Complete oculomotor palsy caused by persistent trigeminal artery.

Primitive trigeminal artery (PTA) is the most frequent embryonic communication between the carotid and vertebro-basilar system. PTA is a pathophysiology phenomenon which has been implicated as a rare cause of cranial nerve dysfunction. We report the case of a 40-year-old woman who developed a complete oculomotor nerve palsy caused by a persistent ecstatic trigeminal artery. Brain MRI and MRA studies documented a neurovascular conflict between the oculomotor nerve and a PTA. To the best of our knowledge there is no report about complete third cranial nerve palsy NC due to a PTA. A role of this rare vascular condition is discussed.