Nervus intermedius sectioning for the treatment of geniculate neuralgia.

Abstract

Objective: Geniculate neuralgia (GN) is a rare facial pain syndrome characterized by severe stabbing pain in the ear canal. The exact cause of GN remains unclear; however, it is thought that the nervus intermedius (NI) is the primary implicated structure. When medical management fails, surgical interventions are offered to treat the pain. This study aimed to present a consecutive series of patients with GN who underwent craniotomy with NI sectioning, to offer insights into the safety and efficacy of the surgical approach.

Methods: A retrospective review of consecutive institutional medical records from January 2000 to February 2024 identified patients diagnosed with GN who underwent surgical treatment. Patient records were manually reviewed for information regarding patient demographics, comorbidities, medication history, surgical techniques, and outcomes.

Results: The study included 47 NI sectioning procedures in 45 patients with GN (mean age 45.5 years). Most patients had concurrent trigeminal neuralgia (TN) and approximately one-third of patients had concurrent TN and glossopharyngeal neuralgia. Surgical procedures involved NI sectioning, often alongside microvascular decompression (MVD) for cranial nerves (CNs) V or IX/X/XI, with favorable early postoperative pain relief. Of 47 procedures, 38 (80.9%) improved pain (Barrow Neurological Institute [BNI] pain intensity score < IV) and 32 (68.1%) resolved pain (BNI score I) by the latest follow-up visit. There was a low incidence of complications, with 2 cases of unexpected hearing loss among all patients, no instances of permanent facial paralysis, and 1 case of permanent vestibular dysfunction. Additionally, 3 patients reported experiencing loss of taste following surgery.

Conclusions: This case series suggests that NI sectioning is safe and likely efficacious in relieving the primary deep ear pain of GN, with a potential additive benefit when performed with MVD on CNs V or IX/X/XI, as needed. Further research is needed to refine treatment guidelines and clarify NI-specific otalgia given the overlapping innervation of the inner ear with other CNs.