Transient Ischemic Attack in a Patient With Absent Carotid Circulation and Dilated Vertebrobasilar Vessels

摘要

Internal carotid ajrtery (ICA) agenesis is a rare vascular anomaly that, in combination with occlusion of the contralateral ICA, produces significant strain on the posterior circulation for collateral flow. We report a patient who presented with transient ischemic attack and was found to have congenital ICA agenesis and contralateral ICA occlusion with cerebral perfusion maintained through dilated vertebrobasilar circulation.