Multiple sclerosis with hydromyelia demonstrated at autopsy.

Multiple sclerosis (MS) associated with intramedullary cysts has been recently documented radiographically in approximately a dozen cases, but histological confirmation in these cases has been lacking. These cysts have been noted to occur centrally in the spinal cord and have been previously diagnosed as syringomyelia. We report a patient with extensive hydromyelia, but no dissecting syringomyelic cavity, of the thoraco-lumbar spinal cord, which was co-existent with centrally located, non-necrotic, chronic demyelinative plaques. A few well demarcated non-necrotic plaques were seen in the cerebrum and cerebellum with sparing of optic chiasm, confirming the diagnosis of chronic, non-Devic type MS. Although a cause and effect between the hydromyelia and MS cannot be proven in this or any of the previously reported radiographic cases our report provides pathological confirmation of the association between these two entities and further delineates the type of cyst.