RESUMO
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.
RESUMO
Objective To study the activated status of insula during the performance of word generation task, and to explore the function of different part of insula with functional MRI (fMRI). Methods Twenty-eight subjects were recruited in this study (male 15, female 13), all of them underwent block-designed fMRI with word generation tasks and resting-state scan. SPM 5 and REST 1.3 were used to process the data. Bilateral anterior insula and posterior insula were selected as seeds to calculate the connectivity coefficiency with other voxels, and differences between the anterior and the posterior insula were compared. Results Bilateral anterior insula was significantly activated, while bilateral posterior insula was significantly deactivated. The functional connectivity areas with left anterior insula included right anterior insula, right posterior insula, supplementary motor area (SMA), left superior temporal gyrus, left middle frontal gyrus, left superior frontal gyrus, left inferior parietal lobe, middle cingulate gyrus, right striatum and right inferior frontal gyrus. The functional connectivity areas with left posterior insula included right posterior insula, left anterior insula, right superior temporal gyrus, middle cingulate gyrus, right precentral gyrus and right striatum. The functional connectivity areas with right anterior insula included SMA, left inferior frontal gyrus, right inferior parietal lobe, left inferior parietal lobe, left superior temporal gyrus, right precentral gyrus, right striatum, middle cingulate gyrus, left middle frontal gyrus, left striatum, right middle frontal gyrus, right inferior frontal gyrus and left transverse temporal gyrus. The functional connectivity areas with right posterior insula included right precentral gyrus, left superior temporal gyrus, left anterior insula, left posterior insula, right supramarginal gyrus and middle cingulate gyrus. Conclusion Anterior insula and posterior insula are functionally connected with different areas, and concerned with the language function in different manners. Left lateral anterior insula may play an important role in the language function.