Lumbosacral spinal cord epidural stimulation improves voiding function after human spinal cord injury

Abstract

Deficits in urologic function after spinal cord injury (SCI) manifest both as a failure to store and empty, greatly impacting daily life. While current management strategies are necessary for urological maintenance, they oftentimes are associated with life-long side effects. Our objective was to investigate the efficacy of spinal cord epidural stimulation (scES) as a promising therapy to improve bladder control after SCI. A bladder mapping study was undertaken for sixteen sessions over the course of four months in an individual with chronic, motor complete SCI. Varying combinations of stimulating cathode electrodes were initially tested during filling cystometry resulting in the identification of an effective configuration for reflexive bladder emptying at the caudal end of the electrode array. Subsequent systematic testing of different frequencies at a fixed stimulus intensity and pulse width yielded lowest post-void residual volumes at 30 Hz. These stimulation parameters were then tested in four additional research participants and found to also improve reflexive voiding efficiency. Taken together with SCI studies on step, stand, voluntary motor control and cardiovascular regulation, these findings further corroborate that scES has an all-encompassing potential to increase the central state of excitability, allowing for the control of multiple body functions, including the urological system.

Emergence of Epidural Electrical Stimulation to Facilitate Sensorimotor Network Functionality After Spinal Cord Injury

“…Reports using EES in rodent models of SCI and using transcutaneous stimulation in healthy macaques have shown efficacy in facilitating urinary function. Initial reports using EES in individuals with SCI have demonstrated an increase in voiding function ; however, further research needs to be performed to understand the effects of EES on urinary function along with studies on bowel and sexual function.…”

2018 Yearbook of Neurorestoratology

“…Implanted electrodes for electrical stimulation with intensive neurorehabilitation could partially restored standing and walking abilities in patients with complete chronic SCI [42,43]. In such cases, improved reflexive voiding efficiency [44], enhanced cardiovascular fitness and body composition [45], better neurological recovery [46] that supported the activities of daily living [47], and reduced that elevated blood pressures to normal ranges from a chronic hypotensive state [48] were observed.…”

A Urodynamic Comparison of Neural Targets for Transcutaneous Electrical Stimulation to Acutely Suppress Detrusor Contractions Following Spinal Cord Injury

“…Urodynamic assessment of the acute effect of SS on NDO has recently been found to facilitate voiding (Gad et al, 2018;Herrity et al, 2018;Niu et al, 2018) at 1 Hz and improve storage dysfunction at 30 Hz (Gad et al, 2018). These improvements were reported to be frequency and location dependant, also applying high frequency carrier within stimulation pulse which may be why use of much higher amplitudes was possible.…”

“…Spinal Stimulation, using stimulation of the dorsal surface or dorsal roots of the spinal cord at the level of the T12 vertebra has had promising reports of improved lower limb and bladder control from both pre-clinical and clinical studies (Harkema et al, 2011;Hofstoetter et al, 2014;Gerasimenko et al, 2015;Gad et al, 2016;Ren et al, 2016;Herrity et al, 2018). Previous studies of epidural stimulation conducted with MS participants have reported acute improvements in LUT function (Meglio et al, 1980), including in the suppression of detrusor contractions with some carry-over effect noted.…”

“…Animal work has reported acute suppression of detrusor contractions using both dorsal root and sacral nerve stimulation in rats, whilst stimulation of ventral roots was unable to suppress detrusor activity (Ren et al, 2016). More recently, application of epidural, magnetic and transcutaneous SS have yielded promising results for both storage and voiding, each in pilot studies involving humans with chronic SCI (Gad et al, 2018;Herrity et al, 2018;Niu et al, 2018). It is possible to stimulate these structures using transcutaneous stimulation techniques (Hofstoetter et al, 2018).…”