Syndrome de dysconnexion calleuse

Interhemispheric disconnection symptoms are usually the manifestation of acute lesions of the corpus callosum. They have to be explored by specific maneuvers. The left (dominant) hemisphere alone is capable of verbal expression, either orally or in writing. This explains left sensory, visual or auditory anomias, but also right olfactory anomia. By contrast, the right hemisphere is more involved in processing visuo-spatial and visuo-praxic information. Tachistoscopic presentations or dichotic listening procedures are necessary to explore interhemispheric transfer disorders, respectively for visual and auditory stimuli. Independence between the two hemispheres may result in an intermanual conflict, in which the left hand is seen by the patient as driven by its own will (alien hand; diagonistic dyspraxia when there is an antagonism between the two hands).