Brain Connectivity Supporting Language Recovery in Aphasia

描述（由申请人提供）：失语症是一种语言处理障碍，是与中风相关的常见疾病。失语症的标志性缺陷是无法命名物体或人（命名障碍）。许多慢性失语症患者可以通过命名疗法改善，但治疗并不普遍有效。如果能更好地理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提供有关康复期间支持大脑可塑性的机制的关键信息。我们的研究小组先前已经证明，治疗引起的命名改善主要与左半球大脑皮层的功能调节有关。因此，左半球皮质区域的结构损伤是恢复的限制因素。尽管如此，大脑皮层的保存 不能完全预测治疗后的恢复。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，并且无法改善。这种明显的不一致性可能与脑标测技术的局限性以及我们迄今无法确定中风后脑损伤的程度和位置有关。具体来说，皮质区域可能由于白色物质丢失而断开。传统的评估工具低估了皮质分离，但它可能在命名恢复中起着重要作用，因为它阻止了治疗期间备用皮质区的招募。随着大脑绘图方法的改进，这一假设可以直接得到验证。现在可以使用磁共振扩散张量成像来绘制整个大脑（大脑连接体）中的神经连接。在这个项目中，我们开发了优化的连接组映射技术，以评估因既往中风而失语的患者的神经连接。我们的目的是研究皮质坏死和皮质切断对慢性命名障碍和治疗诱导的命名恢复的影响。该提案利用了来自失语症大型前瞻性治疗试验的高质量成像和行为数据，以具有成本效益的方式实现我们的目标。我们将评估左半球的特定区域，这些区域与命名过程中的词汇语义提取和语音处理有关。我们还将创建一个临床量表，用于基于对皮质损伤和皮质连接的个性化评估来预测治疗结果，倡导根据每个患者的个性化大脑网络配置文件来治疗每个患者。

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.