Carotid stenting and cerebral hyperperfusion syndrome.

We present a patient who became hemiparetic and drowsy 30 min after insertion of a carotid artery stent for severe (>80%) asymptomatic left common carotid artery stenosis. A carotid angiogram at this time showed widely patent vessels. Non-contrast head computed tomography showed a diffuse increase in signal intensity in the distribution of the left middle cerebral artery. Repeat computed tomography 8 days later showed no evidence of cerebral infarction or haemorrhage. The patient's arm remained weak for several months. A diagnosis of cerebral hyperperfusion syndrome was made. The features of this unusual cause of stroke are reviewed.