[Trigeminal neuralgia in an elderly patient associated with a variant of persistent primitive trigeminal artery]

An 86-year-old woman presented with a 10-year history of right paroxysmal facial pain. The trigger zone was the right maxilla. Magnetic resonance (MR) angiography and MR cisternography sourse images showed an aberrant artery originating from the right internal carotid artery anastomosed to the anterior inferior cerebellar artery territory (AICA) of the cerebellum, and it was closed at the root entry zone of trigeminal nerve. The patient underwent microvascular decompression (MVD), and her pain resolved after the operation. Most of the offending vessels that cause trigeminal neuralgia are the superior cerebellar artery (75-80%) and AICA. Although persistent primitive trigeminal artery (PTA) is the most common type of persistent carotid-basilar anastomosis, trigeminal neuralgia associated with PTA or a PTA variant is very rare, and particularly, a PTA variant is an uncommon, anomalous, intracranial vessel. It is necessary to inspect MR imaging scans carefully prior to MVD surgery because they are frequently associated with intracranial aneurysms. During surgery, we must be careful not to injure the perforating arteries from the PTA variant. MVD for trigeminal neuralgia in elderly patients is effective if the patients can have a tolerate general anesthesia. However, when we plan surgery for elderly patients, we must take care that it does not to lead to unexpected complications.