Ten-year Follow Up of Incidental Spontaneous Extracranial Internal Carotid Artery Dissection in a Japanese Asymptomatic Older Man: A Case Report

This report presents a unique finding of an incidental right internal carotid artery dissection in an asymptomatic 69-year-old man. The report highlights the possible trigger and long-term outcomes of this condition. The patient had participated in Japanese archery competitions for many years. His medical history included hypertension and a prior ischemic stroke in the left lateral medulla, resulting in Wallenberg syndrome. During a routine visit, head magnetic resonance angiography revealed right internal carotid artery dissection. He was managed conservatively with antiplatelet therapy and close monitoring. Follow-up imaging after 10 years showed no changes, and the patient remained asymptomatic. Therefore, routine screening for incidental findings is important even in asymptomatic patients. Archery competitions may be a possible trigger for internal carotid artery dissection. The presence of re-entry in the lesion at the time of onset can be a predictor of a good long-term prognosis.