Early Transcutaneous Tibial Nerve Stimulation Acutely Improves Lower Urinary Tract Function in Spinal Cord Injured Rats

Andrea M Sartori; Souzan Salemi; Anna-Sophie Hofer; Valentin Baumgartner; Daniel Eberli; Martina D Liechti; Martin E Schwab; Thomas M Kessler

doi:10.1089/neur.2021.0058

Early Transcutaneous Tibial Nerve Stimulation Acutely Improves Lower Urinary Tract Function in Spinal Cord Injured Rats

Neurotrauma Rep. 2022 Feb 14;3(1):15-26. doi: 10.1089/neur.2021.0058. eCollection 2022.

Authors

Andrea M Sartori^{1

2}, Souzan Salemi³, Anna-Sophie Hofer¹, Valentin Baumgartner³, Daniel Eberli³, Martina D Liechti², Martin E Schwab¹, Thomas M Kessler²

Affiliations

¹ Institute for Regenerative Medicine, University of Zürich, and Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland.
² Department of Neuro-Urology, Balgrist University Hospital, University of Zürich, Zürich, Switzerland.
³ Laboratory for Tissue Engineering and Stem Cell Therapy, Department of Urology, University Hospital Zürich, Zürich, Switzerland.

Abstract

Despite the fact that a majority of patients with an injury to the spinal cord develop lower urinary tract dysfunction, only few treatment options are available currently once the dysfunction arises. Tibial nerve stimulation has been used in pilot clinical trials, with some promising results. Hence, we investigated whether the early application of transcutaneous tibial nerve stimulation in the animal model of spinal cord injured rats can prevent the development of detrusor overactivity and/or detrusor-sphincter-dyssynergia. Rats were implanted with a bladder catheter and external urethral sphincter electromyography electrodes. A dorsal over-hemisection, resulting in an incomplete spinal cord injury at the T8/9 spinal level, induced immediate bladder paralysis. One week later, the animals received daily tibial nerve or sham stimulation for 15 days. Effects of stimulation on the lower urinary tract function were assessed by urodynamic investigation. Measurements showed improvements of several key parameters of lower urinary tract function-in particular, non-voiding bladder contractions and intravesical pressure-immediately after the completion of the stimulation period in the stimulated animals. These differences extinguished one week later, however. In the dorsal horn of the lumbosacral spinal cord, a small significant increase of the density of C-fiber afferents layers I-II was found in the stimulated animals at four weeks after spinal cord injury. Tibial nerve stimulation applied acutely after spinal cord injury in rats had an immediate beneficial effect on lower urinary tract dysfunction; however, the effect was transitory and did not last over time. To achieve more sustainable, longer lasting effects, further studies are needed looking into different stimulation protocols using optimized stimulation parameters, timing, and treatment schedules.

Keywords: C-fiber bladder afferents; neurogenic lower urinary tract dysfunction (NLUTD); spinal cord injury; tibial nerve stimulation.