Contributor: Gordon K. Klintworth
Multiple sclerosis (disseminated sclerosis) is an idopathic acquired demyelinating disorder of the central nervous system characterized by multiple discrete lesions of variable age in multiple locations. It is the most common disease of the human central nervous system in which myelin is destroyed without damage to axons. Multiple sclerosis is rare in Japan and in many other countries. Presumably, some demyelinated axons in this demyelinating disease transmit impulses, as vision may still be present in an eye that has a completely demyelinated optic nerve. Remission of symptoms can be accounted for on the assumption that demyelinated axons can transmit impulses. Nerve conduction becomes temporarily impaired during acute demyelination, while permanent disability follows the axonal degeneration or interference with nerve conduction by poorly understood mechanisms. Several variants of multiple sclerosis are recognized: classical form of multiple sclerosis [multiple sclerosis - classic], acute multiple sclerosis [multiple sclerosis - acute], Schilder type [multiple sclerosis - Schilder type], Balo type [multiple sclerosis - Balo type], and Devic disease.