Visual evoked potential monitoring for parent artery occlusion of giant posterior cerebral artery aneurysm

Abstract

Giant posterior cerebral artery (PCA) aneurysms often require parent artery occlusion (PAO) because of the difficulty of direct treatment. Recently, reproducible and stable visual evoked potential (VEP) monitoring has been used for the evaluation of visual function, however, there are no reports of VEP monitoring in endovascular treatment of cerebral aneurysms. This case highlights a novel VEP monitoring during balloon occlusion test (BOT) and endovascular PAO for an enlarged giant PCA aneurysm in a pregnant woman. A 17-year-old pregnant girl at 32 weeks of gestation suffered from headache. MRI of the head depicted a giant partially thrombosed aneurysm on the left PCA (P2 segment). After cesarean section at 35 weeks of gestation, endovascular PAO was performed under VEP monitoring. Before PAO, BOT under general anesthesia and no VEP waveform changes were seen during BOT and PAO procedure. Headache completely disappeared after PAO and the patient was discharged without visual deficits. Three-months after PAO, MRI showed marked shrinkage of the aneurysm. This is the first report of giant PCA thrombosed aneurysm successfully treated by PAO under VEP monitoring.

Keywords

• Balloon occlusion test
• Parent artery occlusion
• Posterior cerebral artery aneurysm
• Visual evoked potential