[Callosal dementia: behavioral disorders related to central and extrapontine myelinolysis].

We report the behavioral symptoms presented by a 57-year-old man as the first sign of a Marchiafava-Bignami syndrome and by a 44-year-old woman with centro and extrapontine myelinolysis. These observations define a clinical entity, that we named callosal dementia characterized by: 5) fronto-limbic signs with coarse interjections, repetitive and antisocial behavior, alternation of lack of incitation and agitation; 6) elements of a Balint syndrome (suggestive of a posterior callosal involvement), with a pseudo-hallucinated look and a gaze apraxia; 7) signs of callosal dysconnection and; signs of adjacent white matter involvement, with paucity of vocal and facial expression modulation. Early recognition of these features of callosal dementia may be very helpful for diagnosis of suspected myelinolysis, leading to a more careful research of clinical signs of callosal dysconnection and prompting neuroimaging with MRI. A rapid confirmation of the diagnosis may prevent progression to centro or extrapontine myelinolysis, that may sometimes still be lethal, by adequate supportive measures (slow correction of electrolytes imbalance, correction of deficiencies, total alcohol withdrawal).