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

ABSTRACT

The objective of this article is to examine dynamic changes of ischial blood perfusion during sacral nerve root stimulation against surface functional electrical stimulation (FES). Fourteen adults with suprasacral spinal cord injury (SCI) 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 hemoglobin (IHB) and oxygenation (IOX) was measured.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). Similarly, when using the SARS implant, we also observed 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 = 0.036). Among four participants who completed both the FMS and FES studies, the magnitude of increase in both parameters was significantly higher during FMS. This study demonstrates sacral nerve root stimulation confer better benefit on blood perfusion than applying traditional FES in SCI population.

KEYWORDS:

• blood perfusion
• electrical stimulation
• gluteal muscles
• ischial tuberosity
• pressure ulcer
• sacral nerve roots
• spinal cord injury

Acknowledgments

The authors would like to give special thanks to Dr. Graham Nicholson (deceased) who developed and calibrated the dermal probe, created the template for data process. We would also like to thank Mr. Gary Hearne for his statistics advice for this manuscript; Professor Michael Craggs and Dr. Sarah Knight for their academic advice; and Dr. Angela Gall for clinical advice for conducting the studies. Thanks also go to all participants—without their patience and help, it would be impossible to complete this project.

Disclosure statement

The authors have no conflicts of interest to disclose.

Funding

This work was funded by the Royal National Orthopaedic Hospital, Stanmore, United Kingdom, and the grant number is 03/010. This work was also supported by the ASPIRE Stanmore, United Kingdom for providing equipment to run this project.

Additional information

Funding

This work was funded by the Royal National Orthopaedic Hospital, Stanmore, United Kingdom, and the grant number is 03/010. This work was also supported by the ASPIRE Stanmore, United Kingdom for providing equipment to run this project.