Interventions for Refractory Trigeminal Neuralgia: A Bayesian Mixed Treatment Comparison Network Meta-Analysis of Randomized Controlled Clinical Trials

Introduction Patients with trigeminal neuralgia (TN) are often refractory to recommended first-line agents. Due to the absence of a systematic review, we undertook a network meta-analysis to assess various interventions that can be used to manage refractory TN. Methods Electronic databases were searched using appropriate strategies to identify randomized controlled clinical trials in patients with refractory TN, evaluating the proportion of patients with a minimum of 50% reduction in pain or a minimum of 2 cm reduction in score in an appropriate pain scale or complete pain relief by subjective pain scales. Mixed treatment comparisons were carried out using a Bayesian approach and a random-effects model was developed with Monte-Carlo simulation with 1,000 iterations. Odds ratios with 95% credible intervals were assessed for each comparison. Consistency of direct and indirect results was checked with deviance plots. Rankogram was generated based on the surface area under the cumulating ranking curve (SUCRA). Results A total of 13 studies were included in this systematic review, of which 11 were finally included for the final network meta-analysis. Two different interventions were analyzed: drug-related and radiofrequency related interventions. In the former group, sumatriptan, intranasal lidocaine, botulinum toxin, and intravenous lidocaine were observed to perform better than ophthalmic proparacaine and placebo based on pooled estimates in a Forest plot. In the latter group, conventional radiofrequency (both standalone and in combination with pulsed radiofrequency) was found to be better than pulsed radiofrequency alone. Rankogram plots revealed sumatriptan and combined continuous and pulsed radiofrequency thermocoagualtion have the highest probability of being the best treatments in the respective group of interventions. No inconsistency was observed between direct and indirect comparisons. Conclusion We found that drug-related interventions that include sumatriptan, intranasal lidocaine, intravenous lidocaine, and botulinum toxin and combined continuous and pulsed radiofrequency thermocoagulation had significant effects in reducing pain in patients with refractory TN. However, the quality of evidence was graded as very low for all except botulinum toxin.