Persistent trigeminal artery variant as a duplicate anterior inferior cerebellar artery.

Purpose: A persistent trigeminal artery is the most common persistent carotid-vertebrobasilar anastomosis. Persistent trigeminal artery variants (PTAVs) terminate in the cerebellar arteries without connecting to the basilar artery; of these, the anterior inferior cerebellar artery (AICA) is the most common. AICA duplication is frequently observed. However, to our knowledge, there have been no previous reports of PTAVs associated with duplicated AICAs. Here, we report a case of PTAV as a duplicate AICA, associated with the early bifurcation of the superior cerebellar artery and the aortic arch origin of the vertebral artery.

Methods: The case was diagnosed using digital subtraction angiography.

Results: A 51-year-old woman underwent screening for cerebrovascular disease. She was referred for a catheter angiography because of a suspected dural arteriovenous fistula. Digital subtraction angiography revealed no arteriovenous shunts. A left internal carotid angiogram showed a PTAV terminating into the left AICA. A left vertebral angiogram also showed the left AICA, indicating there were two left AICAs-one arising from the PTAV and the other from the basilar artery. We therefore made a diagnosis of duplicated AICAs. The left posterior inferior cerebellar artery was aplastic, and the left AICA originating from the basilar artery perfused its territory. An angiogram also revealed early bifurcation of the left superior cerebellar artery and an aortic origin of the left vertebral artery.

Conclusion: This report provides evidence that PTAV can occur as a duplicate AICA. Our case also had other anatomical variations. Careful imaging assessments are important for identifying these rare anatomical variations.