Augmenting Neuroplasticity through Visual and Proprioceptive Feedback

描述（由申请人提供）：在美国，中风是继心血管疾病和癌症之后的主要死亡原因，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强化物理治疗。这项研究的总体目标是探索创新的康复技术，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，我们建议探索使用基于视觉的反馈通过Hebbian机制促进运动皮层激活的潜力。通过使用虚拟现实来改变视觉反馈，我们计划测试一个假设，即夸大运动和视觉反馈之间的差异会增加运动皮层的兴奋性。我们将在健康受试者和慢性中风患者中测试这一原理。如果成功，我们的数据可能不仅对慢性脑卒中患者，而且对急性脑卒中患者具有重要的意义，急性脑卒中患者具有最大的神经可塑性潜力。我们还将测试反馈对两个半球交叉和未交叉皮质脊髓通路的影响，以将解剖学位点完全映射到增强视觉反馈产生的神经生理变化上。我们假设，在健康受试者进行手指屈曲时，视觉域误差的夸大会增加经颅磁刺激（sTMS）诱导的静止手的运动诱发电位（MEPs）（相对于真实反馈）。我们的初步数据表明，这种效应可能是在运动手的同侧运动皮层中产生的，可能是由交叉的皮质脊髓通路介导的。我们将通过重复经颅磁刺激（rTMS）进一步测试半球间相互作用，以减少初级运动皮层的半球间抑制（IHI），以测试这是否会增强去抑制运动皮层的兴奋性。最后，我们将测试增强反馈是否也会增加慢性脑卒中患者运动皮层的兴奋性。我们的初步数据表明，受损半球的运动皮层可能易受这种神经可塑性改变的影响。如果成功，该方法将通过选择性地支持对侧和同侧运动通路，从而最佳地重新映射皮质神经回路，为中风康复中基于反馈的新方法的发展铺平道路。对于哪些形式的中风康复治疗是真正有效的，建立强有力的基于证据的理解是至关重要的。通过虚拟现实改变视觉反馈可能是一种增强急性和慢性中风患者感觉运动系统的有效方法。在整个研究期间，主要目标是探索这种技术，以期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组织训练程序，以促进中风后的功能恢复。

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.