Picture of Nerve Fibers and Myelin Attack in MS
Multiple sclerosis is an autoimmune condition in which the immune system attacks and destroys myelin, the insulating material that protects nerves. A virus or foreign antigen may stimulate the immune system and initiate the process. As myelin is damaged or destroyed, nerve impulses traveling along the affected nerves become slower. Nerve damage may occur. The body does its best to repair myelin, but some nerves may experience complete demyelination. Scarring and plaques may form on affected nerves and progressively interfere with walking, speech, writing, memory, and vision.
Text Reference: National Multiple Sclerosis Society: "What Is Myelin?"