Data_Sheet_1_Disrupted Brain Connectivity Networks in Aphasia Revealed by Resting-State fMRI.docx

Aphasia is characterized by the disability of spontaneous conversation, listening, understanding, retelling, naming, reading, or writing. However, the neural mechanisms of language damage after stroke are still under discussion. This study aimed to investigate the global and nodal characterization of the functional networks in patients with aphasic stroke based on resting-state functional MRI (fMRI). Twenty-four right-handed patients with aphasia after stroke and 19 healthy controls (HC) underwent a 3-TfMRI scan. A whole-brain large-scale functional connectivity network was then constructed based on Power's atlas of 264 functional regions of interest, and the global and nodal topological properties of these networks were analyzed using graph theory approaches. The results showed that patients with aphasia had decreased in small-worldness (sigma), normalized clustering coefficient (gamma), and local efficiency (Eloc) values. Furthermore, Eloc was positively correlated with language ability, retelling, naming, and listening comprehension in patients with aphasia. Patients with aphasia also had decreased nodal degree and decreased nodal efficiency in the left postcentral gyrus, central opercular cortex, and insular cortex. Our results suggest that the global and local topology attributes were altered by injury in patients with aphasic stroke. We argue that the local efficiency of brain networks might be used as a potential indicator of basic speech function in patients with aphasia.

失语症以自发交谈、听力、理解、复述、命名、阅读或写作能力的障碍为特征。然而，中风后语言损伤的神经机制仍存在争议。本研究旨在基于静息态功能磁共振成像（fMRI）探究失语性中风患者功能网络的全球和节点特征。二十四名中风后失语的右利手患者和十九名健康对照者接受了3T fMRI扫描。随后，基于Power的包含264个感兴趣区域的脑功能图谱，构建了一个全脑大规模功能连接网络，并利用图论方法分析了这些网络的全球和节点拓扑属性。结果显示，失语症患者的小世界性（sigma）、正常化的聚类系数（gamma）和局部效率（Eloc）值均有所下降。此外，Eloc与失语症患者的语言能力、复述、命名和听力理解呈正相关。失语症患者还表现出左侧后中央回、中央梭状回和岛叶皮层的节点度数和节点效率下降。我们的结果表明，失语性中风患者的全局和局部拓扑属性均受到损伤的影响。我们认为，脑网络的局部效率可能被用作评估失语症患者基本言语功能的潜在指标。