Neuromodulation of spinal reflex pathway for the treatment of detrusor overactivity by medial plantar nerve stimulation at surface of sole of foot in patients with spinal cord injury

Abstract

Objectives: Suprasacral spinal cord lesions are prone to have neurogenic detrusor overactivity leading to urinary incontinence. Current medical management has known side-effects and often surgical managements are irreversible. Electrical stimulation to modulate spinal reflex pathway having same nerve root as urinary bladder is reported in the literature. This study aimed to reduce detrusor overactivity in patients with spinal cord injury (SCI) using surface electrical stimulation of medial plantar nerve at the sole of foot. Materials and Methods: Twenty adults with SCI having episode of at least 1 leak/day due to detrusor overactivity as diagnosed by cystometrogram (CMG), were on clean intermittent catheterization and ankle jerk was present consented for the study. Participants were asked to maintain bladder diary a week before and during 2 weeks of treatment. CMG was done on day-0 and day-14. cmcUroModul@tor®, an inhouse developed electrical stimulator was used for ½ h daily for period of 2 weeks. Patient satisfaction feedback questionnaire was taken on completion of treatment. CMG data were analyzed using Wilcoxon signed-ranked test while bladder diary was analyzed using binomial distribution. P < 0.05 was considered as statistically significant. Institutional Review Board (IRB) and ethics committee of Christian Medical College, Vellore, approved the study (CMC/IRB/11061). Results: Statistical significant improvement in maximum detrusor pressure (P = 0.03) and cystometric capacity (P = 0.04) was observed. Of 20 subjects, 18 showed improvement in bladder diary. Conclusion: Neuromodulation of medial plantar nerve at sole of foot by surface electrical stimulation is non-invasive, cost-effective, and alternative simple treatment modality for urinary incontinence due to detrusor overactivity.