Intracranial artery stenosis (ICAS) is a leading cause of stroke worldwide. It is estimated to account for 10% of ischemic strokes in the US and perhaps up to 50% of strokes in Asia.1 Despite its frequency and role in stroke-related morbidity and mortality, ICAS has received less attention compared with extracranial atherosclerotic disease. In the past 15 years, clinical trials have refined the treatment approach for patients with recent stroke or transient ischemic attack (TIA) and ICAS.2-4 However, less information is available pertaining to asymptomatic ICAS.