A Comparison of Facial Muscle Squeezing versus Non-facial Muscle Squeezing on the Efficacy of BotulinumToxin-A Injections for the Treatment of Facial Dystonia

Abstract

Background:This study was performed to address whether voluntary muscle squeezing post botulinum toxin-A treatment with increased neuronal activity translates into noticeable patient benefit in practice.

Methods: This was a prospective, consecutive, double crossover interventional study. Participants were receiving regular (3 monthly) botulinum toxin-A treatment for aberrant facial nerve regeneration (AFNR), benign essential blepharospasm (BEB) or hemifacial spasm (HFS). Twenty-six participants were recruited and these were randomised into two groups (A and B). Group A performed a program of intensive facial exercises for 5 minutes after their first and third treatment whereas after their second treatment, they were asked to rest in a seated position for 5 minutes, and instructed not to talk or perform any voluntary movements of their face. Conversely group B were only asked to perform squeezing exercises after their second treatment. Outcomes were evaluated objectively using video-recordings and subjectively by questionnaire and telephone interview of participants.

Results: Video-recording data was complete for 21 participants. There was a mean 40% reduction in the frequency of facial muscle spasms and a 33% lower severity score (video-recordings graded by 1 masked investigator) where intensive facial exercises were performed post-treatment. These findings did not reach statistical significance (Mann- Whitney two-tailed test; p = 0.367).

Conclusion: Although statistical significance was not achievable, this study suggested a possible trend towards an increased efficacy of botulinum toxin-A, with facial muscle squeezing post BTX treatment. Future studies with a larger number and a better defined subset of subjects may lead to statistical significance.

KEYWORDS::

• Muscle
• Squeezing
• Botulinum toxin-A
• Efficacy

Declaration of interest: A small research grant was received from QVH and from Allergan Inc. (from which consumables were purchased). The authors report no conflicts of interest. The authors are responsible for the content and writing of the paper.