CORPUS CALLOSOTOMY EFFECTS ON CEREBRAL BLOOD-FLOW AND EVOKED-POTENTIALS (TRANSCALLOSAL DIASCHISIS)

The role of the corpus callosum in diaschisis was examined through the acute effects of stereotactic corpus callosum section on cerebral blood flow and somatosensory or auditory evoked potentials bilaterally during unilateral brain retraction ischemia, using a previously reported swine model. Cerebral blood flow and evoked potential amplitude contralateral to retraction increased during retraction with the corpus callosum intact, compared with post-callosal section values. With retraction following callosal section, there was no increase in cerebral blood flow or evoked potential amplitude contralateral to retraction. Diaschisis during the early stages of a focal, unilateral injury takes the form of a contralateral disinhibition (as measured by cerebral blood flow and evoked potentials), an effect which is lost following callosal section.