Cerebral Hyperperfusion Syndrome After Endovascular Reperfusion Therapy in a Patient with Acute Internal Carotid Artery and Middle Cerebral Artery Occlusions

Background Cerebral hyperperfusion syndrome (CHS) is known to be a rare but devastating complication of carotid artery revascularization. Because patients with acute ischemic stroke due to acute major cerebral and/or cervical artery occlusion treated with endovascular reperfusion therapy may have impaired autoregulation in the cerebral vasculature, these patients may also develop CHS. Despite the growing number of endovascular reperfusion procedures for acute ischemic stroke, this complication has only rarely been reported. Case Description A 77-year-old man developed acute cerebral infarction as the result of occlusions of the right internal carotid artery and right middle cerebral artery. After systemic intravenous injection of recombinant tissue-type plasminogen activator, endovascular reperfusion therapy was initiated. The occluded arteries were successfully recanalized with thrombectomy by using a stent retriever for the middle cerebral artery and stent placement for the origin of the internal carotid artery. However, head computed tomography obtained 12 hours after treatment showed acute intracranial hemorrhage that did not involve the ischemic lesions. Under evaluation with transcranial near-infrared spectroscopy and single-photon emission computed tomography, the hemorrhage was considered to have been caused by CHS after reperfusion therapy. Conclusions CHS may lead to unfavorable outcomes after reperfusion therapy for acute ischemic stroke. Recognizing clinical deterioration caused by CHS can be challenging in patients with neurologic disorders of acute ischemic stroke. Therefore, it is important to perform routine monitoring of regional cerebral oxygen saturation by using near-infrared spectroscopy, perform single-photon emission computed tomography promptly to evaluate cerebral blood flow, and maintain strict antihypertensive therapy to prevent CHS after reperfusion therapy.