Treatment of multiple sclerosis–related trigeminal neuralgia with onabotulinumtoxinA

Abstract Background The effectiveness of onabotulinumtoxinA (BTX‐A) has been established in primary trigeminal neuralgia (TN). However, to the best of our knowledge, the efficacy of BTX‐A in secondary TN has not yet been studied. Objective This study aimed to investigate the efficacy of BTX‐A treatment in patients with multiple sclerosis–related trigeminal neuralgia (TN‐MS) and compare the efficacy of BTX‐A treatment between patients with primary trigeminal neuralgia (TN‐P) and patients with TN‐MS. Methods This was a retrospective medical record–review study. Demographic and clinical features and severity and frequency of pain before and 2 weeks after the BTX‐A administration were extracted from the patient files. BTX‐A was injected into the painful area subcutaneously and/or submucosally. BTX‐A injections were performed by the same physician using the same methods. A reduction in severity and/or frequency of pain ≥50% was considered therapeutic efficacy. Results Fifty‐three patients were included in this study. We classified 22 (42%) as TN‐P and 31 (58%) as TN‐MS. Treatment with BTX‐A was effective in 16 of 31 (52%) patients with TN‐MS and 10 of 22 (45%) with TN‐P. BTX‐A treatment was less effective in patients with a history of interventional treatments and more effective in patients with concomitant continuous pain ( p = 0.007; odds ratio [OR]: 0.020–0.53 and p = 0.047; OR: 0.046–0.98, respectively). Conclusion The BTX‐A treatment was found to be effective in at least half of our cohort with TN‐MS. Concomitant continuous pain and history of interventional treatments to the trigeminal nerve or ganglion might be predictive factors for the efficacy of BTX‐A treatment.