Neural correlates of whole-body motion perception during balance perturbations in stroke survivors and their relationship to balance function

项目总结/摘要 中风后感觉和运动处理都受到损害，但经常被孤立地研究，大多数 康复的重点是运动系统。我们目前对身体位置的理解， 运动（即本体感觉）由于现有的主观的、缺乏精确度的方法而受到限制， 通常在非功能性行为期间在上肢的单个关节中进行评估。我的论文研究 使用机器人的方法来理解本体感受对运动学习的贡献， 神经生理水平。学习与增强的本体感受功能和 感觉运动神经生理学虽然这些发现支持了使用客观措施的价值， 在学习的背景下量化本体感觉，并确定潜在的神经基质，神经 介导本体感受对功能行为（例如平衡）的贡献的机制是未知的。 当平衡受到干扰时，大脑必须整合多个关节和四肢的感觉输入， 身体姿势和计划适当的肌肉反应。我们实验室的研究结果表明， 幸存者改变了皮质反应和肌肉激活模式，以响应扰动，但它是 目前尚不清楚这些异常反应是否与全身运动感知障碍有关。 客观生物标志物，包括结构完整性和皮质对平衡扰动的反应， 功能是必要的，以确定个人的风险福尔斯，并告知发展的目标 利用个体潜在的大脑平衡特征的干预措施。为了实现这一长期目标，我们 将在慢性卒中幸存者（N=20）和神经典型老年人（N=20）中追求以下目标：1）测试 更差的全身运动感知是否与更差的平衡功能相关; 2）确定是否 在平衡扰动期间诱发的皮质反应根据以下困难进行调节： 区分平衡扰动;以及3）测试感官中结构完整性的测量是否 通路和皮层反应潜伏期与平衡功能有关。据我们所知，这是第一个 一项使用多模态方法来确定躯体感觉背后的脑平衡关系的研究 功能性行为中的感知。如果成功，这些发现可能有助于改变现有的 康复干预侧重于运动系统，采用综合方法， 和感知对运动的贡献。鉴于随着年龄的增长，福尔斯跌倒的风险增加， 中风后，开发躯体感觉知觉和平衡功能的结构和功能生物标志物 是必要的，以确定个人的风险福尔斯，并推动发展有效的，循证的 康复干预。

PROJECT SUMMARY/ABSTRACT Both sensory and motor processing are impaired post-stroke, but frequently studied in isolation, with most rehabilitation focused on the motor system. Our current understanding of the perception of body position and movement (i.e. proprioception) is limited due to existing methodologies that are subjective, lack precision, and are often assessed in single joints of the upper limb during non-functional behaviors. My dissertation research used robotic methods to understand proprioceptive contributions to motor learning at a perceptual and neurophysiological level. Learning was associated with enhanced proprioceptive function and changes in sensorimotor neurophysiology. While these findings supported the value of using objective measures to quantify proprioception in the context of learning and identified underlying neural substrates, the neural mechanisms mediating proprioceptive contributions to functional behaviors, such as balance, is unknown. When balance is perturbed, the brain must integrate sensory input across multiple joints and limbs to perceive body position and plan the appropriate muscle response. Findings from our lab demonstrate that stroke survivors have altered cortical responses and muscle activation patterns in response to a perturbation, but it is unknown whether these abnormal responses are related to impairments in whole-body motion perception. Objective biomarkers, including structural integrity and cortical responses to balance perturbations, of balance function are necessary to identify individuals at risk for falls and to inform the development of targeted interventions that capitalize on an individual’s underlying brain-balance profile. Towards this long-term goal, we will pursue the following aims in chronic stroke survivors (N=20) and neurotypical older adults (N=20): 1) test whether worse whole-body motion perception is associated with worse balance function; 2) determine if cortical responses evoked during balance perturbations are modulating according to the difficulty of discriminating between balance perturbations; and 3) test whether measures of structural integrity in sensory pathways and cortical response latency are associated with balance function. To our knowledge, this is the first study using a multi-modal approach to identify brain-balance relationships underlying somatosensory perception during functional behaviors. If successful, such findings may contribute to a shift in existing rehabilitation interventions focused on the motor system towards integrative approaches that address sensory and perceptual contributions to movement. Given increased risk of falls with aging that is further increased post-stroke, developing structural and functional biomarkers of somatosensory perception and balance function is necessary to identify individuals at risk for falls, and to advance development of effective, evidence-based rehabilitation interventions.