Corpus callosum in multiple sclerosis.

A neuropathological study of 20 multiple sclerosis brains using celloidin-embedded slices was carried out to assess the extent of changes in the corpus callosum. Severe atrophy of the callosum was found in cases with marked hydrocephalus. Demyelination of the callosum varied in extent from slight involvement (with a few small plaques) to almost total myelin loss. A clinical history of mental deterioration was usual in the cases with severe callosal lesions, but no symptoms were recorded that indicated a specific disconnection syndrome. The ventricular enlargement noted in this series could not be explained either on the basis of obstruction to the flow of cerebrospinal fluid, or by the effects of shrinkage of the white matter.