Subarachnoid Space
The space between the arachnoid membrane and PIA MATER, filled with CEREBROSPINAL FLUID. It contains large blood vessels that supply the BRAIN and SPINAL CORD.
Subarachnoid Hemorrhage
Bleeding into the intracranial or spinal SUBARACHNOID SPACE, most resulting from INTRACRANIAL ANEURYSM rupture. It can occur after traumatic injuries (SUBARACHNOID HEMORRHAGE, TRAUMATIC). Clinical features include HEADACHE; NAUSEA; VOMITING, nuchal rigidity, variable neurological deficits and reduced mental status.
Arachnoid
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.
Cerebrospinal Fluid
A watery fluid that is continuously produced in the CHOROID PLEXUS and circulates around the surface of the BRAIN; SPINAL CORD; and in the CEREBRAL VENTRICLES.
Meninges
The three membranes that cover the BRAIN and the SPINAL CORD. They are the dura mater, the arachnoid, and the pia mater.
Cisterna Magna
Cerebrospinal Fluid Pressure
Manometric pressure of the CEREBROSPINAL FLUID as measured by lumbar, cerebroventricular, or cisternal puncture. Within the cranial cavity it is called INTRACRANIAL PRESSURE.
Vasospasm, Intracranial
Constriction of arteries in the SKULL due to sudden, sharp, and often persistent smooth muscle contraction in blood vessels. Intracranial vasospasm results in reduced vessel lumen caliber, restricted blood flow to the brain, and BRAIN ISCHEMIA that may lead to hypoxic-ischemic brain injury (HYPOXIA-ISCHEMIA, BRAIN).
Arnold-Chiari Malformation
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)
Arachnoid Cysts
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)
Pneumoencephalography
Radiographic visualization of the cerebral ventricles by injection of air or other gas.
Injections, Spinal
Hydrocephalus
Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, INTRACRANIAL HYPERTENSION; HEADACHE; lethargy; URINARY INCONTINENCE; and ATAXIA.
Cerebral Ventriculography
Radiography of the ventricular system of the brain after injection of air or other contrast medium directly into the cerebral ventricles. It is used also for x-ray computed tomography of the cerebral ventricles.
Cerebral Ventricles
Four CSF-filled (see CEREBROSPINAL FLUID) cavities within the cerebral hemispheres (LATERAL VENTRICLES), in the midline (THIRD VENTRICLE) and within the PONS and MEDULLA OBLONGATA (FOURTH VENTRICLE).
Subdural Space
Intracranial Pressure
Pressure within the cranial cavity. It is influenced by brain mass, the circulatory system, CSF dynamics, and skull rigidity.
Syringomyelia
Longitudinal cavities in the spinal cord, most often in the cervical region, which may extend for multiple spinal levels. The cavities are lined by dense, gliogenous tissue and may be associated with SPINAL CORD NEOPLASMS; spinal cord traumatic injuries; and vascular malformations. Syringomyelia is marked clinically by pain and PARESTHESIA, muscular atrophy of the hands, and analgesia with thermoanesthesia of the hands and arms, but with the tactile sense preserved (sensory dissociation). Lower extremity spasticity and incontinence may also develop. (From Adams et al., Principles of Neurology, 6th ed, p1269)
Arachnoiditis
Acute or chronic inflammation of the arachnoid membrane of the meninges most often involving the spinal cord or base of the brain. This term generally refers to a persistent inflammatory process characterized by thickening of the ARACHNOID membrane and dural adhesions. Associated conditions include prior surgery, infections, trauma, SUBARACHNOID HEMORRHAGE, and chemical irritation. Clinical features vary with the site of inflammation, but include cranial neuropathies, radiculopathies, and myelopathies. (From Joynt, Clinical Neurology, 1997, Ch48, p25)
Spinal Puncture
Anesthesia, Spinal
Procedure in which an anesthetic is injected directly into the spinal cord.
Intracranial Aneurysm
Abnormal outpouching in the wall of intracranial blood vessels. Most common are the saccular (berry) aneurysms located at branch points in CIRCLE OF WILLIS at the base of the brain. Vessel rupture results in SUBARACHNOID HEMORRHAGE or INTRACRANIAL HEMORRHAGES. Giant aneurysms (>2.5 cm in diameter) may compress adjacent structures, including the OCULOMOTOR NERVE. (From Adams et al., Principles of Neurology, 6th ed, p841)
Cerebral Aqueduct
Narrow channel in the MESENCEPHALON that connects the third and fourth CEREBRAL VENTRICLES.
Dura Mater
The outermost of the three MENINGES, a fibrous membrane of connective tissue that covers the brain and the spinal cord.
Cerebrospinal Fluid Shunts
Tubes inserted to create communication between a cerebral ventricle and the internal jugular vein. Their emplacement permits draining of cerebrospinal fluid for relief of hydrocephalus or other condition leading to fluid accumulation in the ventricles.
Microscopy, Electron, Scanning Transmission
A type of TRANSMISSION ELECTRON MICROSCOPY in which the object is examined directly by an extremely narrow electron beam scanning the specimen point-by-point and using the reactions of the electrons that are transmitted through the specimen to create the image. It should not be confused with SCANNING ELECTRON MICROSCOPY.
Magnetic Resonance Imaging
Myelography
X-ray visualization of the spinal cord following injection of contrast medium into the spinal arachnoid space.
Meningitis
Inflammation of the coverings of the brain and/or spinal cord, which consist of the PIA MATER; ARACHNOID; and DURA MATER. Infections (viral, bacterial, and fungal) are the most common causes of this condition, but subarachnoid hemorrhage (HEMORRHAGES, SUBARACHNOID), chemical irritation (chemical MENINGITIS), granulomatous conditions, neoplastic conditions (CARCINOMATOUS MENINGITIS), and other inflammatory conditions may produce this syndrome. (From Joynt, Clinical Neurology, 1994, Ch24, p6)
Cerebral Angiography
Radiography of the vascular system of the brain after injection of a contrast medium.
Battered Child Syndrome
Aneurysm, Ruptured
Foramen Magnum
The large hole at the base of the skull through which the SPINAL CORD passes.
Tomography, X-Ray Computed
Epidural Space
Space between the dura mater and the walls of the vertebral canal.
Spinal Canal
The cavity within the SPINAL COLUMN through which the SPINAL CORD passes.
Meningeal Neoplasms
Benign and malignant neoplastic processes that arise from or secondarily involve the meningeal coverings of the brain and spinal cord.
Meningitis, Pneumococcal
An acute purulent infection of the meninges and subarachnoid space caused by Streptococcus pneumoniae, most prevalent in children and adults over the age of 60. This illness may be associated with OTITIS MEDIA; MASTOIDITIS; SINUSITIS; RESPIRATORY TRACT INFECTIONS; sickle cell disease (ANEMIA, SICKLE CELL); skull fractures; and other disorders. Clinical manifestations include FEVER; HEADACHE; neck stiffness; and somnolence followed by SEIZURES; focal neurologic deficits (notably DEAFNESS); and COMA. (From Miller et al., Merritt's Textbook of Neurology, 9th ed, p111)
Brain
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Spinal Cord
Optic Nerve
The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.
Basilar Artery
The artery formed by the union of the right and left vertebral arteries; it runs from the lower to the upper border of the pons, where it bifurcates into the two posterior cerebral arteries.
Cranial Fossa, Posterior
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.
Cerebrospinal Fluid Proteins
Proteins in the cerebrospinal fluid, normally albumin and globulin present in the ratio of 8 to 1. Increases in protein levels are of diagnostic value in neurological diseases. (Brain and Bannister's Clinical Neurology, 7th ed, p221)
Laminectomy
A surgical procedure that entails removing all (laminectomy) or part (laminotomy) of selected vertebral lamina to relieve pressure on the SPINAL CORD and/or SPINAL NERVE ROOTS. Vertebral lamina is the thin flattened posterior wall of vertebral arch that forms the vertebral foramen through which pass the spinal cord and nerve roots.
Brain Diseases
Anesthesia, Epidural
Procedure in which an anesthetic is injected into the epidural space.
Cerebrospinal Fluid Rhinorrhea
Discharge of cerebrospinal fluid through the nose. Common etiologies include trauma, neoplasms, and prior surgery, although the condition may occur spontaneously. (Otolaryngol Head Neck Surg 1997 Apr;116(4):442-9)
Cerebrovascular Circulation
The circulation of blood through the BLOOD VESSELS of the BRAIN.
Subarachnoid Hemorrhage, Traumatic
Bleeding into the SUBARACHNOID SPACE due to CRANIOCEREBRAL TRAUMA. Minor hemorrhages may be asymptomatic; moderate to severe hemorrhages may be associated with INTRACRANIAL HYPERTENSION and VASOSPASM, INTRACRANIAL.
Blood-Brain Barrier
Specialized non-fenestrated tightly-joined ENDOTHELIAL CELLS with TIGHT JUNCTIONS that form a transport barrier for certain substances between the cerebral capillaries and the BRAIN tissue.