Section Editor: Sandy Cheng-Yu Chen, M.D.
Taipei Medical University Hospital, Taipei, Taiwan
Figure Caption
Persistent hypoglossal artery (PHA; arrows) is the second most common carotid-vertebrobasilar artery anastomosis. PHA originates from the internal carotid artery at the levels of the C1 through C3 vertebral bodies, courses through the hypoglossal canal, and anastomoses with the basilar artery. In most of the cases (79%), the posterior communicating arteries and the vertebral arteries are hypoplastic. Definitive diagnosis is based on the recognition of an anomalous artery in the enlarged hypoglossal canal.