Nakajima Riho, Osada Takahiro, Kinoshita Masashi, Ogawa Akitoshi, Okita Hirokazu, Konishi Seiki, Nakada Mitsutoshi
Department of Occupational Therapy, Faculty of Health Science, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan.
Department of Neurophysiology, Juntendo University School of Medicine, Tokyo, Japan.
Hum Brain Mapp. 2024 Aug 1;45(11):e26801. doi: 10.1002/hbm.26801.
Damage to the posterior language area (PLA), or Wernicke's area causes cortical reorganization in the corresponding regions of the contralateral hemisphere. However, the details of reorganization within the ipsilateral hemisphere are not fully understood. In this context, direct electrical stimulation during awake surgery can provide valuable opportunities to investigate neuromodulation of the human brain in vivo, which is difficult through the non-invasive approaches. Thus, in this study, we aimed to investigate the characteristics of the cortical reorganization of the PLA within the ipsilateral hemisphere. Sixty-two patients with left hemispheric gliomas were divided into groups depending on whether the lesion extended to the PLA. All patients underwent direct cortical stimulation with a picture-naming task. We further performed functional connectivity analyses using resting-state functional magnetic resonance imaging (MRI) in a subset of patients and calculated betweenness centrality, an index of the network importance of brain areas. During direct cortical stimulation, the regions showing positive (impaired) responses in the non-PLA group were localized mainly in the posterior superior temporal gyrus (pSTG), whereas those in the PLA group were widely distributed from the pSTG to the posterior supramarginal gyrus (pSMG). Notably, the percentage of positive responses in the pSMG was significantly higher in the PLA group (47%) than in the non-PLA group (8%). In network analyses of functional connectivity, the pSMG was identified as a hub region with high betweenness centrality in both the groups. These findings suggest that the language area can spread beyond the PLA to the pSMG, a hub region, in patients with lesion progression to the pSTG. The change in the pattern of the language area may be a compensatory mechanism to maintain efficient brain networks.
后语言区（PLA）即韦尼克区受损会导致对侧半球相应区域的皮质重组。然而，同侧半球内重组的细节尚未完全明了。在此背景下，清醒手术期间的直接电刺激可为研究活体人类大脑的神经调节提供宝贵机会，而这通过非侵入性方法很难实现。因此，在本研究中，我们旨在探究同侧半球内PLA的皮质重组特征。62例左侧半球胶质瘤患者根据病变是否扩展至PLA进行分组。所有患者均接受了伴有图片命名任务的直接皮质刺激。我们还对部分患者进行了静息态功能磁共振成像（MRI）的功能连接分析，并计算了脑区网络重要性指标——中介中心性。在直接皮质刺激期间，非PLA组中表现出阳性（受损）反应的区域主要位于颞上回后部（pSTG），而PLA组中的这些区域则从pSTG广泛分布至缘上回后部（pSMG）。值得注意的是，PLA组中pSMG的阳性反应百分比（47%）显著高于非PLA组（8%）。在功能连接的网络分析中，pSMG在两组中均被确定为具有高中介中心性的枢纽区域。这些发现表明，在病变进展至pSTG的患者中，语言区可从PLA扩展至枢纽区域pSMG。语言区模式的改变可能是维持有效脑网络的一种代偿机制。
