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，大多数中风会损害皮质脊髓束 (Cst)与手臂的运动控制密切相关的。然而，中风后手臂的康复 功能缺乏对潜在的神经机制和量化目标的了解 减损衡量标准。这项拟议研究的长期目标是确定 复杂肢体动力学的神经补偿。该项目的目标是确定 CST对被动力矩控制的贡献，被动力矩代表肢体的一个重要方面 动力学。我们的方法将是使用经颅磁刺激和扩散张量成像 测量伴随着目标定向手臂运动的CST的兴奋性和结构完整性 在不同的力约束下，如相互作用扭矩和重力施加的约束。的可行性。 这一方法基于我们强有力的初步数据，我们已经确定科技委参与其中。 在相互作用力矩补偿中，中风后损害伴随着 被动扭矩。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 运动缺陷是由于CST对被动扭矩的控制受损；3)促进职业发展 通过与该领域的领导者进行指导互动来进行发展。我们期待着实现这些目标 将提供CST活动的模型，解释神经运动系统如何补偿内部 以及外力。这项研究具有重要的意义，因为所得到的模型将有助于回答这个问题 CST是如何参与解决肌肉冗余问题的。我们预计，所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增加 目前机器人辅助康复的方法，并有助于开发新的客观诊断方法 用于预测康复潜力和治疗效果。

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.