Abstract
Persistent trigeminal artery (PTA) is the most common residual manifestation of persistent carotid-vertebrobasilar anastomosis, with the medial-type (intrasellar or sphenoidal) PTA being exceptionally rare. Aneurysms originating from the PTA trunk are not common. We present a unique case of an aneurysm located at the trunk of the medial-type PTA in a patient presenting with trigeminal neuralgia who successfully managed by endovascular procedure. Furthermore, we discuss the anatomical features of this aneurysm and relevant reports, and examine the possible pathomechanism of the associated pain.