EMGガイド下ボツリヌス毒素注射による誘発性前庭痛の治療：ランダム化二重盲検プラセボ対照臨床試験

Provoked vestibulodynia is a prevalent and complex disease with a major effect on women's quality of life. This condition is often associated with abnormal reflexes and muscle hypertonicity. Local injections of Onabotulinum toxin A guided by Electromyography (EMG) have been reported as a promising therapeutic possibility, although randomized controlled trials are lacking.

To assess the efficacy of EMG-guided Onabotulinum toxin A in provoked vestibulodynia. The primary end-point was a modification of the pain Visual Analogue Scale after treatment.

This randomized, double blind trial compared EMG-guided injections of Onabotulinum toxin A (50 units) versus placebo into the superficial perineal muscles. Patients were randomized and received EMG-guided injections of either saline or Onabotulinum toxin A (50U on each side in superficial perineal muscles). Data on pain [assessed using a visual analogue scale], quality of life [measured by the Dermatology Life Quality Index] and quality of sex life [assessed using the Female Sexual Function Index] were collected before treatment, and 3 and 6 months after injection.

Sixty patients were randomized. The mean ± SD age was 26.1±0.8 years. After three months, the pain visual analogue scale decreased in the treated group to 5.04±0.61 versus 7.37±0.45 in the placebo group (p=0.008). The Dermatology Life Quality Index differed in the treatment and placebo groups at 3 and 6 months (p<0.01 and p=0.03 respectively). In the Female Sexual Function Index evaluation, the scores of the items "sexual satisfaction" and "sexual desire" were higher in the treated group than in the placebo group (p=0.05 et 0.01 respectively).

Onabotulinum toxin A injections were effective on the pain, quality of life and sexual functions of the patients. We suggest that muscular dysfunction is a key element of vestibulodynia pain. EMG-guided Onabotulinum toxin A injections were associated with improvement of symptoms in provoked vestibulodynia.