Brain Connectivity Supporting Language Recovery in Aphasia

描述(申请人提供)：失语症是一种语言处理障碍，是一种与中风相关的常见疾病。失语症的标志缺陷是不能说出物体或人的名字(失调症)。许多慢性失语症患者可以通过命名疗法改善，但治疗并不是普遍有效。如果更好地了解治疗效果差异的原因，就可以开发一种工具来识别最有潜力改善的患者。此外，更好地了解语言恢复的预测因素可以为康复过程中支持大脑可塑性的机制提供关键信息。我们的小组之前已经证明，由于治疗而导致的命名改善主要与左半球大脑皮层的功能调节有关。由此可见，左半球皮质区域的结构性损伤是恢复的限制因素。尽管如此，大脑皮层的保存 不能完全预测治疗诱导的康复。一些皮质结构明显完整的患者在治疗期间无法招募这些区域，也无法改善。这种明显的不一致可能与大脑地形图技术的局限性以及我们到目前为止无法确定中风后脑损伤的程度和位置有关。具体地说，由于白质丢失，皮质区域可能会断开连接。传统的评估工具低估了皮质断开，但它可能在命名恢复方面发挥重要作用，因为它阻止了治疗期间备用皮质区域的招募。随着脑图方法的新改进，这一假说可以直接得到检验。现在可以使用磁共振扩散张量成像绘制整个大脑(大脑连接体)的神经连接图。在这个项目中，我们开发了优化的连接组图技术来评估因既往中风而患失语症的患者的神经连接性。我们的目的是调查皮质坏死和皮质断开对慢性命名障碍和治疗诱导的命名恢复的影响。这项建议利用了一项大规模的失语症前瞻性治疗试验的高质量成像和行为数据，以成本效益的方式实现了我们的目标。我们将评估在命名过程中与词汇-语义提取和语音处理相关的左半球特定区域。我们还将根据对皮质损伤和皮质连通性的个性化评估，创建用于预测治疗结果的临床量表，倡导根据每个患者的个性化脑网络概况进行治疗。

DESCRIPTION (provided by applicant): Aphasia, an impairment in language processing, is a common disorder associated with stroke. The hallmark deficit of aphasia is the inability to name objects or people (anomia). Many patients with chronic aphasia can improve with naming therapy, but treatment is not universally effective. If the reason for differences in treatment effectiveness were better understood, an instrument could be developed to identify the patients who have the greatest potential to improve. Furthermore, a better understanding of the predictors for language recovery could provide crucial information about the mechanisms supporting brain plasticity during rehabilitation. Our group has previously demonstrated that naming improvements due to therapy are primarily associated with functional modulation of the cerebral cortex in the left hemisphere. It follows that structural damage to cortical regions in th left hemisphere is a limiting factor for recovery. Nonetheless, preservation of the cerebral cortex cannot fully predict therapy-induced recovery. Some patients with apparently intact cortical structures are not able to recruit these areas during therapy and fail to improve. This apparent inconsistency may be related to limitations in brain mapping techniques and our hitherto inability to define the extent and location of brain damage after stroke. Specifically, cortical regions may be disconnected as a result of white matter loss. Conventional assessment tools underappreciate cortical disconnection, but it likely plays an important role in naming recovery because it prevents recruitment of spared cortical areas during therapy. With new methodological improvements in brain mapping, this hypothesis can be directly tested. It is now possible to chart neural connections in the entire brain (the brain connectome) using magnetic resonance diffusion tensor imaging. For this project, we developed optimized connectome-mapping techniques to assess neural connectivity in patients with aphasia due to a previous stroke. We aim to investigate the impacts of cortical necrosis and cortical disconnection on chronic naming impairments and treatment-induced naming recovery. This proposal leverages high-quality imaging and behavioral data from a large prospective treatment trial in aphasia to accomplish our goals in a cost-effective manner. We will assess specific regions in the left hemisphere that have been associated with lexical-semantic retrieval and phonological processing during naming. We will also create a clinical scale for the prediction of treatment outcome based on a personalized assessment of cortical damage and cortical connectivity, advocating for each patient to be treated according to their individualized brain network profile.