Klingbeil Julian, Wawrzyniak Max, Stockert Anika, Saur Dorothee
Language and Aphasia Laboratory, Department of Neurology, University of Leipzig, Liebigstraße 20, Leipzig, Germany.
Language and Aphasia Laboratory, Department of Neurology, University of Leipzig, Liebigstraße 20, Leipzig, Germany.
Brain Cogn. 2019 Apr;131:22-33. doi: 10.1016/j.bandc.2017.08.005. Epub 2017 Aug 31.
Aphasia results both from direct effects of focal damage to eloquent cortical areas as well as dysfunction of interconnected remote areas within the language network. Resting-state functional MRI (rsfMRI) can be used to examine functional connectivity (FC) within these networks. Herein we review publications, which applied rsfMRI to understand network pathology in post stroke aphasia. A common finding in this research is an acute disruption of connectivity within the language network, which is correlated with loss of language function and tends to resolve with recovery from aphasia. All studies are limited by small sample sizes, heterogeneous patient characteristics and a wide range of analytical approaches, which further hinder deduction of common patterns across studies. One recent large-scale study examining FC and behavior across various cognitive domains, however, has made substantial progress with the description of a "network phenotype of stroke injury", which consists of a disruption of interhemispheric connectivity and reduced segregation of intrahemispheric networks. Unlike in other domains, language functions showed substantial dependence on intact left intrahemispheric connectivity (Siegel, Ramsey et al., 2016). In the future, such analyses of network pathology might support prognosis and development of effective treatment strategies in individual patients with aphasia.
失语症既源于优势皮质区域局灶性损伤的直接影响，也源于语言网络中相互连接的远隔区域功能障碍。静息态功能磁共振成像（rsfMRI）可用于检查这些网络内的功能连接（FC）。在此，我们回顾了将rsfMRI应用于理解中风后失语症网络病理学的相关出版物。该研究中的一个常见发现是语言网络内连接性的急性中断，这与语言功能丧失相关，且往往随着失语症的恢复而缓解。所有研究都受到样本量小、患者特征异质性以及广泛的分析方法的限制，这进一步阻碍了跨研究推导共同模式。然而，最近一项针对不同认知领域的FC和行为的大规模研究，在描述“中风损伤的网络表型”方面取得了重大进展，该表型包括半球间连接中断和半球内网络分离减少。与其他领域不同，语言功能对完整的左侧半球内连接有很大依赖性（Siegel、Ramsey等人，2016年）。未来，这种网络病理学分析可能有助于个体失语症患者的预后评估和有效治疗策略的制定。
