伴自杀观念抑郁障碍患者动态和静态低频振幅fMRI研究

Dynamic and static amplitude of low frequency fluctuation in depression patients with suicidal ideation

目的:采用动态和静态低频振幅方法fMRI探讨伴自杀观念的首发抑郁障碍患者静息状态下自发脑功能活动特征。方法:收集24例伴自杀观念(SI组)、24例不伴自杀观念(NSI组)的首发抑郁障碍患者以及24例健康志愿者(对照组)的临床量表(包括汉密尔顿抑郁量表24项和Beck自杀意念量表)评分结果和fMRI数据,采用动态和静态低频振幅(ALFF)方法分析3组间自发脑功能活动的差异,并进一步分析差异脑区的信号值与抑郁严重程度、自杀意念因子和自杀危险因子的相关性。结果:与NSI组相比,SI组右侧中扣带回动态ALFF(dALFF)的时间变异性减低。与对照组比较,SI组和NSI组左侧背外侧前额叶、右侧内侧额上回、右侧眶部额下回、左侧中央旁小叶、右侧中扣带回、左侧后扣带回、左侧海马旁回和右侧小脑后叶dALFF的时间变异性升高,左侧小脑和右侧小脑后叶的静态ALFF(sALFF)值升高,左侧舌回、左侧距状沟、右侧梭状回和右侧小脑后叶的sALFF值降低。SI组右侧小脑Ⅷ区的dALFF时间变异性与Beck自杀量表的自杀危险因子呈正相关(r=0.510,P=0.011),sALFF值与自杀意念因子和自杀危险因子呈正相关(r=0.464,P=0.022;r=0.625,P=0.001);左侧小脑Ⅳ-Ⅴ区的sALFF值与自杀危险因子呈负相关(r=-0.475,P=0.019)。结论:伴自杀观念的抑郁障碍患者存在局部脑活动的改变且与自杀危险性具有相关性,提示fMRI可在一定程度上评价伴自杀观念的抑郁障碍患者自发脑神经功能活动改的变情况。

Objective:This study was aimed to investigate the characteristic of local spontaneous brain activity under resting state in first-episode depression patients with suicidal ideation using fMRI dynamic and static amplitude of low frequency fluctuation(ALFF)methods.Methods:The clinical assessment(including Hamilton Depression scale 24-items and Beck Scale for Suicide Ideation)and fMRI data of 24 depression patients with suicidal ideation(SI group),24 depression patients without suicidal ideation(NSI group)and 24 healthy volunteers[(healthy control,HC)group]were collected.The dynamic and static ALFF based on fMRI were analyzed to discuss the differences of spontaneous brain activity among the three groups,and the correlation between the signal values of brain regions with statistical differences and the severity of depression,the factors of suicidal ideation and suicidal risk.Results:The time variability of dynamic ALFF(dALFF)in right middle cingulate gyrus of SI group was decreased compared with NSI group.Compared with HC group,SI group and NSI group showed a higher dALFF time variability in left dorsolateral prefrontal cortex,right medial superior frontal gyrus,right orbital part of the inferior frontal gyrus,left paracentral lobule,right middle cingulate gyrus,left posterior cingulate gyrus,left parahippocampus gyrus and right cerebellum posterior lobe,and higher static ALFF(sALFF)values in left cerebellum and right cerebellum posterior lobe.And the sALFF values in left lingual gyrus and calcarine sulus,and right fusiform gyrus and cerebellum posterior lobe were decreased in SI group and NSI group.In SI group,the time variability of dALFF in right cerebellum lobules Ⅷ was positively correlated with the factors of suicidal risk(r=0.510,P=0.011),and the sALFF values in right cerebellum lobules Ⅷ were positively correlated with the factors of suicidal ideation(r=0.464,P=0.022)and the factors of suicidal risk(r=0.625,P=0.001).The sALFF values in left cerebellum lobules Ⅳ-Ⅴ were negatively correlated with the factors of suicidal risk(r=-0.475,P=0.019).Conclusion:The changes of local brain activity in depression patients with suicidal ideation are in some brain regions,and the abnormal functional change in the left cerebellum anterior lobe may be associated with suicidal risk,suggesting that fRMI can be used to evaluate abnormal spontaneous neural activity in depressive patients with suicidal ideation.