Glossopharyngeal neuralgia secondary to vascular compression in a patient with multiple sclerosis: a case report

INTRODUCTION: Glossopharyngeal neuralgia is an uncommon, painful syndrome, characterized by paroxysms of pain in the sensory distribution of the 9th cranial nerve. Idiopathic glossopharyngeal neuralgia may be due to compression of the glossopharyngeal nerve by adjacent vessels, while secondary glossopharyngeal neuralgia is associated with identifiable lesions affecting the glossopharyngeal nerve at different levels of its neuroanatomic pathway. Glossopharyngeal neuralgia is rare in the general population, but is more common in patients with multiple sclerosis. CASE PRESENTATION: A 56-year-old Caucasian woman with multiple sclerosis and migraine presented to our facility with intermittent lancinating pain to the right of her throat, tongue, and the floor of her mouth that had been occurring for the past year. The pain was intense, sharp, and stabbing, which lasted two to six seconds with radiation to the right ear. Initially, the attacks were infrequent, however, they had become more intense and frequent over time. Our patient reported weight loss, headache, painful swallowing, and the inability to maintain sleep due to painful attacks. A neurological examination revealed a right-handed woman with trigger points in the back of the tongue and throat on the right side. She also had dysphagia, hoarseness, and pain in the distribution of the right glossopharyngeal nerve. Mild right hemiparesis, hyperreflexia, dysmetria, and an ataxic gait were present. A magnetic resonance imaging scan of the brain was consistent with multiple sclerosis and magnetic resonance angiography demonstrated a loop of the posterior inferior cerebellar artery compressing the right glossopharyngeal nerve. She responded satisfactorily to carbamazepine. Microvascular decompression and Gamma Knife® radiosurgery were discussed in case of failure of the medical treatment; however, she declined these options. CONCLUSIONS: Glossopharyngeal neuralgia in multiple sclerosis may occur due to vascular compressive lesions and it should not be solely attributed to the underlying demyelinating process. Vascular compression of the glossopharyngeal nerve could independently cause glossopharyngeal neuralgia in patients with multiple sclerosis, and vascular imaging to exclude such a diagnosis is recommended.