Posterior inferior cerebellar artery supplied by the jugular branch of the ascending pharyngeal artery diagnosed by MR angiography: report of two cases.

The posterior inferior cerebellar artery (PICA) is extremely rarely supplied by the artery passing through the hypoglossal canal. This anomalous artery can arise from the cervical internal carotid artery or ascending pharyngeal artery (APA). We present what we believe is the first report of PICA supplied by the jugular branch of the APA that passes through the medial side of the jugular foramen pars vascularis, diagnosed using magnetic resonance angiography. To avoid ischemic brain complications during head and neck surgeries and interventional radiologic procedures, preoperative recognition of anomalously originating pial arteries from the APA is important.