左侧半球卒中后完全性失语的神经重塑机制：基于fNIRS的静息-任务态网络功能研究

关键词：脑卒中  完全性失语  功能性近红外光谱  功能连接  脑激活

Keywords:stroke  global aphasia  functional near-infrared spectroscopy  functional connectivity  brain activation

摘要：

      摘要 目的：基于多模态功能性近红外光谱（fNIRS）技术，探究左侧半球卒中后亚急性期完全性失语（GA）患者在静息态与语言任务态下的脑功能重组与神经代偿机制。 方法：纳入20例GA患者及20例健康对照者（HC）。采用高密度（63通道）fNIRS采集静息态及语言任务态（单字、词语复述和图片命名）的皮质血流信号，分析脑网络特性及脑区激活模式。 结果：与HC组相比，GA组在Broca内部及其与FEF&FPA间功能连接显著减弱，VC与PMC&SMA、Wernicke等脑区功能连接显著增强（P<0.05）。单字复述时，GA组Broca区和FEF&FPA等脑区激活明显；词语复述时，GA组FEF&FPA、DLPFC和PMC&SMA等脑区激活明显；图片命名时，GA组DLPFC、VC、FEF&FPA和S1等脑区激活明显（P<0.05）。 结论：本研究证实左侧半球卒中后GA患者的神经重塑机制在静息态下表现为经典语言网络功能连接减弱、视觉-运动网络代偿性连接增强，而在任务态下则展现出随任务难度增加，由视觉-前额叶-感觉运动网络协同介导的代偿性激活模式。

Abstract:

      Abstract Objective： To investigate brain functional reorganization and neural compensation mechanisms in patients with global aphasia （GA） during the subacute phase following left hemisphere stroke， using multimodal functional near-infrared spectroscopy （fNIRS） to assess brain activity under both resting-state and language task conditions. Method： A cohort of 20 GA patients and 20 healthy controls （HC） was included. Cortical hemodynamic signals were recorded using high-density fNIRS （63 channels） during both resting-state and language tasks， including single-word repetition， phrase repetition， and picture naming. The analysis focused on brain network characteristics and regional activation patterns. Result： Compared with the HC group， GA patients showed significantly reduced functional connectivity within Broca's area and between Broca's area and the frontal eye field and frontal pole area（FEF&FPA）， while enhanced functional connectivity was observed between the visual cortex（VC） and regions such as the premotor cortex & supplementary motor area （PMC&SMA） and Wernicke's area（P<0.05）. In single-word repetition， GA patients exhibited significant activation in Broca's area， FEF， and FPA； in phrase repetition， significant activation was observed in FEF & FPA， dorsolateral prefrontal cortex（DLPFC），and PMC & SMA； and in picture naming， activation was most prominent in DLPFC，VC，FEF&FPA， and the primary somatosensory cortex （S1）（P<0.05）. Conclusion： This study indicated that neural remodeling mechanisms in patients with GA following left hemisphere stroke are characterized by reduced functional connectivity within the classical language network and enhanced compensatory connectivity in the visual-motor network during the resting state， while exhibiting task-related compensatory activation patterns mediated by a coordinated visual-prefrontal-sensorimotor network that intensifies with increasing task difficulty.