A demyelinating disease is any condition that results in damage to the protective covering (myelin sheath) that surrounds nerve fibers in your brain, optic nerves and spinal cord. When the myelin sheath is damaged, nerve impulses slow or even stop, causing neurological problems.
Multiple Sclerosis is common demyelinating disease. Other disorders include optic neuritis, NMO spectrum disorder and acute disseminated encephalomyelitis.