Until now,the pathogenesis of Marchiafava-Bignami disease, an extrapontine
myelinolysis, is unknown. Accept an abuse of alcohol for many years additio
nal metabolic and vascular disturbances are supposed. The early performance
of magnetic resonance imaging in patients with a sudden encephalopathy and
history of alcoholism is essential for an assessment of the diagnosis. The
bilateral lack of transcallosal inhibition a parameter for the integrity o
f the transcallosal connections between motor cortices is the consequence o
f the axonal degeneration of transcallosal fibers. Clinical and neuroradiol
ogical features of three patients with extrapontine myelinolysis are report
ed and possible etiologies of the complex disease are discussed. In two cas
es a severe alcohol abuse was present with the typical picture of the March
iafava-Bignami disease. In a third patient an intoxication with methanal wa
s present with a similar clinical picture.
Although severe neurological disturbances were initially apparent in the pa
tients, during the follow-up there was a significant amelioration of the cl
inical course under a high-dose vitamin B supplementation.