Yang Xu, Cao Ding, Liang Xiumei, Zhao Jiannong
Department of Medical Imaging, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China.
Department of Medical Imaging, the Fifth People's Hospital of Chongqing, Chongqing, 400016, China.
Neuroradiology. 2017 Jul;59(7):699-708. doi: 10.1007/s00234-017-1844-9. Epub 2017 May 26.
Several studies have examined the relationships between diffusion tensor imaging (DTI)-measured fractional anisotropy (FA) and the symptoms of schizophrenia, but results vary across the studies. The aim of this study was to carry out a meta-analysis of correlation coefficients reported by relevant studies to evaluate the correlative relationships between FA of various parts of the brain and schizophrenia symptomatic assessments.
Literature was searched in several electronic databases, and study selection was based on précised eligibility criteria. Correlation coefficients between FA of a part of the brain and schizophrenia symptom were first converted into Fisher's z-scores for meta-analyses, and then overall effect sizes were back transformed to correlation coefficients.
Thirty-three studies (1121 schizophrenia patients; age 32.66 years [95% confidence interval (CI) 30.19, 35.13]; 65.95 % [57.63, 74.28] males) were included in this meta-analysis. Age was inversely associated with brain FA (z-scores [95% CI] -0.23 [-0.14, -0.32]; p ˂ 0.00001). Brain FA of various areas was inversely associated with negative symptoms of schizophrenia (z-score -0.30 [-0.23, -0.36]; p ˂ 0.00001) but was positively associated with positive symptoms of schizophrenia (z-score 0.16 [0.04, 0.27]; p = 0.007) and general psychopathology of schizophrenia (z-score 0.26 [0.15, 0.37]; p = 0.00001).
Although, DTI-measured brain FA is found to be inversely associated with negative symptoms and positively associated with positive symptoms and general psychopathology of schizophrenia, the effect sizes of these correlations are low and may not be clinically significant. Moreover, brain FA was also negatively associated with age of patients.
多项研究探讨了扩散张量成像（DTI）测量的分数各向异性（FA）与精神分裂症症状之间的关系，但研究结果各不相同。本研究的目的是对相关研究报告的相关系数进行荟萃分析，以评估大脑各部位FA与精神分裂症症状评估之间的相关关系。
在多个电子数据库中进行文献检索，并根据精确的纳入标准进行研究筛选。首先将大脑某一部位的FA与精神分裂症症状之间的相关系数转换为费舍尔z分数进行荟萃分析，然后将总体效应量反向转换为相关系数。
本荟萃分析纳入了33项研究（1121例精神分裂症患者；年龄32.66岁[95%置信区间（CI）30.19，35.13]；65.95%[57.63，74.28]为男性）。年龄与大脑FA呈负相关（z分数[95%CI]-0.23[-0.14，-0.32]；p＜0.00001）。大脑各区域的FA与精神分裂症的阴性症状呈负相关（z分数-0.30[-0.23，-0.36]；p＜0.00001），但与精神分裂症的阳性症状呈正相关（z分数0.16[0.04，0.27]；p = 0.007）以及精神分裂症的一般精神病理学呈正相关（z分数0.26[0.15，0.37]；p = 0.00001）。
尽管发现DTI测量的大脑FA与精神分裂症的阴性症状呈负相关，与阳性症状和一般精神病理学呈正相关，但这些相关性的效应量较低，可能不具有临床意义。此外，大脑FA也与患者年龄呈负相关。
