Corticospinal Control of Limb Dynamics in Health and After Stroke

中风是导致长期残疾的主要原因之一，大多数中风损害皮质脊髓束 (CST)与手臂的运动控制密切相关。然而， 功能缺乏对潜在神经机制的理解和定量目标 减值措施。这项研究的长期目标是确定 神经对复杂肢体动力学的补偿。本项目的目标是确定 CST对被动扭矩控制的贡献，这是肢体运动的一个重要方面。 动力学我们的方法是使用经颅磁刺激和弥散张量成像， 测量伴随目标导向手臂运动的CST的兴奋性和结构完整性 在不同的力约束下，例如由相互作用扭矩和重力施加的力约束。的可行性 这种方法是基于我们强有力的初步数据，在这些数据中，我们已经确定，科学技术委员会参与了这项工作 在相互作用扭矩的补偿，中风后损害是伴随着变化， 被动转矩为了实现总体目标，提出了三个具体目标：1）确定 CST对健康受试者被动扭矩控制的贡献; 2）确定卒中后是否 运动缺陷是由于CST对被动扭矩的控制受损; 3）促进职业生涯 通过与该领域领导者的指导互动来发展。我们希望，实现这些目标， 将提供一个模型的CST活动，解释如何神经运动系统补偿内部 和外部力量。本文的研究具有重要的意义，因为所得到的模型将有助于回答这一问题 CST是如何参与解决肌肉冗余的。我们希望获得的知识将进一步 我们对人类神经肌肉系统如何在存在的情况下产生准确运动的理解 不可预测的环境。这项研究的结果也有可能提高 目前的机器人辅助康复方法，并帮助开发新的客观诊断措施 用于预测恢复潜力和治疗效果。

Stroke is among the leading causes of long-term disability and most strokes damage the corticospinal tract (CST) that is intimately involved in motor control ofthe arm. However, post-stroke rehabilitation of arm function is lacking both understanding of the underiying neural mechanisms and quantitative objective measures of impairment. The long-term goal ofthe proposed research is to determine the mechanism of neural compensation forthe complex limb dynamics. The objective in this project is to determine the contribution of the CST to the control of passive torques, which represent a significant aspect of limb dynamics. Our approach will be to use transcranial magnetic stimulation and diffusion tensor imaging to measure the excitability and structural integrity of the CST that accompanies goal-directed arm movements under different force constraints, such as those imposed by interaction torques and gravity. The feasibility of this approach is based on our strong preliminary data, in which we have established that the CST is involved in the compensation for interaction torques, and that post-stroke impairment is accompanied by changes in passive torques. To achieve the overall objective, three Specific Aims are proposed: 1) to determine the contribution of CST to the control of passive torques in healthy subjects; 2) to determine whether post-stroke movement deficits are due to the impaired control of passive torques by the CST; 3) to foster career development through mentoring interactions with leaders In the field. We expect that achieving these aims will provide a model of the CST activity that explains how the neural motor system compensates for internal and external forces. This research is significant, because the obtained model will help answer the question of how the CST is involved in solving muscle redundancy. We expect that obtained knowledge would further our understanding of how the human neuromuscular system produces accurate movement in presence of unpredictable environment. Results of this research also have the potential to increase the effectiveness of the current methods of robot-assisted rehabilitation and help develop novel objective diagnostic measures for predicting recovery potential and therapeutic effectiveness.