Endoscopic Microvascular Decompression for Cardiac Syncope/Arrhythmia: Vasoglossopharyngeal Neuralgia

Introduction: Glossopharyngeal neuralgia (GN) is a rare cranial nerve compression, with an annual incidence of 0.8/100,000 and classically characterized by paroxysms of unilateral lancinating pain involving the throat, tongue, soft palate, posterior and lateral pharynx, and ear. Rarely, this syndrome is associated with arrhythmias, cardiac syncope, and cardiac arrest leading to significant disability. This condition, termed vasoglossopharyngeal neuralgia (VGPN), occurs in ~4/217 patients with GN and is often misdiagnosed as cardiac or cerebral episodes. We review our experience of MVD surgery in patients with symptomatic, medication-refractory cardiac syncope secondary to VGPN successfully treated with endoscopic-microvascular decompression (E-MVD).

Methods: Chart abstraction was performed and cases were identified from a prospective database collected by senior surgeon. From 2006 to 2019, 17 patients have undergone E-MVD for ninth/tenth nerve symptoms. Of these, two were identified with cardiac episodes.

Results: The first patient was a 53-year old male with right-sided glossopharyngeal neuralgia symptoms that became associated with syncopal episodes 10-years after the onset of symptoms. The second patient was a 61-year old female with a history of Ehlers–Danlos syndrome and malignant vasovagal syndrome that became associated with painful, shooting left anterior neck spasms consistent with glossopharyngeal neuralgia. Both patients underwent extensive medical and cardiac work-up prior to surgical consideration. Patient 1 was diagnosed with supraventricular tachycardia, underwent cardiac ablation, but continued to have symptoms. Patient 2 underwent bilateral styloidectomy for concern for eagle syndrome, but continued to have both neuralgia and syncopal symptoms. Ultimately, both underwent craniotomy for E-MVD. Patient 1 underwent a right retrosigmoid craniotomy. The glossopharyngeal nerve was noted to be compressed by the posterior inferior cerebellar artery, which was decompressed using Teflon. Patient 2 underwent a left retrosigmoid craniotomy, which showed compression secondary to the dolichoectatic vertebrobasilar artery, which was also decompressed using Teflon. Both had uncomplicated postoperative courses and were seen at follow-up without return of neuralgia or syncopal episodes. At 1.5 years and 0.75 years of follow-up, both patients have not had recurrence of cardiac syncope.

Discussion: The pathogenesis of vasoglossopharyngeal neuralgia is largely unknown and a variety of mechanisms have been proposed. One theory suggests irritation of glossopharyngeal nerve causes reflex bradycardia or asystole via the tractus solitarius to the dorsal motor nucleus of the vagal nerve. Another proposes artificial synapses between the Hering nerve (carotid sinus nerve) and the Jacobson nerve (tympanic branch of glossopharyngeal nerve). Direct neurovascular compression of the root entry zone of both the glossopharyngeal and vagal nerves has also been observed, which was noted in both of these patients. For some, this rare condition can be managed with medical therapy alone. But here, we present two cases demonstrating safe and successful management of VGPN with E-MVD after failure of therapy. These outcomes support previously published case reports of successful treatment of VGPN using microvascular decompression of the glossopharyngeal nerve, and is the first report in the literature using an endoscopic technique.