The tethered effect of the arachnoid in vago-glossopharyngeal neuralgia: a real associated alternative mechanism?

Vago-glossopharyngeal neuralgia (VGPN) is a rarely seen disease when compared to trigeminal neuralgia. When the pain is resistant to medical therapy, microvascular decompression can be performed if a vascular conflict is suspected on magnetic resonance imaging (MRI). In addition, arachnoid pathology may play a role in VGPN. We report two cases of VGPN caused by tethered arachnoid, associated with a vascular contact in which pain was reduced by freeing rootlets from arachnoid compression. We report two cases relating to 50-year-old and 30-year-old men with a history of electric shooting pain triggered by swallowing in the right pharyngeal and auricular regions. Preoperative MRI documented a neurovascular conflict in the first case and an arachnoid cyst in the second. Surgery was performed via a retrosigmoid craniotomy. In both cases, the intraoperative findings documented a tethered arachnoid membrane compressive to cranial nerves IX and X. Untethering was performed by liberation of the rootlets from the arachnoid with microvascular decompression. No additional rhizotomy was performed. The postoperative course was uneventful and pain was relieved in the first case and decreased in the second. In VGPN, a tethered arachnoid may play a role in causing the neuralgia, either alone or associated with a neuro-vascular conflict.