A Case of Severe Common Carotid Artery Stenosis Who Developed Cerebellar Infarction after Cervical Irradiation

Objective: We report a case of cerebellar infarction caused by radiation-induced common carotid artery stenosis.Case Presentation: The patient was a 72-year-old man who underwent irradiation for hypopharyngeal carcinoma 13 years ago. He was referred for asymptomatic left common carotid artery stenosis, but was brought to our hospital by ambulance with transient dysarthria and right facial dysesthesia 2 days after referral. Magnetic resonance imaging (MRI) revealed acute infarction in the left cerebellar hemisphere, and digital subtraction angiography (DSA) demonstrated that the blood flow in the left internal carotid artery perfused the left posterior inferior cerebellar artery (PICA) retrogradely through the left posterior communicating artery. The patient underwent carotid artery stenting (CAS) for left common carotid artery stenosis and blood flow in the left PICA improved; however, in-stent restenosis was revealed during follow-up. Percutaneous transluminal angioplasty (PTA) for in-stent restenosis was performed 9 months after the surgery.Conclusion: We reported a rare case of ischemia in the PICA area caused by radiation-induced common carotid artery stenosis. Although CAS is recommended for the treatment of radiation-induced carotid artery stenosis, careful treatment and follow-up are needed to prevent perioperative complications and detect in-stent restenosis after CAS.