Neurophysiological Correlates of Lower Extremity Motor Asymmetries Post-stroke

描述(由申请人提供)： 1中风是全世界成年人严重、慢性残疾的主要原因。美国每年发生的新中风超过75万例，占所有急性神经科住院患者的一半以上。3尽管三分之二的中风患者恢复了步行功能，但由此产生的步态模式缓慢、不对称和新陈代谢效率低下。步行功能障碍是中风后最大的身体缺陷之一，改善步行是神经康复最常见的目标之一。到目前为止，中风后步行功能障碍的康复治疗已经产生了高度不同的结果，7揭示了步行功能(包括步行速度或步行模式)最小的真实变化。我们的长期目标是改善中风后的步行能力。本应用程序的目标是 目的是研究9条神经通路的生理完整性，为包括行走在内的下肢功能服务。我们建议的10个基本原理源于我们之前的工作，该工作确定了对偏瘫步行功能障碍的11种治疗干预的不同反应模式，即“反应者”和“无反应者”。应答者12的特征是地面行走速度的显著变化，时空协调性的多重变化，以及远端关节的显著强度变化。相比之下，无反应者在地面行走速度上的变化很小，时空协调性几乎没有变化，近端关节的力量变化很小。在16岁以后的卒中人群中，有反应者和无反应者的存在并不令人惊讶，但在研究基线时，使用运动障碍、活动度或步行速度的临床工具无法区分反应者和无反应者。此外，临床上18个慢性和严重程度的特征未能预测这些反应模式。综上所述，19然而，我们的发现表明，存在于关键的下肢肌群下的下行肌束20的功能连通性的差异。21根据我们的初步调查结果，这一小型项目的目标是制定一项评估计划，22将能够区分具有运动恢复能力的人和缺乏这种能力的人。我们建议详细阐述我们现有的方法基础设施，以便能够将下肢/运动区的24个神经生理功能与临床和行为步行测量相关联。我们将使用经颅磁刺激(TMS)探测代表下肢的大脑区域26，并确定：1)皮质兴奋性，2)27)皮层和脊髓水平回路的功能和3)分化，以及4)行走功能之间的关系。关键词：中风，运动，康复，神经生理学，康复，生物力学

DESCRIPTION (provided by applicant): 1 Stroke is the leading cause of serious, chronic disability in adults worldwide. Over 750,000 new strokes 2 occur in the United States each year accounting for over half of all acute neurological hospital admissions. 3 While two-thirds of persons who suffer a stroke regain ambulatory function, the resulting gait pattern is slow, 4 asymmetrical and metabolically inefficient. Walking dysfunction represents one of the greatest physical 5 limitations post-stroke and improved walking is among the most frequently articulated goals of 6 neurorehabilitation. To date, rehabilitation for walking dysfunction post-stroke has produced highly variable 7 outcomes revealing minimal genuine change in walking function including walking speed or walking pattern. 8 Our long term goal is to improve walking post-stroke. The objective of this application is to investigate the 9 physiologic integrity of neural pathways sub-serving lower extremity function, including walking. The 10 rationale for our proposal stems from our previous work, which has identified distinct patterns of response to 11 therapeutic intervention for hemiparetic walking dysfunction, 'responders' and 'non-responders'. Responders 12 are characterized by significant changes in overground walking speed, multiple changes in spatio-temporal 13 coordination and marked strength changes in distal joints. In contrast, Non-responders produced minimal 14 changes in overground walking speed, few, if any, changes in spatio-temporal coordination, and small 15 strength changes in proximal joints. While the presence of responders and non-responders in the post- 16 stroke population is not surprising, at study baseline responders and non-responders could not be 17 differentiated using clinical instruments of motor impairment, activity, or walking speed. Moreover, clinical 18 characteristics of chronicity and severity failed to predict these patterns of response. Taken together, 19 however, our findings suggest the presence of differences in the functional connectivity of descending tracts 20 subserving key lower extremity muscle groups. 21 Based on our preliminary findings, the goal of this small project is to develop an assessment scheme that 22 will enable differentiation between individuals with the capacity for locomotor recovery from those who lack 23 such capacity. We propose to elaborate our existing methodological infrastructure to enable correlation of 24 neurophysiological functioning in the lower extremity/locomotor regions with clinical and behavioral 25 measures of walking. We will use transcranial magnetic stimulation (TMS) to probe brain regions 26 representing the lower extremity and determine the relationships between: 1) cortical excitability, 2) 27 functioning of and 3) differentiation between cortical and spinal level circuits, and 4) walking function. 28 Keywords: stroke, locomotion, recovery, neurophysiology, rehabilitation, biomechanics 29 30