Evaluating cognitive impairment as a moderator of locomotor learning in older adults post-stroke

项目摘要 中风是世界各地长期残疾的主要原因，对老年人的影响不成比例。 中风后，老年人通常表现出步态功能障碍（例如，缓慢、不稳定、不对称行走）， 是患者报告的最高康复目标。除了运动缺陷，大约70%的人生活在 慢性脑卒中患者也有脑卒中后认知障碍（PSCI）。脑卒中后步态康复 干预措施有效地减轻了老年人的步态功能障碍，但仍有很大程度的相互影响， 步行结果的个体差异。我们认为这是因为目前的步态康复干预措施是 主要是为了利用外显与内隐运动学习。重要的是，外显运动 学习对认知的要求很高。它是通过基于外部的运动的有意改变而发生的。 反馈，主要依赖于背外侧前额叶皮层。然而，内隐运动学习 小脑依赖性，并且更自动地响应本体感受反馈。尽管有证据 认知和运动处理之间共享的神经资源，PSCI对认知能力的影响， 行走过程中的这些运动学习形式在很大程度上仍未被探索。本提案的总体目标是 证明PSCI调节慢性中风老年人的外显运动学习，但不调节内隐运动学习 并确定背外侧前额叶皮层在这种关系中的作用。在此职业发展 奖，PI（水蛭）将发展神经心理学，结构神经成像和先进的统计技能。 这项培训将促进她实现长期职业目标：作为一名独立调查员， 制定有效、全面、个性化的干预措施，以减少老年人的残疾。这个项目 有三个研究目标。目的1将确定PSCI严重程度对老年人外显运动学习的影响。 成年人中风后目的2将测试PSCI严重程度对内隐运动学习能力的影响， 同一组参与者。最后，目标3将研究背外侧前额叶皮层结构的作用， 中风后外显运动学习的完整性。患有一系列PSCI的慢性卒中老年人 severity将在总共2个实验会话中完成所有三个目标所需的程序。我们 我希望能证明PSCI的严重程度限制了个体学习更对称行走模式的能力 通过外显，而不是内隐，运动学习，这种关系将介导的结构 背外侧前额叶皮层的完整性这一工作将为项目的实施提供必要的科学依据 研究开发个性化的步态康复干预锚定认知障碍和 中风后老年人运动学习的综合预测模型。

PROJECT SUMMARY Stroke is a leading cause of long-term disability around the world and disproportionately affects older adults. After a stroke, older adults commonly exhibit gait dysfunction (e.g., slow, unstable, asymmetric walking), which is the top patient-reported rehabilitation target. In addition to motor deficits, approximately 70% of people living with chronic stroke also have post-stroke cognitive impairment (PSCI). While post-stroke gait rehabilitation interventions effectively mitigate gait dysfunction in aging adults, there remains a significant degree of inter- individual variability in walking outcomes. We posit this is because current gait rehabilitation interventions are predominantly structured to leverage explicit versus implicit locomotor learning. Importantly, explicit motor learning is cognitively demanding. It occurs through intentional changes to a movement based on external feedback and relies primarily on the dorsolateral prefrontal cortex. Whereas, implicit motor learning is cerebellum-dependent and occurs more automatically in response to proprioceptive feedback. Despite evidence of shared neural resources between cognitive and motor processing, the impact of PSCI on the capacity for these forms of motor learning during walking remains largely unexplored. The overall goal of this proposal is to demonstrate that PSCI moderates explicit, but not implicit, locomotor learning in older adults with chronic stroke and identify the role of the dorsolateral prefrontal cortex in this relationship. Under this career development award, the PI (Leech) will develop skills in neuropsychology, structural neuroimaging, and advanced statistics. This training will promote the achievement of her long-term career goal: as an independent investigator, to develop effective, comprehensive, individualized interventions to reduce disability in older adults. This project has three research aims. Aim 1 will determine the impact of PSCI severity on explicit locomotor learning in older adults post-stroke. Aim 2 will test the impact of the PSCI severity the capacity for implicit locomotor learning in the same group of participants. Finally, Aim 3 will examine the role of dorsolateral prefrontal cortex structural integrity in explicit locomotor learning post-stroke. Older adults with chronic stroke who have a range of PSCI severity will complete the procedures necessary for all three aims over a total of 2 experimental sessions. We expect to show that PSCI severity limits an individual’s capacity to learn a more symmetric walking pattern through explicit, but not implicit, locomotor learning and that this relationship will be mediated by the structural integrity of the dorsolateral prefrontal cortex. This work will provide necessary scientific foundation for a program of research to develop an individualized gait rehabilitation intervention anchored to cognitive impairment and a comprehensive predictive model of locomotor learning in older adults post-stroke.