Blood perfusion changes during sacral nerve root stimulation versus surface gluteus electrical stimulation on in seated spinal cord injury

Objective: To examine dynamic changes of ischial blood perfusion during sacral nerve root stimulation against surface functional electrical stimulation (FES). Methods: Fourteen adults with suprasacral complete spinal cord injury were recruited. The gluteal maximus was activated by surface FES or stimulating sacral nerve roots by functional magnetic stimulation (FMS) or a sacral anterior root stimulator implant (SARS). Ischial skin index of haemoglobin (IHB) and oxygenation (IOX) was measured. Results: Skin blood perfusion was significantly higher during FMS than the baseline (IHB 1.05±0.21 before vs. 1.08±0.02 during stimulation, P=0.03; IOX 0.18 ± 0.21 before vs. 0.46 ± 0.30, P=0.01 during stimulation, n=6). Similarly, when using the SARS implant, we also observed that blood perfusion significantly increased (IHB 1.01 ± 0.02 before vs. 1.07 ±0.02 during stimulation, P=0.003; IOX 0.79±0.81 before vs. 2.2±1.21 during stimulation, P=0.03, n=6). However, there was no significant change of blood perfusion during surface FES. Among 4 participants who completed both the FMS and FES studies, the magnitude of increase in both parameters was significantly higher during FMS. Conclusion: This study demonstrates that using SARS implant is more efficient to activate gluteal muscles and confer better benefit on blood perfusion than applying traditional FES in SCI population.

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Assistive Technology: the Official Journal of RESNA on 29/09/2017 available online: http://www.tandfonline.com/10.1080/10400435.2017.1340360