Intracranial aneurysm on a persistent primitive trigeminal artery

✓ The angiographic demonstration of a rare case of persistent trigeminal artery aneurysm is reported. The incidence of persistent trigeminal artery in the authors' series is 0.6%. Approximately 14% of patients with a persistent trigeminal artery also have an intracranial aneurysm. The embryology involved and related cases are reviewed.