Multiple sclerosis is an autoimmune disease in which the immune system targets the myelin sheath that surrounds and protects nerve fibers.
The myelin sheaths act in the same way as insulation surrounding an electrical wire, allowing the nerve fibers to transmit information throughout the body. When the immune system attacks the myelin sheath, it damages small areas of tissue; these damaged areas are called lesions. The lesions are gaps over which the nerve signals cannot be transmitted, and this results in a wide range of neurological symptoms including loss of sensation and mobility, loss of vision, interference with mental processes, and in extreme cases, death. There are two forms of MS: relapsing-remitting and secondary progressive. As their names suggest, relapsing-remitting MS is characterized by periods of calm interrupted with flare-ups, while secondary progressive is associated with a steady decline in function. Although there is no cure for MS, there are treatments that manage the disease and slow disease progression. Torrey Pines Institute researchers are working to understand the basic mechanisms that explain why and how the immune system attacks the nerve myelin sheath. These studies will help in developing therapies that slow or prevent this debilitating disease.