alzheimers disease: The most common form of dementia in older persons that affects many areas of cognitive function. Specific pathological findings have been identified when the brain has been studied under the microscope, although no cure for the disorder has been found.

amyotrophic lateral sclerosis: (ALS, motor neuron disease, Lou Gehrigs disease). A degenerative disorder affecting the motor neuron cells and the motor tracts in the brain and spinal cord.

angiogram: An invasive diagnostic test that uses a special dye injected into the arteries by a catheter to visualize the blood vessels

aphasia: An aquired abnormality in the production or comprehension of language.

arteries: The blood vessels that carry the oxygenated blood to the organs

atherosclerosis: Thickening of the arterial wall of blood vessels due to deposition of lipids (fats) and blood clots.

atony: A lack of muscle tone, usually leading to temporary debilitation.

atrial fibrillation: An abnormal rhythm of the heart that can result in an increased risk of stroke due to the formation of emboli (blood clots) in the heart.

atrophy: Shrinkage in size of a particular structure, such as muscle groups, or of the brain.

aura: Syptoms that occur prior to a particular neurological problem (such as seizure or migraine) that serve as a warning that the abnormal spell may follow. Includes disturbances in vision, smell or perception.

autoimmune: An abnormal response of the immune system, causing antibodies and immune mediated cells to attack parts of the body. This mechanism may explain many diseases.

axon: The inner core of peripheral nerves.

BAER (brainstem auditory evoked response):Measures function of Central Nervous System, including pathway from brainstem

basal ganglia: A series of structures located deep in the brain responsible for motor movements.

benign: Usually used in the context of referring to tumors that are not cancerous.

blepharospasm: The involuntary closure of the eyes and lids.

bradykinesia: The slowing of motor movements due to dysfunction of the basal ganglia and related structures.

cataplexy: A symptom characterized by the sudden loss of postural tone, often resulting in the individual falling to the floor. Cataplexy is often part of the narcolepsy complex.

CAT Scan (computerized axial tomography): A specialized X-ray examination that is often used to visualize the brain and spinal structures.

cerebral aneurysm: A defect that results in weakness in the wall of a blood vessel that can lead to bleeding in the brain.

cerebrovascular disease: Disorders that affect the blood vessels that supply the brain that may result in a stroke.

central nervous system: Refers to the brain and the spinal cord.

cerebrospinal fluid: The fluid that surrounds the brain and the spinal cord

clonus: Brisk increase in tone with involuntary movements that result in dysfunction of the corticospinal tracts.

cluster headache: A syndrome that is more common in males resulting in one sided severe pain around the eye which usually occurs at night and is associated with nasal stuffiness, and tearing of the eye.

coma: The state of unconsciousness in which patients lie unresponsive with the eyes closed.

corticospinal tract: The nervous system structures that begin in the brain and travel to the motor neuron cell to innervate the motor nerves.

deep tendon reflexes: The deep muscle stretch reflexes that are obtained by tapping on the tendons (such as the "knee jerk").

dementia: An acquired loss of cognitive function that may affect language, attention, memory, personality and abstract reasoning.

demyelinating: An inflammatory process that disrupts the myelin coating of nervous system structures.

echocardiogram: A diagnostic test to detect abnormalities of the heart using an ultrasound probe to image the cardiac structures.

edema: Swelling; fluid is retained resulting in swollen tissues.

EEG: (electroencephalography) The diagnostic test that is used to study the brain wave activity. It is most useful to evaluate the seizure disorders.

EMG/NCV: (electromyography/nerve conduction study) A test that is used to study the nerves and muscles to help diagnose disorders that can affect them. A small needle is placed in the muscle in the EMG. Electrical conduction is studied in the NCV. The results are seen on an oscilloscope screen and compared to normal values.

encephalitis: Inflammation or infection involving the brain.

evoked potentials: A series of electophysiologic tests that help to evaluate the function of specific elements of the nervous system involved in Multiple Sclerosis.

fasciculation: Twitching of the muscles that is seen in diseases involving the peripheral nervous system.

gadolinium: A contrast agent that is given intravenously during MRI (magnetic resonance imaging) to increase visualization of specific abnormalities.

hemiparesis: Weakness that affects one side of the body.

hemorrhage: Bleeding; (such as in brain hemorrhage)

HIV: (Human immunodeficiency virus) This is the virus that affects the immune system and causes the disease known as AIDS (acquired immunodeficiency disorder).

ischemia: Lack of blood flow; (such as in ischemic stroke)

lyme disease: A disease that affects the joints, nervous system and heart that is transmitted by the deer tick, and is caused by a parasite known as a Borrelia.

lumbar puncture: (also known as a spinal tap) A procedure that involves removing some of the cerebrospinal fluid from the base of the spine. The physician will first use a local anesthetic on the skin and soft tissues in the lower back. Cerebrospinal fluid is obtained from the spinal area using a small needle and a syringe.

lacunar: A subtype of stroke that affects the deeper parts of the brain and involves the tiny perforating arteries.

MRI (magnetic resonance imaging): A technique that utilizes the properties of magnetic fields to provide images of the body.

malignant: Usually refers to tumors that are cancerous; may refer to a disease state that has a debilitating unremitting course.

meningitis: Inflammation or infection of the meninges, which are the coverings of the brain.

metastatic: Usually used to describe cancerous lesions that spread to other organs in the body.

migraine: A headache syndrome characterized by throbbing, usually one sided pain, that may be associated with nausea, vomiting and visual disturbances.

motor neuron cells: The cells located in the spinal cord that give rise to the nerves that supply the muscles.

multi-infarct dementia: A dementia that is caused by the cumulative affect of having had many strokes in the brain.

muscular dystrophy: A congenital (hereditary) disorder of the muscles resulting in weakness and dysfunction of the muscles.

myasthenia gravis: A disorder affecting the space between the nerve and the muscle (neuromuscular junction) that results in transient motor weakness of the face and limbs. Due to an autoimmune process affecting the chemical Acetylcholine.

myelin: The outer lipid rich (fatty) layer that covers nerves and nervous system pathways in the brain and spinal cord.

myopathy: A disease resulting in dysfunction of the muscles usually causing weakness and atrophy.

narcolepsy: A syndrome that is often hereditary, and characterized by repeated attacks of sudden sleep that may be associated with other specific abnormalities making up the narcolepsy complex.

NPH: (normal pressure hydrocephalus) Increase in pressure within the ventricles of the brain, causing dementia, gait difficulties and urinary incontinence.

neurons: The nerve cells of the brain that carry out neurological function.

nystagmus: The jerking "to and fro" movement of the eyes that occurs when disorders affect the control of eye movement.

paraneoplastic: Disorders that occur due to the remote effects of cancer, such as through the mechanism of hormonal or antibody production.

paresthesias: Unusual sensory symptoms of tingling, numbness or other abnormal feelings of sensation.

peripheral nervous system: Refers to the nerves and muscular structures

photophobia: Literally means "fear of light", but the term is used when bright light is bothersome to individuals. Often occurs in syndromes such as migraine headache.

plaque: The lesion that occurs in the "white matter" of the brain due to demyelination.

prophylactic: Used to describe medications or treatments that are preventative in the treatment of disease.

ptosis: Drooping of the eyelids due to weakness of the muscles responsible for keeping the lids open.

radiculopathy: Irritation and inflammation of one of the nerve roots in the vicinity of the spinal column.

REM (rapid eye-movement sleep) The stage of sleep that is characterized by decreased muscle tone, rapid eye movements and dreaming.

rigidity: Stiffness in the limbs or body due to dysfunction of the basal ganglia and related structures.

sciatic nerve: A large nerve in the lumbar-sacral spine region that is composed of multiple nerve roots that supply the lower extremities

seizure: The abnormal electrical discharge of brain cells (neurons) that results in a transient disturbance in brain function.

serotonin: An important neurotransmitter (communicates information chemically between brain cells) that is involved in the pain disorders and emotional perceptions.

sleep apnea: A disorder that results in apnea (cessation of breathing) during sleep often due to obstruction of the upper airway.

SEP (Somatosensory Evoked Response):Measures function of Central Nervous System, including pathway from the extremities.

spasticity: stiffness of the body involving the limbs that results from dysfunction of the corticospinal tracts.

spinal stenosis: A syndrome that results in narrowing of the dimensions of the spinal canal due to disc disease, bony changes ligamentous thickening and congenital factors.

status epilepticus: Seizures that continue for more than twenty minutes without an intervening period of responsiveness.

subarachnoid hemorrhage: Bleeding in the area surrounding the brain, that is usually a result of the rupturing of a cerebral aneurysm in the brain.

tensilon test: A diagnostic test that is used to confirm the disease Myasthenia Gravis. A substance that interferes with the breakdown of acetycholine is injected intravenously, and the response is monitored.

TIA: (Transient Ischemic Attack); Neurological symptoms occur due to transient interruption of the blood flow to the brain.

torticollis: The involuntary turning of the neck to one side that can be seen in disorders of the basal ganglia.

toxoplasmosis: A parasitic disease that affects the brain that occurs in patients who are immunosuppressed (such as those individuals with AIDS)

VER(Visual Evoked Responses): Measures function of Central Nervous System, including the pathway from optic tract.

vertebrae: Bones that make up the spinal column.

vertigo: Dizziness or imbalance that often has a spinning or rotational component.

vestibular system: The parts of the nervous system that control equilibrium and balance.

white matter: The lipid rich myelinated portion of the brain and spinal cord.