A case of myelinoclastic diffuse sclerosis in an adult. We report a case of rapidly progressive cerebral demyelinating disease in a previously healthy 40-year-old woman. This case satisfies the diagnostic criteria for myelinoclastic diffuse sclerosis (MDS), but is unusual in the age of onset. This is the 1st case of MDS in an adult with full documentation of clinical, biochemical, radiographic, and pathologic features. 