Stoll Harrison, Kelkar Apoorva, Turkeltaub Peter E, Hamilton Roy H, Coslett Branch, Medaglia John D
Department of Psychological and Brain Sciences, Drexel University, Philadelphia, PA, USA.
Department of Neurology, Georgetown University, Washington, DC, USA.
Neurobiol Lang (Camb). 2025 Sep 2;6. doi: 10.1162/nol.a.11. eCollection 2025.
Left hemisphere stroke causes functional changes to the language network and may shift aspects of language processing to right hemisphere homotopes of perisylvian language regions. The result of right hemisphere recruitment is unclear. Studies suggest the right pars triangularis (rPTr) engagement in language processing corresponds to higher dysfunction. As a result, the region is a site for inhibitory neuromodulation, with evidence that inhibiting the region improves language function in persons with aphasia (PWA). However, studies have also found no relationship between rPTr functional activity and language performance in PWA. The mixed evidence regarding the rPTr suggests additional work is needed to understand the role of the region in PWA. We propose that the white matter connections that support communication between regions may be an important mediator. Thus, we sought to investigate if left hemisphere stroke leads to changes in the structural topological properties of the region. We used measures from network control theory (NCT) to compare the theoretical capacity of the rPTr to integrate communication across brain modules (i.e., boundary controllability [BC]) in the brain, in 60 PWA and 62 controls. We also examined whether BC corresponded to different aspects of language processing (i.e., semantic and phonological) in PWA. We found that PWA had a higher BC in the rPTr relative to controls. Higher BC was associated with fewer phonological errors in a picture naming task. These findings suggest that left hemisphere stroke causes shifts in the structural role of right hemisphere regions that relate to language processing in PWA.
左半球中风会导致语言网络发生功能变化，并可能将语言处理的某些方面转移至外侧裂周语言区域的右半球同形区。右半球参与的结果尚不清楚。研究表明，右侧三角部（rPTr）参与语言处理与更高的功能障碍相对应。因此，该区域是抑制性神经调节的作用部位，有证据表明抑制该区域可改善失语症患者（PWA）的语言功能。然而，研究还发现PWA的rPTr功能活动与语言表现之间没有关系。关于rPTr的证据不一，这表明需要更多研究来了解该区域在PWA中的作用。我们认为，支持区域间交流的白质连接可能是一个重要的调节因素。因此，我们试图研究左半球中风是否会导致该区域结构拓扑特性的变化。我们使用网络控制理论（NCT）的方法，比较了60名PWA患者和62名对照者大脑中rPTr整合跨脑模块交流的理论能力（即边界可控性[BC]）。我们还研究了PWA中BC是否与语言处理的不同方面（即语义和语音）相对应。我们发现，与对照者相比，PWA患者rPTr的BC更高。在图片命名任务中，更高的BC与更少的语音错误相关。这些发现表明，左半球中风会导致PWA患者右半球与语言处理相关区域的结构作用发生变化。
