新兵适应障碍的亚频段低频振幅功能MRI研究

目的:应用亚频段低频振幅(ALFF)分析方法,研究适应障碍新兵脑静息状态下自发性神经活动改变的特点.方法:17例适应障碍新兵及20例健康军人(对照组)行静息态下脑功能MRI扫描,成像数据经后处理,获得各频段的ALFF图,采用双样本t检验比较两组间各频段ALFF值的差异,并分析ALFF值改变与患者临床量表评分之间的相关性.结果:与正常对照组比较,患者组在Slow-5亚频段ALFF值减低的脑区包括右侧小脑脚、左侧眶部额下回、左内侧前额叶、右侧额中回及双侧额上回(P＜0.01,AlphaSim校正),在Slow-4亚频段ALFF值减低的脑区有左内侧前额叶和左侧眶部额下回(P＜0.01,AlphaSim校正).患者组中各ALFF值异常脑区的ALFF值与临床量表评分间的相关性均无统计学意义(P＞0.05).结论:适应障碍新兵有多个脑区存在自发性神经活动异常,这些脑区与认知、情绪调节及执行功能有关,且不同亚频段异常活动脑区的空间分布不同.

Frequency-dependent alterations in amplitude of low-frequency fluctuations in recruits with adjustment disorder: a functional magnetic resonance imaging study

Objective:To investigate changes of spontaneous brain activity in recruits with adjustment disorders by the amplitude of low-frequency fluctuations (ALFF) on subbands.Methods:Seventeen recruits with adjustment disorder and twenty matched healthy controls were recruited and underwent brain rest state (rs)-fMRI scans.The ALFF charts of each frequency band (slow-4～slow-5) were calculated,and then two-sample t-test was used to compare the difference of ALFFs in different frequency bands between the two groups.Pearson correlation analysis was performed to analyze the correlation between the brain areas of abnormal ALFFs and clinical symptoms in patients with adjustment disorder.Results:Compared to the controls,the adjustment disorder subjects demonstrated decreased ALFFs in right cerebellum-crus,left orbit inferior frontal gyrus,left medial prefrontal cortex,right middle frontal gyrus and bilateral superior frontal gyrus in frequency band slow-5 (P＜0.01,AlphaSim corrected).The patients with adjustment disorder in frequency band slow-4 showed decreased ALFFs in left orbit inferior frontal gyrus and left medial prefrontal cortex (P＜0.01,AlphaSim corrected).Compared with the slow-4 band,the slow-5 band showed a more extensive regions with ALFF difference in abnormal spontaneous brain activity.The differences between the ALFFs in the abnormal brain areas and clinical symptoms in patients with adjustment disorder had no statistical significance (P＞0.05).Conclusion:Recruits with adjustment disorder exhibit abnormal spontaneous activity among brain regions associated with cognition,emotion regulation and executive function.Moreover,the abnormal regions exhibit different spatial patterns depending on the subbands of low-frequency fluctuations.