Disconnected Motor Intention and Spatial Attention in a Case of Probable Marchiafava-Bignami Disease.

Marchiafava-Bignami disease (MBD) is a rare complication of chronic alcoholism that typically causes demyelination and necrosis of the corpus callosum. Here, we report a man with probable MBD with callosal and right medial paracentral lesions who presented with abnormal reaching behavior and ideomotor apraxia of the left hand. He exhibited difficulty in reaching with the left hand when a target object was placed on his right-hand side, and he exhibited rightward bias when using his right hand in a line bisection task. These disturbances in reaching suggest disruption of the top-down control of motor intention and spatial attention at the corpus callosum.