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

项目摘要/摘要 失语症是一种大脑疾病，最常发生在中风后，影响多模式语言 超能力。人类是植根于社会的生物，因此沟通上的缺陷会产生巨大的影响 关于职业潜力和生活质量。尽管行为的好处是明确的和可量化的 言语语言治疗，他们仍然达不到治愈的效果，甚至达不到理想的恢复水平。一种方法 增加这种疗法的好处是将它们与经颅直流电刺激(Tdcs)相结合。 虽然这种方法已被证明可以改进命名，但人们对以下方面的了解有限 这种神经调节干预可以补充行为治疗，以提高话语技能和 功能沟通。对于在临床上可行的时间表上提供的治疗而言尤其如此(即， 分散的而不是集中的练习)。在这个项目中，我们采取了一种创新的方法来研究这些影响 在失语症参与者的一项先导性研究中，tdcs对语篇产生的影响。我们将活动或假tdcs与 动词网络强化疗法(VNeST)，一种已被证明具有重要意义的行为疗法 使用间隔的治疗计划来改善话语。此外，我们使用tdcs协议，它具有 在我们的初步工作中证明了间隔治疗的好处。目标1确定 将活跃的tDCs与间隔话语治疗配对，与接受相同治疗的组进行比较 假刺激。这个项目的另一个目标是获取神经成像数据，以告知机制 通过识别与行为变化相关的图论网络属性来实现tDCS效应；我们使用泛函 磁共振成像(FMRI)使用自适应语义识别每个人的语言网络 范例。在AIM 2A中，我们通过计算两种方法来检验成像测量作为tDCS效应的潜在预测因子 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，与匹配的控制组更相似的治疗前组织将预测更大的 从治疗中受益，尤其是积极的刺激。在AIM 2B中，我们评估了治疗后的变化 语言网络，包括tdcs目标区域(下额叶)的功能连通性变化 脑回；IFG)。我们预测，IFG在这个网络中的介数中心度将显著增加 在任务和休息时，主动刺激组与假刺激组比较(接近对照组)，以及 这一增长将与语篇的改善有关。我们的发现将增加对(I)的理解 Tdcs对循证失语治疗的影响，(Ii)语言网络 与治疗相关的特性有益，以及(Iii)靶向刺激如何改变这一网络。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，在失语症患者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.!