[Trigeminal neuralgia caused by arteriovenous malformation of the cerebellopontine angle--report of two cases]

Abstract

Two cases of trigeminal neuralgia caused by arteriovenous malformation (AVM) located in cerebellopontine angle (CP angle) are presented. A 61-year-old woman has been suffered from the left 2nd and 3rd division trigeminal neuralgia, and gasserian ganglion rhizotomy did not relieve the pain. Ten days before admission the patient suddenly got right hemiparesis and left cerebellar ataxia. Bleeding of the left CP angle was noticed by computerized tomography (CT) scan and angiogram revealed AVM of the left CP angle. A 48-year-old man had right facial neuralgia for 4 years along and he received percutaneous retrogasserian glycerol rhizotomy twice, but the pain was not aleviated. Superior petrosal sinus was enhanced on conventional CT scan, and air contrast CT cisternography disclosed network shaped structure at the CP angle, which was revealed as AVM by vertebral angiography. The patient was completely relieved from the neuralgia after removal of the AVM. AVM of the CP angle that causes the trigeminal neuralgia is rare and the gasserian ganglion rhizotomy is little effective in aleviating the pain. Bleeding from AVM causes severe neurological deficits. Removal of AVM is important not only for pain relief but also for protecting bleeding. Air contrast CT cisternography is one of the safety and convenient methods to detect the AVM and other vascular anormalies resulting in trigeminal neuralgia.