Harnessing Neuroplasticity of Postural Sensorimotor Networks Using Non-Invasive Spinal Neuromodulation to Maximize Functional Recovery After Spinal Cord Injury

点击翻译按钮获取中文摘要

ABSTRACT Transcutaneous (TSS) and epidural spinal stimulation (ESS) are both electrophysiological techniques that have been used to investigate the interactions between exogenous electrical stimuli and spinal sensorimotor networks that integrate descending motor signals with afferent inputs from the periphery during motor tasks such as standing and stepping. Recently, pilot phase clinical trials using each of these stimulation modalities have demonstrated restoration of motor functions that were previously lost due to spinal cord injury (SCI). However, the spinal network interactions that occur in response to TSS or ESS with rehabilitation training have yet to be characterized and directly compared. Thus, it is imperative to (1) understand the neurophysiological profiles of individual participants comprehensively, thereby delineating the underlying mechanisms and (2) establish the relative effectiveness of TSS versus ESS in regaining motor function. Our central hypothesis is that ESS and TSS will promote similar levels of stimulation-augmented standing. We will compare the immediate functional and neurophysiological effects of TSS versus ESS in the same participants (Aim 1). We hypothesize that ESS and TSS will generate comparable motor output during standing due to similar level of modulated excitability of sensorimotor networks. Then, we will compare immediate and delayed effects of standing training combined with TSS versus ESS (Aim 2). We hypothesize that both TSS- and ESS-combined trainings will result in similar functional gain. We further predict that after one month of rest following standing training with TSS or ESS, the excitability and responsiveness of spinal and supraspinal sensorimotor networks will differ from baseline levels and Sham. Completion of this study will establish the efficacy of both non-invasive and invasive spinal neuromodulatory approaches to improve functions after SCI, impacting both research and clinical communities. Further, it will shed light on the underlying mechanisms of spinal neuromodulation, allowing ourselves and others to refine and improve stimulation protocols to maximize functional recovery.