An uncommon anastomosis of the posterior inferior cerebellar artery and the external carotid artery with the patent vertebrobasilar system.

The hypoglossal artery arises as a branch of the internal carotid artery and traverses the hypoglossal canal. However, the hypoglossal artery arising from the external carotid artery (ECA) and connecting directly with the posterior inferior cerebellar artery (PICA), instead of the basilar artery or the vertebral artery, is very rare. We present a case of an uncommon variant of the hypoglossal artery arising from the ECA that connected directly with the PICA.