Reducing pain by improving brain and muscle activity with motor cortical neuromodulation in women with interstitial cystitis/bladder pain syndrome: a study protocol for a randomized controlled trial.

INTRODUCTION: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic pain condition creating a wide range of urologic and pain symptoms. There is currently limited evidence to understand the mechanisms of IC/BPS. There have been recent studies suggesting that altered function in brain motor areas, particularly the supplementary motor cortex (SMA), relates to altered bladder sensorimotor control and may play an important role in IC/BPS. This study aims to provide evidence that non-invasive stimulation targeting the motor cortex may help reduce IC/BPS pain, as well as better understand the neural mechanism by which this stimulation targets neuromuscular dysfunction. This study is a two-group quadruple-blinded randomized controlled trial (RCT) of active vs. sham repetitive transmagnetic stimulation (rTMS). In addition, our study will also include functional magnetic resonance imaging (fMRI), pelvic floor electromyography (EMG), pelvic exam, and outcome measures and questionnaires to further study outcomes.

ETHICS AND DISSEMINATION: All aspects of the study were approved by the Institutional Review Board of the University of Southern California (protocol HS-20-01021). All participants provided informed consent by the research coordinator/assistants. The results will be submitted for publication in peer-reviewed journals and disseminated at scientific conferences.

TRIAL REGISTRATION: ClinicalTrials.gov NCT04734847. Registered on February 1, 2021.