We report the case of a 26-year old alcoholic woman who abruptly presented with confusion associated with a major hypertonia. She evolved into a chronically vegetative state. Magnetic resonance imaging (MRI) was consistent with the diagnosis of Marchiafava Bignami disease. The corpus callosum first presented an oedematous aspect, then a central atrophy with an axial band. The clinical presentation and the functional imaging strongly suggest an association between the Marchiafava Bignami disease and diffuse cortical lesions, such as the laminar sclerosis of Morel.