What is multiple sclerosis?
Multiple Sclerosis (MS) is a chronic disease that affects the central nervous system. It causes inflammation and the destruction of myelin. Myelin surrounds nerve fibers and acts like insulation on a wire preventing “short-circuits” that divert a nerve signal from having its desired effects. The “demyelination” process interferes with nerve impulse transmission, affects muscular control, and causes a variety of sensory, motor, and psychological symptoms. Damage to the myelin usually resolves with time and symptoms subside, but repeated attacks can lead to a continual process of demyelination and remyelination, which produces nerve fiber scarring and progressive disability.
The cause of MS is unknown. It is thought to be an autoimmune process triggered by a virus, environmental factors, and/or a genetic predisposition. Typically, MS first surfaces when patients are between 20 and 40 years of age. It affects women more frequently than men, is more common in Northern European Caucasians than other ethnic groups, and is seen in greater numbers in temperate climates than warm ones. According to the National Multiple Sclerosis Society (NMSS), MS affects about 400,000 people in the United States and about 200 new cases are diagnosed each week. The risk of developing this disease is estimated to be less than one tenth of one percent (1 in 1000) in the general population. In families with an affected member, the risk rises to 3%, and it is about 30% for the identical twin of an affected patient, strengthening the notion of a genetic component to the cause.