Sudden coma from acute bilateral internal carotid artery territory infarction.

Six patients with bilateral internal carotid artery occlusion who presented with sudden loss of consciousness, quadriplegia, and initially intact brainstem reflexes are described. They soon lost brainstem reflexes and died within 3 days. The presumed causes of internal carotid artery occlusion were atherothrombosis in three patients and cardiogenic embolism in the others. This catastrophic stroke syndrome mimics severe brainstem stroke and has an extremely poor prognosis.