Effects of Transcranial Direct Current Stimulation (tDCS) on Spaced Discourse Treatment for Chronic Post-Stroke Aphasia

项目总结/摘要 失语症是一种脑部疾病，最常发生在中风后，影响多模态语言 能力.人类是社会嵌入的生物，因此沟通的缺陷会产生戏剧性的影响 职业潜力和生活质量。尽管行为干预的好处是明确的和可量化的， 尽管他们接受了语言治疗，但他们仍然无法治愈，甚至无法达到预期的康复水平。的一种方法 增加这种疗法的益处的方法是将它们与经颅直流电刺激（tDCS）结合联合收割机。 虽然这种方法已被证明可以改善命名，但对这种方法的程度的了解有限。 这种神经调节干预可以补充行为治疗，以有益于话语技能， 功能性沟通。这对于按照临床上可行的时间表提供的治疗尤其如此（即， 而不是集中练习）。在这个项目中，我们采取了一种创新的方法来调查影响 tDCS对失语症参与者话语产生的初步研究。我们将活动或假tDCS与 动词网络强化治疗（VNeST），一种行为疗法，已被证明具有显着的 使用间隔治疗时间表的话语改善。此外，我们使用tDCS协议， 在我们的初步工作中证明了间隔治疗的益处。AIM 1决定了 将主动tDCS与间隔话语治疗配对，与接受相同治疗的组相比， 假刺激该项目的另一个目标是获取神经成像数据，以告知 通过识别与行为变化相关的图论网络特性来影响tDCS;我们使用泛函 磁共振成像（fMRI），以识别每个人的语言网络使用自适应语义 范例在AIM 2A中，我们通过计算两个 任务和静息状态功能磁共振成像的复杂网络的关键特征（整合和分离）。然后我们 分析基线时这些变量与治疗后测量的话语变化之间的关系。 我们预计，治疗前的组织更类似于匹配的对照组，将预测更大的 从治疗中受益，特别是积极刺激。在AIM 2B中，我们评估了治疗后 语言网络，包括tDCS（下额叶）目标区域的功能连接变化 脑回; IFG）。我们预测IFG在这个网络中的介数中心性将显著增加 在任务和休息期间，主动刺激组与假手术组相比（接近对照组），以及 这一增长将与话语改善有关。我们的研究结果将增加对（i） tDCS对间隔时间提供的循证失语症治疗的影响，（ii）语言网络 与治疗益处相关的性质，以及（iii）靶向刺激如何改变该网络。因此我们 将深入了解tDCS如何与当前的临床实践相结合，以及其机制 通过它诱导适应性神经可塑性在失语症中产生有意义的功能结果。

PROJECT SUMMARY/ABSTRACT Aphasia is a brain disorder, most commonly occurring following stroke, that affects multimodal language abilities. Humans are socially embedded creatures, and thus deficits in communication have dramatic effects on occupational potential and quality of life. Despite the unequivocal and quantifiable benefits of behavioral speech-language therapy, they continue to fall short of a cure, or even desired levels of recovery. One way to increase the benefits of such therapies is to combine them with transcranial direct current stimulation (tDCS). Although this approach has been shown to improve naming, there is limited knowledge of the extent to which this neuromodulatory intervention can complement behavioral treatment to benefit discourse skills and functional communication. This is particularly true for treatment provided on a clinically-feasible schedule (i.e., spaced rather than massed practice). In this project, we take an innovative approach to investigate the effects of tDCS on discourse production in a pilot study of participants with aphasia. We pair active or sham tDCS with Verb Network Strengthening Treatment (VNeST), a behavioral therapy that has demonstrated significant discourse improvement using a spaced treatment schedule. Further, we use a tDCS protocol that has demonstrated benefit with spaced treatment in our preliminary work. AIM 1 determines behavioral effects of pairing active tDCS with spaced discourse treatment, in comparison to a group receiving identical therapy with sham stimulation. An additional goal of this project is to acquire neuroimaging data to inform mechanisms of tDCS effects by identifying graph theoretic network properties related to behavioral change; we use functional magnetic resonance imaging (fMRI) to identify each individual's language network using an adaptive semantic paradigm. In AIM 2A, we examine imaging measures as potential predictors of tDCS effect by calculating two key features of complex networks (integration and segregation) for both task and resting state fMRI. We then analyze the relationship between these variables at baseline and discourse changes measured post-therapy. We anticipate that pre-therapy organization more similar to that of a matched control group will predict greater benefit from treatment, particularly for active stimulation. In AIM 2B, we assess post-therapy changes in the language network, including changes in functional connectivity for the region targeted by tDCS (inferior frontal gyrus; IFG). We predict that the betweenness centrality of IFG within this network will increase significantly during both task and rest for the active stimulation group compared to sham (approaching that of controls), and this increase will be associated with discourse improvement. Our findings will increase understanding of (i) tDCS effects on an evidence-based aphasia treatment provided on a spaced schedule, (ii) language network properties associated with therapy benefit, and (iii) how targeted stimulation changes this network. Thus, we will provide insight into how tDCS might be combined with current clinical practice, as well as the mechanisms through which it induces adaptive neuroplasticity to produce meaningful functional outcomes in aphasia.!