Evaluating repetitive transcranial magnetic stimulation for neurogenic overactive bladder management in stroke survivors: A randomized sham-controlled trial protocol

Background: Neurogenic overactive bladder (OAB) is a distressing condition in stroke. Existing neurogenic OAB management is expensive, unstandardized regimens, or invasive. Evaluating the effectiveness of repetitive transcranial magnetic stimulation (rTMS) remains crucial. We aimed to (1) compare the effectiveness of active-rTMS with sham-rTMS on neurogenic OAB symptoms, (2) analyze whether rTMS is cost-effective, and (3) explore the rTMS's experiences on participants’ symptoms. Methods: This is a randomized, sham-controlled, double-blinded trial with embedded qualitative and cost-effectiveness studies. A total of 110 stroke survivors with neurogenic OAB symptoms were screened for eligibility; 60 participants were eligible for inclusion and were randomly assigned to either the active (n = 30) or sham-rTMS (n = 30) groups using a computer-generated randomization schedule. The active-rTMS group received low-frequency rTMS of 1200 pulses per session lasting 20 min thrice weekly to pelvic floor muscle representation at the contralesional primary motor cortex. The sham-rTMS group received low-frequency stimulation at a 20 % resting motor threshold using the same coil as the active-rTMS but was configured to reduce the TMS-induced electrical fields significantly. The primary and secondary outcome measures were assessed at baseline, post-intervention (week 4) and follow-up (week 8). The analysis of covariance (ANCOVA) analysis compared changes in the study groups. Quality-adjusted life-years (QALY) were measured to evaluate the cost-effectiveness while EQ-5D-5L estimated QALY changes. Additionally, the focus group discussion data were thematically analyzed. Conclusions: The findings from this rTMS intervention study will be useful in alleviating neurogenic OAB symptoms and enhancing patient satisfaction in a cost-effective way.