Transcutaneous Tibial Nerve Stimulation for Spinal Cord Injury Neurogenic Bladder

The purpose of this study is to see how well TTNS works at preventing incontinence in people with paraplegia from SCI that perform intermittent catheterization to empty their bladder. This study will compare the effectiveness of TTNS at 2 doses, fixed-dose and variable-dose. It will also evaluate the frequency of use, 2 days weekly compared to 5 days weekly. Based on our pilot trials, tibial nerve stimulation protocols use submotor current intensity with a duration of 200 µs and a frequency of 20Hz. The experimental group will use a submotor "variable dose." The fixed-dose group will use submotor at current intensity at 1mA and designated as "fixed-dose." TTNS will be used 5 days weekly, per our pilot trial. At 4-months post-SCI, the subject will be instructed to switch to 2x daily if he or she was randomized into the variable dose group of 2 days weekly and thus continue to doing so for the remainder of study participation. Because there is support in the literature for reduced doses of tibial nerve stimulation required for maintenance (1-3x weekly), the RCT includes this frequency comparison arm. All subjects will continue for 1-year post-SCI. Additionally, we are collecting surveys to help identify characteristics of people (resilience and confidence) and adherence to medication and TTNS use throughout the study.