Effectiveness of repeat glycerol rhizotomy in treating recurrent trigeminal neuralgia

BACKGROUND: Percutaneous glycerol rhizotomy (GR) is used to treat trigeminal neuralgia (TN), with satisfactory pain relief lasting 2 to 3 years in most patients after the first intervention. The efficacy of subsequent GRs, however, has not been studied. OBJECTIVE: To compare the pain relief and durability achieved by the first GR with those obtained after subsequent GRs in a retrospective cohort of TN patients. METHODS: Between 1998 and 2010, 548 patients with TN underwent 708 GRs. After exclusions, 430 initial GRs (GR1) and 114 subsequent GRs (GR2+) were compared in terms of initial pain relief, durability, sensory change, and complications. Durability was assessed by determining median time to treatment failure for all GRs achieving complete pain relief without medications (n = 375: 264 failures, 111 censored). Predictors of initial pain relief were assessed by logistic regression, and predictors of failure were assessed by Cox regression analysis. RESULTS: After GR1, pain relief results were as follows: 285 patients (66%) were pain free without medications, 26 (6%) were pain free with medications, 66 (15%) improved, and 53 (12%) were unchanged. After GR2+, results were as follows: 90 patients (79%) were pain free without medications, 6 (5%) were pain free with medications, 7 (6%) improved, and 11 (10%) were unchanged (P =.03). Median time to treatment failure was 26 months after GR1 and 25 months after GR2+ (P =.34). On multivariate analysis, prior GR was a positive predictor of initial pain relief (odds ratio, 2.067; 95% confidence interval, 1.243-3.437; P =.005) and had no effect on durability. CONCLUSION: TN patients experienced greater pain relief and equivalent durability after GR2+ beyond the initial treatment.