Teaching NeuroImages: perfusion imaging of cerebral hyperperfusion syndrome following revascularization.

A 69-year-old man developed acute-onset confusion and hypertension with systolic pressures in the 160s 1 day after carotid endarterectomy for right facial droop from left hemispheric lacunar infarcts. CT perfusion (figure, A-D) demonstrated findings consistent with cerebral hyperperfusion syndrome (CHS) following revascularization. CHS is caused by loss of autoregulation, hypertension, and ischemia-reperfusion injury resulting in increased regional blood flow and vascular congestion.(1) CHS following revascularization may present as ipsilateral headache, focal seizure, or neurologic deficit. Nonperfusion imaging may show intraparenchymal hemorrhage or edema. Labetalol and clonidine are used for aggressive blood pressure control until cerebral autoregulation is restored.(2.)