Off-target effects of percutaneous epidural spinal cord and dorsal root ganglion stimulation with task-specific training on lower urinary tract function in individuals with chronic spinal cord injury
TL;DR
Motor-optimized SCS-TST did not lead to significant group-level changes in patient-reported urinary symptoms, however, a subset of individuals experienced improvement or worsening, suggesting that injury characteristics and medication use may influence urinary outcomes.
Abstract
Objective: This study aimed to evaluate the off-target effects of motor-optimized SCS-enabled task-specific training (SCS-TST) on lower urinary tract function through self-reported data from individuals with chronic spinal cord injury (SCI), using the Neurogenic Bladder Symptom Score (NBSS). A secondary objective was to explore whether participant characteristics or bladder treatments were associated with changes in NBSS outcomes. Design: Datasets from two prospective pilot trials using percutaneous spinal cord stimulation (SCS) to enable motor function were analyzed and reported. Setting: Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota. Participants: Adults ≥ 1-year post traumatic SCI. Interventions: Participants received either 12 days of epidural stimulation (ES) or 10 days of ES and dorsal root ganglion stimulation (ESDRS), each coupled with 6–8 SCS-TST sessions. Outcome Measures: NBSS was administered pre- and post-intervention. Results: Analysis of 23 participants (ES, n = 3; ESDRS, n = 20) showed no significant group-level changes in total NBSS (p = 0.49) or functional domains (p = 0.56–0.85). Individually, 83% demonstrated no clinically meaningful change, while 9% improved and 9% worsened. Exploratory analyses identified that symptom change was associated with neurological level of injury (p = 0.017), age (p = 0.026), and marginally associated with injury severity (p = 0.055). Oxybutynin use was associated with lower symptom variability, without statistical significance (p = 0.074). Conclusions: Motor-optimized SCS-TST did not lead to significant group-level changes in patient-reported urinary symptoms. However, a subset of individuals experienced improvement or worsening, suggesting that injury characteristics and medication use may influence urinary outcomes. These preliminary findings warrant confirmation in larger, adequately powered trials. Trial Registration: ClinicalTrials.gov identifiers: NCT05095454, NCT04736849.