Multiple sclerosis is a disease that strikes only the central nervous system, which consists of the brain and spinal cord. These organs control the movements and the functions of the entire body. As the brain sends and receives signals, the spinal cord funnels them in and out to and from different parts of the body through a network of nerves. The nerves are surrounded by insulating matter called myelin – a soft, white, fatty substance that forms a protective sheath for the nerves. The myelin sheath which develops in the first ten years of life insulates the nerve fibers and helps conduct signals through the body. Multiple sclerosis is a disease where the myelin breaks down and is replaced by scar tissue. This demyelination can slow down or even block the flow of signals through the body, impairing such functions as vision, strength or coordination.
