Development of a Non-Invasive, Catheter Based Method to Activate Urethral Afferents

Recent studies in animal models have shown that bladder contractions can be evoked by electrical stimulation of pudendal urethral afferent nerve fibers, even following spinal transection. Control of bladder activity would be a valuable tool to assist individuals with neurological disorders or spinal cord injury. To investigate these neural pathways in humans, a non-invasive approach is required. This project sought to develop and validate a non-invasive method to activate urethral sensory pathways. A stainless steel ring electrode was fabricated onto a 3.5 French urethral catheter and used for intra-urethral stimulation. Robust bladder contractions were generated via intra-urethral electrical stimulation in 3 cats. Peak responses were obtained in the proximal and prostatic urethra. No responses were observed within the bladder neck, urethral sphincter or distal urethra. Bladder responses were equivalent to those evoked by direct stimulation of pudendal urethral sensory nerves. We intend to use this catheter-based method to investigate the effects of intra-urethral stimulation on bladder activity in humans with spinal cord injury.