Multiple sclerosis is a disease that involves an immune system attack against the central nervous system (brain, spinal cord, and optic nerves). MS is a potentially debilitating disease in which a body's immune system causes inflammation and the destruction of the nerve cover myelin (a substance that surrounds and protects the nerve fibers in the central nervous system). Damage to myelin causes interference in the communication between the brain, spinal cord and other areas of the body. This condition may result in deterioration of the nerves themselves, a process that's not reversible.
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. Although MS is thought by some scientists to be an autoimmune disease, others disagree strongly because the specific target of the immune attack in MS has not yet been identified. For this reason, MS is referred to as an immune-mediated disease.
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.
Symptoms vary widely, depending on the amount of damage and the nerves that are affected. People with severe cases of multiple sclerosis may lose the ability to walk or speak clearly. Multiple sclerosis can be difficult to diagnose early in the course of the disease because symptoms often come and go — sometimes disappearing for months.
Multiple sclerosis has no cure. However, treatments may help treat MS attacks, manage symptoms and reduce progress of the disease.