Botulinum neurotoxin type A injection of the pelvic floor muscle in pain due to spasticity: a review of the current literature

The role of muscle spasm is not a new concept in the genesis of pain. Botulinum neurotoxin type A (BoNTA) has been successfully employed in a variety of muscular and inflammatory conditions. The aim of our study was to review the published literature on the role of BoNTA injection of the pelvic floor muscle in the management of women with chronic pelvic pain (CPP). A systematic search of the literature published up to June 2012 on the use of BoNTA in the treatment of female pelvic floor muscle spasm was carried out using relevant search terms in MEDLINE and EMBASE databases. The results were limited to full-text English language articles. Relevant trials as well as relevant reviews were selected and analyzed by two independent reviewers. Five studies (2 case reports, 1 prospective pilot study, 1 retrospective study and 1 randomised double-blind placebo controlled study) were included in this systematic review. Overall, BoNTA has shown to be beneficial in relieving CPP related to pelvic floor spasm. The role of BoNTA as a treatment of CPP has been recognized for more than 10 years. Although data are still scarce preliminary results are encouraging. BoNTA is an attractive option for refractory CPP related to pelvic floor muscle spasm, but further studies using validated and reproducible outcome measures are needed, to establish its effectiveness, safeness, technique, optimal dosage, and duration of symptom relief.