Beneficial carry-over effects of chronic at-home genital nerve stimulation on incontinence in individuals with spinal cord injury: A pragmatic trial

Background: Genital nerve stimulation (GNS) is a promising, but under-researched, alternative treatment for neurogenic detrusor overactivity (NDO) in those with spinal cord injury (SCI). Objectives: To investigate the urodynamic, quality-of-life (QOL) and carry-over effects of GNS when applied at home for 2 weeks by participants with incomplete SCI and NDO during activities of daily living. Methods: Seven men and 1 woman participated in this 1-month protocol study. Urodynamic and QOL data were gathered during week 1 (baseline measurements), followed by 2 weeks of daily GNS at home using a portable device. GNS was applied either on-demand or thrice daily, depending on the individual's sensation. At week 4, post-stimulation tests were repeated to record any carry-over effect from the GNS. Participants maintained voiding diaries throughout the study. Assessments were carried out at the end of each protocol period in a randomized order. Clinical procedures were conducted at Taipei Medical University Hospital (Taipei, Taiwan). Results: Everyone completed the study but only 7 of the 8 participants completed their voiding diary. Two weeks after GNS, average cystometric bladder capacity was increased by 30 compared to baseline (P < 0.05). A 1-week carry-over effect was demonstrated as this capacity remained, on average, 35 greater than baseline in week 4 after GNS was stopped (P < 0.05). Incontinence frequency significantly decreased by the end of week 3 (P < 0.05) but no significant improvements were recorded for either detrusor pressure or bladder compliance. Conclusions: Chronic at-home GNS improved cystometric bladder capacity and reduced urinary incontinence for individuals with incomplete SCI and NDO. A carry-over effect of 1 week was observed following GNS treatment. The use of portable GNS treatment that can be applied by the individual at home merits further investigation as alternative treatment for NDO in those with SCI. © 2023 Elsevier Masson SAS