A
ABCESS - A localized collection of pus in any part of the body.
ACOUSTIC NEURINOMAS - Benign tumor of the hearing nerve (eighth nerve). A progressively enlarging, benign tumor, usually within the internal auditory canal or hearing nerve.
ACROMEGALY - Disorder marked by progressive enlargement of the head, face, hands, feet, and thorax, due to the excessive secretion of growth hormone.
ACTION TREMOR - A type of tremor that occurs during voluntary movements, such as lifting a cup to one's mouth.
ACTIVA TREMOR CONTROL THERAPY - The therapy uses an implanted device to deliver mild electrical stimulation to block the brain signals that cause tremors. The therapy stimulates the target nuclei in the thalamus via an insulated wire lead with electrodes that are surgically implanted in the brain and connected to a pulse generator that is implanted near the collarbone. The stimulation level can be adjusted to get the most possible tremor control with minimal side effects.
ACUTE - Severe, for a short time.
ADENOCARCINOMA - Cancer arising from secretory cells, often in a gland. Breast and pancreatic cancers are usually adenocarcinomas.
ADENOMA - A benign growth formed of glandular tissue.
AEDs - Anti-epileptic drugs.
AFFERENT NEURON - Transmits impulses to the central nervous system.
AGNOSIA - Absence of the ability to recognize the form and nature of persons and things.
AGRAPHIA - Loss of the power of writing, due either to muscular incoordination or to an inability to phrase thought.
ALLOGRAFT BONE - Sterile bone derived from another human, used for grafting procedures.
AMAUROSIS - Loss of vision without discoverable lesion in the eye structures or optic nerve.
AMAUROSIS FUGAX - Temporary blindness occurring in short periods.
AMENORRHEA - Absence of the senses, due to causes other than pregnancy or advancing age.
AMNESIA - Loss of memory caused by brain damage or by severe emotional trauma.
ANALGESIA - Loss of sensibility to pain, and/or loss of response to a painful stimulus.
ANAPLASIA - In the case of a body cell, a reversion to a more primitive condition. A term used to denote the alteration in cell character which constitutes malignancy.
ANASTOMOSIS - In the nervous system, a jointing of nerves or blood vessels.
ANENCEPHALY - Absence of the greater part of the brain, often with skull deformity.
ANESTHESIA - Loss of sensation of a body part or of the body when a drug has been administered.
ANESTHESIOLOGIST - Physician who administers painkilling medications during surgery.
ANEURYSM - Dilation of an artery, formed by a circumscribed enlargement of its wall.
ANGIOGRAM - A study which shows the blood vessels leading to and in the brain by injecting a dye, or contrast substance, through a catheter placed in an artery in the leg.
ANGIOGRAPHY - Radiography of blood vessels using the injection of material opaque to x-rays to give better definition to the vessels.
ANGIOMA - A tumor whose cells tend to form blood vessels (hemangioma) or lymph vessels (lymphangioma).
ANNULUS FIBROSIS - The outer, fibrous, ring-like portion of an intervertebral disc.
ANOREXIA - A condition marked by loss of appetite leading to weight loss.
ANOSMIC - No sense of smell.
ANOXIA - Total lack of oxygen supply.
ANTERIOR - Front of the body or situated nearer the front of the body.
ANTEROLATERAL - Situated or occurring in front of and to the side.
ANTICOAGULANT - A medication that prevents coagulation of the blood.
ANTI-DIURETIC - An agent which reduces the output of urine. Anti-diuretic hormone (ADH) is formed in the hypothalamus and stored in the posterior pituitary gland.
APHASIA - Difficulty with or loss of use of language in any of several ways, including reading, writing, or speaking. Failure of understanding written, printed, or spoken word. Related to specific lesions in the brain.
APNEA - Cessation of respiration; inability to get one's breath.
APOPLEXY - A sudden event that is equivalent to a stroke.
ARACHNOID - 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.
AREA - (Cortical) - A part of the brain having a special function as in
- Motor a. - The cortical portion of the brain controlling movement.
- Sensory a. - The cortical portion of the brain controlling sensation.
ARNOLD-CHIARI MALFORMATION - A condition in which there is displacement of the medulla and cerebellum into the opening in the basilar part of the occipital bone. It is one of the causes of hydrocephalus and is usually accompanied by spina bifida and menigomyelocele.
ARTERIOGRAPHY - See angiography.
ARTERIOSCLEROSIS - Thickening and calcification of the arterial wall with loss of elasticity and contractility.
ARTERIOVENOUS - Relating to both arteries and veins.
ARTERIOVENOUS MALFORMATION (AVM) - Collection of blood vessels with one or several abnormal communications between arteries and veins which may cause hemorrhage or seizures.
ARTHRALGIA - Joint pain.
ARTHRITIS - Inflammation of a joint, usually characterized by swelling, pain and restriction of motion.
ARTHRODESIS - The fusion of bones across a joint space, thereby limiting or eliminating movement. It may occur spontaneously or as a result of a surgical procedure, such as fusion of the spine.
ARTHROPATHY - Any disease or disorder involving a joint.
ARTHROPLASTY - The surgical remodeling of a diseased or damaged joint.
ARTHROSCOPE - An instrument inserted into a joint cavity to view the interior of a joint and correct certain abnormalities.
ARTHROSCOPY - The procedure of visualizing the inside of a joint by means of an arthroscope.
ARTICULAR - Pertaining to a joint.
ASTROCYTE - Cell which supports the nerve cells (neurons) of the brain and spinal cord.
ASTROCYTOMA - 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.
ATHETOSIS - A condition in which there is a succession of slow, writhing, involuntary movements of the fingers and hands, and sometimes of the toes and feet.
ATONIC SEIZURE - Seizures that are characterized by a sudden loss of muscle tone, causing the individual to instantly drop to the floor, commonly known as "drop attacks."
ATROPHY - A wasting of the tissues of a body part.
AURA - Warning sign that people with epilepsy often experience prior to the onset of a seizure, which may consist of a strange taste, bad feeling, or tingling sensation.
AUTOGENOUS BONE - Bone originating from the same individual; i.e., an individual's own bone.
AUTOGRAFT BONE - Bone transplanted from one part to another in the same individual's body.
AUTOLOGOUS GROWTH FACTORS (AGF) - Autologous Growth Factors are the body's own natural healing response, concentrated 6-10 times, suspended in a firm fibrin gel. AGF are collected from a unit of blood at the beginning of surgery and are mixed with both autologous bone (posteriorly) and allograft bone (anteriorly).
AUTONOMIC NERVOUS SYSTEM - Involuntary nervous system. Also termed the vegetative nervous system. A system of nerve cells whose activities are beyond voluntary control.
AVASCULAR - Non-vascular; not provided with blood vessels.
AXON - The part of a nerve cell that usually sends signals to other nerves or structures.
B
BACKBONE - See spine.
BACTERICIDAL - Causing the death of bacteria.
BACTERIOSTATIC - Inhibiting or retarding the growth of bacteria.
BELL'S PALSY - Paralysis of facial muscles (usually one side) due to facial nerve dysfunction of unknown cause.
BENIGN - Not cancerous; does not invade nearby tissue or spread to other parts of the body.
BIOABSORBABLE POLYMER - A substance, such as some plastics, which the human body can break down and absorb.
BIOCOMPATIBILITY - A characteristic of some materials that when they are inserted into the body do not produce a significant rejection or immune response.
BIODEGRADATION - The breakdown of organic materials into simple chemicals commonly found in the body.
BIOPSY - Removal of a small portion of tissue, usually for the purpose of making a diagnosis.
BLOOD-BRAIN BARRIER - The barrier which exists between the blood and the cerebrospinal fluid which prevents the passage of various substances from the bloodstream to the brain.
BONE - The hard tissue that provides structural support to the body. It is primarily composed of hydroxyapatite crystals and collagen. Individual bones may be classed as long, short, or flat.
BONE DERIVATIVE - One of the substances extracted from bone, such as bone morphogenic proteins (BMP).
BONE GRAFT - Bone which is harvested from one location in an individual and placed in another individual (allograft bone) or in a different location in the same individual (autogenous bone).
BONE MARROW - The tissue contained within the internal cavities of the bones. A major function of this tissue is to produce red blood cells.
BONE PLATE - Usually a relatively thin metal device which is affixed to bone via screws. Bone plates are used to immobilize bones or bone fragments so that healing can occur.
BONE SCREW - A threaded metal device which is inserted into bone. The functions of bone screws are to immobilize bones or bone fragments or to affix other medical devices, such as metal bone plates, to bones.
BRADYCARDIA - Slowness of the heart rate.
BRADYKINESIA - Slowness in movement.
BROWN-SEQUARD'S SYNDROME - 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.
BURR - An electrical drilling tool for enlarging atrephine (circular) hole in the cranium.
C
CADAVER - A term generally applied to a dead human body that is preserved for anatomical study.
CALLOSUM - The great commisure of the brain between the cerebral hemispheres.
CANCELLOUS BONE - The spongy or honeycomb structure of some bone tissue typically found at the ends of long bones.
CARCINOMA - Cancer; a malignant growth of epithelial or gland cells.
CAROTID ARTERY - Large artery on either side of the neck that supplies most of the cerebral hemisphere.
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.
CARPAL TUNNEL - Space under a ligament in wrist through which the median nerve enters the palm of the hand.
CARPAL TUNNEL SYNDROME - A condition caused by compression of the median nerve in the carpal tunnel. Characterized especially by discomfort and disturbances of sensation in the hand.
CARTILAGE - The hard, thin layer of white glossy tissue that covers the end of bone at a joint. This tissue allows motion to take place with a minimum amount of friction.
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.
CAUDA EQUINA - The bundle of spinal nerve roots rising from the end of the spinal cord and filling the lower part of the spinal canal (from approximately the thoraco-lumbar junction down).
CAUDATE NUCLEUS - Part of the basal ganglia, which are brain cells that lie deep in the brain.
CENTRAL NERVOUS SYSTEM - Part of the nervous system which consists of the brain and spinal cord, to which sensory impulses are transmitted and from which motor impulses pass out, and which supervises and coordinates the activity of the entire nervous system.
CENTRUM - The body of a vertebra.
CEREBELLUM - The lower part of the brain which is beneath the posterior portion of the cerebrum and regulates unconscious coordination of movement.
CEREBRAL - Relating to the brain or intellect.
CEREBRAL CORTEX - Surface layer of gray matter of the cerebrum that functions chiefly in coordination of higher nervous activity; also called pallium.
CEREBRAL PALSY - Disability resulting from damage to the brain before or during birth and outwardly manifested by muscular incoordination and speech disturbances.
CEREBROSPINAL FLUID (CSF) - Water-like fluid produced in the brain that circulates around and protects the brain and spinal cord. Shrinking or expanding of the cranial contents is usually quickly balanced by increase or decrease of this fluid.
CEREBRUM - The principal portion of the brain that occupies the major portion of the interior of the skull and controls conscious movement, sensation, and thought.
CERVICAL - Of or relating to the neck.
CHEMONUCLEOLYSIS - A treatment of an intervertebral disc that consists of an injection of chymopapain, a drug that dissolves part of the disc.
CHIASM (OPTIC) - Crossing of visual fibers as they head toward the opposite side of the brain. For each optic nerve, most of the visual fibers cross to the opposite side, some run directly backward on each side without crossing.
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 which produce cerebrospinal fluid.
CINGULATE GYRUS - A long, curved convolution of the medial surface of the cortical hemisphere.
CINGULOTOMY - Electronic destruction of the anterior cingulate gyrus and callosum.
CLINICAL STUDIES - A process of strictly controlled evaluations involving patients. Some of these studies are required by the FDA prior to general release of a device or compound for use in humans.
COAGULATION - The process of clotting.
COBALT-CHROME - A term that is used in referring to cobalt-chromium-molybdenum alloy, a mixture of metals used in many surgical implants.
COCCYX - The small bone at the end of the spinal column in humans, formed by the fusion of four rudimentary vertebrae. Also known as the "tail bone."
COLLAGEN - A fibrous protein which is a major constituent of connective tissue, such as skin, tendons, ligaments, cartilage, and bones.
COMA - A state of profound unconsciousness from which one cannot be roused.
COMMINUTED FRACTURE - A fracture in which a bone is broken into more than two pieces. Often, internal or external fixation devices are used to maintain proper alignment of the fragments.
COMPUTED TOMOGRAPHY (CT) SCAN - A diagnostic imaging technique in which a computer reads x-rays to create a three-dimensional map of soft tissue or bone.
CONCUSSION - A disruption, usually temporary, of neurological functions resulting from a blow or violent shaking.
CONTRAST MEDIUM - Any material (usually opaque to x-rays) employed to delineate or define a structure during a radiological procedure.
CONTUSION - A bruise. An area in which blood that has leaked out of blood vessels is mixed with tissue.
CORONAL SUTURE - The line of junction of the frontal bones and the parietal bones of the skull.
CORPUS CALLOSUM - The greatest commissure of the brain between the cerebral hemispheres.
CORTEX - The external layer of gray matter covering the hemispheres of the cerebrum and cerebellum.
CORTICAL - Pertaining to the cortex.
CORTICAL BONE - The dense bone that forms the outer surface of bone.
CRANIECTOMY - Opening of skull and removal of a portion of it.
CRANIOPHARYNGIOMA - 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 - Opening of the skull, usually by cutting a flap of bone.
CRANIUM - The part of the skull that holds the brain.
CSF - See cerebrospinal fluid.
CSF SHUNT - A bypass or diversion of accumulations of cerebrospinal fluid to an absorbing or excreting system.
CYTOLOGY - Study of cells.