MS Terms
MS Glossary
Acute
Characterized by rapid onset – usually with recovery. Not chronic or long- lasting.
Anaphylaxis
An immediate and short-lived, usually severe reaction in which the body responds to what is perceived to be a foreign substance with exaggerated symptoms, such as extreme itching, swelling, and often life-threatening respiratory distress.
Antibodies
Proteins of the immune system that are soluble (dissolved) in blood serum or other body fluids. Antibodies are produced to fight off bacteria, viruses, and other types of foreign antigens.
Antigen
Any substance that triggers the immune system to produce an antibody – generally referring to infectious or toxic substances.
Ataxia
The unsteadiness and lack of coordination 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.
Atrophy
A decrease in size and strength of a part of the body due to disease or inactivity.
Autoimmune disease
A process in which the body’s immune system causes illness by mistakenly attacking healthy cells, organs, or tissues in the body. MS is believed to be an autoimmune disease, along with systemic lupus erythematosus, rheumatoid arthritis, scleroderma, and many others.
The thread-like extensions on a neuron, or nerve cell, which conducts nerve impulses.
Brainstem
The part of the central nervous system that 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.
Biological Response Markers (BRMs)
BRMs are biochemical substances that can be measured in the blood of patients following administration of the interferons.
Black box warnings are designed to highlight special problems, particularly those that are serious, and to give health care professionals a clear understanding of a potential medical complication associated with a drug.
Black hole
An area where a potentially irreversible loss of axons has occurred.
CAT scan
See Computerized axial tomography.
Central nervous system (CNS)
The part of the nervous system that includes the brain, optic nerves, and spinal cord, the parts of the body affected by MS.
Cerebellum
A part of the brain situated above the brainstem that controls balance and coordination of movement.
Cerebral cortex
The outer layer of brain tissue.
A clear fluid that circulates in the space surrounding the brain and spinal cord.
The large upper part of the brain, which acts as a master control system and is responsible for initiating thought and motor activity.
Chronic
Of long duration (the opposite of acute) – a term often used to describe a disease that becomes progressively worse
Cognition
High-level functions carried out by the 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 difficulties
Term used to describe memory loss or difficulty concentrating or solving problems.
Cognitive impairment
Changes in cognitive function caused by trauma or disease process. Some degree of cognitive impairment occurs in approximately 50% to 60% of people with MS. Memory, information processing, and executive functions are among the most commonly affected functions. See Cognition.
Computerized axial tomography (CAT scan)
A non-invasive diagnostic technique using computer-guided x-rays to examine soft tissues of the body.
Coordination
An organized working together of muscles and groups of muscles, which enables movement such as walking or standing.
Cortisone
A glucocorticoid steroid hormone that has anti-inflammatory and immune system suppressing properties. Cortisone may be produced by the adrenal glands or manufactured synthetically.
Cytokines
T cells produce a type of protein called cytokines. In MS, cytokines can damage myelin.
Deep tendon reflexes
The involuntary, jerky movements that are normally produced when certain spots on a limb are tapped with a hammer – usually done during a physical examination by a healthcare professional. Reflexes are tested as part of the standard neurological exam.
Demyelination
A loss of myelin in the white matter of the central nervous system (brain, spinal cord).
Disability
A restriction or lack of ability to perform an activity in the manner or within the range considered normal for a human being (as defined by the World Health Organization).
Disease-modifying therapy
Treatment intended to influence the course of the disease, alter its natural history, and treat the cause of the symptom rather than the symptom itself.
Dosage
Administration of a therapeutic agent in prescribed amounts.
Dose Titration
Starting out with a lower dose of medication and gradually increasing to a full dose over several weeks to let your body adjust to the medicine.
Double-blind clinical study
A study (involving 2 groups of patients) in which none of the participants—including 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 this research design is to avoid inadvertent bias of the test results.
Dysfunction
Difficult or abnormal function.
Dysmetria
A disturbance of coordination, caused by lesions in the cerebellum. Dysmetria is usually characterized by a tendency to over- or underestimate the extent of motion needed to place an arm or leg in a certain position.
EDSS
EDSS stands for Expanded Disability Status Scale. The EDSS is used in MS research to measure disability levels in a variety of functional systems, such as balance, touch, vision, bowel and bladder control, or mood.
Efficacy (Effectiveness)
The extent to which a specific intervention, procedure, or regimen produces a beneficial result under ideal conditions.
Electrical impulses
In the body, electrical impulses travel among the nerves, carrying messages or signals.
Electroencephalography (EEG)
A diagnostic procedure that records, via electrodes attached to various areas of the person’s head, electrical activity generated by brain cells.
Electromyography (EMG)
A diagnostic procedure that records muscle electrical potentials through a needle or small plate electrodes. The test can also measure the ability of peripheral nerves to conduct impulses.
Evoked potentials
A testing method that measures electrical activity in the CNS.
The appearance of new symptoms or the aggravation of old ones, lasting at least 24 hours (synonymous with attack, relapse, flare-up, or worsening).
Food and Drug Administration (FDA)
The US federal agency that is responsible for enforcing governmental regulations pertaining to the manufacture and sale of food, drugs, and cosmetics. Its role is to prevent the sale of impure or dangerous substances. Any new drug that is proposed for the treatment of MS must be approved by the FDA.
Foot drop
A condition of weakness in the muscles of the foot and ankle, caused by poor nerve conduction, which interferes with a person’s ability to flex the ankle and walk with a normal heel-toe pattern. The toes touch the ground before the heel, causing the person to trip or lose balance.
Gadolinium
A chemical compound that can be administered to a person during MRI (magnetic resonance imaging) to help distinguish between new lesions and old lesions in the C NS (Central nervous system).
Genetic factors
In multiple sclerosis (MS), genetic factors may play a role in causing the disease. This means that there may be an increased risk of the disease if a close family member has MS.
Helper T lymphocytes
White blood cells that are a major contributor to the immune system’s inflammatory response against myelin.
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.
Immune system
A complex system of various types of cells that protects the body against disease-producing organisms and other foreign invaders.
Immunoglobulin
Proteins of the immune system that are soluble (dissolved) in blood serum or other body fluids. Immunoglobulin or Antibodies are produced to fight off bacteria, viruses, and other types of foreign antigens.
Immunomodulatory
Capable of modifying or regulating one or more immune functions.
Immuno-suppression
In MS, a treatment that slows or inhibits the body’s natural immune responses, including those directed against the body’s own tissues.
Incidence
The number of new cases of a disease in a specified population over a defined period of time.
Inflammation
A tissue’s response to injury. Inflammation is characterized by mobilization of white blood cells and antibodies, swelling, and fluid accumulation.
Insulin
A hormone that helps the body use glucose (sugar) for energy. The beta cells of the pancreas (in areas called the islets of Langerhans) make the insulin.
Inflammation
The body’s response to insult or injury resulting in increased blood flow with swelling, tenderness, redness, and/or heat.
Interferon
A group of immune system proteins, produced and released by cells infected by a virus, which inhibit viral multiplication and modify the body’s immune response. These proteins are made in the body to help boost the body’s immune system and keeps a virus from multiplying. Synthetic forms of interferon are used in making interferon therapy. One of the interferons, interferon beta-1b (Betaseron) was approved by the Food and Drug Administration in 1993 for treatment of relapsing-remitting MS. It was found in a clinical trial to reduce the frequency and severity of exacerbations by approximately 30%. A second interferon, interferon beta-1a (Avonex®) has also been shown to reduce the frequency and severity of MS exacerbations in people with relapsing-remitting disease. Avonex® was approved for use in MS in 1996.
Intramuscular (IM) injection
Injection with a longer needle that is given deep into the muscle
Intravenous
Meaning within a vein—the term is often used in the context of an injection into a vein.
Damaged area in the brain or spinal cord caused by demyelination (also called plaque or sclerosis).
White blood cell.
Lymphocyte
A type of white blood cell that is part of the immune system. Lymphocytes can be subdivided into 2 main groups: B 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.
Macrophage
A white blood cell with scavenger characteristics that has the ability to ingest and destroy foreign substances such as bacteria and cell debris.
Magnetic resonance imaging (MRI)
A diagnostic procedure that produces visual images of different body parts without the use of x-rays. Nuclei of atoms are influenced by a high-frequency electromagnetic impulse inside a strong magnetic field. The nuclei then give off resonating signals that 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. A MRI can be used to detect plaques or scarring that might be caused by MS in the brain and spinal cord
A general feeling of bodily discomfort and being unwell.
A treatment for RRMS that is presumed to change the way the immune system responds by working on inflammatory cells outside and inside the CNS.
Minimal Record of Disability (MRD)
A standardized method for quantifying the clinical status of a person with MS. The MRD is made up of 5 parts:
Demographic information
o 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)
o The Disability Status Scale (developed by John Kurtzke), which gives a single composite score for the person’s disease
o The Incapacity Status Scale, which is an inventory of functional disabilities relating to activities of daily living
o The Environmental Status Scale, which provides an assessment of social handicap resulting from chronic illness
The MRD has 2 main functions: to assist doctors and other professionals in planning and coordinating the care of people with MS, and 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.
Motor neurons
Nerve cells of the brain and spinal cord that enable movement of various parts of the body.
MRI
Magnetic resonance imaging. A diagnostic procedure that produces visual images of different body parts without the use of x-rays. Nuclei of atoms are influenced by a high-frequency electromagnetic impulse inside a strong magnetic field. The nuclei then give off resonating signals that 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.
Multiple Sclerosis
A disease that attacks the CNS. With MS, the immune system creates swelling and causes damage to the nerve covering (called myelin) that protects the nerve fibers in the brain and spinal cord. This damage prevents nerve cells from communicating properly to relay signals to and from other parts of the body.
A characteristic of a muscle brought about by the constant flow of nerve stimuli to that muscle, which describes its resistance to stretching. Abnormal muscle tone can be defined as: hypertonus (increased muscle tone, as in spasticity); hypotonus (reduced muscle tone [flaccid paralysis]); or atony (loss of muscle tone). Muscle tone is evaluated as part of the standard neurological exam in MS.
Myelin
A soft, white coating that surrounds and protects nerve fibers in the central nervous system (CNS) and the peripheral nervous system. Myelin serves as insulation and as an aid to efficient nerve fiber conduction. Myelin also helps nerve fibers conduct electrical impulses. When myelin is damaged in MS, nerve 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.
Myelitis
An inflammatory disease of the spinal cord. In transverse myelitis, the inflammation spreads across the tissue of the spinal cord, resulting in a loss of its normal function to transmit nerve impulses up and down, as though the spinal cord had been severed.
Myelogram
An x-ray procedure by which the spinal canal and the spinal cord can be visualized. It is performed in conjunction with a lumbar puncture and injection of a special x-ray contrast material into the spinal canal.
Necrosis
Death or decay of tissue that results from loss of the blood supply and oxygen needed to keep tissue alive and healthy.
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 skin, joints, muscles, and inner organs, or efferent (leading away from the brain and mediating contractions of muscles or organs).
Nerve block
A procedure used to relieve otherwise intractable spasticity, including painful flexor spasms. An injection of phenol into the affected nerve interferes with the function of that nerve for up to 3 months, potentially increasing a person’s comfort and mobility.
Nerve fibers
Slender processes of neurons, especially the prolonged axons that conduct nerve impulses.
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.
Neurodegeneration
The malfunctioning or loss of nerve cells which include neurons and axons.
Related to activity of the nervous system, as in “neurogenic bladder.”
Neurologist
Medical doctor (or physician) with specialized training in conditions that affect the nervous system; some have a specialized interest in MS, epilepsy, or Parkinson’s disease.
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 extensions called dendrites and axons.
A doctor who does cognitive assessment and retraining of patients. Neuropsychologists specialize in brain-behavior relationships.
A psychologist with specialized training in the evaluation of cognitive functions. Neuro-psychologists use a battery of standardized tests to assess specific cognitive functions and identify areas of cognitive impairment. They also provide remediation for individuals with MS-related cognitive impairment. See Cognition and Cognitive impairment
Neutralizing antibodies (NAbs)
Proteins produced by the body that may block (“neutralize”) the effectiveness of a drug therapy.
Neutral formulation of Betaseron which helps minimize stinging on injection.
Occupational therapist
A specialist in rehabilitating patients with cognitive problems. The occupational therapist focuses on restoring the patient’s ability to carry out daily tasks at home, at work, and in the community.
A series of distinct bands found in the immunoglobulin (a protein substance from immune cells) of the cerebrospinal fluid (CSF). The bands may be present in other conditions, but are helpful in diagnosing MS if other MS symptoms are present.
A wasting of the optic disc that results from partial or complete degeneration of optic nerve fibers and is associated with a loss of visual acuity.
Optic nerve
The bundle of over one million nerve fibers that carry visual messages from the retina to the brain.
Optic neuritis
Inflammation of the optic nerve. Also called neuropapillitis, retrobulbar neuritis.
Paraparesis
Weakness of 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 receiving the drug and who is receiving the placebo) as a means of assessing the benefits and liabilities of the test drug taken by experimental group subjects.
Placebo effect
An apparently beneficial result of therapy that occurs because of the patient’s expectation that the therapy will help.
Plaque
Damaged area in the brain or spinal cord caused by demyelination (also called lesion or sclerosis).
Safety category for pregnant women considering or taking medication. This category means that when the medication was administered to pregnant animals, there was no detectable harm to the fetus; these studies were not done in women. Because animal studies are not predictive of human response, Pregnancy Category B medications should be used during pregnancy only if clearly needed.
Safety category for pregnant women considering or taking medication. This category means that when the medication was administered to pregnant animals, there was some harm done to the fetus. Category C medication should be used only if clearly needed (that is, if you and your doctor determine that the benefits outweigh the risks).
Safety category for pregnant women considering or taking medication. This category means that when the medication was administered to pregnant women there was evidence of risk to the fetus. Category D medication should be used only if clearly needed (that is, if the drug is needed in a life-threatening situation or safer drugs cannot be used or are not effective).
The number of all new and old cases of a disease in a defined population at a particular point in time.
Primary-progressive MS (also called PPMS)
A less common form of MS than the relapsing-remitting form. PPMS makes up approximately 10% of all people with MS and is characterized by a slow but nearly continuous worsening of disease.
Prediction of the future course of the disease.
Progressive multifocal leukoencephalopathy (PML)
A very rare and potentially fatal disease of the central nervous system (CNS).
Progressive-relapsing MS (also called PRMS)
The rarest form of MS that affects approximately 5% of all diagnosed patients. People with PRMS may go through a steady worsening of their condition after being diagnosed. They may also experience clear, severe relapses with or without complete recovery.
A temporary aggravation of disease symptoms, resulting from an elevation in body temperature or other stressor (eg, an infection, severe fatigue, or constipation). The exacerbation disappears once the stressor is removed. A pseudo exacerbation indicates symptom flare-up rather than new disease activity.
Reconstitution
The restoration to original form of a substance previously altered for preservation and storage
Reflex
An involuntary response of the nervous system to a stimulus, such as the stretch reflex, which is elicited by tapping a tendon with a reflex hammer, resulting in a contraction. Increased, diminished, or absent reflexes can be indicative of neurologic damage, including MS, and are, therefore, tested as part of the standard neurological exam.
Relapse
The worsening of MS symptoms or the appearance of new symptoms (also called attack, exacerbation, and flare-up).
Includes relapsing-remitting MS (the most common form), and secondary progressive MS with relapses.
Relapsing-remitting MS (also called RRMS)
The most common form of MS that affects approximately 85% of newly diagnosed patients. RRMS is characterized by relapses that are usually followed by partial or complete recovery.
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.
Sclerosis
Hardening of tissue. In MS, sclerosis is the body’s replacement of lost myelin around the CNS nerve cells with scar tissue (also called lesion or plaque).
Secondary-progressive MS (also called SPMS)
A stage of MS that may come after RRMS. People with SPMS may have occasional relapses, minor remissions, and plateaus. Late in the course of the disease, they may experience a progressive disability.
A state of increased muscle tone leading to muscle tightness, stiffness and spasms.
A specialist in rehabilitating patients who are having problems speaking and communicating.
The spinal cord is the major bundle of nerves that carry nerve impulses to and from the brain to the rest of the body.
Stance ataxia
An inability to stand upright due to disturbed coordination of the involved muscles, which results in swaying and a tendency to fall in one or another direction.
Subcutaneous
Means under the skin.
Subcutaneous injection
Injections with a shorter needle given into the fatty layer just under the skin.
Suppressor T lymphocytes
White blood cells that act as part of the immune system and may be in short supply during an MS exacerbation.
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.
Transverse myelitis
An acute attack of inflammatory demyelination that involves both sides of the spinal cord. The spinal cord loses its ability to transmit nerve impulses. Paralysis and numbness may be experienced in the legs and trunk below the level of the inflammation.
Vertigo
A dizzying sensation of the environment spinning, often accompanied by nausea and vomiting.
Virus
The specific agent of an infectious disease.
Visual acuity
Clarity of vision. Acuity is measured as a fraction of normal vision. 20/20 vision indicates an eye that sees at 20 feet what a normal eye should see at 20 feet; 20/400 vision indicates an eye that sees at 20 feet what a normal eye sees at 400 feet.
White matter
Part of the brain that contains myelinated nerve fibers and appears white, in contrast to the cortex of the brain, which contains nerve cell bodies and appears gray in color. These differences can be clearly appreciated on MRI images.
