Multiple sclerosis (MS) is thought to be an autoimmune disease of the central nervous system (brain, spinal cord). The disease attacks myelin, the protective covering of the nerves, causing inflammation and often damaging the myelin. Myelin is necessary for the transmission of nerve impulses through nerve fibres. If damage to myelin is slight, nerve impulses travel with minor interruptions; however, if damage is heavy and if scar tissue replaces the myelin, nerve impulses may be completely disrupted, and the nerve fibres themselves can be damaged. more... See more text