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   more »

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   more »

Paraparesis Weakness of the lower extremities (legs). Paraplegia Paralysis of both lower extremities (legs). Paresis Partial or incomplete   more »

Necrosis Death or decay of tissue that results from loss of the blood supply and oxygen needed to keep tissue alive and healthy. 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 skin, joints, muscles, and inner   more »

Lesion Damaged area in the brain or spinal cord caused by demyelination (also called plaque or sclerosis). Leukocyte White blood cell. Lymphocyte A type of white blood cell that   more »

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   more »

MS Glossary 2 of 7 Cerebrospinal fluid (CSF) A clear fluid that circulates in the space surrounding the brain and spinal cord. Cerebrum 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.   more »

Spinocerebellar ataxias. To date, researchers have identified 28 autosomal dominant ataxia genes. The first was called spinocerebellar ataxia type 1 (SCA1), with subsequent ataxia genes generally numbered according to their order of discovery. Cerebellar ataxia   more »

Ataxia describes a lack of muscle coordination when you perform voluntary movements, such as walking or picking up objects. It's a sign of an underlying condition, not a disease itself. Ataxia can affect any part of your body — affecting your movements, your   more »

Acute conditions are severe and sudden in onset. This could describe anything from a broken bone to an asthma attack. A chronic condition, by contrast is a long-developing syndrome, such as osteoporosis or asthma. Note that osteoporosis, a   more »

Anaphylaxis is a medical emergency. This serious type of allergic reaction occurs after a person is exposed to an allergen (a substance they are allergic to), such as certain foods, medications, or insect stings. The body's immune system quickly reacts, causing swelling of the face and throat, difficulty breathing   more »