Neural Mechanisms Mediating Interlimb Transfer Following Stroke

 描述（由申请人提供）： 中风是全球成年人严重慢性残疾的主要原因。在美国，每年发生超过750，000例新发中风，占平民和退伍军人医院所有急性神经系统住院的一半以上。最持久的中风相关运动损伤影响上肢（UE）14。在幸存者中，73 - 88%的人存在影响上肢功能的感觉运动障碍，55 - 75%的人在日常生活活动中难以使用手臂。到目前为止，中风后轻偏瘫的上肢康复已经产生了高度可变的结果，揭示了受影响手臂的运动损伤或功能使用的最小真正变化。这项建议的总体目标是提高我们的神经机制的理解，有助于肢体间和半球间转移后，非麻痹肢体运动任务失败。我们将使用经颅磁刺激来探测皮质兴奋性、皮质内和半球间回路的急性适应，这些回路伴随着麻痹手的行为易化。当前应用中提出的工作将使我们能够获得对我们当前工作假设至关重要的三个数据元素。我们将：1）研究在任务失败的非轻瘫肢体运动后两个半球中皮质内和半球间抑制的变化; 2）使用涉及操纵和灵巧的运动任务测试对轻瘫肢体功能的行为影响; 3）确定持久性（即，时间进程）的急性神经和行为的促进和其一致性在重复的会议。我们的研究结果将告知关于中风后肢体间和半球间转移的机制，并有助于在未来的研究中进行测试的临床干预的发展。在这项小型研究中获得的数据将通过使我们能够开发适当集中的机制假设，了解引起的影响，从而预测样本量，以在我们未来的研究中提供适当的统计功效，从而防止更大规模的临床研究失败。最终，在这个小项目和未来的研究中进行的工作将推进我们关于中风后运动恢复的神经生物学知识，提供关于肢体间转移现象和神经可塑性相关机制的见解。关键词：脑卒中，恢复，神经生理学，康复，上肢

 DESCRIPTION (provided by applicant): Stroke is the leading cause of serious, chronic disability in adults worldwide. Over 750,000 new strokes occur in the United States each year accounting for over half of all acute neurological hospital admissions in both civilian and Veterans' hospitals. The most persistent stroke-related motor impairments affect the upper- extremity (UE)14. Among survivors, 73-88% present with sensorimotor impairments affecting upper-extremity function and 55-75% experience difficulty using the arm for activities of daily living activities. To date, upper- extremity rehabilitation fr post-stroke hemiparesis has produced highly variable outcomes revealing minimal genuine change in motor impairment or functional use of the affected arm. Our long-term goal is to restore UE motor function following stroke. The overall objective of this proposal is to improve our understanding of neural mechanisms contributing to inter-limb and inter-hemispheric transfer following non-paretic limb exercise to task failure. We will use transcranial magnetic stimulation to probe acute adaptations in cortical excitability, intracortical and inter-hemispheri circuits that accompany behavioral facilitation of the paretic hand. The work proposed in the current application will enable us to obtain three data elements that are critical to our current working hypothesis. We will: 1) investigate changes in intracortical and interhemispheric inhibition in both hemispheres following non-paretic limb exercise to task failure; 2) test behavioral effects on paretic limb function using a motor task involving manipulation and dexterity; 3) determine the persistence (i.e., time course) of acute neural and behavioral facilitation and its consistency over repeated sessions. Our results will inform regarding the mechanisms of inter-limb and inter-hemispheric transfer post-stroke and contribute development of a clinical intervention to be tested in future studies. The data obtained in this small study wil prevent failure of a larger, clinical investigation by enabling us to develop appropriately focused mechanistic hypotheses, understand the effects elicited and therefore project a sample size to afford appropriate statistical power in our future study. Ultimately, the work conducted in this small project and future studies will advance our knowledge regarding the neurobiology of motor recovery following stroke, providing insight regarding the phenomenon of interlimb transfer and the associated mechanisms of neural plasticity. Keywords: stroke, recovery, neurophysiology, rehabilitation, upper-extremity