Medical Glossary

Abduction: Movement of an arm or leg away from the body.

Acute: Having rapid onset, severe symptoms, and a short course; not chronic.

Adduction: Movement of an arm or leg toward the body.

Adhesions: The process of uniting tissue surfaces as a result of a wound or inflammation.

Amyotrophic: Muscle wasting.

Anomaly: A deviation from the average or norm. Anything structurally unusual or irregular, i.e., presence of an extra finger or absence of a limb or congenital malformation.

Anterior: Pertaining to the front of the body.

Antiemetics: Medication to stop or prevent vomiting.

Apnea: Cessation of breathing noted by color changes, pallor and/or cyanosis, and lack of chest wall movement. Can be caused by compression of the brainstem or lower cranial nerves.

Arachnoid: Delicate, web-like middle layer of the three membrane layers that covers the brain and spinal cord; arachnoid mater.

Arachnoiditis: Inflammation of the arachnoid membrane.

Arnold Chiari Malformation (CM): Herniation of the brainstem and lower cerebellum through the foramen magnum into the cervical vertebral canal.

Ascending Tracts: Groups of nerve fibers in the spinal cord that transmit sensory impulses upward to the brain.

Aseptic: Sterile, without bacteria; living pathogenic organisms are absent.

Aseptic Meningitis: Inflammation of the membranes (meninges) that cover the brain and spinal cord. NOT an infection.

Aspiration: The act of withdrawing a fluid from the body by a suction device. Inspiratory sucking into the airways of fluid or foreign body, such as vomit.

Astrocytes: A type of neuroglial cell that functions to connect neurons to blood vessels.

Asymptomatic: Without symptoms, or producing no symptoms.

Ataxia: Inability to coordinate the muscles in voluntary muscular movements that is symptomatic of any of several disorders of the nervous system.

Atrophy: A wasting of tissues or decrease in size of a part of the body because of disease or other influences.

Atypical: Not typical.

Autonomic Nervous System: Portion of the nervous system that functions to control the actions of the visceral organs and skin.

Axon: A nerve fiber that conducts a nerve impulse away from a neuron cell body.

Barium Swallow: An x?ray using barium to view the act of swallowing, the esophagus or stomach; can show if a person may be aspirating.

Basal Ganglion: Mass of gray matter located deep within a cerebral hemisphere of the brain; has important functions in automatic movements of the limbs and in the control of muscle tonus.

Basilar Impression: An invagination (to unsheathe or place one part of a structure within the same structure) of the base of the skull into the posterior fossa with compression of the brainstem and cerebellar structure into the foramen magnum.

Bilateral: Something that occurs or appears on both sides. A patient with equal strength bilaterally means he has equal strength on both sides of his body.

Brain Stem: The portion of the brain that includes the midbrain, pons and medulla, thalamus and hypothalamus.

Calamus Sciptorius: Arantius' ventricle, inferior part of the rhomboid fossa; the narrow lower end of the floor of the fourth ventricle of the brain. It is shaped like a pen and lies between the restform bodies.

Canalization Neurulation: The formation of canals or passages to form the neural tube during the early stages of embryonic development.

Catheter: A tube that is designed for insertion into vessels, canals, passageways or body cavities to permit the injection or withdrawal of fluids or substances. It can also be used to keep a passageway open.

Caudal: Toward the end of the spine.

Central Nervous System (CNS): The part of the nervous system consisting of the brain and spinal cord which coordinates the entire nervous system of the body.

Cerebellar Cortex: The outer layer of the cerebellum.

Cerebellar Speech: Abnormal speech patterns seen in people who have a disease of the cerebellum; a slow, jerky, and slurred speech that may come and go or it may be unvaried in pitch.

Cerebellar Tonsils: Two bulges at the bottom of the cerebellum.

Cerebellomedullary: Refers to the area where the cerebellum and the medulla are in the brainstem.

Cerebellum: Portion of the brain that lies in the posterior fossa and coordinates skeletal muscle movement.

Cerebral Aqueduct: A narrow conduit (tube), between the third and the fourth ventricles; located in the midbrain. CSF moves from the third ventricle through the cerebral aqueduct to the fourth ventricle.

Cerebral Cortex: The outer layer of the cerebrum.

Cerebral Hemisphere: One of the large, paired structures that together constitute the cerebrum of the brain.

Cerebral Spinal Fluid (CSF): Fluid that occupies the ventricles of the brain, subarachnoid space of the meninges, and the central canal of the spinal cord.

Cerebrum: Portion of the brain that occupies the upper part of the cranial cavity.

Cervical: Pertaining to the area of the neck where there are seven cervical vertebrae. They are counted from top to bottom. At the top there is the first cervical vertebra often referred to as C1, then the second, C2, followed by C3, C4, C5, C6, and C7.

Charcot Joint: A type of diseased joint associated with varied conditions; syringomyelia among them, which involves disease or injury to the spinal cord. It is characterized by hypermobility. Decalcification of bone on joint surfaces occurs accompanied by overgrowth of bone. This results in deformity and instability of the joint. Pain is uncharacteristic, but may occur.

Choroid Plexi: A network or interjoining; a vascular proliferation or fringe of the tela choridea (the pia mater brain membrane which covers part of the roof of the fourth ventricle) in one of the cerebral ventricles; by secretion or absorption of the CSF the choroid plexi serves to regulate the intraventricular pressure.

Choroid Plexus: Mass of specialized capillaries that lines the ventricles in the brain; these capillaries secrete cerebral spinal fluid.

Chronic: Long lasting; a disease having a long course; not acute.

CINE MRI: A test that is done in the MRI scanner that looks at the flow of CSF around the cerebellum and into the spinal canal.

Cisterna Magnum: A cavity, a dilation of the subarachnoid space which is located between the cerebellum and the medulla. It receives CSF from the fourth ventricle via the medial foramen of Magendie.

Clonus: A series of alternating muscle contractions and partial relaxations that produce a convulsive spasm.

CM: Chiari malformation.

Coele or Cele: Related to a cavity or space; refers to swelling tumor protrusion.

Congenital: Existing at birth; usually refers to certain mental or physical traits, peculiarities, or diseases; is a more general term than hereditary since congenital includes conditions due to influences arising during gestation.

Contraindicated: A medication or procedure that is not advisable. i.e., tetracycline is contraindicated during pregnancy.

Contrast: The difference between two areas in an image; it enables the radiologist to see details.

Conus medullaris: The lowest end of the spinal cord.

Cranial nerves: The 12 nerves of the brain that control motor and sensory functions, including swallowing, heart rate, eye movement and smell.

Craniectomy: The excision (removal) of part of the skull.

CSF: Cerebral spinal fluid.

CT scan: A specialized x?ray that takes images around the body that are reconstructed by a computer to give a more detailed image than a standard x-ray.

Cyanosis: Blue or purple color to the skin and mucous membranes caused from not having enough oxygen in the blood.

Dandy Walker: A syndrome characterized by hydrocephalus in infants associated with an abnormal closure of the passage at the foramina of Luschka and Magendie.

Decompression: To take pressure off, relieve pressure.

Diencephalon: Portion of the brain in the region of the third ventricle that includes the thalamus and hypothalamus.

Diplopia: Double vision; occurs when the two eyes are unable to fix (look at) the same point.

Dissociation of Sensation: The simultaneous preservation of light touch sensation and loss of pain and temperature sensation.

Distal: Moving further from the midline of the body.

Dorsal: Same as posterior, pertains to the back of the body.

Dura Mater: Tough outer layer of the membranes surrounding the brain and spinal cord.

Dysarthria: Speech that is difficult and poorly articulated caused by damage to a motor nerve.

Dysequilibrium: Inability to maintain proper balance.

Dyesthesia: Impairment in sensation. Sensation of pins and needles, loss of feeling of touch, painfulness of any sensation which is not normally painful.

Dysmetria: An inability to fix the range of movement in muscular activity. Rapid and brisk movements are made with more force than necessary. Often seen in cerebellar disorders.

Dysphagia: Inability to swallow or difficulty in swallowing.

Dysplastic Tonsil: Abnormal development of a cerebellar tonsil. The cerebellum base has two areas called tonsils.

Dyspnea: Labored or difficulty in breathing resulting in air hunger.

Ectopia: Malposition or displacement of any organ or structure ? congenital or acquired.

Edema: An excessive accumulation of fluid within the tissue spaces.

Elongated: To make or to grow longer.

Enuresis: Involuntary passage of urine, usually during sleep.

Epidural Space: The space between the dura and the bone of the vertebral canal.

Esophagus: The muscular tube extending from the back of the throat from the pharynx to the stomach.

Excision: To cut away a portion.

Extremity: A limb; an arm or leg.

Fascialata graft: A graft?covering or repair of tissue with fascia ? the fibrous membrane which covers and separates muscles, organs.

Fasciculations: Involuntary contractions, or twitching of groups of muscle fibers, a courser form of muscle contractions than fibrillation.

Filum Terminale: A long slender filament at the end of the spinal cord.

Foramen: An opening usually in a bone or organ of membrane (plural is foramina).

Foramen Magnum: A large opening in the base of the skull through which the spinal cord becomes continuous with the medulla oblongata.

Foramina of Luschka: An opening or passage ? lateral of the fourth ventricle

Fossa: A depression on the surface of the end of a bone.

Fourth ventricle: Ventricle (a normal cavity) of the rhombencephalon of the brain; a cavity of irregular tent-like shape extending from the obex frontward to its communication with the sylvian aqueduct, enclosed between the cerebellum and the rhombencephalic tegmentum. The ventricle of the brain which lies between the cerebellum and the brainstem. It expresses CSF into the subarachnoid space via the two lateral foramina of Luschka and the single medial foramen of Magendie.

Gait: Manner of walking.

Giliogenous: Of the nature of neuroglia, glia ? the tissue which forms the support element of cells and fibers of the nervous system.

Gliosis: Proliferation (growth by reproduction) of the neuroglial tissue in the central nervous system.

Greenstick Fracture: A bone break in which the bone is bent but broken only on the outside of the bend.

Gyrus: One of the convolutions of the cerebral hemispheres of the brain. The upraised ridges of the cerebrum.

Hemiplegia: Paralysis or severe weakness (paresis) of one side of the body, usually due to injury or disease of the brain or spinal cord.

Hemivertebrae: A congenital absence of half of a vertebra.

Horner Syndrome: A condition with contraction of the pupil, partial drooping of the eyelid, recession of eyeball back into socket, and sometimes loss of sweating over the affected side of the face, due to paralysis of the cervical sympathetic nerve trunk.

Hydro: Water, or collection of watery fluid.

Hydrocephalus: An increased accumulation of CSF within the ventricles of the brain, resulting from interference with normal circulation and with absorption of the fluid, especially from destruction of the formation of the foramina of Magendie and Lushka. This may also result from developmental anomalies, infection, injury, or brain tumors.

Hydromyelia: Accumulation of fluid in the enlarged central canal of the spinal cord.

Hyper: Prefix meaning above, excessive, or beyond.

Hyperreflexia: Increase in action of the reflexes.

Hypo: Prefix meaning less than, below, or under.

Hypoplasia: Defective development of tissue.

Hyporeflexia: Decrease in the action of the reflexes.

Hypotonia: Reduced tension, relaxation of arteries. Loss of muscle tone.

ICP: Intercranial pressure.

Idiopathic: Pertaining to conditions without clear cause, as of spontaneous origins.

Impulse: A wave of depolarization conducted along a nerve fiber or muscle fiber.

Increased Intracranial Pressure (ICP): An increase in CSF production or blockage resulting in pressure on the brain. The skull cannot expand to accommodate the pressure which leads to symptoms.

Inferior: Situated below something else, pertaining to the lower surface of a part.

Insidious: A disease which comes on in such a manner, with a lack of symptoms, that the patient is unaware of the onset of the disease.

Interpedicular Spaces: Space between the pedicles of the vertebrae.

Invasive Procedures: A medical procedure which necessitates entrance into the body as part of the action required.

Ipsilateral: On the same side; affecting the same side of the body. Said of findings (paralysis) appearing on the same side of the body as the brain or spinal cord lesion producing them.

Ischemia: A deficiency of blood in a part of the body.

Klippel Feil Syndrome: Congenital anomaly characterized by a short wide neck, low hairline, reduction in the number of cervical vertebrae, and fusion of the cervical spine. The hairline on the back of the neck is quite low. The central nervous system may be affected.

Kyphosis: Abnormal curvature of the spine. Gives rise to the condition commonly called hunchback.

Laminectomy: The surgical removal of the posterior arch of a vertebra.

Larynx: Structure located between the pharynx and trachea that houses the vocal cords.

Lateral: Pertaining to the side of the body.

Lumbar: The lower portion of the spine that consists of 5 vertebrae.

Magnetic Resonance Imagery (MRI): A scanner using magnetic energy to give a clear black and white picture of the brain and cervical canal.

Medial: Toward or near the middle of the body.

Medulla Oblongata: Portion of the brain stem located between the pons and the spinal cord.

Meninges: A group of three membranes that covers the brain and spinal cord. Closest to the brain and spinal cord is the pia, then the arachnoid, and the outermost covering is the dura.

Meningitis: Infection or swelling of the membrane (meninges) that covers the brain and spinal cord.

Meningo: Refers to the meninges, membranes covering the brain and spinal cord.

Mesencephalon: The midbrain, one of three primitive cerebral sacs from which develop the copora quadrigemina, the crura cerebri, and the aqueduct of Sylvius.

Microgyri: Smallest of the cerebral convolutions.

Morvans Chorea type: A condition with irregular uncontrollable movements.

Myelo: Refers to the spinal cord.

Myelodysplasia: Defective formation of the spinal cord.

Myelogram: X?ray inspection of the spinal cord by use of a radiopaque medium injected into the intrathecal space (area within the spinal cord) of the spine.

Myelomeningocele: Form of spina bifida in which portions of the spinal cord and its membranes protrude through the open space in the vertebral column.

Myelotomy: Surgical severing of nerve fibers of the spinal cord.

Necrosis: Death of areas of tissue surrounded by healthy parts connect the brain and the spinal cord with other parts of the body.

Neurovascular Bundle: Structure consisting of a group of nervous and blood vessel tissues.

Nissen Fundoplication: An operation of the fundus of the stomach which sutures the fundus of the stomach to the esophagus as a treatment for gastric reflux.

Nuchal Rigidity: Muscle stiffness in the back of the neck.

Nystagmus: Constant, involuntary, cyclical movement of the eyeball. Movement may be in any direction. May be constant or elicited. May be due to congenital conditions, occupational, labyrinithine irritability, or neurological disease.

Obex: A thin, crescent?shaped band of tissue covering the calamus scriptorius ? at the point of convergence of the nervous tissue at the end position of the fourth ventricle. The point on the midline of the top surface of the medulla oblongata that marks the tail end of the fourth ventricle.

Occipital: The back of the head.

Occipital Bone: The cup-like bone at the back of the skull, marked by a large opening known as the foramen magnum.

Opisthotonos: Backward arching of the head, neck, or back with stiffness of the entire body.

Papilledema: Swelling of the optic nerve at the point of entrance into the eyeball. Choked disk.

Paraparesis: Partial paralysis affecting the lower limbs.

Paraspinous muscles: Muscles on either side of the spine.

Paresthesia: Abnormal sensation such as numbness, prickling, and tingling.

Paucity: Smallness or lower in number.

Peduncle: A band connecting parts of the brain. A stem or stalk. There are many of these in the brain connecting various structures.

Percutaneous aspiration: Drawing in or out through the skin.

Peritoneum: The membrane covering the visceral organs and lining the abdominal cavity.

Permeable: Capable of allowing passage of fluid or substances in solution.

Pia Mater: The inner membrane of the meninges that encloses the brain and spinal cord.

Platybasia: A developmental anomaly of the skull or an acquired softening of the skull bones so that the floor of the posterior cranial fossa bulges upward in the region adjacent to the foramen magnum.

Pleural: The membranes around the lungs.

Pleural Space: Space between the lungs and the membranes that surrounds the lungs.

Polygyria: Excess of the normal number of convolutions of the brain.

Posterior: Toward the back of the body.

Posterior Fossa: Depression in the back of the skull where the cerebellum lies.

Posterior Fossa Angiogram: A study of the blood vessel structures of the back of the brain cerebrum.

Prone: Lying horizontal with face down.

Proprioception: The awareness of posture, movement, and changes in equilibrium and the knowledge of position, weight, and resistance of an object in relation to the body.

Proximal: Closer to the midline or origin; opposite of distal.

Ptosis: When one or both upper eyelids droop because of weakness often related to the third cranial nerve.

Queckenstedt: A sign or maneuver used for diagnostic purposes. Upon compression of the veins of the neck, unilaterally or bilaterally, CSF pressure rises rapidly in healthy persons; this disappears when pressure is released. In ventral canal block, the pressure is scarcely affected by this procedure.

Reflex: A rapid automatic response mediated by the nervous system.

Reflux: A return or backwards flow. Regurgitation.

Respiratory Distress: Noisy congested breathing, difficulty breathing and retractions.

Reticular Formation: Groups of cells and fibers arranged in a diffuse network throughout the brain stem. They fill and connect the tracts which ascend and descend through this area. They are important in controlling or influencing alertness, wakefulness, sleeping, and some other reflexes.

Rhomboencephalon: A primary division of the embryonic brain which gives rise to the metencephalon and myelencephalon. It includes the pons, cerebellum, and medullar oblongata. Sometimes called the hindbrain.

Sagittal: A plane or section that divides a structure into right and left portions.

Scoliosis: A side to side curvature of the vertebral column.

Sensory: Pertaining to or conveying sensation (i.e., pain, touch, temperature).

Sheath: A covering structure, usually elongated.

Shunt: Passage constructed to divert flow from a normal route to another.

Skull Series: A group of x?rays taken of the skull from various positions.

Sleep Apnea: To stop breathing for brief periods while sleeping.

SM: Syringomyelia

Somatosensory Evoked Potentials: A test of the brain using electrical stimulation to look at reactions of body sensations relating to the bodys superficial and deep parts as contrasted to specialized senses such as sight. Responses to these tests are used in evaluations of neurological diseases.

Spasticity: Stiffness or position that is difficult to release.

Spina Bifida: Failure of the spine to close properly during the first month of pregnancy. In severe cases, the spinal cord protrudes through the back and may be covered by skin or a thin membrane.

Stenosis: A constriction or narrowing of a passage.

Stent: A material used to hold tissues in place or provide a support for a graft or a suturing of two ends of a tissue until healing takes place.

Strabismus: Disorder in which the two eyes cannot be directed at the same object; when one eye fixes upon a point (sees an object), the other eye deviates to some other point; vision in the deviated eye is usually suppressed, if not, diplopia results; squint.

Stridor: A harsh sound made during respiration. It is high pitched and sounds like the howling of the wind. It is due to constriction of the air passages.

Subarachanoid Space: The space within the meninges between the arachnoid mater and the pia mater.

Subcutaneous Tissue: Tissue beneath the skin.

Suboccipital: Area beneath the back of the head; below the occipital bone.

Subperiosteal: Beneath the periosteum (the membrane covering of the bones).

Sulcus: A furrow, fissure or depression, especially of the brain. There are many named in the anatomy of the brain.

Supine: Lying on the back ? a position.

Sylivan Aqueduct: A narrow canal from the third to the fourth ventricle.

Syncope: A partial or complete temporary cessation of breathing and circulation due to cerebellar ischemia. It is characterized by sudden pallor, coldness of the skin and partial or complete unconsciousness.

Syringo: Relationship to a tube or fistula (abnormal tube like passage from a normal tube or cavity to a free surface or cavity.

Syringocoele or ?cele: The central cavity or canal of the spinal cord continuous with the 4th ventricle of the brain stem; the cavity containing protrusion of the spinal cord in spina bifida.

Syringomyelia (SM): A chronic progressive disease of the spinal cord characterized by the development of fluid-filled cavities of surrounding tissues. Cavitation can occur in any area of the spinal cord. It can involve pathways of the cord that carry impulses of pain and temperature sensations resulting in sensory losses. Pain and paresthesia also occur. Destruction of lateral and anterior gray matter in the cord causes muscular atrophy, spastic paralysis, and weakness. Scoliosis is often found in association with SM.

Syringotomy: An operation to excise a fistula (an abnormal tube-like passage).

Syrinx: A pipe, tube, or cavity.

Telencephalon: The embryonic endbrain or the anterior division of the prosencephalon from the cerebral hemispheres, corpora striata, and the rhinencephalon develop.

Tentorium: A tent-like structure or part. In the brain the tentorium berebelli is the process of the fura mater between the cerebellum and the cerebrum supporting the occipital bone.

Tethered Cord: A defect in the fusion of the spinal processes and laminas seen in spinal bifida occulta. Sometimes the spinal cord is trapped at the level of the defect and may produce neurologic dysfunction. The spinal cord can also become entrapped in scar tissue that results from injury, surgery or disease process.

Thoracic: The area of the back between the cervical and lumbar region comprised of 12 vertebrae.

Tinnitus: A ringing, tinkling or buzzing sound in the ear.

Torticollis: A stiff neck caused by spasms of the neck muscles drawing the head to one side with the chin pointed to the other side. It may be congenital or acquired.

Trachea: Tubular organ that leads from the larynx to the bronchi.

Trachea Malasia: Softening of the cartilage of the trachea.

Trophic: Concerning nourishment; applied to a type of nerve believed to control the growth and nourishment of the parts they enervate (supply).

Unilateral: Pertaining to one side.

Ventral: Pertaining to the front or to the belly.

Ventricle: A cavity such as those of the brain that are filled with cerebrospinal fluid.

Ventriculography: An x?ray process used to visualize the size and shape of the brains ventricles by injecting air to displace the CSF which normally fills this space.

Ventriculo?peritoneal Shunt: A shunt or tube inserted into the ventricles of the brain attached to tubing which is placed into the abdominal or peritoneal cavity to drain excess spinal fluid from the brain.

Ventriculostomy: Establishment of an opening performed on the third ventricle to relieve hydrocephalus.

Ventriculo-subarachnoid Shunt: A shunt or tube placed in the space occupied by the cerebral spinal fluid (CSF).

Vermis: A worm-like shaped structure between the two hemispheres of the cerebellum.

Visceral: Any one of the organs found in the skull, chest, abdomen or pelvis.

Weakness: Inability to grasp or transfer an object.