Aim: To investigate the efficacy, safety and tolerability of intradermal and/or submucosal administration of botulinum toxin type A (BTX-A) for patients with trigeminal neuralgia (TN).
Methods: In this randomized, double-blind, placebo-controlled study, 42 TN patients were randomly allocated into two groups, namely, intradermal and/or submucosal injection of BTX-A (75 U/1.5 mL; n = 22) or saline (1.5 mL; n = 20) in the skin and/or mucosa where pain was experienced. The primary endpoints were pain severity (assessed by the visual analogue scale) and pain attack frequency per day. The secondary endpoint was the patient's overall response to treatment, assessed using the Patient Global Impression of Change scale. Patients with ≥ 50% reduction in mean pain score at week 12 were defined as responders.
Results: A total of 40 patients completed the study. BTX-A significantly reduced pain intensity at week 2 and pain attack frequency at week 1. The efficacy was maintained throughout the course of the study. More BTX-A treated patients reported that pain had improved by the end of the study. Significantly more responders were present in the BTX-A group (68.18%) than in the placebo group (15.00%). BTX-A was well tolerated, with few treatment-related adverse events.
Conclusions: BTX-A may be an efficient, safe and novel strategy for TN treatment.