Characterizing Lower Extremity Neurophysiological Responses to Sensory Augmentation after Stroke

中风后下肢对感觉增强的神经生理反应特征

• 批准号: 10829133
• 负责人: Jasmine Jamilah Cash
• 金额: $ 4.41万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-07 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10829133
• 关键词: Academic Medical Centers; Activities of Daily Living; Address; Award; Behavior; Biological Assay; Biological Markers; Brain Stem; Central Nervous System; Clinical; Communication; Complex; Corticospinal Tracts; Diffusion; Effectiveness; Electric Stimulation; Electroencephalography; Electrophysiology (science); Equilibrium; Exhibits; Feedback; Foundations; Functional Magnetic Resonance Imaging; Functional disorder; Goals; Hypesthesia; Image; Impairment; Individual; Individual Differences; Investigation; Knowledge; Learning; Lower Extremity; Measures; Mediating; Mediator; Mentors; Mentorship; Methods; Motor; Motor Cortex; Motor Evoked Potentials; Motor output; Muscle; Nervous System; Neuronal Plasticity; Outcome; Performance; Phase; Postdoctoral Fellow; Process; Prognosis; Protocols documentation; Quality of life; Recovery; Rehabilitation therapy; Research; Research Personnel; Research Training; Role; Route; Sensory; Shapes; Signal Transduction; Somatosensory Cortex; Somatosensory Evoked Potentials; Spinal Cord; Stimulus; Stroke; Structure; Synapses; System; Techniques; Time; Training; Transcranial magnetic stimulation; Translations; Upper Extremity; Walking; Work; balance recovery; career; career development; conventional therapy; equilibration disorder; experience; fall risk; falls; functional independence; high risk; improved; independent ambulation; interest; method development; multimodality; neural; neural correlate; neuroimaging; neurophysiology; neuroregulation; novel; post stroke; postsynaptic neurons; pre-doctoral; presynaptic neurons; response; sensory cortex; sensory input; sensory integration; skills; spasticity; stroke recovery; stroke survivor; treatment response

PROJECT SUMMARY/ABSTRACT After a stroke, walking ability can be compromised, which can lead to reduced quality of life and decreased ability to perform activities of daily living. Post-stroke walking recovery is mediated by nervous system reorganization (e.g., neuroplasticity), however our understanding of these processes related to improvements in walking function are limited due to the neurophysiological complexity of walking itself. Additionally, current practices of assessing stroke- impacted neuroplasticity are heavily focused on the motor system. Of keen interest is the integration of sensory and motor systems (e.g., sensorimotor integration-SMI), which are necessary for initiating, sustaining, and coordinating walking while providing continuous feedback on body state and actions. Additionally, impaired sensation post-stroke can lead to lower extremity dysfunction, balance problems, and falls, highlighting the need to investigate the effects of stroke on SMI in relation to walking function and recovery. Given the importance of SMI in walking, the capacity for these sensorimotor networks to exibit plastic changes may be a crucial mediator for improvements in walking funciton, thus necessitating relevant methods of assaying sensorimotor plasticity. To address this gap in knowledge, in the F99 Phase (Aim 1) I will characterize lower extremity sensorimotor plasticity in individuals post-stroke. I will specifically target the connections between the primary sensory cortex (S1) and and the primary motor cortex (M1) using paired associative stimulation (PAS), a novel method of assaying sensorimotor plasticity. PAS is based on the Hebbian principle of associative plasticity, in that repetitive stimulation of pre- and post-synaptic neurons within S1 and M1 leads to increased synaptic efficacy, evidenced by rapid and long-lasting increases in transcranial magnetic stimulation-induced muscle responses, or motor evoked potential (MEP) amplitude. We intend to account for individual differences in SMI by adjusting the timing between stimuli, and measuring the time it takes the electrical stimulation to reach S1, via somatosensory evoked potentials. Changes in MEP amplitude following PAS are thought to reflect the induced associative plasticity between S1 and M1, and are shown to be reflective of upper extremity function, with limited work done in the lower extremities. Therefore, we hypothesize that individualized PAS protocols, will facilitate increases in MEP amplitude, and changes will be associated with clinical measures of walking function. In the K00 Phase (Aim 2), I will pursue advanced training in post-stroke sensory and motor reorganization via multi- modal techniques to understand walking and balance recovery. I will seek out postdoctoral mentorship that will allow me to build on my predoctoral work by acquiring advanced electrophysiological and neuroimaging skills. I will also focus on individualized assessments and the identification of mechanisms underlying the response to treatment between individuals over the course of rehabilitation. The F99/K00 will help facilitate my path to independence through research training and career development, enroute to my long-term goal of becoming an independent researcher at an academic medical center. The proposed work and career direction aim to inform lower extremity rehabilitation efforts by providing functional and structural neural correlates of recovery.

项目摘要/摘要 中风后，行走能力可能会受到影响，这可能导致生活质量下降， 进行日常生活活动。中风后步行恢复是由神经系统重组介导的（例如， 神经可塑性），然而，我们对这些与步行功能改善相关的过程的理解是 由于行走本身的神经生理复杂性而受到限制。此外，目前评估中风的做法- 神经可塑性的影响主要集中在运动系统。最令人感兴趣的是将感官和 电动机系统（例如，感觉运动整合（sensorimotor integration，SMI），这是启动、维持和协调所必需的 行走时提供身体状态和动作的持续反馈。此外，中风后感觉受损 可导致下肢功能障碍、平衡问题和福尔斯，强调需要研究其影响 SMI与步行功能和恢复的关系。考虑到SMI在行走中的重要性， 这些表现出可塑性变化的感觉运动网络可能是改善行走的关键媒介 功能，因此需要相关的方法来测定感觉运动可塑性。为了弥补这一知识差距， 在F99阶段（目标1），我将描述中风后个体的下肢感觉运动可塑性。我会 专门针对初级感觉皮层（S1）和初级运动皮层（M1）之间的连接 使用配对联想刺激（PAS），一种新的方法，测定感觉运动可塑性。PAS基于 Hebbian联合可塑性原理，在S1内突触前和突触后神经元的重复刺激中 和M1导致突触功效增加，通过经颅磁刺激的快速和持久增加证明。 刺激诱发的肌肉反应或运动诱发电位（MEP）幅度。我们打算说明 通过调整刺激之间的时间，并测量电刺激所需的时间， 刺激到达S1，通过体感诱发电位。PAS后MEP振幅的变化被认为是 反映了S1和M1之间的诱导关联可塑性，并显示出反映了上肢 功能，在下肢做有限的工作。因此，我们假设个性化PAS方案， 将促进MEP振幅的增加，并且变化将与步行功能的临床测量相关。 在K 00阶段（目标2），我将通过多种方法进行中风后感觉和运动重组的高级训练， 模式技术，以了解步行和平衡恢复。我会寻找博士后导师， 我通过获得先进的电生理学和神经成像技术来建立我的博士前工作。我也会 重点关注个性化评估和确定治疗反应的机制 在康复过程中的个体之间。F99/K 00将帮助我通过以下方式实现独立 研究培训和职业发展，我的长期目标是成为一名独立的研究人员， 一个学术医疗中心建议的工作和职业方向旨在告知下肢康复 通过提供恢复的功能和结构神经相关的努力。