LAUSR

BACKGROUND Double origin of the posterior inferior cerebellar artery (DOPICA) is rare. It has important clinical implications especially in cases of aneurysms of the vertebral artery (VA) or the posterior inferior cerebellar artery (PICA). Several radiologic reports of this variant exist. However, no anatomical illustration of this rarity exists in the literature. This brief report provides the first anatomic illustration of this important variation of the vertebrobasilar system. CASE DESCRIPTION A cadaveric specimen was prepared for dissection. A far lateral craniotomy was performed on the right side. While exploring the right cerebellomedullary cistern, two separate origins of PICA were found from the vertebral artery (VA) as the caudal and rostral trunks that joined to form the distal PICA trunk at the tonsillomedullary segment. Microscopic and endoscopic illustrations are provided. CONCLUSIONS To the best of the authors' knowledge, this is the first anatomic report on the DOPICA. Cadaveric illustration of this variant helps with understanding its anatomical relationship with adjacent neurovascular structures of the cerebellomedullary cistern including the perforating arteries and the lower cranial nerves.