原发性闭角型青光眼不同频段低频振幅的静息态功能磁共振研究

目的：应用静息态功能磁共振(rs-fMRI)分析原发性闭角型青光眼(PACG)患者不同频段(slow-4：0.027~0.073 Hz, slow-5：0.01~0.027 Hz)大脑低频振幅(ALFF)值改变。方法40例 PACG 患者及36例年龄、性别匹配的正常健康对照(HC)均接受 rs-fMRI 检查,应用 rs-fMRI 数据处理助手(DPARSF)对数据进行预处理。Statistical Parametric Mapping (SPM8)2因素水平重复方差分析比较 PACG 及 HC 组组间效应以及 slow-4,slow-5频段间效应。随后,两样本 t 检验分别比较 PACG 组及 HC 组2个频段 ALFF 值差异并分析差异脑区 ALFF 值与临床参数的相关性。结果频段间结果显示右侧尾状核、左侧眶部额下回 slow-5频段的 ALFF 值较 slow-4频段高(P <0.05,FDR 校正)。与 HC 组相比,楔前叶、楔叶、双侧舌回、双侧枕中回、双侧距状裂、双侧中央后回、右侧中央前回、右侧颞中回、右侧额中回、双侧顶上小叶、右侧中央旁小叶、左侧顶下小叶 ALFF 减低；PACG 组 ALFF 值增高的脑区包括左侧颞下回、左侧颞上回、左侧小脑后叶、双侧海马旁回、左侧额下回、右侧边缘叶、右侧岛叶、后扣带回(P <0.05, FDR 校正)。此外,笔者发现 slow-4、slow-5频段均能检出 PACG 患者异常脑功能活动区。结论PACG 患者存在视觉以及视觉以外相关脑区神经元活动异常,slow-4、slow-5能从不同的角度发现异常脑区,为进一步探究 PACG 的神经病理机制提供了新思路。

Frequency-dependent alterations in the amplitude of low-frequency fluctuations in primary angle-closure glaucoma:a resting-state fMRI study

Objective To investigate the altered amplitude of low-frequency fluctuation (ALFF)of the brain using resting-state functional magnetic resonance imaging (rs-fMRI)within different band of fluctuation(slow-4:0.027-0.073 Hz,slow-5:0.01 -0.027 Hz) in patients with primary angle-closure glaucoma (PACG).Methods Forty PACG patients and thirty-six age-,gender-rmatched healthy controls (HC)were included in the rs-fMRI scans.The data preprocessing was performed using Data Processing Assistant For Resting-state (DPARSF).A two-way repeated-measures ANOVA were performed using SPM8 to analyze the effects of group (PACG,HC) and frequency band (slow-4,slow-5 ).Then,two-sample t tests were performed to observe the ALFF between PACG and HC in slow-4 and slow-5 and the correlations between ALFF values and the ophthalmologic measurements were analyzed.Results Regional differences in ALFF at two bands showed that right caudate nucleus,the left inferior orbitofrontal gyrus had increased ALFF in slow-5band compared to slow-4 (P<0.05,FDR corrected).Compared to HC,the precuneus,cuneus,bilateral lingual gyrus,bilateral middle occipital gyrus,bilateral calcarine,bilateral postcentral gyrus,right precentral,right middle temporal gyrus,right middle frontal gyrus,bilateral superior parietal lobule,right paracentral lobule,left inferior parietal lobule showed decreased ALFF,meanwhile,left superior and inferior temporal gyrus,left cerebellum posterior lobe,bilateral parahippocampa gyrus,left inferior frontal gyrus,right limbic lobe,right insula,posterior cingulated showed increased ALFF (P <0.05,FDR corrected).Furthermore,PACG exhibited abnormal brain function in both slow-4 and slow-5 bands. Conclusion PACG patients have abnormal neurons activity within and beyond the visual pathway,slow-5 band and slow-4 band can detect brain abnormalities from a different perspective,it provides new insights into the understanding of the pathological changes of PACG.