基于局部一致性的重度抑郁症患者脑静息态功能磁共振成像研究

Study of brain regional homogeneity in patients with major depressive disorder using resting-state functional MRI

目的采用脑静息态功能磁共振成像(rs-fMRI)局部一致性(ReHo)方法探讨重度抑郁症(MDD)患者脑区自发性活动特征,评价其与抑郁严重程度的相关性。方法对24例MDD患者和26例相匹配的康对照组(HC)进行rs-fMRI扫描,分析两组ReHo值,将差异显著的脑区内平均ReHo值与HAMD-17评分进行相关性分析。结果 MDD患者较HC组左侧直回、左侧海马、右侧楔前叶、右侧顶上回、左侧顶下缘角回、右侧楔叶ReHo值显著升高;右背外侧前额叶、右侧后扣带回、左侧枕下回、双侧颞下回、右侧颞上回ReHo值降低(P<0.05,Alphasim矫正)。Pearson相关分析显示两组差异脑区左侧海马ReHo值与HAMD-17评分呈正相关(r=0.593,P=0.002),右侧后扣带回ReHo值与HAMD-17评分呈负相关(r=-0.431,P=0.035)。结论 MDD患者静息态下脑功能损害主要集中于边缘系统及默认网络等多个脑区,且左侧海马与右侧后扣带回局部脑区自发活动的时间同步性与抑郁严重程度存在相关性。ReHo分析可作为抑郁症严重程度评价的潜在生物学标记。

Objective To explore the neural activity characteristics of patients with major depressive disorder(MDD) by brain regional homogeneity(ReHo) of resting state between and controls using resting-state functional magnetic resonance imaging(rs-fMRI), and analyze the relationship between the characteristics and degree of depression.Methods Twenty-four patients with MDD(MDD group) and 26 healthy controls(HC group) were scanned with 3.0 T MRI scanner. ReHo values of the two groups were analyzed, and the correlation between the values and the severity of depressive symptoms was explored. Results In the MDD group, ReHo values in the left rectus, left hippocampus, right precuneus, right superior parietal gyrus, left inferior parietal gyrus, right cuneus were significantly higher than those in HC group, and ReHo values in the right dorsolateral prefrontal corte(dl PFC), right cingulate gyrus, left inferior occipital gyrus, left inferior temporal gyrus, right superior temporal gyrus, right inferior temporal gyrus in the MDD group were significantly lower than those in HC group(P<0.05, Alphsim corrected). Pearson correlation analysis showed that the ReHo values in left hippocampus were positively correlated with the total score of HAMD-l7(r=0.593,P=0.002), and the ReHo values in right posterior cingulum were negatively correlated with the total score of HAMD-l7(r=-0.431,P=0.035). Conclusion Compared to healthy controls, abnormal brain spontaneous activity within default mode network and limbic system could emerge in major depressive patients during resting-state, which may be neurobiological substrate of major depressive disorder. Positive or negative correlation between neural activity and HAMD-17 was found in major depressive patients. This further supports the point that the abnormal activity of these areas play an important role in the pathogenesis of major depressive patients. The ReHo values in left hippocampus and right posterior cingulum may be associated with the severity of depressive symptoms.