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

项目概要/摘要 失语症是一种脑部疾病，最常发生在中风后，影响多模式语言 能力。人类是社会性生物，因此沟通缺陷会产生巨大影响 职业潜力和生活质量。尽管行为的好处是明确且可量化的 言语语言治疗中，他们仍然达不到治愈的目标，甚至达不到预期的恢复水平。一种方法是 增加此类疗法的好处是将它们与经颅直流电刺激（tDCS）相结合。 尽管这种方法已被证明可以改善命名，但对于其改善程度的了解有限。 这种神经调节干预可以补充行为治疗，以有益于言语技能和 功能性沟通。对于按临床可行的时间表提供的治疗尤其如此（即， 间隔练习而不是集中练习）。在这个项目中，我们采用创新方法来研究其影响 在失语症参与者的试点研究中，tDCS 对话语产生的影响。我们将主动或假 tDCS 与 动词网络强化治疗（VNeST）是一种行为疗法，已被证明具有显着的效果 使用间隔治疗计划改善话语。此外，我们使用 tDCS 协议 在我们的前期工作中证明了间隔治疗的好处。 AIM 1 确定行为影响 将主动 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。该项目的另一个目标是获取神经影像数据以告知机制 通过识别与行为变化相关的图论网络属性来产生 tDCS 效应；我们使用函数式 磁共振成像 (fMRI) 使用自适应语义识别每个人的语言网络 范式。在 AIM 2A 中，我们通过计算两个值来检查成像测量作为 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（整合和分离）的关键特征。我们然后 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，与匹配对照组更相似的治疗前组织将预测更大的结果。 从治疗中获益，特别是主动刺激。在 AIM 2B 中，我们评估了治疗后的变化 语言网络，包括 tDCS 目标区域功能连接的变化（额下叶） 脑回；国际金融集团）。我们预测 IFG 在该网络中的介数中心性将显着增加 与假手术组相比，主动刺激组在任务和休息期间（接近对照组），以及 这种增长将与话语的改善相关。我们的研究结果将加深对 (i) 的理解 tDCS 对按时间间隔提供的循证失语症治疗的影响，(ii) 语言网络 与治疗效果相关的特性，以及 (iii) 针对性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，从而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.!