although larger ones may cause pressure-related symptoms due to compression of nearby structures. Rarely, these tumors can undergo malignant transformation, leading to a condition called malignant peripheral nerve sheath tumor or neurofibrosarcoma.

The zygoma is the scientific name for the cheekbone. It is a part of the facial skeleton that forms the prominence of the cheek and houses the maxillary sinus, one of the pairs of paranasal sinuses. The zygomatic bone, also known as the malar bone, contributes to the formation of the zygoma.

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.

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.

Cerebral veins are the blood vessels that carry deoxygenated blood from the brain to the dural venous sinuses, which are located between the layers of tissue covering the brain. The largest cerebral vein is the superior sagittal sinus, which runs along the top of the brain. Other major cerebral veins include the straight sinus, transverse sinus, sigmoid sinus, and cavernous sinus. These veins receive blood from smaller veins called venules that drain the surface and deep structures of the brain. The cerebral veins play an important role in maintaining normal circulation and pressure within the brain.

The occipital bone is the single, posterior cranial bone that forms the base of the skull and encloses the brain. It articulates with the parietal bones anteriorly and the temporal bones laterally. The occipital bone also contains several important structures such as the foramen magnum, through which the spinal cord connects to the brain, and the external and internal occipital protuberances, which serve as attachment points for neck muscles.

Synovial chondromatosis is a rare condition that affects the synovial membrane, which is the lining of joints, bursae (fluid-filled sacs that cushion bones), and tendon sheaths. In this condition, nodules made up of cartilage form in the synovial membrane. These nodules can detach from the synovial membrane and float freely in the synovial fluid, which lubricates the joint. If they become numerous, they can cause joint pain, stiffness, and decreased range of motion. In some cases, the loose bodies may also cause locking or catching sensations in the joint. Surgery is typically required to remove the cartilaginous nodules and relieve symptoms. If left untreated, synovial chondromatosis can lead to osteoarthritis and other joint problems.

A subdural hematoma is a type of intracranial hemorrhage, which means it involves bleeding within the skull. More specifically, a subdural hematoma occurs between the dura mater (the outermost layer of the meninges that covers the brain) and the brain itself. This condition is usually caused by trauma or injury to the head, which results in the rupture of blood vessels in the brain. The bleeding then forms a collection of blood in the subdural space, which can compress the brain and lead to various neurological symptoms.

Subdural hematomas can be acute, subacute, or chronic, depending on the time course of symptom onset and the rate of blood accumulation. Acute subdural hematomas typically result from severe head trauma and require immediate medical attention due to their rapid progression and potential for causing significant brain damage or even death. Chronic subdural hematomas, on the other hand, may develop more slowly over time and can sometimes be asymptomatic, although they still have the potential to cause long-term neurological problems if left untreated.

Treatment options for subdural hematomas depend on various factors, including the patient's age, overall health status, the severity of symptoms, and the size and location of the hematoma. In some cases, conservative management with close monitoring may be appropriate, while in other situations, surgical intervention may be necessary to alleviate pressure on the brain and prevent further damage.

A subdural effusion is an abnormal accumulation of fluid in the potential space between the dura mater (the outermost layer of the meninges that covers the brain and spinal cord) and the arachnoid membrane (one of the three layers of the meninges that surround the brain and spinal cord) in the subdural space.

Subdural effusions can occur due to various reasons, including head trauma, infection, or complications from neurosurgical procedures. The fluid accumulation may result from bleeding (subdural hematoma), inflammation, or increased cerebrospinal fluid pressure. Depending on the underlying cause and the amount of fluid accumulated, subdural effusions can cause various symptoms, such as headaches, altered mental status, or neurological deficits.

Subdural effusions are often asymptomatic and may resolve independently; however, in some cases, medical intervention might be necessary to alleviate the pressure on the brain or address the underlying condition. Imaging techniques like computed tomography (CT) or magnetic resonance imaging (MRI) scans are typically used to diagnose and monitor subdural effusions.

The arachnoid is one of the three membranes that cover the brain and the spinal cord, known as the meninges. It is located between the dura mater (the outermost layer) and the pia mater (the innermost layer). The arachnoid is a thin, delicate membrane that is filled with cerebrospinal fluid, which provides protection and nutrition to the central nervous system.

The arachnoid has a spider-web like appearance, hence its name, and it is composed of several layers of collagen fibers and elastic tissue. It is highly vascularized, meaning that it contains many blood vessels, and it plays an important role in regulating the flow of cerebrospinal fluid around the brain and spinal cord.

In some cases, the arachnoid can become inflamed or irritated, leading to a condition called arachnoiditis. This can cause a range of symptoms, including pain, muscle weakness, and sensory changes, and it may require medical treatment to manage.

A frontal sinus is a paired, air-filled paranasal sinus located in the frontal bone of the skull, above the eyes and behind the forehead. It is one of the four pairs of sinuses found in the human head. The frontal sinuses are lined with mucous membrane and are interconnected with the nasal cavity through small openings called ostia. They help to warm, humidify, and filter the air we breathe, and contribute to the resonance of our voice. Variations in size, shape, and asymmetry of frontal sinuses are common among individuals.

Skull neoplasms refer to abnormal growths or tumors that develop within the skull. These growths can be benign (non-cancerous) or malignant (cancerous). They can originate from various types of cells, such as bone cells, nerve cells, or soft tissues. Skull neoplasms can cause various symptoms depending on their size and location, including headaches, seizures, vision problems, hearing loss, and neurological deficits. Treatment options include surgery, radiation therapy, and chemotherapy. It is important to note that a neoplasm in the skull can also refer to metastatic cancer, which has spread from another part of the body to the skull.

Meningeal neoplasms, also known as malignant meningitis or leptomeningeal carcinomatosis, refer to cancerous tumors that originate in the meninges, which are the membranes covering the brain and spinal cord. These tumors can arise primarily from the meningeal cells themselves, although they more commonly result from the spread (metastasis) of cancer cells from other parts of the body, such as breast, lung, or melanoma.

Meningeal neoplasms can cause a variety of symptoms, including headaches, nausea and vomiting, mental status changes, seizures, and focal neurological deficits. Diagnosis typically involves imaging studies (such as MRI) and analysis of cerebrospinal fluid obtained through a spinal tap. Treatment options may include radiation therapy, chemotherapy, or surgery, depending on the type and extent of the tumor. The prognosis for patients with meningeal neoplasms is generally poor, with a median survival time of several months to a year.

Facial paralysis is a loss of facial movement due to damage or dysfunction of the facial nerve (cranial nerve VII). This nerve controls the muscles involved in facial expressions, such as smiling, frowning, and closing the eyes. Damage to one side of the facial nerve can cause weakness or paralysis on that side of the face.

Facial paralysis can result from various conditions, including:

1. Bell's palsy - an idiopathic (unknown cause) inflammation of the facial nerve
2. Trauma - skull fractures, facial injuries, or surgical trauma to the facial nerve
3. Infections - Lyme disease, herpes zoster (shingles), HIV/AIDS, or bacterial infections like meningitis
4. Tumors - benign or malignant growths that compress or invade the facial nerve
5. Stroke - damage to the brainstem where the facial nerve originates
6. Congenital conditions - some people are born with facial paralysis due to genetic factors or birth trauma

Symptoms of facial paralysis may include:

* Inability to move one or more parts of the face, such as the eyebrows, eyelids, mouth, or cheeks
* Drooping of the affected side of the face
* Difficulty closing the eye on the affected side
* Changes in saliva and tear production
* Altered sense of taste
* Pain around the ear or jaw
* Speech difficulties due to weakened facial muscles

Treatment for facial paralysis depends on the underlying cause. In some cases, such as Bell's palsy, spontaneous recovery may occur within a few weeks to months. However, physical therapy, medications, and surgical interventions might be necessary in other situations to improve function and minimize complications.

Paranasal sinus neoplasms refer to abnormal growths or tumors that develop within the paranasal sinuses, which are air-filled cavities located inside the skull near the nasal cavity. These tumors can be benign (noncancerous) or malignant (cancerous), and they can arise from various types of tissue within the sinuses, such as the lining of the sinuses (mucosa), bone, or other soft tissues.

Paranasal sinus neoplasms can cause a variety of symptoms, including nasal congestion, nosebleeds, facial pain or numbness, and visual disturbances. The diagnosis of these tumors typically involves a combination of imaging studies (such as CT or MRI scans) and biopsy to determine the type and extent of the tumor. Treatment options may include surgery, radiation therapy, chemotherapy, or a combination of these approaches, depending on the specific type and stage of the neoplasm.

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.

Neurosurgical procedures are operations that are performed on the brain, spinal cord, and peripheral nerves. These procedures are typically carried out by neurosurgeons, who are medical doctors with specialized training in the diagnosis and treatment of disorders of the nervous system. Neurosurgical procedures can be used to treat a wide range of conditions, including traumatic injuries, tumors, aneurysms, vascular malformations, infections, degenerative diseases, and congenital abnormalities.

Some common types of neurosurgical procedures include:

* Craniotomy: A procedure in which a bone flap is temporarily removed from the skull to gain access to the brain. This type of procedure may be performed to remove a tumor, repair a blood vessel, or relieve pressure on the brain.
* Spinal fusion: A procedure in which two or more vertebrae in the spine are fused together using bone grafts and metal hardware. This is often done to stabilize the spine and alleviate pain caused by degenerative conditions or spinal deformities.
* Microvascular decompression: A procedure in which a blood vessel that is causing pressure on a nerve is repositioned or removed. This type of procedure is often used to treat trigeminal neuralgia, a condition that causes severe facial pain.
* Deep brain stimulation: A procedure in which electrodes are implanted in specific areas of the brain and connected to a battery-operated device called a neurostimulator. The neurostimulator sends electrical impulses to the brain to help alleviate symptoms of movement disorders such as Parkinson's disease or dystonia.
* Stereotactic radiosurgery: A non-invasive procedure that uses focused beams of radiation to treat tumors, vascular malformations, and other abnormalities in the brain or spine. This type of procedure is often used for patients who are not good candidates for traditional surgery due to age, health status, or location of the lesion.

Neurosurgical procedures can be complex and require a high degree of skill and expertise. Patients considering neurosurgical treatment should consult with a qualified neurosurgeon to discuss their options and determine the best course of action for their individual situation.

The sphenoid sinuses are air-filled spaces located within the sphenoid bone, which is one of the bones that make up the skull base. These sinuses are located deep inside the skull, behind the eyes and nasal cavity. They are paired and separated by a thin bony septum, and each one opens into the corresponding nasal cavity through a small opening called the sphenoethmoidal recess. The sphenoid sinuses vary greatly in size and shape between individuals. They develop during childhood and continue to grow until early adulthood. The function of the sphenoid sinuses, like other paranasal sinuses, is not entirely clear, but they may contribute to reducing the weight of the skull, resonating voice during speech, and insulating the brain from trauma.

The pterygopalatine fossa is a small, irregularly shaped space located in the skull, lateral to the nasal cavity and inferior to the orbit. It serves as a critical communications center for several important nerves, arteries, and veins that provide sensory innervation, vasomotor control, and blood supply to various structures in the head and neck region.

The following are some key components of the pterygopalatine fossa:

1. Nerves: The pterygopalatine ganglion is a major component of this fossa, which contains postganglionic parasympathetic fibers, sympathetic fibers, and sensory fibers from various nerves, including the maxillary nerve (V2), greater petrosal nerve, deep petrosal nerve, and nerve of the pterygoid canal.

2. Arteries: The maxillary artery, a branch of the external carotid artery, enters the fossa through the foramen rotundum and divides into several branches that supply various structures in the head and neck region, such as the sphenopalatine artery, posterior superior alveolar artery, infraorbital artery, and greater palatine artery.

3. Veins: The pterygoid venous plexus is a complex network of veins located in and around the fossa that communicates with various venous systems, including the facial vein, cavernous sinus, and inferior ophthalmic vein.

The pterygopalatine fossa plays an essential role in several physiological functions, such as lacrimation, salivation, and vasodilation of blood vessels in the nasal cavity and paranasal sinuses. Additionally, it is a potential site for the spread of infection or neoplasm from the oral cavity, nasal cavity, or paranasal sinuses to other regions of the head and neck.

An arteriovenous fistula is an abnormal connection or passageway between an artery and a vein. This connection causes blood to flow directly from the artery into the vein, bypassing the capillary network that would normally distribute the oxygen-rich blood to the surrounding tissues.

Arteriovenous fistulas can occur as a result of trauma, disease, or as a planned surgical procedure for patients who require hemodialysis, a treatment for advanced kidney failure. In hemodialysis, the arteriovenous fistula serves as a site for repeated access to the bloodstream, allowing for efficient removal of waste products and excess fluids.

The medical definition of an arteriovenous fistula is:

"An abnormal communication between an artery and a vein, usually created by surgical means for hemodialysis access or occurring as a result of trauma, congenital defects, or disease processes such as vasculitis or neoplasm."

The skull is the bony structure that encloses and protects the brain, the eyes, and the ears. It is composed of two main parts: the cranium, which contains the brain, and the facial bones. The cranium is made up of several fused flat bones, while the facial bones include the upper jaw (maxilla), lower jaw (mandible), cheekbones, nose bones, and eye sockets (orbits).

The skull also provides attachment points for various muscles that control chewing, moving the head, and facial expressions. Additionally, it contains openings for blood vessels, nerves, and the spinal cord to pass through. The skull's primary function is to protect the delicate and vital structures within it from injury and trauma.

Orbital diseases refer to a group of medical conditions that affect the orbit, which is the bony cavity in the skull that contains the eye, muscles, nerves, fat, and blood vessels. These diseases can cause various symptoms such as eyelid swelling, protrusion or displacement of the eyeball, double vision, pain, and limited extraocular muscle movement.

Orbital diseases can be broadly classified into inflammatory, infectious, neoplastic (benign or malignant), vascular, traumatic, and congenital categories. Some examples of orbital diseases include:

* Orbital cellulitis: a bacterial or fungal infection that causes swelling and inflammation in the orbit
* Graves' disease: an autoimmune disorder that affects the thyroid gland and can cause protrusion of the eyeballs (exophthalmos)
* Orbital tumors: benign or malignant growths that develop in the orbit, such as optic nerve gliomas, lacrimal gland tumors, and lymphomas
* Carotid-cavernous fistulas: abnormal connections between the carotid artery and cavernous sinus, leading to pulsatile proptosis and other symptoms
* Orbital fractures: breaks in the bones surrounding the orbit, often caused by trauma
* Congenital anomalies: structural abnormalities present at birth, such as craniofacial syndromes or dermoid cysts.

Proper diagnosis and management of orbital diseases require a multidisciplinary approach involving ophthalmologists, neurologists, radiologists, and other specialists.

The middle ear is the middle of the three parts of the ear, located between the outer ear and inner ear. It contains three small bones called ossicles (the malleus, incus, and stapes) that transmit and amplify sound vibrations from the eardrum to the inner ear. The middle ear also contains the Eustachian tube, which helps regulate air pressure in the middle ear and protects against infection by allowing fluid to drain from the middle ear into the back of the throat.

The cavernous sinus is a venous structure located in the middle cranial fossa, which is a depression in the skull that houses several important nerves and blood vessels. The cavernous sinus is situated on either side of the sphenoid bone, near the base of the skull, and it contains several important structures:

* The internal carotid artery, which supplies oxygenated blood to the brain
* The abducens nerve (cranial nerve VI), which controls lateral movement of the eye
* The oculomotor nerve (cranial nerve III), which controls most of the muscles that move the eye
* The trochlear nerve (cranial nerve IV), which controls one of the muscles that moves the eye
* The ophthalmic and maxillary divisions of the trigeminal nerve (cranial nerve V), which transmit sensory information from the face and head

The cavernous sinus is an important structure because it serves as a conduit for several critical nerves and blood vessels. However, it is also vulnerable to various pathological conditions such as thrombosis (blood clots), infection, tumors, or aneurysms, which can lead to serious neurological deficits or even death.

Orbital neoplasms refer to abnormal growths or tumors that develop in the orbit, which is the bony cavity that contains the eyeball, muscles, nerves, fat, and blood vessels. These neoplasms can be benign (non-cancerous) or malignant (cancerous), and they can arise from various types of cells within the orbit.

Orbital neoplasms can cause a variety of symptoms depending on their size, location, and rate of growth. Common symptoms include protrusion or displacement of the eyeball, double vision, limited eye movement, pain, swelling, and numbness in the face. In some cases, orbital neoplasms may not cause any noticeable symptoms, especially if they are small and slow-growing.

There are many different types of orbital neoplasms, including:

1. Optic nerve glioma: a rare tumor that arises from the optic nerve's supportive tissue.
2. Orbital meningioma: a tumor that originates from the membranes covering the brain and extends into the orbit.
3. Lacrimal gland tumors: benign or malignant growths that develop in the lacrimal gland, which produces tears.
4. Orbital lymphangioma: a non-cancerous tumor that arises from the lymphatic vessels in the orbit.
5. Rhabdomyosarcoma: a malignant tumor that develops from the skeletal muscle cells in the orbit.
6. Metastatic tumors: cancerous growths that spread to the orbit from other parts of the body, such as the breast, lung, or prostate.

The diagnosis and treatment of orbital neoplasms depend on several factors, including the type, size, location, and extent of the tumor. Imaging tests, such as CT scans and MRI, are often used to visualize the tumor and determine its extent. A biopsy may also be performed to confirm the diagnosis and determine the tumor's type and grade. Treatment options include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

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.

Three-dimensional (3D) imaging in medicine refers to the use of technologies and techniques that generate a 3D representation of internal body structures, organs, or tissues. This is achieved by acquiring and processing data from various imaging modalities such as X-ray computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, or confocal microscopy. The resulting 3D images offer a more detailed visualization of the anatomy and pathology compared to traditional 2D imaging techniques, allowing for improved diagnostic accuracy, surgical planning, and minimally invasive interventions.

In 3D imaging, specialized software is used to reconstruct the acquired data into a volumetric model, which can be manipulated and viewed from different angles and perspectives. This enables healthcare professionals to better understand complex anatomical relationships, detect abnormalities, assess disease progression, and monitor treatment response. Common applications of 3D imaging include neuroimaging, orthopedic surgery planning, cancer staging, dental and maxillofacial reconstruction, and interventional radiology procedures.

Dandy-Walker Syndrome is a congenital brain malformation characterized by the absence or underdevelopment of the cerebellar vermis (the part of the brain that helps coordinate movement) and an enlarged fluid-filled space (fourth ventricle) surrounding it. This condition can also be associated with an upward bulging of the back of the skull (occipital bone), and in some cases, hydrocephalus (excessive accumulation of cerebrospinal fluid in the brain). The syndrome can vary in severity, and symptoms may include problems with balance, coordination, developmental delays, and increased intracranial pressure. It is usually diagnosed through imaging tests such as ultrasound, CT scan, or MRI. Treatment typically involves managing symptoms and addressing complications, which may include surgical procedures to relieve hydrocephalus if present.

The Posterior Cerebral Artery (PCA) is one of the major arteries that supplies blood to the brain. It is a branch of the basilar artery, which is formed by the union of the two vertebral arteries. The PCA supplies oxygenated blood to the occipital lobe (responsible for visual processing), the temporal lobe (involved in auditory and memory functions), and the thalamus and midbrain (relay station for sensory and motor signals).

The PCA has two segments: the precommunicating segment (P1) and the postcommunicating segment (P2). The P1 segment runs posteriorly along the cerebral peduncle, while the P2 segment courses around the midbrain to reach the occipital lobe.

Atherosclerosis, embolism, or other vascular conditions can affect the PCA and lead to a variety of neurological symptoms, including visual loss, memory impairment, and difficulty with language processing.

The Posterior Cruciate Ligament (PCL) is one of the major ligaments in the knee, providing stability to the joint. It is a strong band of tissue located in the back of the knee, connecting the thighbone (femur) to the shinbone (tibia). The PCL limits the backward motion of the tibia relative to the femur and provides resistance to forces that tend to push the tibia backwards. It also assists in maintaining the overall alignment and function of the knee joint during various movements and activities. Injuries to the PCL are less common compared to injuries to the Anterior Cruciate Ligament (ACL) but can still occur due to high-energy trauma, such as motor vehicle accidents or sports incidents involving direct impact to the front of the knee.

Cerebellar neoplasms refer to abnormal growths or tumors that develop in the cerebellum, which is the part of the brain responsible for coordinating muscle movements and maintaining balance. These tumors can be benign (non-cancerous) or malignant (cancerous), and they can arise from various types of cells within the cerebellum.

The most common type of cerebellar neoplasm is a medulloblastoma, which arises from primitive nerve cells in the cerebellum. Other types of cerebellar neoplasms include astrocytomas, ependymomas, and brain stem gliomas. Symptoms of cerebellar neoplasms may include headaches, vomiting, unsteady gait, coordination problems, and visual disturbances. Treatment options depend on the type, size, and location of the tumor, as well as the patient's overall health and age. Treatment may involve surgery, radiation therapy, chemotherapy, or a combination of these approaches.

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.

Posterior uveitis is a type of uveitis that specifically affects the back portion of the uvea, which includes the choroid (a layer of blood vessels that provides nutrients to the outer layers of the retina), the retina (the light-sensitive tissue at the back of the eye), and the optic nerve (which carries visual information from the eye to the brain).

Posterior uveitis can cause symptoms such as blurred vision, floaters, sensitivity to light, and decreased vision. It may also lead to complications such as retinal scarring, cataracts, glaucoma, and retinal detachment if left untreated. The condition can be caused by a variety of factors, including infections, autoimmune diseases, and trauma. Treatment typically involves the use of corticosteroids or other immunosuppressive medications to reduce inflammation and prevent complications.

Cerebellar diseases refer to a group of medical conditions that affect the cerebellum, which is the part of the brain located at the back of the head, below the occipital lobe and above the brainstem. The cerebellum plays a crucial role in motor control, coordination, balance, and some cognitive functions.

Cerebellar diseases can be caused by various factors, including genetics, infections, tumors, stroke, trauma, or degenerative processes. These conditions can result in a wide range of symptoms, such as:

1. Ataxia: Loss of coordination and unsteady gait
2. Dysmetria: Inability to judge distance and force while performing movements
3. Intention tremors: Shaking or trembling that worsens during purposeful movements
4. Nystagmus: Rapid, involuntary eye movement
5. Dysarthria: Speech difficulty due to muscle weakness or incoordination
6. Hypotonia: Decreased muscle tone
7. Titubation: Rhythmic, involuntary oscillations of the head and neck
8. Cognitive impairment: Problems with memory, attention, and executive functions

Some examples of cerebellar diseases include:

1. Ataxia-telangiectasia
2. Friedrich's ataxia
3. Multiple system atrophy (MSA)
4. Spinocerebellar ataxias (SCAs)
5. Cerebellar tumors, such as medulloblastomas or astrocytomas
6. Infarctions or hemorrhages in the cerebellum due to stroke or trauma
7. Infections, such as viral encephalitis or bacterial meningitis
8. Autoimmune disorders, like multiple sclerosis (MS) or paraneoplastic syndromes
9. Metabolic disorders, such as Wilson's disease or phenylketonuria (PKU)
10. Chronic alcoholism and withdrawal

Treatment for cerebellar diseases depends on the underlying cause and may involve medications, physical therapy, surgery, or supportive care to manage symptoms and improve quality of life.

The posterior hypothalamus is a region in the brain that plays a crucial role in various autonomic functions. It is located in the posterior part of the hypothalamus, which is a small region at the base of the brain that helps regulate many bodily functions, including body temperature, hunger, thirst, fatigue, sleep, and circadian rhythms.

The posterior hypothalamus contains several groups of neurons that are involved in the regulation of autonomic responses, such as the control of heart rate, blood pressure, and body temperature. It also plays a role in the regulation of hormones released from the pituitary gland, which is located below the hypothalamus.

One important function of the posterior hypothalamus is to help regulate body temperature. When the body's temperature rises, neurons in the posterior hypothalamus detect this change and send signals to other parts of the brain to initiate responses that help cool the body down, such as sweating and dilation of blood vessels near the skin surface. Conversely, when the body's temperature drops, the posterior hypothalamus helps to generate heat by stimulating muscle contractions and constricting blood vessels in the skin.

Overall, the posterior hypothalamus is an essential component of the brain's complex system for maintaining homeostasis and regulating various physiological functions.

The fourth ventricle is a part of the cerebrospinal fluid-filled system in the brain, located in the posterior cranial fossa and continuous with the central canal of the medulla oblongata and the cerebral aqueduct. It is shaped like a cavity with a roof, floor, and lateral walls, and it communicates rostrally with the third ventricle through the cerebral aqueduct and caudally with the subarachnoid space through the median and lateral apertures (foramina of Luschka and Magendie). The fourth ventricle contains choroid plexus tissue, which produces cerebrospinal fluid. Its roof is formed by the cerebellar vermis and the superior medullary velum, while its floor is composed of the rhomboid fossa, which includes several important structures such as the vagal trigone, hypoglossal trigone, and striae medullares.

Ossification of the Posterior Longitudinal Ligament (OPLL) is a medical condition where there is abnormal growth and hardening (ossification) of the posterior longitudinal ligament in the spine. The posterior longitudinal ligament runs down the length of the spine, along the back of the vertebral bodies, and helps to maintain the stability and alignment of the spinal column.

In OPLL, the ossification of this ligament can cause narrowing of the spinal canal (spinal stenosis) and compression of the spinal cord or nerve roots. This condition is more commonly found in the cervical spine (neck), but it can also occur in the thoracic (chest) and lumbar (lower back) regions of the spine.

The symptoms of OPLL may include neck pain, stiffness, numbness, tingling, or weakness in the arms and/or legs, depending on the location and severity of the compression. In severe cases, it can lead to serious neurological deficits such as paralysis. The exact cause of OPLL is not fully understood, but it is believed to be related to genetic factors, aging, and mechanical stress on the spine.

The mandibular condyle is a part of the temporomandibular joint (TMJ) in the human body. It is a rounded eminence at the end of the mandible (lower jawbone) that articulates with the glenoid fossa of the temporal bone in the skull, allowing for movements such as opening and closing the mouth, chewing, speaking, and swallowing. The mandibular condyle has both a fibrocartilaginous articular surface and a synovial joint capsule surrounding it, which provides protection and lubrication during these movements.

... at human fetus Base of skull Posterior cranial fossa Posterior cranial fossa A tumor of the posterior ... Demonstrationg how cerebellum sits in the posterior cranial fossa. Anterior cranial fossa Middle cranial fossa Rea, Paul (2016 ... Anteriorly, the posterior cranial fossa is bounded by the dorsum sellae, posterior aspect of the body of sphenoid bone, and the ... The posterior cranial fossa is the part of the cranial cavity located between the foramen magnum, and tentorium cerebelli. It ...
Arachnoiditis of posterior cranial fossa (blindness, deafness, hemiplegia). Her cure was recognised on 15 August 1956. Visited ...
The cerebellum is located in the posterior cranial fossa. The fourth ventricle, pons and medulla are in front of the cerebellum ... the posterior lobe (below the primary fissure), and the flocculonodular lobe (below the posterior fissure). These lobes divide ... The medial zone of the anterior and posterior lobes constitutes the spinocerebellum, also known as paleocerebellum. This sector ... Campbell J, Gilbert WM, Nicolaides KH, Campbell S (August 1987). "Ultrasound screening for spina bifida: cranial and cerebellar ...
About 60% will be in the posterior cranial fossa (particularly the cerebellum). One review estimated 52% in the posterior fossa ... Since many of the tumors occur in the posterior fossa, they present like other posterior fossa tumors, often with headache, ... are located in the posterior fossa or cerebellar area. The ASCO study showed 52% posterior fossa; 39% sPNET; 5% pineal; 2% ... Taylor MD, Gokgoz N, Andrulis IL, Mainprize TG, Drake JM, Rutka JT (April 2000). "Familial posterior fossa brain tumors of ...
It is the largest vessel supplying the dura of the posterior cranial fossa.[citation needed] It may occasionally arise from ... It passes through the jugular foramen to enter the posterior cranial fossa. ... The posterior meningeal artery is one of the meningeal branches of the ascending pharyngeal artery (and is typically considered ... ISBN 978-0-7020-7707-4. OCLC 1201341621.{{cite book}}: CS1 maint: location missing publisher (link) "posterior meningeal artery ...
... is a groove in the posterior cranial fossa. It starts at lateral parts of occipital bone, curves ... around jugular process, and ends at posterior inferior angle of parietal bone. After that, groove for sigmoid sinus continues ...
Anterior cranial fossa Posterior cranial fossa This article incorporates text in the public domain from page 190 of the 20th ... Animation Middle cranial fossa at human foetus Base of skull Middle cranial fossa Middle cranial fossa Middle cranial fossa ... It is separated from the posterior cranial fossa by the clivus and the petrous crest. It is bounded in front by the posterior ... The middle cranial fossa is formed by the sphenoid bones, and the temporal bones. It lodges the temporal lobes, and the ...
... the roof of orbits in the anterior cranial fossa, and the areas between the mastoid and dural sinuses in the posterior cranial ... The middle cranial fossa, a depression at the base of the cranial cavity forms the thinnest part of the skull and is thus the ... "Growing skull fracture of the posterior cranial fossa and of the orbital roof". Acta Neurochir (Wien). 145 (3): 201-8, ... A cranial burst skull fracture, usually occurring with severe injuries in infants less than 1 year of age, is a closed, ...
The inner surface of the occipital bone forms the base of the posterior cranial fossa. The foramen magnum is a large hole ... Like the other cranial bones, it is classed as a flat bone. Due to its many attachments and features, the occipital bone is ... The basion is the most anterior point of the opening and the opisthion is the point on the opposite posterior part. The basion ... The occipital bone (/ˌɒkˈsɪpɪtəl/) is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull ...
They also occur in the posterior cranial fossa, and near the falx cerebri and tentorium cerebelli. Unlike epidural hematomas, ...
... the small posterior space- the posterior cranial fossa contains the cerebellum, the pons, and the medulla. Clinical Anatomical ... The larger anterior space includes the anterior and middle cranial fossas and lodges the cerebrum; ... The tentorium cerebelli divides the cranial cavity into two closed spaces which communicate with each other through the ...
The tumor destroys the mastoid air spaces and extends into the middle ear and/or posterior cranial fossa. The microscopic ... The tumor involves the endolymphatic sac, a portion of the intraosseous inner ear of the posterior petrous bone. Heffner DK ( ...
Walter Dandy in 1925 was an advocate of partial sectioning of the nerve in the posterior cranial fossa. During this procedure ... along with other cranial nerve neuralgias), a pain syndrome characterized by severe episodes of intense facial pain, and ...
Meningeal branch: supplies the dura mater in the posterior cranial fossa Descending branches: This is the largest branch. It ... The occipital artery arises from (the posterior aspect of) the external carotid artery (some 2 cm distal to the origin of the ... It then changes its course and runs vertically upward, pierces the fascia connecting the cranial attachment of the trapezius ... The artery passes superoposteriorly deep to the posterior belly of the digastricus muscle. It crosses the internal carotid ...
From the brain stem, the motor and sensory parts of the facial nerve join and traverse the posterior cranial fossa before ... The intermediate nerve reaches the posterior cranial fossa via the internal acoustic meatus before synapsing in the solitary ... It arises from the brainstem from an area posterior to the cranial nerve VI (abducens nerve) and anterior to cranial nerve VIII ... The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges ...
Shoja MM, Tubbs RS, Khaki AA, Shokouhi G. A rare variation of the posterior cranial fossa: duplicated falx cerebelli, occipital ... Shoja MM, Tubbs RS, Khaki AA, Shokouhi G. A rare variation of the posterior cranial fossa: duplicated falx cerebelli, occipital ... A complex dural-venous variation in the posterior cranial fossa: a triplicate falx cerebelli and an aberrant venous sinus. ... A triple dural-venous variation in the posterior cranial fossa: A duplicated plus accessory falx cerebelli and an aberrant ...
... cochlear aqueduct connects the Perilymphatic space of the inner ear with the subarachnoid space of the posterior cranial fossa ... The cranial bones fuse by the end of the third year of life. For head enlargement to occur, hydrocephalus must occur before ... Since the skull bones have not yet firmly joined, bulging, firm anterior and posterior fontanelles may be present even when the ...
... s are divided into anterior fossa, middle fossa and posterior fossa fractures. Facial fractures often ... Surgery may be performed to seal a CSF leak that does not stop, to relieve pressure on a cranial nerve or repair injury to a ... Due to the proximity of the cranial nerves, injury to those nerves may occur. This can cause loss of function of the facial ... Serious cases usually result in death Basilar skull fractures include breaks in the posterior skull base or anterior skull base ...
... especially of posterior fossa structures, by using the mastoid fontanelle, the posterior fontanelle and/or the temporal window ... Some brain structures are poorly visualised, notably posterior fossa structures such as the cerebellum if only the anterior ... It is not usual for this technique to be referred to simply as "cranial ultrasound". Additionally, cranial ultrasound can be ... Cranial ultrasound is a technique for scanning the brain using high-frequency sound waves. It is used almost exclusively in ...
... s most often occur in the posterior cranial fossa, in contrast with adult ependymomas which usually occur ... U-King-Im, JM; Taylor, MD; Raybaud, C (2010). "Posterior fossa ependymomas: New radiological classification with surgical ... Tumors that occur in the posterior fossa have also been shown to have a less favorable prognosis. Expression of TERT in ... posterior fossa), intracranial supratentorial, and spinal ependymoma, and subependymomas. Reports have shown that location- ...
In the case of epidural hematoma in the posterior cranial fossa, tonsillar herniation causes Cushing's triad: hypertension, ... In children, however, they occur with similar frequency in the occipital, frontal, and posterior fossa regions. Epidural bleeds ... The eye will be positioned down and out due to unopposed innervation of the fourth and sixth cranial nerves.[citation needed] ... As blood accumulates, it starts to compress intracranial structures, which may impinge on the third cranial nerve, causing a ...
... middle and posterior cranial fossae changes rapidly. The anterior cranial fossa changes especially during the first trimester ... These cranial measurements are the basis of what is known as craniology. These cranial measurements were also used to draw a ... "Clinical anatomy of the human anterior cranial fossa during the prenatal period". Folia Morphologica. 62 (3): 271-3. PMID ... forms the protective cranial cavity that surrounds and houses the brain and brainstem. The upper areas of the cranial bones ...
Infection may then further spread into the middle cranial fossa or posterior cranial fossa, causing meningitis or abscess of ... posterior cranial fossa, middle cranial fossa, carotid canal, abducens nerve, sigmoid sinus) to which they may disseminate ... and be separated from the posterior cranial fossa and sigmoid sinus by a mere slip of bone or not at all. They may extend into ... 366 The cells receive arterial supply from the stylomastoid branch of the occipital artery or posterior auricular artery, and ( ...
Neoplasms and giant aneurysms of the posterior fossa have also been associated with the midbrain syndrome. Vertical ... Diagnosis can be made via combination of physical exam, particularly deficits of the relevant cranial nerves. Confirmation can ... origin of cranial nerve III) and Edinger-Westphal nuclei, causing dysfunction to the motor function of the eye. Classically, it ...
... or surgery or radiation to treat posterior cranial fossa tumors. With the VMH disabled and no longer responding to peripheral ...
Neuroradiological diagnostics evaluate the severity of crowding of the neural structures within the posterior cranial fossa and ... In normal adults, the posterior fossa comprises 27% of the total intracranial space, while in adults with Chiari Type I, it is ... These modifications resulted in significant reduction of the size of the posterior fossa in modern humans. ... Philadelphia: Mosby; 2002[page needed] Furtado SV, Reddy K, Hegde AS (November 2009). "Posterior fossa morphometry in ...
... injured by ongoing treatment for acute lymphoblastic leukemia or surgery or radiation to treat posterior cranial fossa tumors. ... Retrieved 17 June 2013.{{cite journal}}: CS1 maint: location (link) Lygidakis NJ (March 1984). "Posterior truncal vagotomy and ...
Care is given to prevent spilling dye into the posterior cranial fossa (back of the head) or to enter the cranial cavity in ... With metrizamide the issue is that if entering the cranial cavity and high dose exposure to the blood brain barrier, side ...
The vertebral artery supplies a number of vital structures in the posterior cranial fossa, such as the brainstem, the ... The vertebral artery supplies the part of the brain that lies in the posterior fossa of the skull, and this type of stroke is ... therefore called a posterior circulation infarct. Problems may include difficulty speaking or swallowing (lateral medullary ...
The neuron cell bodies reside within the superior ganglion and innervate the dura mater in the posterior cranial fossa of the ... Keller, Jeffrey T.; Saunders, Mary C.; Beduk, Altay; Jollis, James G. (1985-01-01). "Innervation of the posterior fossa dura of ... Kemp, William J.; Tubbs, R. Shane; Cohen-Gadol, Aaron A. (2012-11-01). "The Innervation of the Cranial Dura Mater: ...
Posterior cranial fossa at human fetus Base of skull Posterior cranial fossa Posterior cranial fossa A tumor of the posterior ... Demonstrationg how cerebellum sits in the posterior cranial fossa. Anterior cranial fossa Middle cranial fossa Rea, Paul (2016 ... Anteriorly, the posterior cranial fossa is bounded by the dorsum sellae, posterior aspect of the body of sphenoid bone, and the ... The posterior cranial fossa is the part of the cranial cavity located between the foramen magnum, and tentorium cerebelli. It ...
Complications of posterior cranial fossa surgery-an institutional experience of 500 patients.. ...
... and the posterior inferior angle of the PARIETAL BONE. ... It is formed by the posterior third of the superior surface of ... Cranial Fossa, Posterior. The infratentorial compartment that contains the CEREBELLUM and BRAIN STEM. It is formed by the ... and the posterior inferior angle of the PARIETAL BONE. ... Cranial Fossa, Anterior * Cranial Fossa, Middle * Cranial Fossa ... posterior third of the superior surface of the body of the sphenoid (SPHENOID BONE), by the occipital, the petrous, and mastoid ...
Posterior fossa tumor is a type of brain tumor located in or near the bottom of the skull. ... Symptoms from posterior fossa tumors also occur when the tumor damages local structures, such as the cranial nerves. Symptoms ... The best way to look at the posterior fossa is with an MRI scan. CT scans are not helpful to see that area of the brain in most ... The posterior fossa is a small space in the skull, found near the brainstem and cerebellum. The cerebellum is the part of the ...
The posterior cranial fossa volume, in absolute terms and expressed as a ratio of supratentorial volume (posterior fossa ratio ... The line joining the basion to the opisthion defines the lower limit of the posterior cranial fossa and is the reference point ... The line joining the basion to the opisthion defines the lower limit of the posterior cranial fossa and is the reference point ... The line joining the basion to the opisthion defines the lower limit of the posterior cranial fossa and is the reference point ...
... cranial nerve VII). This movement disorder triggers involuntary short or longer contractions of the facial muscles. Although ... Nerve Compression Syndromes in the Posterior Cranial Fossa. Baldauf, Jörg; Rosenstengel, Christian; Schroeder, Henry W. S. ... The axial-plane CISS sequence shows a loop of the posterior inferior cerebellar artery (Arrow A) which compresses the facial ... The axial-plane CISS sequence shows a loop of the posterior inferior cerebellar artery (Arrow A) which compresses the facial ...
Advanced cholesteatoma with exposure of posterior cranial fossa dura. View Media Gallery ... Retraction of the posterior quadrant of the tympanic membrane into the posterior middle ear results in the second type of ... In the canal wall-down (open) procedure, the posterior canal wall is removed. A large meatoplasty is created to allow adequate ... A study by Rosito et al suggested that in patients with posterior epitympanic cholesteatoma confined to the pars flaccida or a ...
Anatomy and malformations of the posterior cranial fossa]. Struffert T. Struffert T. Radiologe. 2016 Nov;56(11):960-966. doi: ...
tumors of spinal cord and or posterior cranial fossa;. - chordoma;. - congenital anomalies of C-spine:. - unilateral absence of ... posterior fossa masses;. - Klippel feil syndrome. - opthalmologic dz that may require child to tilt head to see normally;. - ...
LOINC Code 30811-4 RF Posterior fossa Views W contrast IT ... Posterior fossa to Head,Posterior fossa for conformance with ... Head,Posterior fossa. Scale. Doc. Method. RF. Additional Names. Short Name. RF Post fossa Views W contr IT. Associated ... RF Posterior fossa Views W contrast IT Active Fully-Specified Name. Component. Views^W contrast IT. Property. Find. Time. Pt. ... FL Posterior Fossa Myelogram. RadLex Playbook 2.4. Basic Attributes. Class. RAD. Type. Clinical. First Released. Version 2.04. ...
Clinical Anatomy of the Posterior Cranial Fossa and its Foramina. Stuttgart: Thieme; 1991. ... In the 20 patients with indications for 3DRA of the posterior circulation, we reconstructed the stored raw data of 3D DSA runs ... Vascular microanatomy of the pontomedullary junction, posterior inferior cerebellar arteries, and the lateral spinal arteries. ... Microsurgical anatomy of the posterior circulation. Neurol India 2007;55:31-41. ...
Tumor extended into the posterior cranial fossa in all nine patients and produced mass effect on the brain stem and/or ... D, Axial T2-weighted MR image shows a large tumor with high, slightly inhomogeneous signal in the posterior cranial fossa ... B, Coronal contrast-enhanced T1-weighted MR image shows dumbbell-shaped tumor extending both into the posterior cranial fossa ( ... Most tumors were large, extending both into the posterior cranial fossa and below the skull base. The most common clinical ...
Comparative analysis of endoscopic assisted and purely microvascular decompression for posterior fossa cranial nerves. Our ... Clinical and Radiological Outcomes of Posterior Cervical Fusion with Medtronic Infinity Occipitocervical-Upper Thoracic (OCT) ... Clinical and Radiological Outcomes of Posterior Cervical Fusion Supplemented with Interfacet Spacers ... Spinal System with Posterior Supplemental Fixation For The Treatment Of Symptomatic Degenerative Disease Of The Lumbosacral ...
... cranial nerves III, VI, IX, X) despite having a well-functioning ventricular-peritoneal shunt. He required a posterior fossa ... A functioning shunt is imperative prior to exploring the posterior fossa in these children. Often times, especially in older ... This photograph also reveals an absence of the calvaria and posterior bone elements of the cervical canal, as well as the ... Those that do usually present in their first year of life with similar symptoms, stridor and cranial nerve paresis. ...
Less often, abnormalities are found in the posterior fossa, corpus callosum, thalamus, and basal ganglia. The affected areas ... Cranial CT shows hypodense lesions. Contrast enhancement and mass effect are seen only rarely on imaging studies.8 ...
Temporal Bone Neoplasms and Lateral Cranial Base Surgery. *Neoplasms of the Posterior Fossa ...
... of all posterior fossa tumors.{file44823}It is a highly invasive embryonal neuroepithelial tumor that arises in the cerebellum ... Posterior fossa syndrome (mutism, cerebellar dysfunction, cranial nerve palsy, and hemiparesis; generally temporary) ... of all posterior fossa tumors. [1] It is a high-grade (WHO grade IV) embryonal neuroepithelial tumor that arises in the ... Diplopia and other cranial nerve findings, such as facial weakness, tinnitus, hearing loss, head tilt, and stiff neck ...
... including posterior cranial fossa and posterior cervical spine.. The benefits of the BCP in orthopedic surgery include access ... The benefits of the sitting position in neurosurgery include access to the posterior cervical spine and cranial fossa; it also ... to the anterior and posterior shoulder, reduced traction induced brachial plexus neuropathies, decreased port placement related ...
... tighter posterior fossa; and a somewhat larger foramen magnum.1,6 Chiari II malformation presents in one out of three children ... downward displacement of the brainstem with potential for altered pressures on the lower cranial nerves; a smaller, ...
2007;21:522-524). Moreover, the trajectory provided by the park bench position better serves a retro-sigmoid, posterior fossa ... How to: Positioning for Middle Cranial Fossa Repair of Superior Semicircular Canal Dehiscence. by Nicholas S. Andresen, MD, ... via a middle cranial fossa (MCF) or transmastoid approach (Curr Opin Otolaryngol Head Neck Surg. 2020;28:340-345; Laryngoscope ...
The second most substantial portion occupies the middle cranial fossa and lies posterior to the frontal lobe and inferior to ... It is located in the most posterior region of the brain, posterior to the parietal lobe and temporal lobe. The role of this ... It is located posterior to the frontal lobe and superior to the temporal lobe and classified into two functional regions. ... The posterior parietal lobe has two regions: the superior parietal lobule and the inferior parietal lobule. ...
Numerous nuanced approaches have been used to access posterior inferior cerebellar artery (PICA) aneurysms for microsurgical ... anomalies are well aware of the problem with issues of space when managing vascular lesions in the posterior cranial fossa. In ... Hudgins RJ, , Day AL, , Quisling RG, , Rhoton Al Jr, , Sypert GW, & Garcia-Bengochea F: Aneurysms of the posterior inferior ... Hudgins RJ, , Day AL, , Quisling RG, , Rhoton Al Jr, , Sypert GW, & Garcia-Bengochea F: Aneurysms of the posterior inferior ...
1-3) suggestive of cortical nodules and subependymal tubers, with signs of volume loss in the posterior fossa (Fig. 4). ... Contrast cranial nuclear magnetic resonance (NMR) spectroscopy revealed multiple subependymal lesions (Figs. ... Un ecocardiograma posterior evidenció la presencia de múltiples lesiones endomiocárdicas sugestivas de rabdomiomas. Controles ... The patient remained cardiovascularly asymptomatic and posterior echocardiogram follow-ups revealed that the foramen ovale ...
Sixth Cranial (Abducens) Nerve Palsy - Etiology, pathophysiology, symptoms, signs, diagnosis & prognosis from the MSD Manuals ... posterior fossa, and cranial nerves. If imaging results are normal but meningitis or benign intracranial hypertension is ... Symptoms and Signs of Sixth Cranial Nerve Palsy Symptoms of 6th cranial nerve palsy include binocular horizontal diplopia when ... See also Overview of Neuro-ophthalmologic and Cranial Nerve Disorders Overview of Neuro-ophthalmologic and Cranial Nerve ...
Hemangioblastomas are well-differentiated, vascular, benign tumors primarily located in the posterior cranial fossa. They are ... Background:Hemangioblastomas are the most common primary tumor of the posterior fossa. There are few cases of hemangioblastoma ... Solid haemangioblastomas of the posterior fossa: Radiological features and results of surgery. J Neurol Neurosurg Psychiatry. ... Preoperative Endovascular Embolization for Hemangioblastoma in the Posterior Fossa. Neurol Med Chir (Tokyo). 2012. 52: 878-84 ...
... namely deviation of the ipsilateral posterior fossa, enlargement of the contralateral middle cranial fossa, and ipsilateral ... The facial scoliosis is likely secondary to asymmetries of the cranial base.14 Although the posterior cranial base is tilted ... posterior cranial base tilt, ipsilateral posterior/inferior position of the ear, and overall trapezoid shape of the head. These ... Although largely a posterior cranial anomaly, the sequelae of premature unilateral lambdoid suture obliteration clearly have a ...
Results The FTOZ TCA represented a wide access to the anterior, middle, and posterior fossa. When combined with an anterior ... Methods Microsurgical dissection was performed in four freshly injected cadaver heads at the Cranial Base Neuroanatomy ... Posterior clinoidectomy: dural tailoring technique and clinical application. Skull Base 2009; 19 (03) 183-191 ...
Results The FTOZ TCA represented a wide access to the anterior, middle, and posterior fossa. When combined with an anterior ... Methods Microsurgical dissection was performed in four freshly injected cadaver heads at the Cranial Base Neuroanatomy ... Posterior clinoidectomy: dural tailoring technique and clinical application. Skull Base 2009; 19 (03) 183-191 ...
Transposition of vessels for microvascular decompression of posterior fossa cranial nerves: Review of literature and ... Cranial falling bullet injuries, a series of 30 cases in Iraq. Br J Neurosurg. 2020. 34: 135-41 ... Cranial gravitational (falling) bullet injuries: Point of view. J Neurosci Rural Pract. 2018. 9: 278-80 ... The use of non-living animals as simulation models for cranial neurosurgical procedures: A literature review. Chin Neurosurg J ...
  • It transmits the facial (VII) and vestibulocochlear (VIII) cranial nerves into a canal in the petrous temporal bone. (wikipedia.org)
  • Symptoms from posterior fossa tumors also occur when the tumor damages local structures, such as the cranial nerves. (medlineplus.gov)
  • Facial symptoms or loss of hearing due to compression of cranial nerves. (brainsciencefoundation.org)
  • Palsy resulting from a cavernous sinus lesion can cause severe head pain, chemosis (conjunctival edema), anesthesia in the distribution of the 1st and 2nd division of the 5th cranial nerve, and paralysis of the 3rd, 4th, and 6th cranial nerves. (msdmanuals.com)
  • MRI provides greater resolution of the orbits, cavernous sinus, posterior fossa, and cranial nerves. (msdmanuals.com)
  • The primary afferent fibers that go into the trigeminocervical nucleus are from the trigeminal nerve (cranial nerve V), and from the upper three cervical nerves (C1, C2, C3). (greatsmilemakers.com)
  • These symptoms and signs are due to entrapment of cranial nerves, occlusion of cerebrospinal fluid (CSF) flow, venous sinuses, and, rarely, arteries. (surgicalneurologyint.com)
  • Other pathologies that can occur in this area include meningiomas, vascular malformations, epidermoid tumours, or even primary schwannomas of other cranial nerves (e.g. facial). (pulsenotes.com)
  • Patients with an acoustic neuroma may present with a myriad of clinical features depending on the size of the lesion and how it impacts on the surrounding cranial nerves and cerebellum. (pulsenotes.com)
  • Most tumors of the posterior fossa are primary brain cancers. (medlineplus.gov)
  • Posterior fossa tumors have no known causes or risk factors. (medlineplus.gov)
  • Most tumors of the posterior fossa are removed with surgery, even if they are not cancerous. (medlineplus.gov)
  • There is no primary medical therapy for posterior fossa brain tumors. (medscape.com)
  • The most common operative approaches to the posterior fossa tumors are midline, paramedian, or retromastoid. (medscape.com)
  • Preoperative ETV has proved to be an effective long-term cerebrospinal fluid diversion procedure for managing hydrocephalus associated with posterior fossa brain tumors, with a relatively low rate of complications. (medscape.com)
  • Posterior fossa tumors are associated with vasogenic edema causing symptoms of raised intracranial pressure. (medscape.com)
  • Complex craniocervical malformations are not uncommon in clinical practice, but reports of combined posterior cranial fossa tumors are rare. (biomedcentral.com)
  • 4. [Microsurgical treatment of posterior cranial fossa tumors via keyhole approaches]. (nih.gov)
  • Anatomy of the posterior Fossa: a comprehensive description for pediatric brain tumors. (amedeo.com)
  • Also visible in the posterior cranial fossa are depressions caused by the venous sinuses returning blood from the brain to the venous circulation: Right and left transverse sinuses which meet at the confluence of sinuses (marked by the internal occipital protuberance). (wikipedia.org)
  • The dura mater has been stripped from the left half of the posterior fossa to open venous sinuses. (stanford.edu)
  • The posterior cranial fossa is the part of the cranial cavity located between the foramen magnum, and tentorium cerebelli. (wikipedia.org)
  • The foramen magnum is a large opening of the floor of the posterior cranial fossa, its most conspicuous feature. (wikipedia.org)
  • These pass along the articulation between the posterior edge of the petrous temporal bone and the anterior edge of the occipital bones to the jugular foramen, where the sigmoid sinus becomes the internal jugular vein. (wikipedia.org)
  • New growths in this location are due either to a downward extension of a tumor which began in the posterior fossa of the skull or to one that originated within the vertebral canal and that has grown into the cranial chamber through the foramen magnum. (jamanetwork.com)
  • 16. Foramen magnum meningiomas--experience with the posterior suboccipital approach. (nih.gov)
  • On the basis of clinical history and supportive MRI finding, she was previously diagnosed as a case of high cervical compressive myelopathy with cord changes due to thickening of ligamentum flavum and posterior longichudinal ligament extending from foramen magnum up to C4 vertebral level. (surgicalneurologyint.com)
  • An underdeveloped posterior cranial fossa can cause Arnold-Chiari malformation. (wikipedia.org)
  • A third group, heavily represented by Chiari malformation, was associated with cranial surgery. (medscape.com)
  • Dandy-Walker Malformation (DWM) is a rare congenital anomaly of the posterior cranial fossa. (org.pk)
  • 15. [Meningioma of the posterior cranial fossa]. (nih.gov)
  • 17. [Microsurgical anatomy of meningioma of the posterior cranial fossa]. (nih.gov)
  • Lies in the anterior wall of the posterior cranial fossa. (wikipedia.org)
  • Anterior cranial fossa Middle cranial fossa Rea, Paul (2016). (wikipedia.org)
  • the anterior surface forms the posterior part of the middle cranial fossa . (pacs.de)
  • On lateral radiographs the sella turcica or pituitary fossa is a radiodense saddle-shaped outline of the fossa extending between the anterior and posterior clinoid processes 1 . (bvsalud.org)
  • Demonstrationg how cerebellum sits in the posterior cranial fossa. (wikipedia.org)
  • The posterior fossa is a small space in the skull, found near the brainstem and cerebellum. (medlineplus.gov)
  • The patient was then transferred to a tertiary pediatric hospital, where a brain MRI demonstrated a large, lobulated and septated T2 hyperintense mass within the posterior bodies of the lateral ventricles (Figure 2). (appliedradiology.com)
  • Sixth cranial nerve palsy affects the lateral rectus muscle, impairing eye abduction. (msdmanuals.com)
  • Since the introduction of lateral cephalometric radiography by Broadbent4 in 1931, this radiographic technique has been widely used in orthodontics to evaluate cranial and dentofacial growth. (bvsalud.org)
  • Anteriorly, the posterior cranial fossa is bounded by the dorsum sellae, posterior aspect of the body of sphenoid bone, and the basilar part of occipital bone/clivus. (wikipedia.org)
  • Laser interstitial thermal therapy (LITT) has emerged as a treatment option for deep-seated primary and metastatic brain lesions, but few data are available for lesions of the posterior fossa. (medscape.com)
  • Trigeminal schwannomas are uncommon lesions of the skull base that may occur in the middle fossa, posterior fossa, or both. (nih.gov)
  • This can be used as an approach to posterior cranial fossa lesions. (medicoapps.org)
  • The descending part presents two openings through each of which a branch of the facial nerve passes: the nerve to stapedius enters the canaliculus for nerve to stapedius , and the chorda tympani enters the posterior canaliculus of chorda tympani ( canaliculus chordae tympani , or iter chordae posterius [7] ). (cloudfront.net)
  • V) and the facial nerve (cranial nerve VII). (greatsmilemakers.com)
  • The dilation of the dural blood vessels is via the facial nerve (cranial nerve VII), from the parasympathetic production and release of the neurotransmitter acetylcholine. (greatsmilemakers.com)
  • In patients with cerebellar infarction, brainstem compression is found more often in those who have involvement of the posterior inferior cerebellar artery. (medscape.com)
  • It is formed by the posterior third of the superior surface of the body of the sphenoid ( SPHENOID BONE ), by the occipital, the petrous, and mastoid portions of the TEMPORAL BONE , and the posterior inferior angle of the PARIETAL BONE . (nih.gov)
  • Está formado por la superficie superior del tercio posterior del cuerpo del ESFENOIDES, por el occipital, por las porciones petrosa y mastoidea del HUESO TEMPORAL y por el ángulo posteroinferior del HUESO PARIETAL. (bvsalud.org)
  • Physical examination revealed high cervical compressive myelo-radiculopathy with lower cranial nerve palsy and neck rigidity. (surgicalneurologyint.com)
  • In case of multilevel cervical compressive myelo-radiculopathy with lower cranial involvement, possibility of hypertrophic pachymeningitis should be kept in mind. (surgicalneurologyint.com)
  • 5. [Skull base meningiomas spreading into the infratemporal fossa: clinical picture, diagnosis, and treatment policy]. (nih.gov)
  • Moreover, caudal extension results in their presentation in the infratemporal fossa. (nih.gov)
  • 8. Sanakoeva A. V. The results of posterior decompression of the craniovertebral transition in syringomyelia with Chiari-1 anomaly in children Asp. (panor.ru)
  • Today's Unlocking Common ED Procedures post looks at an uncommon but emergent procedure: the burr hole for cranial decompression. (emdocs.net)
  • If a tumor grows in the area of the posterior fossa, it can block the flow of spinal fluid and cause increased pressure on the brain and spinal cord. (medlineplus.gov)
  • Additionally, the mass in the posterior cranial fossa was considered a congenital tumor based on the characteristics of the image presented in Fig. 1 . (biomedcentral.com)
  • Symptoms of 6th cranial nerve palsy include binocular horizontal diplopia when looking to the side of the paretic eye. (msdmanuals.com)
  • The posterior cranial fossa is formed by the sphenoid bones, temporal bones, and occipital bone. (wikipedia.org)
  • 19. [Meningiomas of the posterior petrous bone: diagnostic and therapeutic aspects]. (nih.gov)
  • [ 1 , 2 ] The clinical triad of a short neck, low posterior hairline, and limited neck range of motion first described by Klippel and Feil in 1912 [ 3 ] was originally thought to be the hallmark presentation of this condition. (medscape.com)
  • 20. [Magnetic resonance imaging and meningiomas of the posterior cerebral fossa. (nih.gov)
  • no reduction existed by applying posterior thumb pressure, by anteriorly compressing the C2 spinous process [ 1 ]. (biomedcentral.com)
  • The surgical risk of irreducible atlantoaxial dislocation combined with posterior cranial fossa tumor is huge. (biomedcentral.com)
  • 1. [Posterior fossa meningiomas--topographic and anatomopathologic aspects]. (nih.gov)
  • 8. Gamma knife radiosurgery in meningiomas of the posterior fossa. (nih.gov)
  • 9. Conventional posterior fossa approach for surgery on petroclival meningiomas: a report on an experience with 28 cases. (nih.gov)
  • Seizures are the most common symptom associated with cranial meningiomas, appearing in 30 to 40% of patients pre-treatment. (brainsciencefoundation.org)
  • Recent contrast MRI was suggestive of circumferentially, grossly thickened, enhancing dura extending from caudal aspect of posterior fossa up to C7 level with variable compression of cord and emerging nerve roots [Figures 1 - 4 ]. (surgicalneurologyint.com)
  • a - c Excision of the posterior fossa lesion through suboccipital craniectomy, the lesion was pearly white with hair inside. (biomedcentral.com)
  • 4 ] It has a nonspecific clinical picture comprising headache, vomiting, cranial nerve palsy, ataxia, raised intracranial pressure, and focal neurological deficit. (surgicalneurologyint.com)
  • A near-total excision of the lesion was done from the small window craniectomy on both sides of the posterior cranial fossa. (biomedcentral.com)
  • Significant PCs were included as independent variables in multivariable logistic regression models designed to test associations with three primary outcomes: cervical spine surgery, thoracolumbar/sacral spine surgery, and cranial surgery. (medscape.com)
  • 6,8 Epidermoids are classically extra-axial, most frequently in the posterior fossa, and most commonly at the cerebellopontine angle. (appliedradiology.com)
  • There is limited space in the posterior fossa, and the tumor can easily press on delicate structures if it grows. (medlineplus.gov)
  • This cranial nerve, also known as the vestibulocochlear nerve, has important functions in both hearing and balance. (pulsenotes.com)
  • Complications of transient cranial nerve paresis related to EVT occurred in two cases (20%) with intracranial AVMs. (bmj.com)
  • citation needed] Animation Posterior cranial fossa at human fetus Base of skull Posterior cranial fossa Posterior cranial fossa A tumor of the posterior fossa leading to mass effect and shift of the fourth ventricle Video (44 sec). (wikipedia.org)
  • Acoustic neuromas usually occur sporadically from Schwann cells of the vestibular branch of the eighth cranial nerve. (pulsenotes.com)
  • The posterior cranial fossa is formed in the endocranium, and holds the most basal parts of the brain. (wikipedia.org)
  • Secondary locations include the pineal region, the suprasellar cistern and the middle cranial fossa. (appliedradiology.com)
  • It is a triangular space in the posterior cranial fossa that contains the CPA cistern. (pulsenotes.com)
  • 2 ] Involvement of the meninges can be diffuse or focal and both cranial and spinal meninges can be affected. (surgicalneurologyint.com)
  • thus, they can be considered cranial nerve disorders, neuro-ophthalmologic. (msdmanuals.com)
  • Features of DWM include hypoplasia of the cerebellar vermis, enlargement of the posterior fossa, and cystic dilatation of the fourth ventricle. (org.pk)
  • Atypical teratoid/rhabdoid tumor of the central nervous system is a highly malignant neoplasm and that usually arises in the posterior fossa, survival from this is frequently poor. (karger.com)
  • An acoustic neuroma is a benign Schwann-cell derived tumour , which commonly arises from the eight cranial nerve. (pulsenotes.com)
  • It is typically a slow growing tumour that arises from the eighth cranial nerve supplying the inner ear. (pulsenotes.com)