Unsuspected (clinically silent) multiple sclerosis. Quantitative investigations in one autoptic case.

The incidental retrieval of a few, well-circumscribed, chronic multiple sclerosis plaques in a 49-year-old female who died from myocardial infarct is reported. In serial gallocyanin stained frontal sections of the brain one plaque in the left and four plaques in the right hemisphere were encountered. A total of 1.25 cm3 or 0.24% of the right hemispheric volume and a total of 0.93 cm3 or 0.2% of the left hemispheric volume was afflicted. The size as well as the topography of the plaques could explain the absence of clinical symptoms. Methodological issues concerning in vivo and post mortem diagnosis of multiple sclerosis and their impact on the epidemiology of this disease are discussed.