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GALACTORRHEA - The discharge of milk from the breasts.
GAMMA KNIFE - Equipment that precisely delivers a concentrated dose of radiation to a predetermined target using gamma rays.
GASSERION GANGLION - Mass of nervous tissue lying on the sensory root of the trigeminal nerve.
GENERALIZED SEIZURES - Seizures involving widespread areas on both sides of the brain at the time of onset. The generalized nature of these seizures accounts for their dramatic manifestations, which include loss of consciousness or awareness and convulsions. About 39% of epileptics suffer primarily from generalized seizures.
GLASGOW COMA SCALE - The most widely used system of classifying the severity of head injuries or other neurological diseases.
GLASGOW OUTCOME SCALE - A widely used system of classifying outcome after head injury or other neurological diseases.
GLIA - The major support cells of the brain. These cells are involved in the nutrition and maintenance of the nerve cells. Also known as neuralgia.
GLIOBLASTOMA - A general term for malignant forms of astrocytoma.
GLIOMA - A tumor formed by glial cells.
GLOBUS PALLIDUS - Part of the basal ganglia, which are brain cells that lie deep in the brain.
H
HEMANGIOMA - A benign tumor consisting of a mass of blood vessels.
HEMATOMA - A blood clot.
HEMIANOPIA - Loss of vision of one-half of the visual field.
HEMIATROPHY - Atrophy of half of an organ or half of the body.
HEMIPLEGIA - Paralysis of one side of the body.
HEMISPHERECTOMY - Excision of one cerebral hemisphere undertaken for malignant tumors. Intractable epilepsy sufferers usually associate with infantile hemiplegia due to birth injury and other cerebral conditions.
HEMORRHAGE - Bleeding due to the escape of blood from a blood vessel.
HERNIATED DISC - Extrusion of part of the nucleus pulposus material through a defect in the annulus fibrosis.
HERNIATED NUCLEUS PULPOSUS (HNP) - Extrusion of the central portion of an intervertebral disc through the outer cartilaginous ring. The material can compress the spinal cord or nerves in or exiting the spinal canal.
HETEROTOPIC BONE FORMATION - The occurrence of bone growth in an abnormal location.
HOOK - For spinal applications, a metallic medical device used to connect spinal structures to a rod.
HORMONE - A chemical substance formed in one gland or part of the body and carried by the blood to another organ, which it stimulates to functional activity.
HYDROCEPHALUS - A condition, often congenital, marked by abnormal and excessive accumulation of cerebrospinal fluid in the cerebral ventricles. This dilates the ventricles, and in infants and young children causes the head to enlarge.
HYDROMYELIA - Expansion of the spinal cord due to increased size of the central canal of the cord which is filled with CSF.
HYDROXYAPATITE (HA) - The lattice-like structure of bone composed of calcium and phosphorous crystals which deposits on collagen to provide the rigid structure of bone.
HYPERACUSIS - Abnormal acuteness of hearing or auditory sensation.
HYPERESTHESIA - Excessive sensibility to touch, pain, or other stimuli.
HYPERTENSION - High blood pressure.
HYPOPHYSECTOMY - Excision of the hypophysis cerebri.
HYPOPHYSIS CEREBRI - A gland of internal secretion lying on the upper surface of the sphenoid (wedge shaped) bone.
HYPOTHALAMUS - A collection of specialized nerve cells at the base of the brain which control the anterior and posterior pituitary secretions and is involved in other basic regulatory functions, such as temperature control and attention.
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ILIAC BONE - A part of the pelvic bone that is above the hip joint and from which autogenous bone grafts are frequently obtained.
ILIAC CREST - The large, prominent portion of the pelvic bone at the belt line of the body.
IMMOBILIZATION - Limitation of motion or fixation of a body part usually to promote healing.
IN VITRO - Describing biological phenomena that are made to occur outside the living body traditionally in a test tube. In vitro is Latin for in glass.
IN VIVO - Within a living body. In vivo is Latin for in life.
INFERIOR - Situated below or directed downward.
INFORMED CONSENT - Consent of the patient who has received sufficient information to have surgery, receive medication, or participate in a clinical study.
INFRATENTORIAL - Beneath the tentorium.
INFUNDIBULUM - A stalk extending from the base of the brain to the pituitary gland.
INSTITUTIONAL REVIEW BOARD (IRB) - A committee designated by an institution, such as a hospital, to review and approve research projects, e.g., clinical studies in that institution.
INTERNAL FIXATION - The immobilization of bone fragments or joints with implants in order to promote healing or fusion.
INTERVERTEBRAL DISC - See disc.
INTRA-AORTIC BALLOON COUNTER PULSATION DEVICE - A pump which is inserted into the main vessel of the body, the aorta, to help the heart deliver blood to critical organs, such as the brain or kidneys.
INTRA-ARTERIAL CATHETERIZATION ANGIOGRAPHY - An invasive study in which a catheter is placed in the artery and contrast material is injected which makes the blood vessels visible on an x-ray image. The catheter is inserted in the groin into the femoral artery through a needle and is guided into the arteries in the neck and head. This study is associated with a very small (less than 0.05% chance of serious complications) and requires the patient to lie in bed for approximately six hours to allow the leg vessel to heal.
INTRACEREBELLAR - Within the cerebellum.
INTRACEREBRAL - Within the cerebrum.
INTRACEREBRAL HEMATOMA - A blood clot within the brain.
INTRACRANIAL - Within the cranium of the skull.
INTRAOPERATIVE CISTERNOGRAPHY - Administration of a contrast dye into the ventricles, which are chambers in the brain that contain brain fluid.
INTRINSIC - Situated entirely within or pertaining exclusively to a part.
INVESTIGATIONAL DEVICE EXEMPTION (IDE) - A FDA regulatory status which permits the human use of an unapproved medical device for the purposes of collecting clinical data under strictly controlled conditions.
ISCHEMIA - Inadequate circulation of blood generally due to a blockage of an artery.