阻塞性睡眠呼吸暂停综合征患者频率依赖的低频振幅的静息态功能磁共振研究

Frequency-Dependent Alterations in the Amplitude of Low Frequency Fluctuations in Patients with Obstructive Sleep Apnea Syndrome:a Resting-State Functional MRI Study

目的 探讨阻塞性睡眠呼吸暂停综合征（OSAS）患者静息态不同频段下低频振幅（ALFF）脑自发活动的特点。方法 40例OSAS患者及40名正常睡眠志愿者（GS）进行静息态下脑功能磁共振（f MRI）数据采集。计算两个频段slow-4（0.027~0.073 Hz）和slow-5（0.01~0.027 Hz）ALFF信号值。采用SPM8软件进行两因素水平方差分析比较组间及频段间主效应ALFF值的差异。采用两样本t检验分别比较组间两个频段ALFF值的差异,同时分析ALFF值差异脑区与临床量表的相关性。结果 与GS组相比,OSAS组双侧楔前叶、后扣带回、左侧颞中回、右侧角回及顶下小叶ALFF值显著减低（P﹤0.05）;而双侧颞下回、梭状回、左侧眶部额下回、颞上极及双侧辅助运动区ALFF值显著增高（P﹤0.05）。与slow-5频段相比,slow-4频段左侧颞上极ALFF值显著增高;而左侧眶部额下回,双侧额中回,直回ALFF值显著减低。OSAS患者组slow-4频段比slow-5频段显示更广泛ALFF差异脑区包括右侧角回、顶下小叶,双侧颞中回及额中回,左侧眶部额下回。结论 OSAS患者存在多个脑区神经元内在自发活动异常,部分脑区脑自发活动存在频率依赖性,slow-4频段对检测OSAS患者的脑自发活动更敏感。

Objective The aim of this study was to investigate whether there were abnormalities of amplitude of low fre- quency fluctuation （ALFF） with different frequency bands in patients with obstructive sleep apnea syndrome （OSAS） dur- ing the resting state. Methods Forty untreated severe OSAS male patients and 40 male good sleepers （GS） were includ- ed in this study. Two frequency bands （ slow-5 ： 0.01 - 0. 027 Hz ; slow-4 ： 0. 027 - 0. 073 Hz） were analyzed. To examine the effects of group and frequency band in ALFF, a two way measure analysis of variance （ANOVA） was used by SPMS. Two-sample t tests were compared between two groups in different frequency bands. Pearson correlation analysis was performed between the brain areas of abnormal ALFF and clinical symptoms in OSAS patients. Results were compared between the GS and OSAS groups and the latter had a significantly decreased ALFF in bilateral precuneus, posterior cingulate cortex, left middle temporal gyrus, right angular gyrus, inferior parietal lohule. OSAS patients had a significantly increased ALFF in the bilateral superior temporal gyrus, fusiform gyrus, left orbit inferior frontal gyrus, superior temporal gyrus and bilateral supplementary motor areas, Compared with the slow-5 band, slow-4 band had a significantly higher ALFF value in the upper pole of left temporal; and had a significantly lower ALFF value in the left orbit inferior frontal gyrus, bilateral middle frontal gyrus, rectus gyrus. Significant differences in ALFF were observed between the two bands in widespread regions including the right angular gyrus, inferior parietal lobule, bilateral middle temporal gyrus, middle frontal gyrus and left orbit inferior frontal gyrus in OSAS patients. Conclusion OSAS patients have widespread abnormal intrinsic neural oscillations, a portion of which are dependent on specific frequency bands. Slow-4 band is more sensitive for detecting spontaneous brain activity in OSAS patients.