A Case of Isolated Unilateral Glossopharyngeal Nerve Palsy.

Isolated palsy of the glossopharyngeal nerve is rare. We report the case of an elderly patient with unilateral right glossopharyngeal nerve palsy secondary to extra cranial ischemia. On examination there was no other deficit other than an absent right gag reflex. She was diagnosed clinically with ischemic stroke of the ninth nerve, and her daily dose of aspirin was increased from 81 mg to 325 mg. Magnetic resonance imaging of the brain showed a normal brainstem and cerebellum with patent intracranial circulation. Total resolution of the paralysis was seen 2 months later. The possible mechanisms suspected were diabetic or hypertensive stenosis of the vasa nervorum or compression of the ninth nerve by an internal carotid artery dissection or aneurysm. This article discusses the various etiologies and mechanisms of this rare condition. It is unique because of the nerve's location and relationship to other structures.