This glossary provides definitions for the most common neurosurgery terms. Simply click on the first letter of the term you are searching for or scroll down to the list of terms below.
ACOUSTIC NEURINOMA/NEUROMA - A benign tumor of the hearing nerve (eighth cranial nerve).
ADENOMA - A benign growth formed of glandular tissue.
ALLOGRAFT - A graft of bone or tissue between individuals of the same species. Allografts are usually obtained from cadavers.
ANEURYSM - An abnormal bulging or stretching of a weakened wall of a blood vessel. Cerebral aneurysms are usually of three types: saccular with a narrow "neck" (also known as "berry" aneurysms because of their shape and their occurrence in clusters; saccular with a broad base; and fusiform in which a section of artery bulges all the way around.
ANGIOGRAPHY - Radiography of blood vessels using the injection of contrast material (dye) to better visualize the vessels. Derived from angio (blood vessels) and gram (record or picture). (see also Intra-arterial catheterization angiography)
ANGIOPLASTY - Reconstitution or recanalization of a blood vessel; may involve balloon dilation, mechanical stripping of intima (innermost layer of an artery), forceful injection of a thrombolytic (clot-busting) agent, or placement of a stent (vessel prosthesis).
ANNULUS - The tough outer ring of a spinal disk.
ANTICOAGULANT - A medication that prevents coagulation of the blood.
APHASIA - Difficulty with, or loss of use of language, in any of several ways including reading, writing, or speaking. Failure of understanding of the written, printed, or spoken word not related to intelligence but to specific lesions in the brain.
ARACHNOID - The middle layer of membranes covering the brain and spinal cord.
ARACHNOIDITIS - Inflammation of the arachnoid membrane, most commonly seen within the spinal cord around the spinal cord and cauda equina.
ARTERIOSCLEROSIS - Thickening and calcification of the arterial wall with loss of elasticity and contractility.
ARTERIOGRAPHY - (see ANGIOGRAPHY.)
ARTERIOVENOUS - Relating to both arteries and veins.
ARTERIOVENOUS MALFORMATION (AVM) - A collection of blood vessels with one or several abnormal communications between arteries and veins which may cause hemorrhage or seizures.
ARTHRODESIS - Surgical fixation or fusion of a joint.
ASTROCYTOMA - A tumor within the substance of the brain or spinal cord made up of astrocytes - often classified from Grade I (slow-growing) to Grade III (rapid-growing).
ATAXIA - A loss of muscular coordination, abnormal clumsiness.
ATHEROSCLEROSIS - Arteriosclerosis (see above) characterized by irregularly distributed lipid deposits in the arteries [adapted from Stedman's].
ATROPHY - A wasting of the tissues of a body part.
AUTOGRAFT - A graft of bone obtained from the patient for transplantation elsewhere on the patient.
BENIGN ESSENTIAL BLEPHAROSPASM - A rare disorder in which the muscles of the eyelids (orbiculares oculi) do not function properly. There are intermittent and involuntary contractions or spasms of the muscles around the eyes. Although the eyes themselves are unaffected, the patient may eventually become functionally blind because of an inability to open the eyelids. Benign Essential Blepharospasm is a form of dystonia, which is a group of neuromuscular disorders characterized by muscle spasms.
BENIGN ESSENTIAL TREMOR - A neurologic movement disorder characterized by involuntary fine rhythmic tremor of a body part or parts, primarily the hands and arms (upper limbs). In many affected individuals, upper limb tremor may occur as an isolated finding. However, in others, tremor may gradually involve other anatomic regions, such as the head, voice, tongue, or roof of the mouth (palate), leading to difficulties articulating speech (dysarthria). Less commonly, tremor may affect muscles of the trunk or legs.
BIOPSY - Removal of a small portion of tissue, usually for the purpose of making a diagnosis.
BLEPHAROSPASM - (see BENIGN ESSENTIAL BLEPHAROSPASM)
BONE GRAFT - Small piece(s) of extra bone that act as the "cement" for fusing vertebrae together.
BRACHIAL PLEXUS - A network of nerves in the neck, passing under the collarbone and into the the/omit armpit. These nerves originate from the 5th, 6th, 7th and 8th cervical spinal nerves and the first 2 thoracic spinal nerves.
BRADYKINESIA - Slowness in movement.
BRAINSTEM, BRAIN STEM - Bulge at the top of the spinal cord, forming the bottom part of the brain. The brainstem controls most vital functions.
BROWN-SEQUARD'S SYNDROME - The loss of sensation of touch, position sense, and movement on the side of a spinal cord lesion, with loss of pain sensation on the other side. Caused by a lesion limited to one side of the spinal cord.
CARCINOMA - Cancer, a malignant growth of epithelial or gland cells.
CAROTID ARTERY - The large artery on either side of the neck that supplies most of the cerebral hemisphere.
CAROTID CAVERNOUS FISTULA (CCF) - An abnormal communication between the internal and external portions of the carotid arteries or any of their branches and the cavernous sinus.
CAROTID SINUS - Slight dilatation on the common carotid artery at its bifurcation containing nerve cells sensitive to blood pressure. Stimulation can cause slowing of the heart, vasodilatation and a fall in blood pressure.
CARPEL TUNNEL - The narrow space formed by bones and a ligament in the center of the wrist through which the median nerve and tendons enter the palm of the hand.
CARPEL TUNNEL SYNDROME - The compression of the median nerve within the carpal tunnel resulting in numbness, tingling, "pins and needles," and pain in the hand and fingers.
CATHETER - A small tube used to inject a dye to see the blood vessels, similar to that used for looking at vessels in the heart. (See also Intra-arterial catheterization angiography)
CAUDA EQUINA - The bundle of long spinal nerve roots arising from the end of the spinal cord and filling the lower part of the spinal canal (from approximately the thoracolumbar junction down). These long nerves resemble a horse's tail (cauda equina).
CENTRAL NERVOUS SYSTEM (CNS) - The brain and the spinal cord.
CEREBELLUM - The lower part of the brain, which is beneath the posterior portion of the cerebrum and regulates unconscious coordination of movement.
CEREBROSPINAL FLUID (CSF) - A clear, water-like fluid that circulates around the brain and spinal cord.
CEREBRUM - The principal portion of the brain, which occupies the major portion of the interior of the skull and controls conscious movement, sensation, and thought. Separated into right and left hemispheres.
CERVICAL SPINE - Upper spine, neck. Made up of seven vertebrae.
CHIARI MALFORMATION - The downward (caudal) displacement of part of the cerebellum or brainstem below the foramen magnum. May also have/cause hydrocephalus, cord symptoms.
CHOREA - A disorder, usually of childhood, characterized by irregular, spasmodic involuntary movements of the limbs or facial muscles.
CHOROID PLEXUS - A vascular structure in the ventricles of the brain that produces cerebrospinal fluid.
COCCYX - The small bone at the end of the spinal column, formed by the fusion of four rudimentary vertebrae. The "tail bone."
COMA - A state of profound unconsciousness from which one cannot be roused.
COMPUTERIZED TOMOGRAPHY (CT) SCAN- A diagnostic imaging technique that rapidly x-rays the body in cross-sections, or slices. A computer pieces together the x-rays to create a three-dimensional map of soft tissue or bone.
CONCUSSION - A disruption, usually temporary, of neurological function resulting from a blow or violent shaking.
CONTRAST MEDIUM (dye) - Any material (usually opaque to x-rays) employed to delineate or define a structure during a radiologic procedure.
CORONAL SUTURE - The line of junction of the frontal bones and the parietal bones of the skull.
CORPECTOMY - Removal of the body of a vertebra. The body is the solid bony mass, almost circular in appearance, that forms the front part of each vertebra.
CORPUS CALLOSUM - The fibrous band connecting the hemispheres of the brain.
CORTEX - The external layer of gray matter covering the hemispheres of the cerebrum and cerebellum.
CRANIECTOMY - Surgical removal of a portion of the skull.
CRANIOPHARYNGIOMA - A congenital tumor arising from the embryonic duct between the brain and pharynx.
CRANIOPLASTY - The operative repair of a defect of the skull.
CRANIOSYNOSTOSIS - Premature closure of cranial sutures, limiting or distorting the growth of the skull.
CRANIOTOMY - Surgical opening of the skull, usually by creating a flap of bone.
CRANIUM - The part of the skull that holds the brain.
CSF - Cerebrospinal fluid.
CT SCAN - (computed tomography scan): A diagnostic imaging technique in which a computer reads x-rays to create a three-dimensional map of soft tissue or bone.
DIPHENYLHYDANTOIN - Dilantin; a medication used to control seizures.
DIPLOPIA - Double vision, due usually to weakness or paralysis of one or more of the extra-ocular muscles.
DISC - The intervertebral disc - cartilaginous cushion found between the vertebrae of the spinal column. It may bulge beyond the vertebral body and compress the nearby nerve root, causing pain. The terms "slipped disc," "ruptured disc," and "herniated disc" are often used interchangeably even though there are subtle differences.
DISC DEGENERATION - Flattening or "wear and tear" of the disc.
DOME - The round balloon-like portion of an aneurysm which usually arises from the artery from a smaller portion called the neck of the aneurysm.
DOPPLER - A non-invasive study that uses sound waves to show the flow in a blood vessel and can be used to determine the degree of narrowing (percent stenosis) of the vessel. A wand is placed on the skin over the vessel to be imaged. This study has no risks and is not painful.
DURA MATER - A tough fibrous membrane that covers the brain and spinal cord but is separated from them by a small space.
DYSESTHESIA - A condition in which a disagreeable sensation is produced by ordinary touch, temperature or movement.
DYSPHASIA - Difficulty in the use of language without mental impairment due to a brain lesion.
DYSTONIAS - A group of movement disorders that vary in their symptoms, causes, progression, and treatments. This group of neurological conditions is generally characterized by involuntary muscle contractions that force the body into abnormal, sometimes painful, movements and positions (postures).
EDEMA Swelling caused by an excessive accumulation of fluid in the body's tissues, most commonly the legs, feet, or ankles.
ELECTROENCEPHALOPGRAHY (EEG) - The study of the electrical currents set up by brain actions; the record made is called an electroencephalogram.
ELECTROMYOGRAPHY (EMG) - A method of recording the electrical currents generated in a muscle during its contraction.
ENCEPHALOCELE - The herniation of brain meninges through a skull defect.
ENDARTERECTOMY - The removal of fatty or cholesterol plaques and calcified deposits from the internal wall of an artery.
ENDOSCOPE - A thin, telescope-like instrument. A video camera attached to the endoscope records images a surgeon can view on a monitor. Specially designed surgical tools enable a surgeon to operate through small incision(s).
ENDOVASCULAR (also intravascular or endoluminal) or ENDOVASCULAR THERAPY - Referring to within a blood vessel, especially a minimally invasive catheter-based approach for the treatment of a central nervous system disorders (for example, a cerebral aneurysm).
EPENDYMA - The membrane that lines the cerebral ventricles of the brain and central canal of the spinal cord.
EPENDYMOMA - A growth in the brain or spinal cord arising from ependymal tissue.
EPIDURAL - Immediately outside the dura mater. Same as extradural.
EPIDURAL HEMATOMA - A blood clot between the dura mater and the inside of the skull.
EPILEPSY - Disorder characterized by abnormal electrical discharges in the brain, causing abnormal sensation, movement, or level of consciousness.
FACET - A small, smooth-surfaced end of a bony projection (articular process) that functions as part of a joint.
FACET JOINT - Each of four joints formed above and below and on either side of a vertebra. The lower bony projection of one vertebra meets the upper projections of the vertebra below it, forming facet joints.
FACETECTOMY - Surgical removal of one of the facets; excision of a facet joint.
FALX (CEREBRI) - An extension of dura between the right and left hemispheres of the brain.
FONTANELLE - Normal openings in he skull of infants; the largest of these is the anterior fontanel or "soft spot" in the middle of the head.
FORAMEN - A hole or opening that acts as a passageway for nerves or blood vessels.
FORAMINOTOMY - Surgical enlargement of the foramen/foramina.
FUSIFORM ANEURYSM - A sausage-like enlargement of the blood vessel
GAMMA KNIFE - Equipment that precisely delivers a concentrated dose of radiation to a predetermined target using gamma rays.
GCS - Glasgow Coma Scale.
GLASGOW COMA SCALE - The most widely used system of classifying the severity of head injuries or other neurologic diseases.
GLASGOW OUTCOME SCALE - A widely used system of classifying outcome after head injury or other neurologic diseases.
GLIA (Also termed neuroglia) - The major support cells of the brain. These cells are involved in the nutrition and maintenance of the nerve cells.
GLIOMA - A tumor formed by glial cells.
GLIOBLASTOMA - A rapidly growing tumor composed of primitive glial cells, mainly arising from astrocytes.
GLOBUS PALLIDUS - Part of the basal ganglia which are brain cells that lie deep in the brain.
GREATER OCCIPITAL NERVE - A branch of the second cervical spinal nerve that innervates the middle portion of the occipital area (at the back of the skull) of the scalp.
HEMANGIOMA - An aggregation of multiple, dilated, blood vessels.
HEMATOMA - A blood clot.
HEMIANOPIA - Loss of vision of one-half of the visual field.
HEMIPLEGIA - Paralysis of one side of the body.
HEMORRHAGE - Bleeding due to the escape of blood from a blood vessel.
HERNIATED NUCLEUS PULPOSUS (HNP) - The extrusion of the central portion (NUCLEUS) of an intervertebral disc through the outer cartilaginous ring (ANNULUS). The herniated portion can compress the spinal cord or nerves in or exiting the spinal canal.
HYDROCEPHALUS - A condition, often congenital, marked by abnormal and excessive accumulation of cerebrospinal fluid in the cerebral ventricles. This dilates the ventricles and increases intracranial pressure.
HYDROCEPHALUS, COMMUNICATING - Hydrocephalus where flow of cerebrospinal fluid is not blocked but there is absorption failure. Also known as "normal pressure" hydrocephalus (NPH).
HYDROCEPHALUS, OBSTRUCTIVE - Hydrocephalus where flow of CSF is blocked.
HYDROMYELIA - Expansion of the spinal cord due to increased size of the central canal of the cord which is filled with CSF.
HYPERESTHESIA - Excessive sensibility to touch, pain or other stimuli.
HYPERTENSION - High blood pressure.
HYPOPHYSECTOMY - Surgical removal of the hypophysis (pituitary gland).
HYPOTHALAMUS - A collection of specialized nerve cells at the base of the brain which controls the anterior and posterior pituitary secretions, and is involved in other basic regulatory functions such as temperature control and attention.
INFRATENTORIAL - Below the tentorium.
INFUNDIBULUM - A stalk extending from the base of the brain to the pituitary gland.
INSTRUMENTATION - Metal supports sometimes used in spinal fusions to help steady your/the spine while it fuses. Common types of support include plates, rods, or screws.
INTRA-ARTERIAL CATHETERIZATION ANGIOGRAPHY - An invasive study in which a catheter (a small tube) is placed in the artery and contrast material is injected to which makes the blood vessels visible on an x-ray image.
INTRACRANIAL PRESSURE (ICP) - The overall pressure inside the skull.
INTRATHECAL - Within a theca or the dura mater membrane that surrounds the spinal canal.
INTERNAL FIXATION - The insertion of metal rods, wires, pins, screws, or plates (or a combination of these) into bone fragments.
ISCHEMIA - Inadequate circulation of blood generally due to a blockage of an artery.
LAMINA - The portion of bone that extends from the pedicle and curves around to complete the vertebral arch on the right and left sides.
LAMINECTOMY - Removal of of/omit one or more entire lamina. Used when greater access is needed to perform a diskectomy. Helps release pressure on the nerve when a disk bulges.
LAMINOTOMY - A surgical procedure where part of the lamina of a vertebra is removed for access to the disk.
LEPTOMENINGES - Two thin layers of fine tissue covering the brain and spinal cord (the pia mater and arachnoid).
LEPTOMENINGITIS - Inflammation of the membranes covering the brain and spinal cord.
LIPOMA - A benign fatty tumor, usually composed of mature fat cells.
LORDOSIS - Curvature of the spine with the convexity forward.
LUMBAR DRAIN - A device (usually a long, thin, flexible tube) inserted through the skin into the cerebrospinal fluid space of the lower back; provides a method of draining cerebrospinal fluid.
LUMBAR PUNCTURE (spinal tap) - Diagnostic test in which a sample of cerebrospinal fluid is "tapped" from an area just below the end of the spinal cord through a thin needle inserted into the spinal canal. Used to detect blood in the CSF.
LUMBAR SPINE - Lower spine, lower back; usually consists of 5 vertebrae.
MAGNETIC RESONANCE ANGIOGRAPHY (MRA) - A non-invasive study that is conducted in a magnetic resonance imager. The magnetic images are assembled by a computer to provide an image of the arteries in the head and neck. No contrast material is needed, but some patients may experience claustrophobia in the imager.
MAGNETIC RESONANCE IMAGING (MRI) - Diagnostic test that produces three-dimensional images of body structures using powerful magnets and computer technology rather than x-rays.
MEDIAN NERVE - The nerve formed from the brachial plexus that supplies muscles in the anterior forearm and thumb as well as sensation of the hand. It may be compressed or trapped at the wrist in carpal tunnel syndrome.
MEDULLOBLASTOMA - A tumor composed of medulloblasts, which are cells that develop in the roof of the fourth ventricle (medullary velum).
MENINGES - The three membranes covering the spinal cord and brain termed dura mater, arachnoid mater, and pia mater.
MENINGIOMA - A firm, often vascular, tumor arising from the meninges of the brain or spinal cord.
MENINGITIS - An inflammation or infection of the meninges.
MENINGOCELE - A protrusion of the meninges of the spinal cord through a defect in the spinal column.
MENINGOENCEPHALITIS - An inflammation or infection of the brain and meninges.
MENINGOENCEPHALOCELE - A protrusion of both the meninges and brain tissue through a skull defect.
MRI - Magnetic Resonance Imaging - Scanning technique for views of the brain or spinal cord. No radiation is involved, but rather pulsed magnetic waves are used to delineate the structures within the brain.
MYELOGRAM - An x-ray of the spinal canal following injection of a contrast material into the surrounding cerebrospinal fluid spaces.
MYELOPATHY - Any functional or pathologic disturbance in the spinal cord.
MYELOMENINGOCELE - A protrusion of the spinal cord and its coverings through a defect in the vertebral column.
MYOPATHY - Any disease of muscle.
NERVE ROOT - The end of a spinal nerve nearest its attachment to the spinal cord.
NEURALGIA - A paroxysmal pain extending along the course of one or more nerves.
NEURECTOMY - Excision of part of a nerve.
NEURITIS - Inflammation of a nerve; may also be used to denote non-inflammatory nerve lesions of the peripheral nervous system.
NEUROBLASTOMA - A tumor of sympathetic nervous system origin, found mostly in infants and children.
NEUROFIBROMA - A tumor of the peripheral nerves due to an abnormal collection of fibrous and insulating cells.
NEUROFIBROMATOSIS - A familial condition characterized by developmental changes in the nervous system, muscles and skin, marked by numerous tumors affecting these organ system.
NEUROLYSIS - Removal of scar or reactive tissue from a nerve or nerve root.
NEUROMA - A tumor or new growth largely made up of nerve fibers and connective tissue.
NEUROPATHY - Any functional or pathologic disturbance in the peripheral nervous system. Localized secondary to lesion or generalized secondary to medical disorder.
NUCLEUS - The soft center of a spinal disk.
NYSTAGMUS - Involuntary rapid movement of the eyes in the horizontal, vertical, or rotary planes of the eyeball.
OCCIPUT - The back part of the head.
OLIGODENDROGLIA - Non-nerve cells, (see GLIA) forming part of the supporting structure of the central nervous system.
OLIGODENDROGLIOMA - A growth of new cells derived from the oligodendroglia.
OSTEOMA - A benign tumor of bone.
OSTEOMYELITIS - Inflammation of bone due to infection, which may be localized or generalized.
OSTEOPHYTECTOMY - Surgical removal of osteophytes (bony outgrowths). Osteophytes may develop on the upper and/or lower edges of the vertebral bodies, often causing pressure on the spinal cord.
PAPILLEDEMA - Swelling of the optic nerve head, can be seen in the back of the retina during eye examination.
PARAPLEGIA - Paralysis of the lower part of the body including the legs.
PARESTHESIA - Numbness, tingling, or a "pins and needles" feeling.
PARS INTERARTICULARIS - The area between the upper and lower articulating (joining) facets of two vertebrae.
PEDICLE - One of the two short stems of bone that project outward from the body of each vertebra.
PERIPHERAL NERVOUS SYSTEM - The peripheral part of the nervous system external to the brain and spinal cord from their roots to their peripheral terminations.
PITUITARY - The gland at the base of the brain which secretes hormones into the blood stream. Those hormones then regulate other glands including the thyroid, adrenals, and gonads. The "Master Gland."
POLYNEURITIS - Inflammation of two or more nerves simultaneously.
POSTERIOR FOSSA - A hollow depression in the back of the skull in which the cerebellum and several other structures are located.
PROPRIOCEPTION - Sensation concerning movements of joints and position of the body in space.
PSEUDARTHROSIS - Failure of fusion to achieve proper union of vertebrae
PSEUDOMENINGOCELE - A collection of cerebrospinal fluid that is due to a dural leak after spine surgery, not a congenital disorder.
PSEUDOTUMOR CEREBRI - Raised intracranial pressure, usually causing only headache and papilledema. No clear underlying structural abnormality.
PUPIL - The black part of the eye through which light enters; enlarges in dim light, and decreases in size in bright light.
RADIATION ONCOLOGIST - A medical doctor who has received advanced training in the treatment of persons receiving x-ray treatment for an illness.
RADIATION PHYSICIST - A person having a PhD degree who is trained in the science dealing with the properties, changes, and interactions of continuous energy.
RADICULITIS - Inflammation of the spinal nerve roots. Accompanied by pain and hyperesthesia.
RADIOLOGIST - A medical doctor who has received specialized training in interpreting x-rays, CTs, MRIs, and performing angiography.
RADIOTHERAPY - Treatment of a lesion with radiation.
REFLEX SYMPATHETIC DYSTROPHY - A condition characterized by burning pain, abnormal sensitivity to sensory stimuli, poor circulation, and changes in the skin, muscle, bone, and joints.
REVASCULARIZATION - Reestablishment of blood supply to a part.
SACCULAR ANEURYSM - A balloon-like outpouching of a vessel (the more common type of aneurysm).
SCIATIC NERVE - The largest nerve in the body. It extends from the sacral plexus, emerges from the pelvis and travels deep within the buttocks. It then descends down the back of the thigh to the back of the knee at which point it divides into the common peroneal and tibial nerves. The sciatic nerve supplies sensation to the back of the thigh, outer side of the leg, and essentially the whole foot.
SHUNT - A tube that diverts body fluid from one body cavity or vessel to another.
SPASMODIC TORTICOLLIS - Also known as cervical dystonia, is a form of dystonia characterized by intermittent spasms of the neck muscles resulting in involuntary rotation and tilting of the head. These movements are frequently painful.
SPINA BIFIDA - A congenital defect of the spine marked by the absence of a portion of the spine.
SPINAL FUSION - Operative method of strengthening and limiting motion of the spinal column. Can be performed with a variety of metal instruments and bone grafts or bone grafts alone.
SPINAL INSTABILITY - Damage to a disc or tearing of the ligament holding the spine, which causes the spine to be unable to carry out its supporting function.
SPINAL TAP - (see LUMBAR PUNCTURE)
SPINOUS PROCESS - A bony prominence projecting backward from a vertebra that can be felt under the skin on one's back.
SPONDYLOLISTHESIS - Forward displacement or slippage (subluxation) of one vertebra over another.
SPONDYLOSIS - Degenerative bone changes in the spine usually most marked at the vertebral joints with bony spur formation.
STENOSIS - Narrowing of the openings of the foramen and/or the spinal canal; narrowing of a blood vessel.
STENT - An endovascular prosthetic device, usually an open mesh cylinder; placed within a blood vessel to provide the support to keep that vessel open.
STEREOTACTIC SURGERY - Surgical technique whereby the exact target (i.e., tumor, lesion, AVM) is calculated three-dimensionally utilizing CT or MRI and computer. From stereo (3D) and tactic (touch).
SUBARACHNOID - Located under the arachnoid membrane and above the pia mater.
SUBARACHNOID HEMORRHAGE - Blood in, or bleeding into, the space under the arachnoid membrane, most commonly from trauma or from rupture of an aneurysm.
SUBDURAL - Located below the dura mater and above the arachnoid meninges.
SUBDURAL HEMATOMA - A collection of blood (clot) trapped under the dura matter, the outermost membrane surrounding the brain and spinal cord.
SUPRASCAPULAR NERVE - The nerve that originates from the superior trunk of the brachial plexus. Supplies the shoulder joint and deep shoulder structures.
SUPRATENTORIAL - Located above the tentorium.
SYRINGOMYELIA (SYRINX) - A fluid-filled cavity in the spinal cord.
TENTORIUM - A fold of one of the meninges, the dura mater, that separates the cerebrum from the cerebellum. It runs horizontally under the back portion of the cerebrum, separating it from the cerebellum below.
TERATOMA - Tumor or growth made up of several different types of tissue (fat, bone, muscle, skin).
THALAMUS - Brain cells that lie in the upper part of the brainstem.
THROMBOLYTIC AGENT - A "clot-busting" drug; such agents may be administered into veins or arteries.
THROMBUS - A blood clot attached to the wall of an artery.
TIC DOULOUREUX - (see TRIGEMINAL NEURALGIA)
TORTICOLLIS - The spasmodic contraction of neck muscles drawing the head to one side with the chin pointing to the other side.
TRANSSPHENOIDAL APPROACH - Operative method of reaching the pituitary gland or skull base traversing the nose and sinuses.
TRANSVERSE PROCESS - The wing of bone on either side of each vertebral arch where the pedicle meets the lamina.
TREMOR - (see BENIGN ESSENTIAL TREMOR)
TRIGEMINAL NERVE - The fifth cranial nerve and the largest. It is mainly sensory except for a small motor branch that supplies the muscles for chewing. The branches of the trigeminal nerve provide sensation to the eye and forehead, midface, and upper and lower jaw.
TRIGEMINAL NEURALGIA - Paroxysmal pain in the face. Pain may be so severe that it causes an involuntary grimace or "tic." (Tic Douloureux)
ULTRASOUND - The use of high-frequency sound to create images of internal body structures.
VASODILATATION - An increase in the diameter of blood vessels.
VASOPRESSIN - A hormone secreted by the hypothalamus and stored in the posterior pituitary, which raises blood pressure and increases reabsorption of water by the kidneys.
VASOPRESSOR - An agent that constricts the arteries and raises blood pressure.
VASOSPASM - A state of spasm tightening and narrowing of blood vessels around a brain aneurysm that are irritated by the blood from cerebral hemorrhage. The body's own attempt to prevent a second hemorrhage by restricting the flow of blood around the aneurysm.
VENTRICLE - The cavities or chambers within the brain that contain the cerebrospinal fluid. There are two lateral ventricles and midline third and fourth ventricles.
VENTRICULAR DRAINAGE - Insertion of a small tube into the ventricles to drain cerebrospinal fluid, usually when pressure is increased.
VENTRICULITIS - Inflammation and/or infection of the ventricles.
VENTRICULOSTOMY - An opening into the ventricles of the brain, such as by inserting a small, thin, hollow catheter.
VENTRICULO-ATRIAL - Describing a CSF shunt from one of the ventricles in the brain to the right atrium of the heart.
VENTRICULOGRAM - An x-ray study of the ventricles.
VENTRICULOMEGALY - Enlarged cerebral ventricles. (see also HYDROCEPHALUS)
VENTRICULO-PERITONEAL - Describing a CSF shunt from one of the ventricles of the brain to the peritoneal cavity in the abdomen.
VERMIS - The middle part of the cerebellum between the two hemispheres.
VERTEBRA - Any of the 33 bones of the spinal column.
VERTIGO - An abnormal sensation of rotation or movement of one's self or the environment.