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Glossary

Acute relapse: rapid onset of MS signs or symptoms, in need of urgent treatment.

Adhesion molecule: a protein molecule located on the surface of a cell and involved in the binding of cells to the extracellular matrix. Natalizumab binds to the adhesion molecule, alpha4-integrin. This inhibits the binding of white blood cells to blood brain barrier and thereby prevents the transfer to white blood cells from the blood into the brain.

Alpha4-integrin: a specific type of adhesion molecule expressed on the surface of most white blood cells and involved in the transfer of white blood cells across the blood-brain barrier into the central nervous system (CNS).

Amino acids: are the building blocks of proteins. 20 basic amino acids in various combinations make up all the proteins in the human body. The body produces many amino acids; those it needs but cannot make are known as essential amino acids and must be obtained through the diet.

Anaphylactic shock: severe immune reaction leading to a sudden drop in blood pressure and constriction of the vessels in the lungs, resulting in difficulty breathing. This severe allergic reaction can be fatal in a matter of minutes if left untreated.

Angina: chest pain resulting from the heart’s demand for blood being greater than can be met by the coronary arteries.

Anorexia: loss of appetite over a long period of time.

Antibody: a protein that is produced in response to an antigen (often a virus or bacterium). It is able to combine with and neutralize the antigen.

Antigen presentation: the process by which a foreign molecule (known as an antigen) elicits an immune response, i.e. stimulates the production of antibodies directed against the antigen and/or the activation of immune effector cells which kill cells expressing the antigen.

Antigen: anything e.g. bacterium, virus, vaccine that produces a response by the immune system and leads to the production of antibodies.

Arrhythmia: abnormal rate or rhythm of the heart beat, resulting from disturbances in the electrical impulses that control beating within the heart.

Autoimmune disease: disease that causes the body's own defence system to react against its own cells and tissue.

Axon: Or nerve fibre, is a long projection of a nerve cell or neuron away from the cell body. Axons connect through synapses to other neurons and to muscles . Weak electrical signals are sent along the axons, so that instructions and information are transmitted between the CNS and the body.

Blood-brain barrier (BBB): a membrane that prevents harmful substances crossing over from the blood circulation to the tissues of the brain.

Capillary: literally this means: as a thin as a hair. The word is almost always used to describe a fine, small blood vessel.

Cardiac disease: disorders associated with the heart.

Cell: the smallest unit of living structure in the body. Cells in the human body have many different functions and are highly evolved. However, they can all form proteins and amino acids.

Central nervous system (CNS): the brain and spinal cord, the part of the nervous system that receives sensory impulses and transmits motor (movement) impulses. The CNS keeps us in touch with the world outside while controlling our conscious and unconscious activities.

Cerebral spinal fluid (CSF): bodily fluid that surrounds the brain, providing mechanical and immunological protection to the brain.

Chlamydia Pneumoniae: infects humans and is a common cause of pneumonia throughout the world. It has also been linked with many chronic inflammatory conditions, but the link with MS is only theoretical.

Cognitive function: the word cognitive is used to describe mental activities such as thinking, learning and remembering. Thus, somebody with normal cognitive function can perform these activities to a good standard.

Cognitive symptoms: symptoms that relate to disorders in thought processes, such as learning, comprehension, memory, reasoning, and judging.

Cognitive therapy: form of talking therapy that aims to retrain the mind to banish negative thoughts and change emotional responses and behaviour.

Contraindications: reasons for not prescribing a drug to a particular patient.

Corticosteroids: substances related to the hormones (chemical messengers) produced by the adrenal glands that help to reduce inflammation and have been used to shorten the periods of relapse in MS.

CT (computed tomography) scan: form of imaging which uses a large series of two-dimensional X-ray images to generate a 3-D image of internal organs, such as the brain.

Decompensated liver disease: liver disease in which the liver is damaged and not functioning normally. Decompensated liver disease can be fatal.

Demyelinating event: sign or symptom characteristic of MS.

Demyelination: destruction of the myelin sheath that surrounds the axons in the CNS.

Dendrites: branching fibres attached to the cell body of the neuron, which receive electronic signals transmitted through the axons of other neurons.

Depression/depressive disorders: a collection of psychological symptoms including sadness, depressive thoughts, worry, poor self-image, low self-confidence, and a feeling of hopelessness which may lead to thoughts of suicide.

Disease-modifying therapies (DMTs): medications that, while not curing a disease, are able to reduce or change (modify) some of the symptoms. In MS, disease-modifying therapies such as interferon beta may reduce the frequency of relapses and delay the course of the disease.

Epilepsy: disorder of the brain characterised by the patient experiencing epileptic seizures/fits or spasms.

Epstein-Barr Virus (EBV): is one of the most common viruses in humans. The majority of us are infected with EBV during childhood; often this infection has no visible symptoms (asymptomatic) but can cause glandular fever. Its involvement with MS is a subject of debate, but no definite link has been established.

Evoked potential: this test measures the time required by the brain to receive and process nerve messages. This involves placing small electrodes on the head to monitor brain waves in response to visual or auditory (hearing), or sensory (touch) stimuli. Sensory stimuli are generated by stimulating the nerves or the legs or arms by an electrical pulse. This test can determine whether the speed of transmission of messages along particular nerves is slowed down. If so, this indicates the presence of demyelination in these particular nerves.

Exacerbation: flare-up or attack of symptoms. People with MS experiencing an exacerbation might report numbness or tingling of the hands and feet that typically last for a few weeks; exacerbations come and go throughout the disease course of MS. Exacerbations are commonly called relapses.

Flu-like symptoms: symptoms associated with flu and other conditions and reflect the body’s general method of reacting to a serious infection. Flu-like symptoms can include fever, shivering, chills, malaise, dry cough, loss of appetite, and body aches.

Glatiramer acetate: a synthetic drug made of amino acids used as a disease modifying therapy in MS.

Heart failure: failure of the heart to pump adequately, resulting in symptoms such as breathlessness; tiredness; cough; swollen legs, feet or ankles; and abnormal weight gain.

Highly Active RRMS: this generally refers to persons with RRMS who experience 2 or more attacks within a 12 month period, these attacks need to be backed up by an MRI which clearly shows areas of damage to the brain.

Human serum albumin: most abundant protein in human blood plasma and a common ingredient of medicinal products including interferons.

Hypersensitive reaction/hypersensitivity: also known as an allergic reaction, this is an abnormal immune response to a drug, which occurs when the patient is re-exposed to the particular drug.

Immune system: the body's natural defence system that protects against infection and disease.

Immunomodulatory therapies: medications that enhance or reduce (modify) immune responses such as inflammation. In MS, immunomodulatory medications such as interferon beta and glatiramer acetate are also called disease-modifying therapies.

Inflammation: the response of the immune system to injury, infection or irritation. Inflammation is a key part of the healing process and is often accompanied by redness, warmth, swelling and/or pain of the affected area. With autoimmune diseases such as MS, inflammation can have a harmful effect on the body’s organs and tissues.

Insomnia: not being able to sleep.

Interferons: a family of proteins naturally produced in the body that play a role in controlling the immune system. One type of interferon, interferon beta is used in MS as a disease modifying therapy.

Intramuscular (IM) injection: an injection given directly into the muscle of the body, such as the thigh or upper arm.

Intravenous (IV): administration of a drug directly into a blood vessel, usually a vein. The drug may be injected over a short period of time – bolus injection – or over a prolonged period – by infusion. In the latter, the drug is dissolved in a volume of fluid and placed in a sterile bag. A pump then controls the release of fluid from the bag into the vein via a sterile tube. Some drugs can only be administered intravenously. Other drugs can also be delivered by other routes but intravenous delivery results in a faster onset of action compared with subcutaneous or oral delivery.

Lesion: a wound or injury, or a change in the tissues caused by a disease. The plaques or areas of sclerosis that occur in the CNS in MS may be also be referred to as lesions.

Leukaemia: type of cancer of white blood cells.

Licence: before a drug can be prescribed to a member of the public, it goes through an approval procedure to check that it has acceptable levels of quality, safety and effectiveness. There may be a delay between approval and launch; so a drug can be licensed but unavailable.

Lumbar puncture or ‘spinal tap’: this procedure involves, under a local anaesthetic, using a hollow needle to take fluid from around the spinal cord (Cerebro Spinal Fluid or CSF). The needle is inserted in the lower back or lumbar region. CSF from people with MS may show specific changes that reveal the presence of inflammation.

Lupus: type of chronic skin disease.

Magnetic resonance imaging (MRI): an imaging process whereby the magnetic signature of molecules in regions of the body (e.g. the brain) are detected and converted into pictures by computer. It is a useful tool that helps the physician to actually see brain lesions in people with MS.

Membrane: a thin layer of flexible tissue that separates or connects two structures or acts as a covering for a body part. For example, each cell in the body is enclosed in a membrane.

Monoclonal antibody: type of antibody produced synthetically in vitro such that all the antibodies are identical and recognise a specific antigen. Monoclonal antibodies were originally produced by fusing spleen cells from a mouse which had been immunised against the specific antigen with antibody-producing cancer cells to produce hybrid cells that produce large amounts of the monoclonal antibody. Nowadays monoclonal antibodies are produced by manipulating antibody genes to obtain the desired antibody and then expressing this gene in yeasts or cells in culture so that large amounts of the specific antibody can be produced. The latter are known as recombinant monoclonal antibodies.

Monotherapy: treatment with only one drug (in contrast to combination therapy in which two or more drugs are used together).

Multiple sclerosis (MS): a disease of unknown origin (thought to be caused in part by dysfunction of the immune system) that affects the central nervous system and may result in the progressive loss of certain body functions and physical abilities.

Myelin: the insulation that surrounds the axons and is damaged in MS. Areas of the CNS where there are large amounts of myelin are known as white matter because they look paler than surrounding areas.

Myelosuppression: reduction in the number of blood cells in the bone marrow, often as a result of chemotherapy for cancer.

Natalizumab: a recombinant humanised monoclonal antibody directed against the adhesion molecule, alpha4-integrin. The adhesion molecule is expressed on the surface of most white blood cells and is involved in allowing white blood cells to cross the blood-brain barrier and enter the brain. Natalizumab binds to the adhesion molecule, thus inhibiting the entry of white blood cells into the brain. Since white blood cells are involved in the inflammatory reactions that cause new MS lesions, blocking their entry into the brain helps slow the progression of MS.

Necrosis: death of a limited portion of tissue.

Neurological: anything to do with the study of the brain or central nervous system.

Neurons: the body’s ‘controlling’ cells, responsible for many of the complex functions of the human body such as thought, memory, control of bodily functions, movement and transmission of electrical signals between the CNS and the body. Neurons consist of a cell body and two types of extension - dendrites and axons. They vary in size and construction, depending on their location and function. Some can be the longest cells in the human body, while others may be very small.

Neutralising antibodies: over a period of time, an antibody may develop against protein based drugs (e.g. interferons) that limit their effectiveness. In these cases, some people with MS may experience a loss of the drug’s effectiveness. However, the full implications of developing neutralising antibodies are not yet fully understood.

Opportunistic infection: infection that arises in an individual with a poorly functioning immune system. In a healthy individual, such an infection would be unlikely to occur.

Optic neuritis: inflammation of the optic nerve, which can lead to complete or partial loss of vision.

Palpitations: irregular and/or forcible beatings of the heart so that the individual becomes aware of them.

Pathology:

Pathogenic: changes that lead to the manifestation of disease.

Placebo: an inactive substance that often in the form of a tablet, injection or other medication, given to people instead of an active drug during some clinical studies. People taking placebo are often compared to those taking an active drug to judge the effectiveness and safety of the active medication.

Plaque: scar in the nervous system caused by inflammation covering a large area.

Polypeptide: molecule consisting of a number of amino acids linked via a specific bond known as a peptide bond. Proteins are large polypeptide chains.

Primary Progressive MS (PPMS): form of MS in which there is a continual loss of physical and cognitive function, with no relapses, from the very beginning of the condition.

Progressive MS: There is a continual loss of physical and cognitive function with no relapses, in contrast to relapsing-remitting MS where there are clearly defined relapses followed by periods during which some amount of recovery occurs.

Progressive multifocal leucoencephalopathy (PML): rare viral disease characterised by progressive damage or inflammation of the white matter of the brain at multiple sites. It usually occurs in people with severe immune deficiency and is often fatal.

Proteins: naturally occurring complex combinations of amino acids that are present in plant and animal cells and are essential to life. The human body contains over 100,000 proteins.

Psychiatric: symptoms that relate to how the patient feels such as anxiety, depression, emotional control and feelings of well being.

Randomised controlled trial (RCT): an essential tool of medical research. An RCT is a study in which people are allocated (randomised) to different treatments and the effects of those treatments are compared. Some of these people may be randomised to a placebo or a standard treatment (the control), so that the effects of the test medication can be more clearly observed.

Recombinant: protein produced synthetically using recombinant technology. This involves cloning the gene for the protein in a bacterium or virus and then producing large quantities of the protein by growing the bacteria or cells infected with the virus in culture and purifying the protein from the culture. Betaferon and Rebif are recombinant interferons.

Relapse: this refers to the return of MS signs and/or symptoms after a period of recovery. It’s sometimes known as an exacerbation.

Relapsing-Remitting MS (RRMS): a form of MS characterised by relapses (exacerbations) followed by complete or partial recovery of function.

Remission: a period in which the signs and/or symptoms of MS are lessened or disappear for a while.

Rheumatoid arthritis: chronic inflammation of the joints.

Sclerosis: the hardening or scarring of an organ or tissue. The term Multiple Sclerosis refers to the fact that people have many areas of sclerosis or plaques in the CNS, due to the process of inflammation and demyelination.

Secondary Progressive MS (SPMS): a form of MS that starts with relapses and remissions, but in which a more continual loss of bodily function starts to take over.

Seizure/Convulsions: fit resulting from abnormal electrical activity within the brain.

Subcutaneous: using a needle to deliver medications into the tissue just under the skin.

Suppressor T-cells: a specific type of T-cell (which is a type of white blood cell) involved in suppressing the activity of white blood cells that promote immune responses and hence inflammatory reactions.

T-cells: a type of white blood cell that plays an important role in regulating the immune system.

Thyroid problems: disorders of the thyroid, an endocrine gland located in the neck which controls protein production and how rapidly the body burns food to produce energy. The most common disorders are hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid).

Urinary tract infection: infection involving the kidneys, the ureters (the vessels connecting the kidneys to the bladder), the bladder or the urethra (tube by which urine leaves the body).

Urticaria: rash characterised by itching, redness and whealing.

White blood cells: cells of the blood involved in defence of the body against infectious agents such as viruses and bacteria and other materials recognised as being foreign.

White matter: parts of the CNS (central nervous system) where there are large amounts of myelin wrapped around axons.

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