Compared with intensive medical therapy alone, intracranial angioplasty and stenting combined with intensive medical therapy will decrease the risk of the primary endpoint by 35% over a mean follow-up of two years in high-risk patients patients with 70% - 99% intracranial stenosis who had a transient ischemic attack (TIA) or stroke within 30 days prior to enrollment) with symptomatic stenosis of a major intracranial artery.