Efficacy and Safety Profile of Gamma Knife Radiosurgery in Classic and Idiopathic Trigeminal Neuralgia

Background: Trigeminal neuralgia is a debilitating disease, with severe recurrent paroxysms of shock-like facial pain. Although pharmacotherapy may suffice in the majority of cases, a proportion of patients require surgical treatment. Gamma knife radiosurgery (GKRS) represents a potential noninvasive alternative to surgery in these patients.

Methods: We retrospectively analyzed all patients that underwent GKRS for classic/idiopathic TN between 2013 and 2023. Pain prior to GKRS was graded per the Barrow Neurological Institute (BNI) pain score, which was also used to define outcomes. "Complete pain relief (CPR)" was defined as a BNI pain score of I or II, while "Adequate pain relief" was defined as a BNI pain score of III, and "Failure" as a BNI score of IV or V.

Results: The mean age of 70 patients (50 females and 20 males) was 47.4 ± 12.4 years. The mean follow-up was 51.3 ± 16.2 months. Although initial pain relief was achieved in 64 patients (91.4%), recurrence of pain at the latest follow-up occurred in 10 patients (14.3%). Overall, 41 patients (58.6%) achieved CPR, while 13 patients (18.6%) achieved APR. Multivariate analysis revealed that multiple prior failed procedures for TN predicted failure of pain relief.

Conclusions: GKRS is effective among patients with classic/idiopathic TN, with complete pain relief in 58.6% of patients, and adequate pain relief in 18.6% of patients. The most frequent complication is facial hypesthesia, affecting 38.6% of patients. Multiple prior failed procedures for TN significantly predict failure of pain relief at latest follow-up.