脑梗死运动性失语后静息态功能 MRI功能连接的初步研究

Resting-state functional connectivity in post-stroke expressive aphasia：a preliminary study

目的：采用静息态功能MRI技术，分析正常人静息态下左侧额下回后部的功能连接，并初步探讨该技术在脑梗死运动性失语患者中的应用。方法采用1.5 T MR扫描仪对11例男性脑梗死运动性失语患者和11名男性正常志愿者行静息态fMRI数据采集。应用统计参数图（SPM）2、功能神经成像分析（ AFNI）、矩阵实验室（ MATLAB）等软件进行预处理和统计分析，基于词语联想任务脑激活结果选择左侧额下回后部作为种子点，与全脑其他所有体素的时间序列做相关分析。采用单样本t检验和两样本t检验进行组内和组间分析。结果对照组在静息状态下与左侧额下回后部语言中枢正相关的脑区包括左侧额下回、左侧额中回、左侧运动前区、左侧楔前叶、左岛叶、左侧壳核、右侧额下回、右侧小脑半球、双侧顶下小叶（体素范围33～809，t值为5.80～23.55，P值均＜0.005）。患者组与左侧额下回后部存在功能连接的脑区包括左侧额下回、左侧额中回、左侧运动前区、左侧楔前叶、左侧顶下小叶和右侧额下回（体素范围34～833，t值为5.08～20.34，P值均＜0.005），组间分析显示患者组左侧梭状回与左侧额下回后部的功能连接低于对照组（体素84，t＝6.25，P＜0.005）。结论正常人在静息状态下存在由多个脑区构成的与语言输出功能相关的神经网络，静息态下的脑功能连接方法可用于研究脑梗死患者运动性失语发生和语言功能恢复的神经机制。

Objective To analyze the resting-state functional connectivity of the left posterior inferior frontal gyrus in normal subjects with functional MRI and to investigate its preliminary application in post-stroke aphasia.Methods Eleven male patients with post-stroke aphasia and 11 male normal subjects were recruited in this study.Resting-state fMRI data were obtained with GE 1.5 T Twin speed MR Scanner.The fMRI data were processed with SPM2, AFNI and Matlab programs.Based on the results of previous fMRI study with category member generation task , the region of interest （ ROI ） was created in the left posterior inferior frontal gyrus The time course correlations between the ROI and other voxels within whole brain were analyzed.Intra-and inter-group analysis was performed with single sample t-test and two sample t-test.Results Brain regions showed positive resting-state functional connectivity with the ROI in normal subjects including left inferior/middle frontal gyrus , left premotor cortex , left precuneus , left insula , left putamen, right inferior frontal gyrus, right cerebellum and bilateral inferior parietal lobules （voxels 33-809, t=5.80-23.55,P〈0.005,uncorrected）.Brain regions functionally connected with the ROI in patients with post-stroke aphasia included left inferior/middle frontal gyrus , left premotor cortex , left precuneus , left inferior parietal lobules and right inferior frontal gyrus （ voxels 34-833, t =5.08-20.34, P〈0.005, uncorrected ）.The left fusiform gyrus was the only region showed significantly decreased functional connectivity with the ROI in the patients group （voxels 84,t=6.25,P〈0.005, uncorrected）.Conclusions The neural network related to language output exists in normal subjects at the resting-state.Resting-state functional connectivity can be used to investigate the neural mechanism of development and restoration of post-stroke aphasia.