Multiple sclerosis

The papers in this chapter illustrate the picture that has emerged of multiple sclerosis as an inflammatory disorder of the central nervous system, caused by a complex interplay of multiple genetic susceptibility alleles and unknown environmental triggers. Multiple sclerosis is a disease in which there is first demyelination of nerves, followed by axonal degeneration. Demyelination is caused by inflammation, as shown by the synthesis of immunoglobulins within the CNS, and magnetic resonance imaging has shown that only the minority of inflammatory lesions cause symptoms. All of these discoveries were made in the twentieth century, which ended with the first demonstration that a treatment—interferon-beta—could influence the natural history of the disease.