Cerebral hyperperfusion syndrome: an etiology of seizures following carotid endarterectomy.

Cerebral hyperperfusion syndrome after carotid endarterectomy is an uncommon but distressing complication. Findings in nearly all these patients include the presence of ipsilateral high-grade carotid artery stenosis, postoperative ipsilateral headache followed by seizures, and transient neurologic deficits. It appears to be caused by the loss of autoregulation within the brain, usually occurring between 5 and 7 days postoperatively.