Intravesical Injections of Botulinum Neurotoxin A to Treat Overactive Bladder And/or Detrusor Overactivity Related to Multiple Sclerosis: 5-Year Continuation Rate and Specific Risk Factors for Discontinuation-a Study from the Neuro-Urology Committee of the French Association of Urology

Background: While intravesical injections of botulinum neurotoxin A (BoNT-A) are currently recommended for patients experiencing refractory neurogenic overactive bladder and/or detrusor overactivity (OAB/DO), it is unclear how much this therapy is effective and sustainable in the long-term in patients with multiple sclerosis (MS). Objectives: To assess the mid-term continuation rate of BoNT-A injections to treat neurogenic OAB/DO in MS patients and to investigate MS-specific risk factors for discontinuation. Methods: This retrospective study involved 11 French university hospital centers. All MS patients who received BoNT-A to treat neurogenic OAB/DO between 2008 and 2013 and were subsequently followed up for at least 5 years were eligible. Results: Of the 196 MS patients included, 159 (81.1%) were still under BoNT-A 5 years after the first injection. The combination of the Expanded Disability Status Scale (EDSS < 6 or 6) and of the MS type (relapsing-remitting vs progressive) predicted the risk of discontinuation. This risk was 5.5% for patients with no risk factor, whereas patients presenting with one or two risk factors were 3.3 and 5.7 times more likely to discontinue, respectively. Conclusion: BoNT-A is a satisfying mid-term neurogenic OAB/DO therapy for most MS patients. Combining EDSS and MS type could help predict BoNT-A discontinuation.