Salvage Gamma Knife Radiosurgery after failed management of bilateral trigeminal neuralgia

BACKGROUND: The incidence of bilateral trigeminal neuralgia (TN) is 1-6% of total number of TN cases. Gamma Knife Radiosurgery (GKRS) is effective in treating unilateral TN; however, outcomes of bilateral TN treated by GKRS have not been well evaluated. The purpose of this study is to evaluate the long-term GKRS outcomes of bilateral TN at our institution and compare with our published treatment outcomes of unilateral TN. METHODS: Between 2000 and 2006, eight patients with bilateral TN were treated with GKRS. Data available on seven patients were collected. Facial pain outcomes were defined using the Barrow Neurological Institute pain intensity scale. Outcomes and toxicities were compared to published outcomes of unilateral TN patients treated with GKRS at our institution. RESULTS: The incidence of bilateral TN in our series is 2.3%. Treatment outcomes were excellent in 5/14, good in 1/14, and poor in 8/14. Median follow-up time was 58 months. Median time-to-failure was 38 months. Pain control rate was 80% at 12 months and 65% at 36 months. Bothersome side effects were seen in 4/14 nerves treated. Compared with our long-term unilateral TN cohort, there was no statistically significant difference in outcome, time-to-failure, or rate of toxicity. CONCLUSION: Bilateral TN is rare, and effective treatment is crucial to improve the quality of life of those afflicted. Salvage GKRS is a reasonable treatment modality for individuals with bilateral TN.