Infiltration of the Vestibulum Vaginae With Botulin Toxin in Patients With Localized Provoked Vulvodynia

In this study we will investigate the efficacy and safety of infiltration of the vestibulum vaginae with botulin toxin in women who were diagnosed with localized provoked vulvodynia. In literature covering this subject we find that the prevalence of this condition is between 10 and 15%. Especially young, sexually active women suffer from this problem and some of them are not capable of having sexual relations with their partner because of this burning pain.

The most probable explanation for the physiopathological mechanism is an increase of nerve endings in the epithelium of the vestibulum, with an increase and activation of pain receptors in the vestibular mucosa. It also seems that patients with vestibulodynia have a higher tonus of the pelvic floor muscles, a greater muscle contraction in response to pain and a lower capacity of relaxation.

Botulin toxin (Botox) is a neurotoxin that causes a temporary paralysis of the muscle cells. That way it can decrease the increased tension of the pelvic floor muscles Botox also inhibits the pain receptors in the vestibulum.

Patients will be recruited through the gynecology consultations. Every patient with localized provoked vulvodynia that has tried previous treatments (pelvic floor muscle therapy, antidepressants, anti-epileptics, local anesthetics) will undergo Q-tip testing. If positive and there are no underlying diseases, the patient will be invited to participate in the study and after oral and written informed consent, will be included in the study population. Every 6 weeks there will be given injections with 50 units of botulin toxin, on 6 different spots in the vestibulum. 50 % of the subjects will receive physiological water instead of Botox (control population). After 3 sessions, we will assess if there is any difference in provoked pain in treated patients vs. placebos through Q-tip testing.