Glossary of MS Terminology

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Having rapid onset, usually with recovery; not chronic or long lasting.
Ataxia: The incoordination and unsteadiness that result from the brain's failure to regulate the body's posture and the strength and direction of limb movements. Ataxia is most often caused by disease activity in the cerebellum.
Autoimmune disease: A process in which the body's immune system causes illness by mistakenly attacking healthy cells, organs, or tissues in the body that are essential for good health. Multiple sclerosis is believed to be an autoimmune disease, along with systematic lupis erythematosus, rheumatoid arthritis, scleroderma, and many others. The precise origin and pathophysiologic processes of these diseases are unknown.
autoimmunity: in medicine, condition where the body’s immune responses are mobilized not against “foreign” matter, such as invading germs, but against the body itself. Diseases considered to be of autoimmune origin include myasthenia gravis, rheumatoid arthritis, and lupus erythematosus.; In autoimmune diseases T-lymphocytes reproduce to excess to home in on a target (properly a foreign disease-causing molecule); however, molecules of the body's own tissue that resemble the target may also be attacked, for example insulin-producing cells, resulting in insulin-dependent diabetes; if certain joint membrane cells are attacked, then rheumatoid arthritis may result; and if myelin, the basic protein of the nervous system, then multiple sclerosis results. In 1990 in Israel a T-cell vaccine was produced that arrests the excessive reproduction of T-lymphocytes attacking healthy target tissues.
Autonomic nervous system: The part of the nervous system which regulates involuntary vital functions, including the activity of the cardiac (heart) muscle, smooth muscles (eg of the gut), and glands. The autonomic nervous system has two divisions: the sympathetic nervous system accelerates heart rate, constricts blood vessels, and raises blood pressure; the parasympathetic nervous system slows heart rate, increases intestinal and gland activity, and relaxes sphincter muscles.
Axon: The axon is the core nerve fiber extending from a cell body which is protected by the myelin sheath. It carries signals from a cell to another nerve cell or to a muscle.

B
Babinski reflex: A neurological sign in MS in which stroking the outside sole of the foot with a pointed object causes an upward (extensor) movement of the big toe rather than the normal (flexor) bunching and downward movement of the toes.
Benign Multiple Sclerosis: Some people with Multiple Sclerosis are described as having a benign form of the disease. It is not possible to diagnose someone initially as having this form of MS, as it is only by looking at the disease ten or fifteen years after its onset that the pattern is visible. Benign Multiple Sclerosis has little impact on daily living. Individuals may experience a few mild attacks, or relapses, but no ongoing disability.
Blood-brain barrier: A semi-permeable cell layer around blood vessels in the brain and spinal cord that prevents large molecules, immune cells, and potentially damaging substances and disease-causing organisms (eg viruses) from passing out of the blood stream into the central nervous system (brain and spinal cord). A break in the blood-brain barrier may underlie the disease process in MS.
Brain stem: the part of the central nervous system which houses the nerve centers of the head as well as the centers for respiration, and heart control. It extends from the base of the brain to the spinal cord.

Catheter: A hollow, flexible tube, made of plastic or rubber, that can be inserted through the urinary opening into the bladder to drain excess urine that cannot be excreted normally.
Cerebrospinal fluid (CSF): A watery, colorless, clear fluid that bathes and protects the brain and spinal cord. the composition of this fluid can be altered by a variety of diseases. Certain changes in CSF that are characteristic of MS can be detected with a lumbar puncture (spinal tap), a test sometimes used to help make the MS diagnosis.
Central nervous system: The central nervous system (CNS) consists of the brain and spinal cord, which control the main bodily functions.
Chronic: Of long duration, not acute; a term often used to describe a disease showing gradual worsening.
Chronic progressive MS: In most cases, people with Multiple Sclerosis will experience a relapsing/remitting form of the disease. For some people, however, the symptoms will increase over time with no periods of remission (when there are less or no symptoms). The degree of progression and the time over which it takes place will vary from one person to another.
Cognition: High level functions carried out by the human brain, including comprehension and use of speech, visual perception and construction, calculation ability, attention (information processing), memory, and executive functions such as planning, problem-solving, and self-monitoring.
Cognitive impairment: Changes in cognitive function caused by trauma or disease process. Some degree of cognitive impairment occurs in approximately 50-60% of people with MS, with memory, information processing, and executive functions being the most commonly affected functions.
Coordination: An organized working together of muscles and groups of muscles aimed at bringing about a purposeful movement such as walking or standing.
Cortisone: A glococorticoid steroid hormone produced by the adrenal glands or synthetically, that has anti-inflammatory and immune-system suppressing properties. Prednisone and prednisolone also belong to this group of substances.

D
Demyelination: A loss of myelin in the white matter of the central nervous system (brain, spinal cord).
Diagnosis: Diagnosis is the process by which a person is identified as having Multiple Sclerosis. There is no one test to date which shows categorically that a person has MS. The most accurate test to date is the MRI scan. The main diagnostic techniques are outlined in What is Multiple Sclerosis?.
Diplopia: Double vision, or the simultaneous awareness of two images of the same object that results from a failure of the two eye to work in a coordinated fashion. Covering one eye will erase one of the images.
Disability: As defined by the World Health Organization, a disability (resulting from an impairment) is a restriction or lack of ability to perform an activity in the manner or within the range considered normal for a human being.
Double-blind clinical study: A study in which none of the participants, including experimental subjects, examining doctors, attending nurses, or any other research staff, know who is taking the test drug and who is taking a control or placebo agent. The purpose of their research design is to avoid inadvertent bias of the test results./ In al studies, procedures are designed to "break the blind" if medical circumstances require it.
Dysarthria: Poorly articulated speech resulting from dysfunction of the muscles controlling speech, usually caused by damage to the central nervous system or a peripheral motor nerve. The content and meaning of the spoken works remain normal.
Dysphagia: Difficulty in swallowing. It is a neurological or neuromuscular symptom which may result in aspiration (whereby food or saliva enters the airway), slow swallowing (possibly resulting in inadequate nutrition), or both.

E
Evoked potential(EP): EP's are recordings of the nervous system's electrical response to the stimulation of specific sensory pathways(eg visual, auditory, general sensory). In tests of evoked potentials, a person's recorded responses are displayed on a oscilloscope and analyzed on a computer which allows comparison with normal response times. Demyelination results in a slowing of response time. EP's can demonstrate lesions along specific nerve pathways whether or not the lesions are producing symptoms, thus making this test useful in confirming the diagnosis of MS.
Exacerbation (in MS): The appearance of new symptoms or the aggravation of old ones, lasting at lease 24 hours (synonymous with attack, replace, flare-up, or worsening); usually associated with inflammation and demyelination in the brain or spinal cord.

H
Handicap: As defined by the World Health Organization, a handicap is a disadvantage, resulting from an impairment or a disability, that interferes with a person's efforts to fulfill a role that is normal for that person. Handicap is therefore a social concept, representing the social and environmental consequences of a person's impairments and disabilities.

Hemiparesis: Weakness of one side of the body, including one arm and one leg.
Hemiplegia: Paralysis of one side of the body, including one arm and one leg.
Hyperbaric oxygen: A procedure in which the person breathes oxygen under greater than atmospheric pressure in a specially constructed chamber. Once thought to be a potential treatment for MS, is has been evaluated in several controlled, double-blind studies and found to be ineffective for this purpose.

I
Immune system: A complex system of various types of cells that protects the body against disease producing organisms and other foreign invaders.
Immunosuppression: In MS, a form of treatment which slows or inhibits the body's natural immune responses, including those directed against the body's own tissues. Examples of immunosuppressive treatments in MS include cyclosporin, methotrexate, and azathioprine.
Impairment: As defined by the World Health Organization, an impairment is nay loss or abnormality of psychological, physiological, or anatomical structure or function. It represents a deviation from the person's usual biomedical state. An impairment is thus any loss of function directly resulting from injury or disease.
Incidence: The number of new cases of a disease in a specified population over a defined period of time.
Incontinence: Also called spontaneous voiding; the inability to control passage of urine or bowel movements.
Inflammation: A tissue's immunologic response to injury, characterized by mobilization of white blood cells and antibodies, swelling, and fluid accumulation.
Intention tremor: Rhythmic shaking which occurs in the course of a purposeful movement, such as reaching to pick something up or bringing an outstretched finger in to touch one's nose.
Interferon: A group of immune system proteins, produced and released by cells infected by a virus.

L
Lumbar puncture: A diagnostic procedure that uses a hollow needle (canula) to penetrate the spinal canal at the level of third-fourth or fourth-fifth lumbar vertebrae to remove cerebrospinal fluid for analysis. This procedure is used to examine the cerebrospinal fluid for changes in composition that are characteristic of MS (eg elevated white cell count, elevated protein content, the presence of oligoclonal bands).
Lymphocyte: A type of white blood cell that is part of the immune system. Lymphocytes can be subdivided into two main groups: D-lymphocytes which originate in the bone marrow and produce antibodies; T-lymphocytes which are produced in the bone marrow and mature in the thymus. Helper T-lymphocytes heighten the production of antibodies by B-lymphocytes; suppressor T-lymphocytes suppress B-lymphocyte activity and seem to be in short supply during an MS exacerbation.

M
Magnetic Resonance Imaging (MRI): A diagnostic procedure which produces visual images of different body parts without the use of W-rays. Nuclei of atoms are influenced by a high frequency electromagnetic impulse inside a strong magnetic field. The nuclei then give off resonating signals which can produce pictures of parts of the body. An important diagnostic tool in MS, MRI makes it possible to visualize and count lesions in the white matter of the brain and spinal cord.
Minimal Record of Disability(MRD): A standardized method for quantifying the clinical status of a person with MS. The MRD is made up of five arts; demographic information; the Neurological Functional Systems (developed by John Kurtzke) which assign scores to clinical findings for each of the various neurologic systems in the brain and spinal cord (pyramidal, cerebellar, brainstem, sensory, visual, mental, bowel and bladder); the Disability Status Scale(developed by John Kurtzke) which gives a single composite score for the person's disease; the Incapacity Status Scale which is an inventory of functional disabilities relating to activities of daily living; the environmental Status Scale which provides an assessment of social handicap resulting from chronic illness. The MRD has two main functions; to assist doctors and other professionals in planning and coordinating the care of persons with MS; to provide a standardized means of recording repeated clinical evaluations of individuals for research purposes.
Monoclonal antibodies: Laboratory-produced antibodies, which can be programmed to react against a specific antigen in order to suppress the immune response.
Multiple Sclerosis: Multiple Sclerosis (literally, "many scars") is a disease of the central nervous system. The demyelination of the myelin sheath which coats the nerves impedes the transmission of signals from the brain. Most people diagnosed with Multiple Sclerosis will experience relapses in which the number of symptoms is increased. The main patterns which Multiple Sclerosis takes are: relapsing/remitting; chronic progressive; secondary progressive; and benign. For further details see What is Multiple Sclerosis?; multiple sclerosis (MS) or disseminated sclerosis incurable chronic disease of the central nervous system, occurring in young or middle adulthood. Most prevalent in temperate zones, it affects more women than men. It is characterized by degeneration of the myelin sheath that surrounds nerves in the brain and spinal cord.; Depending on where the demyelination occurs - which nerves are affected - the symptoms of MS can mimic almost any neurological disorder. Typically seen are unsteadiness, ataxia (loss of muscular coordination), weakness, speech difficulties, and rapid involuntary movements of the eyes. The course of the disease is episodic, with frequent intervals of remission. Its cause is unknown, but it may be initiated in childhood by some environmental factor, such as infection, in genetically susceptible people.; In 1993 interferon beta 1b became the first drug to be approved in the United States for treating MS. It reduces the number and severity of relapses, and slows the formation of brain lesions giving hope that it may slow down the progression of the disease.
Myelin: A soft, white coating of nerve fibers in the central nervous system, that is composed of lipids (fats) and protein. Myelin serves as insulation and as an aid to efficient nerve fiber conduction. When myelin is damaged in MS, nerve fiber conduction. When myelin is damaged in MS, verve fiber conduction is faulty or absent. Impaired bodily functions or altered sensations associated with those demyelinated nerve fibers are identified as symptoms of MS in various parts of the body.
Myelin basic protein: Proteins associated with the myelin of the central nervous system that may be found in higher than normal concentrations in the cerebrospinal fluid of individuals with MS and other diseases that damage myelin.
Myelin sheath: The coating of the nerve fibers of the axon is referred to as the myelin sheath. This is made up of essential fatty acids which insulate the nerve fiber. During attack of symptoms, or relapses, the sheath becomes inflamed, impeding the flow of signals from the brain. After the initial inflammation, the section of myelin sheath may become scarred, or demyelinated. The inflammation of the sheath does not always result in visible symptoms - so MRI assessments in clinical trials do not always relate to disability.

N
Nerve: A bundle of nerve fibers (axons). The fibers are either afferent - leading toward the brain and serving in the perception of sensory stimuli of the ski, joints, muscles, and inner organs; or efferent - leading away from the brain and mediating contractions of muscles or organs.
Nervous system: Includes all of the neural structures in the body: the central nervous system consists of the brain, spinal cord, and optic nerves; the peripheral nervous system consists of the nerve roots, nerve plexi, and nerves throughout the body.
Neurogenic bladder: Bladder dysfunction associated with neurologic malfunction in the spinal cord and characterized by a failure to empty, failure to store, or a combination of the two. Symptoms which result from these three types of dysfunction include urinary urgency, frequency, hesitancy, nocturia, and incontinence.
Neurologist: Physician who specializes in the diagnosis and treatment of conditions related to the nervous system.
Neurology: Study of the central, peripheral, and autonomic nervous system.
Neuron: The basic nerve cell of the nervous system. A neuron consists of a nucleus within a cell body and one or more processes (extensions) called dendrites and axons.
Nocturia: The need to urinate during the night.
Nystagmus: Rapid, involuntary movements of the eyes in the horizontal or, occasionally, the vertical direction.

O
Occupational therapist (OT): Occupational therapists assess functioning in activities of everyday living, including dressing, bathing, grooming, meal preparation, writing, and driving, that are essential for independent living. In making treatment recommendations, the OT addresses: 1) fatigue management 2) upper body strength, movement, and coordination 3) adaptations to the home and work environment including both structural changes and specialized equipment for particular activities, and 4)compensatory strategies for impairments in thinking, sensation, or vision.
Oligoclonal bands: A diagnostic sign indicating abnormal levels of certain antibodies in the cerebrospinal fluid seen in approximately 90% of people with multiple sclerosis, but not specific to MS.
Oligodendrocyte: A type of cell in the central nervous system that is responsible for making and supporting myelin.
Optic neuritis: Inflammation or demyelination of the optic (visual) nerve with transient or permanent impairment of vision and occasionally pain.

P
paralysis: loss of voluntary movement due to failure of nerve impulses to reach the muscles involved. It may result from almost any disorder of the nervous system, including brain or spinal cord injury, poliomyelitis, stroke, and progressive conditions such as a tumor or multiple sclerosis. Paralysis may also involve loss of sensation due to sensory nerve disturbance.
Paraparesis: A weakness but not total paralysis the lower extremities (legs).
Paraplegia: Paralysis of both lower extremities (legs).
Paresis: Partial or incomplete paralysis of a part of the body.
Paresthesia: A spontaneously occurring sensation of burning prickling, tingling, or creeping on the skin that may or may not be associated with any physical findings on neurological examination.
Placebo: An inactive, non-drug compound that is designed to look just like the test drug. It is administered to control group subjects in double-blind clinical trials (in which neither the researchers nor the subjects know who is getting the drug and who is getting the placebo) as a means of assessing the benefits and liabilities of the test drug taking by experimental group subjects.
Placebo effect: An apparently beneficial result of therapy that occur because of the patient's expectation that the therapy will help.
Plantar reflex: a reflex response obtained by drawing a pointed object along the outer border of the sole of the foot from the heel to the little toe. The normal flexor response is a bunching and downward movement of the toes. An upward movement of the big tow is called an extensor response, or Babinski reflex, which is a sensitive indicator of disease in the brain or spinal cord.
Plaque: An area of inflamed or demyelinated central nervous system tissue.
Primary progressive Multiple Sclerosis: An alternative name for chronic progressive Multiple Sclerosis.
Prevalence: the number of all new and old cases of a disease in a defined population at a particular point in time
Prognosis: Prediction of the future course of the disease.
Pseudo-exacerbation: A temporary aggravation of disease symptoms, resulting from an elevation in body temperature or other stressor (eg an infection, severe fatigue, constipation). That disappears once the stressor is removed. A pseudo-exacerbation involves symptom flare-up rather than new disease activity or progression.

R
Relapsing/remitting Multiple Sclerosis: The pattern which Multiple Sclerosis follows differs for different people. The relapsing/remitting form of Multiple Sclerosis follows a course of relapses (also known as "attacks") where there is an increased level of symptoms, followed by remissions in which there are less, or no, evident symptoms. The periods of acute attack occur when the myelin sheath is inflamed, squeezing the nerve fibers so that messages do not pass clearly from the brain to other parts of the body. The frequency and severity of relapses varies. In a few cases, people with relapsing/remitting MS may go on to develop secondary progressive Multiple Sclerosis.
Remission: A lessening in the severity of symptoms or their temporary disappearance during the course of the illness.
Remyelination: The repair of damaged myelin. Myelin repair occurs spontaneously in MS but very slowly. Research is currently under way to find a way to speed the healing process.

S
Scanning speech: Abnormal speech characterized by staccato-like articulation that sounds clipped because the person unintentionally pauses between syllables and skips some of the sounds.
Sclerosis: Hardening of tissue. In MS, sclerosis is the body's replacement of lost myelin around CNS nerve cells with scar tissue.
Secondary progressive multiple sclerosis: In some instances, people who begin with a relapsing/remitting form of MS may find that over time the symptoms which they are experiencing increase. This may be a case of the remaining symptoms after each attack increasing over time, or the relapsing/remitting pattern may be replaced by a progressive pattern.
Sensory: Related to bodily sensations such as pain, smell, taste, temperature, vision, hearing, acceleration and position in space.
Spasticity: The loss of normal elasticity in the muscles of the legs and/or arms as a result of disease in the central nervous system. It often results in extreme stiffness of the muscles.
Symptom: A subjectively perceived problem or complaint reported by the patient. In multiple sclerosis, common symptoms include visual problems, fatigue, sensory changes, weakness or paralysis of limb, tremor, lack of coordination, poor balance, bladder or bowl changes, and psychological changes.

T
T-cell: A lymphocyte (white blood cell) that develops in the bone marrow, matures in the thymus, and works as part of the immune system in the body.
Trigeminal neuralgia: Lightning-like, acute pain in the face caused by demyelination of nerve fibers at the site where the sensory (trigeminal) nerve root for that part of the face enters the brainstem.

V
Vertigo: A dizzying sensation of the environment spinning often accompanied by nausea and vomiting.
Visual evoked potential: A test in which the brain's electrical activity in response to visual stimuli(eg a flashing checkerboard) is recorded by an electroencephalograph and analyzed by computer. Demyelination results in a slowing of response time. Because this test is able to confirm the presence of a suspected brain lesion (area of demyelination) as well as identify the presence of an unsuspected lesion which has produced no symptoms, it is extremely useful in diagnosing MS. VEP's are abnormal in approximately 90% of people with MS.

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