Moving from mechanisms to clinical practice: non-invasive spinal cord stimulation for recovery of autonomic functions after spinal cord injury – a protocol for a pilot randomised controlled trial

Introduction Spinal cord injury (SCI) impairs autonomic functions, which are ranked among the highest priorities for recovery. The loss of autonomic control, including bowel, bladder, sexual and cardiovascular functions, interferes with rehabilitation and decreases health-related quality of life (HRQoL). Preliminary evidence indicates that non-invasive transcutaneous spinal cord stimulation (TCSCS) has the potential to improve autonomic stability in people with SCI. However, the optimal stimulation site for improving autonomic responses remains to be determined. This pilot randomised clinical trial aims to explore the efficacy of non-invasive mid-thoracic and lumbosacral TCSCS (proof-of-concept) for blood pressure stability (orthostatic hypotension and autonomic dysreflexia burden) alongside end-organ autonomic functions (lower urinary tract, bowel and sexual function) and HRQoL. Methods 30 participants with chronic (>1 year) motor-complete SCI (American Spinal Injuries Association Impairment Scale A and B) at or above T6 will be enrolled in this open-label, two-arm randomised pilot clinical trial. Participants will be block randomised into either the mid-thoracic or lumbosacral TCSCS group. Participants will then undergo 8 weeks of TCSCS (3 times per week for 60 min; 24 sessions total) while in a seated position. Post-treatment effects will be recorded following the 8-week intervention and follow-up effects will be recorded 8 weeks after the end of the intervention. Primary and secondary outcomes will assess resting blood pressure, autonomic dysreflexia, orthostatic hypotension and lower urinary tract, bowel and sexual functions as well as HRQoL. Ethics and dissemination This study is approved by The University of British Columbia’s Clinical Research Ethics Board (UBC CREB H22-00365), and by Health Canada for Investigational Testing Authorisations (ITA) for Class II medical devices used in this trial (ITA#346875 TESCoN; ITA#381 154 SCONE). The findings will be disseminated through peer-reviewed publications, conferences, seminars and SCI community outreach. Trial registration number NCT05369520 .