Persistent trigeminal artery and associated vascular variations.

Persistent trigeminal artery (PTA) is the most frequent type of persistent primitive carotid-basilar artery anastomoses. Persistent trigeminal artery is usually associated with small or absent posterior communicating artery (Pcom). It may also be associated with hypoplastic vertebral and basilar arteries. Patients may present with symptoms related to hypo-perfusion of posterior circulation or microembolization from carotid artery to posterior circulation. We are presenting a 60-year-old who had recurrent episodes of vertigo and parasthesia, in whom MR angiography revealed a medial, Saltzman type 1 PTA on the left with absent ipsilateral Pcom, duplicated ipsilateral superior cerebellar artery, hypoplastic A1 segment of contralateral anterior cerebral artery (ACA), azygous ACA and hypoplastic ipsilateral vertebral artery.