联合运用VBM方法和DTI技术揭示精神分裂症的神经元基质

Neural Substrate of Schizophrenia Revealed by Combining Voxel-based Morphometry and Diffusion Tensor Imaging

目的:运用基于体素形态学VBM(voxel-based morphometry)方法探索未用药的首发精神分裂症患者与正常人脑结构差异,并用弥散张量成像DTI(diffusion tensor imaging)技术观察脑白质结构完整性。方法:纳入18个首发精神分裂症患者,和19个年龄性别都相符的正常人,分别采集高分辨T1WI图像和DTI图像。T1WI图像的处理采用优化的VBM方法进行全脑分析比较。结果:与健康对照组相比,首发精神分裂症患者双侧枕叶和双侧丘脑明显的灰质密度降低,左侧顶枕束、左上纵束及右扣带回后部白质密度降低。而右枕额纤维束,右胼胝体压部到右扣带回后部有相应FA值降低。结论:联合优化的VBM以及DTI图像分析技术,发现首发精神分裂症患者枕叶视辐射区,丘脑皮质回路(边缘系统)皮质以及白质完整性受损,提示在精神分裂症早期就存在边缘系统和视觉通路的神经发育异常。

Objective：To investigate abnormalities in the cerebral structure by voxel based morphometry and deficit in structural integrity of white matter as suggested by diffusion tensor imaging in first episode neuroleptics nave schizophrenia patients.Methods：High-resolution volumetric T1-weighted images and diffusion tensor images were acquired from 18 first-episode schizophrenia patients and 19 age-and gender-matched healthy control subjects. Images were processed using optimized voxel-based morphometry,which allows whole-brain analysis.Results：Compared with healthy volunteers,patients demonstrated most prominent grey matter deficit in bilateral occipital lobe and bilateral thalamus.White matter decrease was found in left occipitofrotal fasciculus,left superior longitudinal fasciculus and right posterior cingular Corresponding reduction of FA values was fond in right occipital frontal fasciculus and right splenium extended to right posterior cingular.Conclousion：The analysis of anatomical images provided evidence for macroscopical changes in cortical regions and diffusion tensor images revealed microstructural anomalies in the related white matter.These data gave convergent evidence of the disruption in occipital optic radiate area and thalamocortical circuit（limbic system）associate with schizophrenia which are highly consistent with it＇s cognitive deficit and these abnormalities began at the very beginning of the disease which supports the neurodevelopmental hypothesis of its etiology.