Elucidating the role of the contralesional corticoreticulospinal tract for lower limb function after stroke.

项目摘要/摘要 慢性行走障碍，如行走速度、耐力和独立性减慢是很常见的 中风后，限制体力活动、生活质量和社区参与。这些行走障碍 导致高昂的医疗费用和继发性残疾的发展。行走障碍倾向于 尽管步态康复了，但仍然存在，部分原因是我们缺乏对哪一个大脑的全面了解 路径有助于中风后肢体和行走的恢复。新出现的证据表明 从非病变半球到中风患肢的同侧下行运动通路， 特别是皮质网状脊髓束，可能会得到增强。然而，以往工作中使用的测量工具， 单独考虑时，对该通路是否功能增强和 有助于改善腿部功能。这项提议的主要目标就是解决这个问题 其长期目标是通过识别与康复相关的运动路径来改善中风后的步态康复 这是可以成为目标的。我们的中心假设是来自非损毁大脑的皮质网状脊髓束 中风后，大脑半球到受影响更严重的肢体的功能将得到增强。这项提议的次要目标是 为了确定非皮损大脑半球皮质网状脊髓束的强度 影响腿部运动控制。为了实现这项提案的目标，将测试两个具体目标 在有一系列损害的慢性中风患者中。在目标1中，我们将开发一个多维的 结合三种测量方法评估卒中后皮质网状脊髓束是否增强 先前研究：功能磁共振成像(非损伤性脑激活)、弥散张量成像 (结构完整性)和经颅磁刺激(功能兴奋性)。在目标2中，协会 非病变大脑半球皮质网状脊髓束强度与下肢运动的关系 将对控制进行评估。这项分析将考虑中风严重程度的测量(病变负荷和下肢 减损)。拟议的工作将是第一次使用多方面的方法来全面和 严格评估从非病变大脑半球到中风患肢的大脑通路 在中风后都会增强。这项工作的结果将提高我们对大脑通路的理解 有助于中风后的步行康复，这是提高步行康复的必要信息。这个 拟议的工作还将提供对中风损害如何影响康复机制和 最佳康复策略。对中心假说的支持将是支持 神经调节应用于非损害性脑通路的潜力导致改善 中风后步行康复。拟议工作带来的步行康复方面的改善可能 从而大幅减少慢性行走障碍、残疾和中风的社会成本。

Project Summary/Abstract Chronic walking impairments such as decreased walking speed, endurance, and independence are common after stroke and limit physical activity, quality of life, and community involvement. These walking impairments contribute to high healthcare costs and the development of secondary disabilities. Walking impairments tend to persist despite gait rehabilitation, partly because we lack a comprehensive understanding of which brain pathways contribute to lower limb and walking recovery after stroke. Emerging evidence suggests that ipsilaterally-descending motor pathways from the non-lesioned hemisphere to the stroke-affected limb, specifically the corticoreticulospinal tract, may be enhanced. However, the measurement tools used in prior work, when considered in isolation, provide limited insight into whether this pathway is functional enhanced and contributes to improved lower limb function. The primary objective of this proposal is to address this question with the long-term goal of improving gait rehabilitation after stroke by identifying recovery-related motor pathways that can be targeted. Our central hypothesis is that the corticoreticulospinal tract from the non-lesioned brain hemisphere to the more affected limb will be enhanced after stroke. The secondary objective of this proposal is to determine whether the strength of the corticoreticulospinal tract from the non-lesioned brain hemisphere influences lower limb motor control. To achieve the objectives of this proposal, two specific aims will be tested in individuals with chronic stroke with a range of impairment. In Aim 1, we will develop a multi-dimensional estimate of whether the corticoreticulospinal tract is enhanced after stroke by combining three measures used in prior research: functional magnetic resonance imaging (non-lesioned brain activation), diffusion tensor imaging (structural integrity), and transcranial magnetic stimulation (functional excitability). In Aim 2, the association between the strength of the corticoreticulospinal tract from the non-lesioned hemisphere and lower limb motor control will be assessed. This analysis will account for measures of stroke severity (lesion load and lower limb impairment). The proposed work would be the first to use a multifaceted approach to comprehensively and rigorously assess whether brain pathways from the non-lesioned hemisphere to the stroke-affected lower limb are enhanced after stroke. Results from this work will improve our understanding of the brain pathways that contribute to walking recovery after stroke, essential information for improving walking rehabilitation. The proposed work will also provide insight into how stroke impairment influences the mechanisms of recovery and the optimal rehabilitative strategy. Support for the central hypothesis will be a major breakthrough that supports the potential for neuromodulation applied to non-lesioned brain pathways pathways to lead to improvements in walking recovery after stroke. Improvements in walking rehabilitation that result from the proposed work could lead to substantial reductions in chronic walking impairment, disability, and societal cost of stroke.