Chronic methanol poisoning with the clinical and pathologic-anatomical features of multiple sclerosis.

The details of two cases of chronic methanol poisoning are presented. Both patients initially developed clinical symptoms of multiple sclerosis: visual disturbances, intention tremor, reduced abdominal reflexes, impaired coordination and difficulties with walking. After the exposure to methanol had ceased the multiple sclerosis symptoms persisted in patient 1 but disappeared gradually in patient 2 (patient 2 had a history of excessive alcohol consumption, which is a critical fact in this discussion). Ultimately autopsies confirmed this picture: histological examination of patient 1 revealed plaques in the spinal cord, in the stem and in the proximity of the lower horn of one lateral ventricle, whereas no localized demyelination could be found in patient 2. The results are discussed in connection with the theory ("Methanol Hypothesis") that under certain circumstances multiple sclerosis itself is induced by formaldehyde stemming from the metabolism of methanol.