原发性闭角型青光眼患者初级视觉皮层功能连接的静息态fMRI研究

Functional Connectivity of the Primary Visual Cortex in Primary Angle-Closure Glaucoma Patients:A Resting State Functional MRI Study

目的应用静息态功能磁共振成像(rs-fMRI)技术研究原发性闭角型青光眼(PACG)患者初级视觉皮层(PVC)功能连接的变化情况。方法选取临床确诊的PACG患者(PACG组)及与之年龄、性别相匹配的健康对照组(HC组)行3T磁共振T_1结构像及功能像扫描,最终纳入PACG组和HC组各25例进行rs-fMRI分析。磁共振数据经预处理后,以PVC中心区作为种子点,计算其与全脑体素时间序列的相关性并比较组间静息态功能连接的差异,并分析患者组显著差异脑区功能连接系数与临床变量的相关性。结果与HC组相比,PACG组左侧距状皮层(BA18)、左侧舌回(BA18)、右侧楔叶(BA18)、右侧后扣带回、右侧小脑前叶与PVC之间的功能连接减低,PVC功能连接增强的脑区包括左侧颞上回、右侧海马、右侧顶下小叶、双侧岛叶、双侧Extra-nuclear gyrus及双侧壳核(P﹤0.01,Alphasim校正)。PVC与左侧颞上回、右侧顶下小叶间增强的功能连接与视力(VA)呈正相关。结论PACG患者PVC区存在与高级视觉皮层和视觉外脑区功能连接下降,与视力相关的功能连接代偿性增强,提示PVC功能连接异常在PACG疾病进展中起重要作用。

Objective To investigate the alteration of functional connectivity of the primary visual cortex （PVC） in pri-mary angle-closure glaucoma （PACG） patients by using resting-state functional MRI （rs-fMRI）. Methods PACG pa-tients confirmed by clinical examination and age-and gender-matched healthy controls （HC） were evaluated by 3T MR u- sing TI anatomical and functional magnetic resonance imaging. Twenty-five PACG patients and 25 HC were included in the analysis of rs-fMRI. After MRI data preprocessing, the center of PVC was chosen as the seed point; calculation of its corre- lation with the time series of the whole brain voxels was then done and the differences of the resting state functional connectivity between groups were compared. The correlation between functional connectivity coefficient in significantly different brain regions of PACG patients and the clinical variables were investigated. Results Compared to HC, PACG patients showed decreased functional connectivity between the PVC and the left calcarine cortex （BA18）, left lingual gyrus （ BA18 ） , right cuneus （ BA18 ） , right posterior cingulate and right cerebellum anterior lobe. Concurrently, increased functional connectivity was found between the PVC and the left superior temporal gyms, right hippocampus, right inferior parietal lobule, bilateral insula, bilateral extra-nuclear gyrus, bilateral putamen （P 〈 0.01, Alphasim corrected）. Positive correlations were found between the Visual activity （VA） and the enhanced functional connectivity of the PVC with the left superior temporal gyrus and right inferior parietal lobule. Conclusion Decreased functional connectivity between the PVC and the senior visual cortex and extravisual brain areas was found in PACG patients, with co-existent compensatory increased functional connectivity correlated with the VA. This suggests that the abnormal functional connectivity of the PVC plays an important role in the disease progression of PACG.