Guo Wenbin, Liu Feng, Chen Jindong, Wu Renrong, Li Lehua, Zhang Zhikun, Chen Huafu, Zhao Jingping
Department of Psychiatry, the Second Xiangya Hospital, Central South University, Changsha, Hunan Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, Sichuan Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, Hunan, China Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, Hunan Sheng National Clinical Research Center on Mental Disorders, Changsha, Hunan, China National Technology Institute on Mental Disorders, Changsha, Hunan, China Hunan Key Laboratory of Psychiatry and Mental Health, Changsha, Hunan, China.
Medicine (Baltimore). 2017 Mar;96(13):e6223. doi: 10.1097/MD.0000000000006223.
Abnormal regional activity and functional connectivity of the default-mode network (DMN) have been reported in schizophrenia. However, previous studies may have been biased by unmatched case-control design. To limit such bias, the present study used both the family-based case-control design and the traditional case-control design to investigate abnormal regional activity of the DMN in patients with schizophrenia at rest.Twenty-eight first-episode, drug-naive patients with schizophrenia, 28 age-, sex-matched unaffected siblings of the patients (family-based controls, FBC), and 40 healthy controls (HC) underwent resting-state functional magnetic resonance imaging (fMRI) scans. The group-independent component analysis and fractional amplitude of low-frequency fluctuation (fALFF) methods were used to analyze the data.Patients with schizophrenia show increased fALFF in an overlapped region of the right superior medial prefrontal cortex (MPFC) relative to the FBC and the HC. Compared with the HC, the patients and the FBC exhibit increased fALFF in an overlapped region of the left posterior cingulate cortex/precuneus (PCC/PCu). Furthermore, the z values of the 2 overlapped regions can separate the patients from the FBC/HC, and separate the patients/FBC from the HC with relatively high sensitivity and specificity.Both the family-based case-control and traditional case-control designs reveal hyperactivity of the DMN in first-episode, drug-naive patients with paranoid schizophrenia, which highlights the importance of the DMN in the neurobiology of schizophrenia. Family-based case-control design can limit the confounding effects of environmental factors in schizophrenia. Combination of the family-based case-control and traditional case-control designs may be a viable option for the neuroimaging studies.
精神分裂症患者已被报道存在默认模式网络（DMN）的异常区域活动和功能连接。然而，以往的研究可能因病例对照设计不匹配而存在偏差。为了限制这种偏差，本研究采用基于家系的病例对照设计和传统病例对照设计，来研究精神分裂症患者静息状态下DMN的异常区域活动。28例首发、未用药的精神分裂症患者、28例年龄和性别匹配的患者未患病同胞（家系对照，FBC）以及40例健康对照（HC）接受了静息态功能磁共振成像（fMRI）扫描。采用组独立成分分析和低频振幅分数（fALFF）方法对数据进行分析。与FBC和HC相比，精神分裂症患者右侧额内侧前额叶皮质（MPFC）重叠区域的fALFF增加。与HC相比，患者和FBC在左侧后扣带回皮质/楔前叶（PCC/PCu）重叠区域的fALFF增加。此外，这两个重叠区域的z值能够以相对较高的敏感性和特异性将患者与FBC/HC区分开，并将患者/FBC与HC区分开。基于家系的病例对照设计和传统病例对照设计均显示，首发、未用药的偏执型精神分裂症患者存在DMN功能亢进，这突出了DMN在精神分裂症神经生物学中的重要性。基于家系的病例对照设计可以限制环境因素在精神分裂症中的混杂效应。基于家系的病例对照设计与传统病例对照设计相结合可能是神经影像学研究的一个可行选择。
