Anterior Callosal Disconnection Syndrome

Choi, Young Bin; Kim, Yeong In; Lee, Sang Bong; Lee, Kwang Soo

Abstract

It has been known that right ACA occlusions can cause callosal disconnection syndrome. A 61-year old right-handed man was admitted because of a left ACA occlusion. MRI showed infarction of the medial frontal cortex and the anterior two-thirds of the corpus callosum. He presented with weakness and gait initiation failure in the right leg with grasp reflex, suspicious alien hand sign, and tactile anomia in the right hand. He was diagnosed with transcortical motor aphasia. He was unable to successfully complete written tasks in response to dictations and writing down spontaneous answers. He wrote down incorrect words and demonstrated paragraphism with his left hand. He could copy simple items but not written words and complex items with his left hand. Finally, he had difficulties in writing answers in response to complex verbal and written commands with his left hand, but preserved the ability to simple verbal commands, somato-sensory, and visually guided tasks. We attribute these results to the anterior callosal disconnection of the right sensorimotor cortex from the left language area.