Influence of neuromodulatory input on ankle control and spasticity in persons with spinal cord injury.

脊髓损伤（SCI）患者可能有一定的行走能力，但是，他们经常受到挑战， 痉挛性步态模式，其特征是对抬起脚的肌肉（背屈肌）的随意控制较差， 控制蹬离的肌肉（足底屈肌）痉挛。这两种缺陷都有助于削弱能力， 实现脚地间隙，使行走费力和不稳定。两个主要的神经贡献者 痉挛性步态包括皮质脊髓下行束（CST）驱动踝背屈肌中断， 足底屈肌脊髓反射回路（SRC）的调制。目前还不清楚是否减少下降 意志驱动或反射调节障碍更易导致痉挛性步态。传入输入具有很强的 对CST和SRC的兴奋性的神经调节作用。全身振动（WBV）是一种鲁棒的 传入输入的一种形式，它提供了一种探针来了解痉挛性瘫痪的神经生理机制。 步态本研究的长期目标是制定康复策略，以提高步行功能， 通过改善踝关节控制，提高SCI患者的活动能力。本提案的总体目标是了解 CST和SRC在踝关节的意志和反射控制中的作用。该项目的基本原理是， 了解神经生理学对增加意志控制和减少痉挛的贡献， 踝关节将是发展重要的非侵入性康复策略以改善痉挛的第一步。 SCI和其他上运动神经元疾病患者的步态。核心假设是， 踝关节功能与CST变化的相关性大于与SRC变化的相关性 皮质脊髓驱动影响意志控制和反射调制。使用WBV 激活皮层和脊髓回路，中心假设将通过两个特定的目标进行测试：1）确定 背屈肌CST和跖屈肌SRC兴奋性对踝关节自主控制的贡献 确定背屈肌CST和跖屈肌SRC兴奋性对踝关节损伤的贡献。 SCI患者的痉挛状态。这项研究是创新的，因为还没有一项研究 研究同时针对CST和SRC的干预措施如何影响不同的 SCI后痉挛步态的组成部分。了解痉挛性步态的机制是非常重要的 因为它为靶向非侵入性治疗的发展提供了基础， 受这种受损步态模式影响的人的功能结果。总的来说，在这方面获得的知识 该提案将提供更多的了解踝关节控制和痉挛的人的潜在机制， SCI.

People with spinal cord injury (SCI) may have some walking ability, however, they are often challenged with a spastic gait pattern, characterized by poor voluntary control of the muscles that lift the foot (dorsiflexors) and spasms of the muscles that control push-off (plantar flexors). Both deficits contribute to impaired ability to achieve foot-ground clearance, making walking laborious and unstable. Two major neural contributors to spastic gait include disrupted descending corticospinal tract (CST) drive to the ankle dorsiflexors and impaired modulation of the plantar flexor spinal reflex circuit (SRC). It is still unknown whether diminished descending volitional drive or impairment of reflex modulation contributes more to spastic gait. Afferent input has a strong neuromodulatory effect on the excitability of both the CST and SRC. Whole body vibration (WBV) is a robust form of afferent input that provides a probe to understand the neurophysiologic mechanisms underlying spastic gait. The long-term goal of this research is to develop rehabilitation strategies to enhance walking function and mobility in persons with SCI by improving ankle control. The overall objective of this proposal is to understand the roles of the CST and SRC in volitional and reflex control of the ankle. The rationale for this project is that understanding the neurophysiological contributions to increased volitional control and decreased spasticity in the ankles will be the first step to developing important non-invasive rehabilitation strategies to improve spastic gait in persons with SCI and other upper motor neuron disorders. The central hypothesis is that improvements in ankle function will have a greater association with changes in the CST than with changes in SRC modulation, as corticospinal drive influences both volitional control and reflex modulation. Using WBV to activate cortical and spinal circuits, the central hypothesis will be tested via two specific aims: 1) Determine the contribution of dorsiflexors CST and plantar flexor SRC excitability to ankle volitional control in individuals with SCI; and 2) Determine the contribution of dorsiflexors CST and plantar flexor SRC excitability to ankle spasticity in individuals with SCI. The proposed research is innovative, because there has yet to be a study examining how an intervention that targets the CST and SRC simultaneously, impacts the different components of spastic gait after SCI. Understanding the mechanisms underlying spastic gait is significant because it provides a foundation for the development of targeted non-invasive therapies to increase the functional outcomes of the people impacted by this impaired gait pattern. Overall, the knowledge gained in this proposal will provide more insight in the underlying mechanisms of ankle control and spasticity in persons with SCI.