Zhang Chao, Xia Yingying, Feng Tao, Yu Ke, Zhang Haiyan, Sami Muhammad Umair, Xiang Jie, Xu Kai
Department of Radiology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China.
Department of Rehabilitation, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China.
Front Neurosci. 2021 Dec 1;15:746264. doi: 10.3389/fnins.2021.746264. eCollection 2021.
Post-stroke aphasia (PSA) results from brain network disorders caused by focal stroke lesions. However, it still remains largely unclear whether the impairment is present in intra- and internetwork functional connectivity (FC) within each resting-state network (RSN) and between RSNs in the subacute stage of PSA. This study aimed to investigate the resting-state FC within and between RSNs in patients with PSA and observe the relationships between FC alterations and Western Aphasia Battery (WAB) measures. A total of 20 individuals with subacute PSA and 20 healthy controls (HCs) were recruited for functional MRI (fMRI) scanning, and only patients with PSA underwent WAB assessment. Independent component analysis was carried out to identify RSNs. Two-sample -tests were used to calculate intra- and internetwork FC differences between patients with PSA and HCs. The results were corrected for multiple comparisons using the false discovery rate (FDR correction, < 0.05). Partial correlation analysis was performed to observe the relationship between FC and WAB scores with age, gender, mean framewise displacement, and lesion volume as covariates ( < 0.05). Compared to HCs, patients with PSA showed a significant increase in intranetwork FC in the salience network (SN). For internetwork FC analysis, patients showed a significantly increased coupling between left frontoparietal network (lFPN) and SN and decreased coupling between lFPN and right frontoparietal network (rFPN) as well as between lFPN and posterior default mode network (pDMN) (FDR correction, < 0.05). Finally, a significant positive correlation was found between the intergroup difference of FC (lFPN-rFPN) and auditory-verbal comprehension ( < 0.05). Altered FC was revealed within and between multiple RSNs in patients with PSA at the subacute stage. Reduced FC between lFPN and rFPN was the key element participating in language destruction. These findings proved that PSA is a brain network disorder caused by focal lesions; besides, it may improve our understanding of the pathophysiological mechanisms of patients with PSA at the subacute stage.
中风后失语症（PSA）由局灶性中风病变引起的脑网络障碍所致。然而，在PSA亚急性期，各静息态网络（RSN）内以及RSN之间的网络内和网络间功能连接（FC）是否存在损伤仍不清楚。本研究旨在调查PSA患者RSN内和RSN之间的静息态FC，并观察FC改变与西方失语症成套测验（WAB）测量结果之间的关系。共招募了20例亚急性PSA患者和20名健康对照（HC）进行功能磁共振成像（fMRI）扫描，且仅对PSA患者进行WAB评估。采用独立成分分析来识别RSN。使用双样本t检验计算PSA患者与HC之间的网络内和网络间FC差异。结果采用错误发现率进行多重比较校正（FDR校正，P<0.05）。进行偏相关分析以观察FC与WAB评分之间的关系，将年龄、性别、平均帧位移和病变体积作为协变量（P<0.05）。与HC相比，PSA患者突显网络（SN）内的网络内FC显著增加。对于网络间FC分析，患者左侧额顶叶网络（lFPN）与SN之间的耦合显著增加，lFPN与右侧额顶叶网络（rFPN）之间以及lFPN与后默认模式网络（pDMN）之间的耦合减少（FDR校正，P<0.05）。最后，发现FC的组间差异（lFPN - rFPN）与听觉语言理解之间存在显著正相关（P<0.05）。在亚急性期PSA患者的多个RSN内和RSN之间发现了FC改变。lFPN与rFPN之间FC的降低是参与语言破坏的关键因素。这些发现证明PSA是由局灶性病变引起的脑网络障碍；此外，这可能会增进我们对亚急性期PSA患者病理生理机制的理解。
