Reversible cerebral vasoconstriction complicated with brain infarction immediately after carotid artery stenting.

Reversible cerebral vasoconstriction is a very rare complication after carotid artery stenting (CAS). It has been reported to occur more than several hours after CAS and to have a good clinical course. A 73-year-old man underwent CAS for a high-grade symptomatic stenosis of his left carotid artery. Immediately after CAS, he had consciousness disturbance and right hemiparesis. We first suspected hyperperfusion syndrome, but antihypertensive therapy exacerbated his symptoms. On repeated postoperative angiography, the middle cerebral artery (MCA) appeared to become progressively narrower. Perfusion computed tomography indicated hypoperfusion in the left MCA territory, so we diagnosed the patient with ischemic symptoms due to hypoperfusion associated with MCA vasoconstriction. Although these findings were temporary, right weakness and cognitive dysfunction lingered and caused severe disability. As vasoconstriction after CAS may result in a poor outcome, it must be promptly distinguished and treated accordingly.