抑郁症与精神分裂症患者静息态功能磁共振成像与认知功能的差异

Differences of resting-state functional magnetic resonance imaging and cognitive function between depressive and schizophrenic patients

目的探讨抑郁症与精神分裂症患者脑功能活动及认知功能损害的特点及其相关性。方法对健康对照组、抑郁症组及精神分裂症组(每组各36例)患者进行数字符号测试(digital symbol test,DST)、数字广度测试(digital span test,DSPT)和语言流畅性测试(verbal fluency test,VFT),同时行静息态功能磁共振成像(resting-state functional magnetic resonance imaging,rs-fMRI)扫描,对rs-fMRI数据进行常规预处理,计算3组局部一致性(regional homogeneity,ReHo)及比率低频振幅(fractional amplitude of low frequency fluctuation,fALFF)值,分别比较3组认知功能测评及脑功能活动特点,采用Pearson相关分析认知功能与脑功能活动的相关性。结果(1)与健康对照组(68.75±10.40、9.22±1.07、5.95±1.67、22.39±4.53)比较,抑郁症组(60.86±10.75、8.06±0.80、5.19±1.12、19.36±2.85)与精神分裂症组(46.64±9.50、7.50±0.91、4.08±1.05、14.86±3.78)DST、DSPT顺背、DSPT倒背及VFT评分均下降,精神分裂症组较抑郁症组下降更显著(F=2.39、1.43、1.52、2.16,均P<0.01);(2)3组ReHo值存在差异的脑区为左侧豆状核-脑岛-罗兰岛盖(F=22.1,P<0.001,AlphaSim校正,体素个数>99),与健康对照组相比,抑郁症组在该脑区ReHo值升高,与抑郁症组相比,精神分裂症组在该脑区ReHo值降低。3组fALFF值存在差异的脑区为左侧顶上回及双侧脑岛-豆状核(F=28.46,13.12,P<0.001,AlphaSim校正,体素个数>90),与健康对照组和抑郁症组相比,精神分裂症组在左侧顶上回及双侧脑岛-豆状核的fALFF值均升高(P<0.05);(3)相关分析显示,抑郁症患者DST评分与左侧豆状核-脑岛-罗兰岛盖区ReHo值呈负相关(r=-0.38,P=0.02);精神分裂症患者DSPT倒背评分与脑岛-豆状核的fALFF值呈负相关(r=-0.39,P=0.02)。结论精神分裂症较抑郁症患者认知功能损害更为严重;抑郁症及精神分裂症患者顶叶、脑岛及纹状体活动异常,这些功能活动异常脑区可能是区分精神分裂症与抑郁症的核心脑区,且与认知功能损害密切相关。

Objective To compare the characteristics and correlation of brain activity and cognitive function between depression and schizophrenia.Methods 36 normal controls(NC),major depression disorder(MDD)and schizophrenia(SZ)patients participated in this study.Digital symbol test(DST),digital span test(DSPT),and verbal fluency test(VFT)were performed.All subjects underwent resting-state fMRI.Routine preprocessing of resting-state fMRI data was performed.The regional homogeneity(ReHo)and fractional amplitude of low frequency fluctuation(fALFF)values were calculated.Cognitive function assessment and brain functional activity characteristics were compared among the three groups.Pearson correlation was used to analyze the correlation between cognitive impairment and brain functional activity.Results(1)Compared with NC(68.75±10.40,9.22±1.07,5.95±1.67,22.39±4.53),DST,DSPT and VFT scores decreased in MDD(60.86±10.75,8.06±0.80,5.19±1.12,19.36±2.85)and SZ(46.64±9.50,7.50±0.91,4.08±1.05,14.86±3.78).The decline was more significant in the schizophrenia group(F=2.39,1.43,1.52,2.16,P<0.01).(2)Significant differences of the ReHo values in the three groups were all in the left lentiform nucleus-insula-Roland′s island(F=22.1,P<0.001,AlphaSim correction,voxel number>99),with higher ReHo value in MDD,while lower in SZ.Significant differences of fALFF value in the three groups were in the left superior parietal areas and bilateral insula-lentiform nucleus(F=28.46,13.12,P<0.001,AlphaSim correction,voxel number>90).Compared with MDD and NC,SZ showed higher fALFF value in the left superior parietal areas and the bilateral insula-lentiform nucleus(P<0.05).(3)The results of correlation analysis showed that DST score of MDD was negatively correlated with ReHo value in the left lentil-insula region(r=-0.38,P=0.02).DSPT score was negatively correlated with fALFF value in insula-lentiform nucleus in SC(r=-0.39,P=0.02).Conclusion The cognitive impairment of schizophrenia is more serious than that of depression;Abnormal activity of parietal lobe,insula and striatum can be prominent in both depressive and schizophrenias patients,and the three brain regions might be the key locations that distinguish schizophrenia from depression in terms of the cognitive impairment.