Strategies for recovery of dexterity post stroke

描述(申请人提供)：中风是导致成人残疾的主要原因。尽管进行了常规治疗，但大多数中风幸存者都有持续性的手功能障碍。本研究将加深我们对手功能恢复机制的认识，为临床制定卒中后康复方案提供科学依据。运动恢复通过运动学习进行，这至少依赖于三个过程：适应、重复和强化。适应是根据动作的预期结果预测力量和动作的能力，是运动技能学习的基础。当经过调整的动作通过重复得到加强时，学习就会得到加强。我们已经证明，中风后指尖力量和运动的适应被破坏。然而，我们发现，来自未受影响手的上下文特定感觉信息可以恢复受影响手的适应。这些结果表明，“好”手可以教给“坏”手抓握控制的基本方面。我们还发现，反重力姿势肌肉的活动增加与手指运动效率的提高有关。基于这些结果，我们假设，交替的手练习策略，加上姿势肌肉的激活，将提高运动再学习的速度，并促进中风后手功能的恢复。这一策略将利用大脑两侧的冗余连接，促进技能学习过程中感觉运动的整合。在目标1中，我们将改进交替手练习策略，以恢复受影响手的适应。鉴于中风后现有的感觉运动障碍，这些实验将导致更好地理解运动、触觉和视觉感觉模式在适应过程中如何相互作用。在目标2中，我们将描述提高抓握效率和减少异常方向偏差的姿势策略，以促进练习中更有效的动作的重复。在目标3中，我们将使用“增强型交替手训练模式”检验训练期间和训练期间运动学习的比率以及手功能的改善，并将其与使用新的任务小组和结构化训练方案进行单独训练的患手进行比较。我们将通过对指尖力量、手指运动学、3-D手臂和躯干运动学的定量心理物理测量，以及在功能性伸展抓取和举起任务中双侧上肢肌肉活动的肌电记录来测试我们的目标。 我们期望确定直接影响功能的损害，提供关于如何执行任务的客观信息，并为加强再学习提供治疗策略和治疗剂量。本项目将促进我们对如何利用冗余电路来整合感觉输入和运动输出以进行再学习的理解，并为练习内容和结构的选择提供科学依据。所获得的知识将成为恢复手功能的最佳实践康复方案，这将影响中风和其他神经疾病患者的生活质量。

DESCRIPTION (provided by applicant): Stroke is the leading cause of adult disability. Despite conventional therapy, a majority of stroke survivors have persistent hand dysfunction. This proposed research will further our understanding of mechanisms of recovery of hand function and provide a scientific basis for post-stroke rehabilitation protocols in clinical practie. Motor recovery occurs through motor learning, which depends on at least three processes: adaptation, repetition and reinforcement. Adaptation is the ability to predict forces and movements according to the expected consequences of an action, and is fundamental to motor skill learning. When adapted movements are reinforced through repetition, learning is enhanced. We have shown that adaptation of fingertip forces and movements is disrupted after stroke. However, we found that context-specific sensory information from the unaffected hand can restore adaptation in the affected hand. These results suggest that the 'good' hand can teach the 'bad' hand fundamental aspects of grasp control. We also found that increased activity in anti-gravity postural muscles is associated with increased efficiency of finger movements. Based on these results we hypothesize that an alternate hand practice strategy, enhanced with postural muscle activation, will improve the rate of motor re-learning and enhance recovery of hand function post stroke. This strategy will tap into redundant connectivity between the two sides of the brain to facilitate sensorimotor integration during skill learning. In Aim 1, we will refine the alternate hand practice strategy to restore adaptation in the affected hand. The experiments will lead to a better understanding of how kinesthetic, tactile and visual sensory modalities interact during adaptation, given existing sensorimotor impairments after stroke. In Aim 2, we will delineate postural strategies that improve grasp efficiency and reduce abnormal directional biases to facilitate repetition of more efficient movements during practice. In Aim 3, we will examine the rate of within-session and between- session motor learning and improvement in hand function with the 'enhanced alternate hand training paradigm', and compare this to training with the affected hand alone, using a novel task panel and structured training protocols. We will test our Aims using quantitative psychophysical measurements of fingertip forces, finger kinematics, 3-D arm and trunk kinematics, and electromyographic recordings of bilateral upper limb muscle activity during functional reach-to-grasp and lift tasks. We expect to identify impairments that directly affect function, provide objective information about how a task is performed, and inform treatment strategies and dosing of therapy for enhanced re-learning. This project will advance our understanding of how redundant circuitry can be harnessed for integration of sensory input with motor output for re-learning, and provide a scientific basis for the selection of content and structure of practice. The knowledge obtained will inform best- practice rehabilitation protocols for recovery of hand function, which will impac the quality of life of individuals after stroke and other neurological conditions.