A Pilot Feasibility Trial of Multi-Program Epidural Spinal Cord Stimulation for Bladder Function Recovery in Chronic...

Background/Objectives: Spinal cord epidural stimulation (scES) holds significant potential for restoring autonomic function after chronic spinal cord injury (SCI). A significant and often debilitating sequela of SCI is neurogenic lower urinary tract dysfunction, characterized by loss of voluntary bladder control, which adversely impacts patients' dignity, urological health, and overall quality of life. In a pilot study of three individuals with SCI, an epidural electrode array was implanted between L2 and sacral segments to modulate lower urinary tract function for efficient emptying. Methods: Three participants with chronic thoracic clinically complete SCI were implanted with an epidural stimulator over the lumbosacral spinal cord. Array placement was confirmed using intraoperative and postoperative spatiotemporal mapping of known motor neuron pools following published protocols. In a controlled laboratory mapping, bladder storage and voiding neural networks were targeted during filling cystometry by interactively optimizing lower urinary tract stimulation parameters (electrode configuration, frequency, intensity, and pulse width). Efficacy was assessed during six-hour laboratory sessions of natural bladder filling, followed by approximately four months of daily at-home use. Results: Pre-implant cystometry revealed poor voiding efficiency and absent bladder sensation. Following bladder scES mapping and home training, one of the three participants regained direct bladder sensation, exceeded the 90% clinical threshold for efficient voiding, and continues to use scES for bladder management instead of intermittent catheterization, with no urinary tract infections reported since completion of training (February 2022). The inability of two participants to attain high voiding efficiency may be due to suboptimal adherence to prescribed bladder training protocols in one case and the presence of an elevated bladder neck in the other. All three participants reported off-target improvements in bowel and sexual functions. Conclusions: The present novel pilot study provides the first evidence supporting the potential use of epidural stimulation for bladder management and the importance of activity-based recovery training for durable performance.