Mechanisms of Arm Recovery in Stroke Patients with Hand Paralysis

严重卒中后手臂损伤是卒中相关残疾的主要原因，目前的治疗方法包括 疗效有限，患者往往终身残疾。虽然手臂和手的恢复机制 已经被广泛研究，有障碍的达到运动和没有手功能的患者往往是前， 由于其损伤的严重性而被排除在这些研究之外。因此，对机制知之甚少 在大部分中风人群中， 皮质运动系统和缺乏手功能。 长期目标是获得所需的机制信息，以制定干预措施，以改善接触 严重皮质运动系统损伤患者的能力。本建议的目的是确定 未受影响的半球（UH）在受影响的手臂运动在这个人群中。虽然UH激活通常 被认为对复苏有害，新的模型表明，在那些“结构性储备”较少的国家， 有助于运动恢复。这里，中心目标是确定UH电机在多大程度上 在严重皮质运动损伤的患者中，这些区域可能有助于受影响的手臂伸展运动。 中心目标将通过2个具体目标实现：1）比较未受影响与受影响半脑的作用， 脑卒中严重损害患者的伸展运动，2）确定兴奋性 非侵入性脑刺激UH运动区对患者练习诱导的伸展改善的影响 严重损伤。根据目标1，非侵入性脑刺激将被用于暂时干扰亲- 在未受影响和受影响的半球区域进行切割，以观察其是否对受影响的运动有任何影响 手臂根据目标2，非侵入性脑刺激将用于诱导更持久的兴奋性增加 在一轮伸手练习之前，未受影响或受影响的半球的活动。我们将比较 在刺激每个目标脑区域后达到能力的改善。我们还将测试 运动中目标脑区的作用。 这种方法是创新的，因为它解决了一个很少研究的主题（严重不发达国家的恢复机制）， 配对的患者），并靶向被认为对恢复有害的大脑区域（UH）。亲- 姿势的研究是重要的，因为，开发干预措施，以改善中风后手臂的恢复， 必须了解损害和恢复的机制。因为很大一部分与中风有关的残疾 是由于手臂损伤，手臂功能的改善可能会带来巨大的好处（和成本节约） 在这个庞大且急剧增长的人口中繁殖。

Current treatments for severe post-stroke arm impairment, a major contributor to stroke-related disability, are of limited efficacy and patients are often permanently disabled. While mechanisms of arm and hand recovery have been extensively studied, patients with impaired reaching movements and no hand function are often ex- cluded from these studies due to the severity of their impairment. Thus there is little known about mechanisms of arm recovery in the large proportion of the stroke population that has sustained more severe damage to the corticomotor system and lacks hand function. The long-term goal is to gain the mechanistic information needed to develop interventions to improve reaching ability in patients with severe corticomotor system damage. The objective in this proposal is to identify the role of the unaffected hemisphere (UH) in affected arm movements in this population. While UH activation is often considered deleterious to recovery, new models suggest that in those with less "structural reserve", UH motor areas could contribute to motor recovery. Here, the central aim is to determine the extent to which UH motor areas can contribute to affected arm reaching movements in patients with severe corticomotor damage . The central aim will be achieved via 2 specific aims: 1) Compare the role of the unaffected vs. affected hemi- sphere in reaching movements of stroke patients with severe impairment, 2) Determine the effect of excitatory non-invasive brain stimulation to UH motor areas on practice-induced reaching improvements in patients with severe impairment. Under Aim 1, non-invasive brain stimulation will be used to momentarily interfere with pro- cessing in unaffected and affected hemisphere areas to see if it has any effect on movement of the affected arm. Under Aim 2, non-invasive brain stimulation will be used to induce a longer-lasting increase in excitability of the unaffected or affected hemisphere prior to a bout of reaching practice. We will compare the amount of improvement in reaching ability after stimulation of each targeted brain area. We will also test for any change in the role of the targeted brain areas in the movement. The approach is innovative because it addresses a little-studied topic (recovery mechanisms in severely im- paired patients) and targets brain areas that have been thought to be deleterious to recovery (UH). The pro- posed research is significant because, to develop interventions to improve post-stroke arm recovery, the mechanisms of impairment and recovery must be understood. Since a large portion of stroke-related disability is due to arm impairment, improvements in arm function could result in enormous benefits (and cost savings) when multiplied across this large and steeply growing population.