[Rapid improvement of callosal edema by thiamine administration in Marchiafava-Bignami disease: a case report].

Marchiafava-Bignami disease (MBD) associated with chronic alcoholism is a fatal disorder characterized by demyelination of the corpus callosum. A 62-year-old Japanese man, a heavy drinker for his last over 10 years, was admitted to our hospital because of acute onset of speech disturbance. The first MR images showed abnormal signal intensity of the corpus callosum, which was a typical finding of MBD, but no signal abnormality on diffusion-weighted images. At three days after large doses of thiamine administration, MR studies revealed the disappearance of callosal high signal intensity. His symptom gradually improved, the pathogenesis and therapy of MBD were discussed.