Teaching neuroimages: anoxic brain injury with unilateral hemispheric cortical involvement.

A 55-year-old woman collapsed with chest pain and cardiac arrest. Her pulse was restored after 6 minutes of cardiopulmonary resuscitation, but she remained comatose. Brain MRI (figure) revealed bilateral basal ganglia and right hemispheric cortical lesion, which was typical for anoxic brain injury except for the unilateral cortical involvement. Neck CT angiography showed severe stenosis in the right proximal internal carotid artery. The unilateral cortical injury could be explained by compromised cerebral blood flow due to preexisting carotid stenosis. This case demonstrates an atypical pattern of anoxic brain injury secondary to focal vascular stenosis.