Glossary of MS Terms


Acute Having rapid onset, usually with recovery; not chronic or long lasting.

Antibodies Proteins produced by the immune system in response to antigens on foreign organisms or other substances. Antibodies attach selectively to their specific antigens as part of the process by which foreign material is cleared from the body by the immune system.

Antigen A substance that stimulates the production of an antibody. Common antigens include protein components of viruses and bacteria, and other foreign substances.

Ataxia The lack of coordination and unsteadiness that results 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 damage to the cerebellum. Autoimmune disease A process in which the body’s immune system causes illness by inappropriately attacking healthy cells, or tissues in the body. Multiple sclerosis is widely believed to be an autoimmune disease, but that is not firmly established. Avonex trade name for Interferon beta 1-a.

Axon The core nerve fibre that transmits electrical signals from a nerve cell to other nerve cells or to muscles. It is covered by the myelin sheath which speeds electrical conduction and insulates the axon from other nerve fibres.


Babinski sign A neurological sign, common 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 downward (flexor) movement of the big toe. It results from damage to motor pathways in the CNS.

Benign MS Some people with relapsing/remitting MS 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 evident. Benign multiple sclerosis has little impact on daily living. Individuals may experience a number of mild attacks or relapses, but little or no ongoing disability.

Betaferon Trade name for Interferon beta 1-b.

Beta-interferons (See also Interferons and Immune-Modulating Therapy) Type of interferons which are produced using genetic engineering techniques and are used for treatment in MS.

Blood-brain barrier A semi-permeable layer around blood vessels in the brain and spinal cord that prevents large molecules, immune cells, and disease-causing organisms (e.g. viruses) from passing out of the blood stream into the central nervous system (brain and spinal cord). A temporary break in the blood-brain barrier occurs as part of the inflammatory process in MS.

Brain stem The part of the central nervous system which houses the nerve centres of the head as well as the centres 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 urine that cannot be excreted normally.

Central nervous system The central nervous system (CNS) consists of the brain and spinal cord, and includes the optic nerves but not other peripheral nerves.

Cerebrospinal fluid (CSF) A watery, colourless, clear fluid that bathes and protects the brain and spinal cord. It can be sampled by a lumbar puncture (spinal tap). The composition of this fluid can be altered by a variety of diseases, including MS where there is characteristically an increase in proteins produced by immune cells (immunoglobulins).

Chronic Of long duration, not acute; a term often used to describe a disease showing gradual worsening over months or years.

Cognition High level intellectual functions carried out by the human brain, including comprehension, speech, visual perception, 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 injury or disease process. Some degree of cognitive impairment occurs in many people with MS, with memory, information processing, and executive functions being the most commonly affected functions.

Coordination An organised working together of muscles and groups of muscles aimed at bringing about a purposeful movement such as walking or standing.

Copaxone Trade name for glatiramer acetate. See also Immune-Modulating Therapy.

Corticosteroids Natural hormones produced by the adrenal glands that have anti-inflammatory and immune-system suppressing properties. Prednisone and methylprednisolone are synthetic steroids used to treat acute MS relapses.


Demyelination A loss of myelin with relative sparing of axons characteristic of the inflammatory process in MS.

Diplopia Double vision, or the simultaneous awareness of two images of the same object resulting from a failure of the two eyes to work in a coordinated fashion. Covering one eye will erase one of the images.

Disability As defined by the World Health Organisation, 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 this research design is to avoid inadvertent bias of the test results. In all studies, procedures are designed to “break the blind” if medical circumstances require it.

Dysarthria Poorly articulated (slurred) speech resulting from dysfunction of the muscles controlling speech. The content and meaning of the spoken words remain normal.

Dysphagia Difficulty in swallowing.


EDSS See Expanded Disability Status Scale.

Etiology The study of all factors that may be involved in the development of a disease, including the patient’s susceptibility, the nature of the disease-causing agent, and the way in which the person’s body is invaded by the agent.

Evoked potentials (EPs) Recordings of the nervous system’s electrical response to the stimulation of specific sensory pathways (e.g. visual, auditory, general sensory). Demyelination in MS results in a slowing of response time. EPs can demonstrate lesions along nerve pathways whether or not they are producing symptoms. EPs are infrequently used for the diagnosis of MS now that MR scanning is widely available.

Exacerbation (see Relapse) The appearance of new symptoms or the aggravation of old ones, lasting at least 24 hours (synonymous with attack, replace, flare-up, or worsening); usually associated with inflammation and demyelination in the brain or spinal cord.

Expanded Disability Status Scale (EDSS) A scale used to measure a patient’s level of disability due to MS. The score ranges from 0 (no disability) to 10 (death) in 20-½ point steps. It is determined using a standard neurological examination and assessment of walking ability.


Glia The central nervous system consists of neurons and glial cells. Neurons constitute about half the volume of the central nervous system and glial cells make up the rest. Glial cells provide support and protection for neurons. They are thus known as the “supporting cells” of the nervous system. The four main functions of glial cells are: to surround neurons and hold them in place, to supply nutrients and oxygen to neurons, to insulate one neuron from another, and to destroy and remove the carcasses of dead neurons (clean up). The three types of glial cells are: astrocytes, oligodendrocytes, and microglia.


Handicap As defined by the World Health Organisation, 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 Total 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, it has been evaluated in several controlled, double-blind studies and found to be ineffective for this purpose.


Immune system A complex system of various types of cells that protects the body against disease producing organisms and other foreign substances.

Immune-Modulating Therapy Medication that changes the response of the immune system without producing general immune suppression. Includes beta-interferons and glatiramer acetate (Copaxone) which have a similar, partial effect in MS in reducing the frequency of relapses by about a third, and reducing the patches of inflammation seen on MR scans. The therapy must be given by regular injections and must be continued indefinitely to maintain the effect. It is expensive and its availablility in NZ is limited by PHARMAC to MS patients with frequent relapses and significant residual disability (see PHARMAC and MSTAC) [link within Glossary]. In NZ the beta-interferons Avonex (beta-interferon 1a) and Betaferon (beta-interferon 1b) are funded by PHARMAC but not Rebif (interferon beta-1a). Copaxone, which is a different, non-interferon medication, is also now fully funded by PHARMAC.

Immunosuppression A form of treatment which slows or inhibits the body’s natural immune responses, including those directed against the body’s own tissues. Examples used in MS include cyclophosphamide, methotrexate, azathioprine and mitoxantrone.

Impairment As defined by the World Health Organisation, an impairment is any 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.

Interferons A group of immune system proteins that are produced naturally in response to viral infections. They restrict the spread of infection and also modulate immune reactions. There are three main types: alpha, beta and gamma interferon. Beta interferon is used as therapy in MS.


Lumbar puncture A diagnostic procedure that uses a hollow needle to enter the spinal canal in the lower (lumbar) spine to remove cerebrospinal fluid (CSF) for analysis.

Lymphocytes Type of white blood cells that are major components of the immune system. The main types are T and B-lymphocytes and there are many sub-types with different functions in immune reactions.


Magnetic Resonance Imaging (MRI) A diagnostic procedure which produces 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, which differ in different types of body tissue. MR scanning is very sensitive to the inflammatory changes and scarring that occur in MS and is an important in diagnosis and in assessing the effects of new treatments.

Monoclonal antibodies Laboratory-produced antibodies, which can be developed to react selectively against a specific antigen in order to suppress a particular response, usually to modify immune reactions.

MSTAC Multiple Sclerosis Treatment Assessment Committee, which assesses applications for funding for disease modifying drugs (such as interferons) for PHARMAC in NZ.

Myelin A coating (sheath) of nerve fibres that is composed of lipids (fats) and protein. Myelin serves as insulation and as an aid to efficient nerve fibre conduction. When myelin is damaged in MS, nerve fibre conduction is faulty or absent, with impaired bodily functions or altered sensations the result.

Myelin basic protein (MBP) A major protein component of myelin that may be the target of an autoimmune reaction. The possibility of using oral MBP as MS treatment has led to the controversial development in NZ of genetically modified cows that produce human MBP in their milk.

Myelitis Inflammation of the spinal cord. A common manifestation of an MS relapse.


Nerve A bundle of nerve fibres (axons). The fibres 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.

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 plexuses, and nerves throughout the body.

Neurogenic bladder Bladder dysfunction associated with neurologic malfunction in the spinal cord in MS and characterized by a failure to empty, failure to store, or a combination of the two. Symptoms which result include urinary urgency, frequency, hesitancy, nocturia, and incontinence.

Neurologist A doctor who specialises in the diagnosis and treatment of conditions related to the nervous system, such as MS, stroke, epilepsy, Parkinson’s Disease.

Neurology Study of the central, peripheral, and autonomic nervous system.

Neuron The basic nerve cell of the nervous system. A neuron consists of a cell body containing a nucleus and one or more processes (extensions) called dendrites and axons.

Nocturia The need to urinate during the night.

Nystagmus Rapid, involuntary jerky movements of the eyes in the horizontal or the vertical direction.


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 An abnormal pattern of immune proteins (immunoglobulins) on electrophoresis of CSF. Common in MS and helpful diagnostically but not specific for MS.

Oligodendrocytes Glial cells that produce and support the myelin sheath, in the CNS.

Optic neuritis Inflammation of the optic (visual) nerve which produces impairment of vision in the affected eye, often with pain on eye movement, often associated with MS.


Paraparesis A weakness, but not total paralysis, of the lower extremities (legs).

Paraplegia Total paralysis of both lower extremities (legs).

Paresis Partial or incomplete paralysis of a part of the body.

Paresthesiae Sensations of burning, prickling, tingling, or creeping on the skin, often with impairment of sensation.

PHARMAC The Pharmaceutical Management Agency of New Zealand, PHARMAC, manages a list of subsidised pharmaceuticals, the Pharmaceutical Schedule, on behalf of the Crown. Pharmaceutical suppliers may apply to PHARMAC to have a medicine listed on the Pharmaceutical Schedule for subsidy. Decisions on listing, subsidy levels and prescribing guidelines and conditions are made by the PHARMAC Board with input from independent medical experts who sit on the Pharmacology and Therapeutics Advisory Committee (PTAC) and its specialist sub-committees, as well as PHARMAC staff. Patients and consumers also have input into PHARMAC’s decision-making processes through the Consumer Advisory Committee. PHARMAC also has functions to promote the responsible use of pharmaceuticals and to manage the purchasing of hospital pharmaceuticals on behalf of District Health Boards.

Physiotherapist (PT) Physiotherapists are trained to evaluate and improve movement and function of the body, with particular attention to physical mobility, balance, posture, fatigue, and pain. The physical therapy program typically involves (1) educating the person with MS about the physical problems caused by the disease, (2) designing an individualized exercise program to address the problems, and (3) enhancing mobility and energy conservation through the use of a variety of mobility aids and adaptive equipment.

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 taken by experimental group subjects.

Placebo effect An apparently beneficial result of inactive therapy that occurs because of the patient’s expectation that the therapy will help.

Plantar reflex See Babinski sign

Plaque An area of scarring in CNS in MS resulting from a patch of inflammation.

Prevalence The number of all new and existing cases of a disease in a defined population at a particular point in time.

Primary 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. The degree of progression and the time over which it takes place will vary from one person to another.

Prognosis Prediction of the future course of a disease.

Pseudo-exacerbation A temporary aggravation of symptoms, resulting from an elevation in body temperature or other physiological change such as exercise.

PTAC Pharmacology and Therapeutics Advisory Committee.

PwMS People or person with multiple sclerosis.


Rebif Trade name for Interferon beta 1-a.

Relapse Sudden deterioration of current symptoms or development of new symptoms resulting from an area of active inflammation in the CNS in MS.

Relapsing/remitting MS The pattern which multiple sclerosis follows differs for different people. The relapsing/remitting form of MS 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 frequency and severity of relapses varies. In a few cases, people with relapsing/remitting MS may go on to develop secondary progressive MS.

Remission A lessening in the severity of symptoms or their disappearance following a relapse.

Remyelination The repair of damaged myelin. Myelin repair occurs spontaneously in MS but to a limited degree. Research is currently under way to find a way to speed the healing process.


Sclerosis Hardening or scarring of tissue. In MS, sclerosis is the result of healing of a patch of inflammation.

Secondary progressive multiple sclerosis In some instances, people who begin with a relapsing/remitting form of MS may find that over time the symptoms 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 A type of increased tone (resistance to passive movement) in the limbs that results from damage to motor pathways in the CNS. May be associated with involuntary spasms of the muscles.

Spinal Tap See lumbar puncture.

Symptom A subjectively perceived problem or complaint reported by the patient.


T-cell See Lymphocytes.

Transverse myelitis A severe form of myelitis that involves both sides of the spinal cord. The spinal cord loses its ability to transmit nerve impulses up and down. Paralysis and numbness are experienced in the limbs and trunk below the level of the inflammation with loss of urinary function.

Trigeminal neuralgia Lightning-like, brief severe pain in the face caused by demyelination of nerve fibres at the site where the sensory (trigeminal) nerve root for that part of the face enters the brainstem.

Tremor Uncontrolled trembling or shaking.


Urethra Duct or tube that drains the urinary bladder.

Urinary sphincter The muscle closing the urethra at the base of the bladder, which in a state of flaccid paralysis causes urinary incontinence and in a state of spastic paralysis results in an inability to urinate.

Urologist A doctor who specialises in the branch of medicine (urology) concerned with disorders, and care of the male and female urinary tract, as well as the male genital tract.

Urology A medical specialty that deals with disturbances of the urinary (male and female) and reproductive organs.


Vertigo A dizzying sensation of the environment spinning, often accompanied by nausea and vomiting.

Vibration sense The ability to feel vibrations against various parts of the body. Vibration sense is tested (with a tuning fork) as part of the sensory portion of the neurological exam.

Videofluoroscopy A radiographic study of a person’s swallowing mechanism that is recorded on videotape. Videofluoroscopy shows the physiology of the pharynx, the location of the swallowing difficulty, and confirms whether or not food particles or fluids are being aspirated into the airway.

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.

Visual evoked potential A test in which the brain’s electrical activity in response to visual stimuli (e.g. a flashing checkerboard) is recorded by an electroencephalograph and analysed 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.


White matter That part of the brain which contains myelinated nerve fibres and appears white, in contrast to the cortex of the brain which contains nerve cell bodies and appears grey.

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