[Marchiafava-Bignami disease. Interhemispheric disconnection, favourable outcome, neurological aspect].

We report two cases of Marchiafava-Bignami disease studied by CT and MR imaging. Both had hemispheric disconnection syndrome and favorable outcome. The only residual signs were agraphia with the left hand in the two cases and mild dementia in one. In one case, a control CT scan performed 3 weeks after the first one was normal whereas T2-weighted MR images showed high intensity signal in the corpus callosum. We conclude that: 1. there are benign forms of MB disease; 2. neuroimaging has diagnostic and prognostic value; 3. vitamin B deficiency may play a role in the pathogenesis of the disease.