Augmenting Neuroplasticity through Visual and Proprioceptive Feedback

描述(申请人提供)：在美国，中风是仅次于心血管疾病和癌症的主要死亡原因，也是导致老年患者身体残疾的主要原因。目前中风康复的标准是高强度的物理治疗。该奖学金的总体目标是探索创新的康复技术，以优化运动中心的神经元可塑性。由于视觉系统对运动系统的广泛影响，我们建议探索基于视觉的反馈通过Hebbian机制促进运动皮质激活的可能性。通过使用虚拟现实来改变视觉反馈，我们计划测试这样一个假设，即夸大运动和该运动的视觉反馈之间的差异将增加运动皮质的兴奋性。我们将在健康受试者和慢性中风患者身上测试这一原理。如果成功，我们的数据可能不仅对慢性中风患者有重要意义，而且对具有最大神经可塑性潜力的急性中风患者也有重要意义。我们还将测试反馈对两个半球的交叉和非交叉皮质脊髓通路的影响，以完全将解剖位置映射到增强视觉反馈产生的神经生理变化上。我们假设，健康受试者屈指时视觉区域的夸大误差会增加静止手的经颅磁刺激(STMS)诱发的运动诱发电位(MEP)(相对于垂直反馈)。我们的初步数据表明，这种效应可能发生在移动手的同侧运动皮质，可能是由交叉的皮质脊髓通路介导的。我们将通过使用重复的经颅磁刺激(RTMS)来减少初级运动皮质的半球间抑制(IHI)来进一步测试大脑半球之间的相互作用，以测试这是否会增强被抑制的运动皮质的兴奋性。最后，我们将测试增强反馈是否也会增加慢性中风患者运动皮质的兴奋性。我们的初步数据表明，受损大脑半球的运动皮质可能对这种神经可塑性变化敏感。如果成功，建议的方法将为中风康复中基于反馈的新方法的发展铺平道路，通过选择性地支持对侧和同侧运动通路，从而最佳地重新定位皮质神经回路。对哪些形式的中风康复治疗真正有效，建立一个强有力的循证理解是至关重要的。通过虚拟现实改变视觉反馈可能是增强急慢性中风患者感觉运动系统的一种强有力的方法。在整个团契期间，主要目标是探索这项技术，希望确定一种新的全面的中风康复方法，从而帮助治疗师为他们的患者构建训练程序，以促进中风后的功能恢复。 公共卫生相关性：随着美国老年人口在接下来的十年里迅速增长，中风等神经疾病将不幸地变得更加普遍。除了提高认识和建立卒中预防计划外，我们还必须集中精力完善目前的卒中康复技术。至关重要的是，必须建立一个强有力的循证理解，了解哪些形式的治疗可能奏效，为什么它们可能奏效，以及它们可能对谁最有益。

DESCRIPTION (provided by applicant): Stroke is a leading cause of death in the United States, following cardiovascular disease and cancer, and is also the leading cause of physical disability among elderly patients. The current standard in stroke rehabilitation is intense physical therapy. The overall goal of this fellowship is to explore innovative rehabilitation techniques that optimize neuronal plasticity in motor centers. Because of the extensive influence of the visual system on the motor system, we propose to explore the potential of using visually-based feedback to facilitate activation of motor cortex via Hebbian mechanisms. By using virtual reality to alter visual feedback, we plan to test the hypothesis that exaggerating a discrepancy between movement and visual feedback of that movement will increase excitability of the motor cortex. We will test this principle in healthy subjects and in patients with chronic stroke. If successful, our data may have important implications not only in chronic stroke patients but also for patients in the acute stroke phase, who have the greatest potential for neural plasticity. We will also test the effects of feedback on the crossed and uncrossed corticospinal pathways of both hemispheres to fully map anatomical loci onto the neurophysiological changes produced by augmented visual feedback. We hypothesize that exaggerating error in the visual domain during finger flexion performed by healthy subjects will increase transcranial magnetic stimulation (sTMS)-induced motor evoked potentials (MEPs) in the stationary hand (relative to veridical feedback). Our preliminary data suggest that this effect may be produced in the motor cortex ipsilateral to the moving hand, potentially mediated by crossed corticospinal pathways. We will further test interhemispheric interactions by using repetitive transcranial magnetic stimulation (rTMS) to diminish interhemispheric inhibition (IHI) of the primary motor cortex to test if this will enhance the excitability of the disinhibited motor cortex. Last, we will test if augmented feedback will also increase the excitability of motor cortex in chronic stroke patients. Our preliminary data suggest that the motor cortex of the lesioned hemisphere may be susceptible to such neuroplastic changes. If successful, the proposed approach will pave the way for development of novel feedback-based approaches in stroke rehabilitation by selectively bolstering contralateral and ipsilateral motor pathways, thus optimally remapping cortical neural circuits. It is vital to establish a strong evidence-based understanding of which forms of stroke rehabilitation therapy are truly effective. Altering visual feedback via virtual reality may be a robust way of augmenting the sensorimotor system of acute and chronic stroke patients. Throughout this fellowship period, the primary objective is to explore this technique in hopes of determining a novel comprehensive approach to stroke rehabilitation, thus aiding therapists in structuring training routines for their patients to facilitate functional recovery following stroke. PUBLIC HEALTH RELEVANCE: As the elderly population in the United States skyrockets throughout the next decade, neurological disorders such as stroke will unfortunately become more prevalent. In addition to increasing awareness and instituting stroke prevention programs, we must also focus our efforts on perfecting current stroke rehabilitation techniques. It is vital to establish a strong evidence-based understanding of which forms of therapy may work, why they may work, and for whom they may be most beneficial.