Article Text
PDF
Statistics from Altmetric.com
Introduction
Trigeminal neuralgia is the most common and best known of the cranial neuralgias; glossopharyngeal neuralgia (GPN) is much rarer and less well-recognised. First described by Weisenberg1 in 1920, GPN is characterised by severe paroxysms of pain affecting the ear, beneath the angle of the jaw, base of tongue and tonsillar fossa. The pain lasts seconds to minutes and typically worsens with swallowing, talking and coughing. The stereotyped nature of the attacks, lack of alternative explanation and normal neurological examination, fulfil the International Headache Society Diagnostic criteria for GPN.2 Like trigeminal neuralgia it can result from microvascular or other causes of compression of the nerve, or from demyelination.3
Case report
A 77-year-old woman presented with stereotyped and brief (<30 s) paroxysms of excruciating pain affecting her left ear, jaw and throat. The symptoms had been present for 1 year and attributed to trigeminal neuralgia. Despite taking carbamazepine, the symptoms had increased in frequency and severity. While attending her general practitioner, she developed her typical symptoms followed by two syncopal episodes, prompting her admission. During ambulance transfer, there was a further episode of syncope with significant bradycardia and a 7 s period of systole (figure 1). She was treated with atropine, temporary, and subsequent permanent cardiac pacing. Intravenous phenytoin greatly reduced the frequency and severity of attacks. MR and CT angiography showed that the left posterior inferior cerebellar artery was in contact with the left glossopharyngeal nerve (figures 2 and 3), confirming a diagnosis of symptomatic GPN.
ECG lead II rhythm strip, demonstrating asystole.
MR scan of brain (GE Healthcare, USA) using a FIESTA sequence—a high resolution T2-weighted sequence—demonstrating contact between an artery and the left glossopharyngeal nerve, close to its brainstem origin.
CT angiogram showing that the vessel in contact with the left glossopharyngeal nerve is the left posterior inferior cerebellar artery.
Discussion
Syncope is a rare complication of GPN. In a Mayo Clinic series of 217 patients, only four had associated syncope.4 The exact mechanism of syncope is incompletely understood but probably relates to the carotid sinus reflex.5 When increased stretch tone stimulates baroreceptors, afferent impulses pass along the sinus nerve of Hering, joining the glossopharyngeal nerve and eventually synapsing in the nuclei tractus solitarius of the medulla. Stimulation of interneurons that synapse on the dorsal nucleus of the vagus nerve can result in a vagal response with consequent pre-syncope or syncope.6 Our patient developed syncope presumably through pain activating one or more of these pathways. Phenytoin and subsequently gabapentin reduced the frequency of episodes but they ceased only following the cardiac pacemaker. She has therefore deferred surgical treatment in favour of continuing medical treatment. Microvascular decompression would be the treatment of choice in appropriate pharmacoresistant cases.7
Practice points
-
Glossopharyngeal neuralgia should be considered in any patient presenting with facial pain and altered consciousness.
Footnotes
Contributors SH was responsible for drafting and revising the manuscript. MS edited drafts of the manuscript and was responsible for the care of the patient. KD edited drafts of the manuscript and provided commentary for the radiological images.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed. This article was reviewed by Ellie Marsh, Cardiff, UK.