The outcomes of a second and third Gamma Knife radiosurgery for recurrent essential glossopharyngeal neuralgia

Introduction Gamma Knife radiosurgery (GKR) is a minimally invasive surgical option for drug-resistant essential glossopharyngeal neuralgia (GPN). The authors reviewed pain outcomes and complications in GPN patients who underwent a second or a third GKR for recurrent or persistent pain. Methods A retrospective review of all patients treated in a single center (Marseille, France) since 2004 was performed. Median prescribed dose was 85 Gy (range 70-90 Gy) at second GKR and 85 Gy at third GKR. Clinical outcome was evaluated using the Barrow Neurological Institute (BNI) scale. Results Six patients (4 males, 2 females) underwent second or third GKR. The median age was 70.2 years (range 64-83 years) at second GKR and 79.8 years at third GKR. No patient had any previous surgery but GKR. Five cases had a neurovascular conflict. Median follow-up period was 12 months (range 10-94 months) after second GKR and 16 months after third GKR. The median delay to initial pain freedom response was 30 days (range 3-120 days). One patient experienced pharyngeal hypoesthesia after second GKR. After a third GKR, up to 16 months, no side effects were encountered. At the last follow-up, 3 patients were BNI I, 2 were BNI IIIa, and one did not have any improvement. Conclusions Second GKR resulted in pain reduction with low risk of additional morbidity. In patients unsuitable for microvascular decompression, GKR as a repeat or third treatment for intractable GPN is safe and effective. Third GKR was not associated with any side effects up to 16 months after the procedure.