Botulinum Toxin A vs Anticholinergic Treatment of Neurogenic Overactive Bladder in Patients With Multiple Sclerosis

Botulinum toxin type A (BOTOX®) injections will performed on an outpatient basis by cystoscopy under local anesthesia. Twenty minutes after an intravesical instillation of 20 ml of 0.2% ropivacaine, the botulinum toxin is injected into the detrusor muscle using a flexible injection needle at a rate of 10 U of BOTOX® per mL (10 points of 1 mL injections). Intravenous prophylaxis (cefuroxime 1.5 g) will be performed 30 minutes before the injections. Patients in the Vesicare® arm will be given the tablets at the baseline visit to be taken once a day in the morning for 12 weeks. For this arm, there will be no antibiotic prophylaxis. Randomization will be carried out via eCRF in the secuTrial® environment with an integrated Interactive Web Response System (IWRS) function allowing the allocation of a participant to one of the two intervention groups. Randomization will be carried out using a randomization table in blocks of 2, predefined without the knowledge of the investigator, respecting a balanced allocation between the two groups, necessary given the modest number of participants in the study. The intensity of therapeutic responses for each treatment is not precisely known in this patient population. As a result, there are no reliable preliminary data which would allow the investigators to calculate under these "effect size" assumptions the necessary numbers of participants to be randomized between the two intervention groups in order to demonstrate a possible superiority of treatment by injection of BOTOX® 100 U in comparison to the reference anticholinergic treatment. The comparative study will therefore only be accessible after determining the intensity of these effects. Within the framework of a pilot study not directly comparative of the therapeutic approaches but seeking to identify the amplitude of the effects obtained independently by the two treatments, it does not appear necessary to resort to a study design with "double-dummy" to leave the patient blind to the method used. Such an approach would require the use of a sham injection by cystoscopic route in the group treated with anticholinergics and would not appear ethical in this context.