Acute

Characterized by rapid onset - usually with recovery. Not chronic or long- lasting.

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.

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.

A decrease in size and strength of a part of the body due to disease or inactivity.

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.

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.

BRMs are biochemical substances that can be measured in the blood of patients following administration of the interferons.

Black box warning:

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.

An area where a potentially irreversible loss of axons has occurred.

The part of the nervous system that includes the brain, optic nerves, and spinal cord, the parts of the body affected by MS.

A part of the brain situated above the brainstem that controls balance and coordination of movement.

The outer layer of brain tissue.