Cognitive impairment associated with intraoperative and postoperative hypoperfusion without neurologic deficits in a patient undergoing carotid endarterectomy

Abstract Background Neuropsychological testing detects cognitive impairment in 20% to 30% of patients after carotid endarterectomy (CEA). Case Description A 51-year-old man with asymptomatic right cervical internal carotid artery (ICA) stenosis underwent a CEA. Intraoperative transcranial regional cerebral oxygen saturation monitoring revealed ischemia in the right cerebral hemisphere during ICA clamping and transient hyperemia subsequent to ICA declamping. The patient recovered without the appearance of new neurologic deficits. Brain single-photon emission computed tomography performed immediately after CEA showed a decrease in cerebral blood flow in the right cerebral hemisphere. Diffusion-weighted magnetic resonance imaging showed no new abnormal findings. Positron emission tomography performed 2 months after surgery revealed decreased cerebral metabolic rate of oxygen in the right cerebral hemisphere, and neuropsychological testing demonstrated a decline in performance IQ relative to preoperative levels. Conclusions Intraoperative ischemia and postischemic delayed hypoperfusion in CEA can impair cognition even in the absence of development of postoperative neurologic deficit.