Deficits in Neurite Density Underlie White Matter Structure Abnormalities in First-Episode Psychosis
Deficits in Neurite Density Underlie White Matter Structure Abnormalities in First-Episode Psychosis
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DOI：
10.1016/j.biopsych.2017.02.008
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发表时间：
2017-11-15
影响因子：
10.6
通讯作者：
Critchley, Hugo D.
中科院分区：
文献类型：
--
作者：
Rae, Charlotte L.;Davies, Geoff;Critchley, Hugo D.
背景技术背景：在早期精神病患者中，多个白色物质束的结构异常被识别，与作为症状表达的神经病理学解释的连接障碍一致。我们应用先进的神经影像学技术来表征微结构白色物质异常，以更深入地了解精神病的发育病因学。35名首发精神病患者和19名健康对照者参加了一项使用神经突方向分散和密度成像的定量神经成像研究，一种多壳层扩散加权磁共振成像技术，可将白色物质纤维排列和几何形状与神经突密度的变化区分开来。分数各向异性（FA）和平均扩散率的图像也来自。道为基础的空间统计学比较白色物质结构患者和对照组之间的测试协会与年龄，症状严重程度，和medication.Results：首发精神病患者有较低的区域FA在多个连合，皮质脊髓，和关联tracts。这些异常主要与神经突密度降低的区域共定位，而不是异常的纤维束排列（取向分散指数）。与活动性症状无直接关系。FA下降和方向分散指数随着年龄的增加，患者，但不是对照组，这表明加速效应的白色物质的几何形状changes.CONCLUSIONS：神经突密度的缺陷出现根本异常的白色物质的完整性在早期精神病。在精神病的神经突方向分散和密度成像的第一个应用中，我们发现，损害轴突纤维数量，密度和髓鞘形成的过程，而不是导致纤维组织空间破坏的过程，与精神病的病因有关。这符合神经发育起源的异常脑结构连接诱发个人精神病。
BACKGROUND: Structural abnormalities across multiple white matter tracts are recognized in people with early psychosis, consistent with dysconnectivity as a neuropathological account of symptom expression. We applied advanced neuroimaging techniques to characterize microstructural white matter abnormalities for a deeper understanding of the developmental etiology of psychosis.METHODS: Thirty-five first-episode psychosis patients, and 19 healthy controls, participated in a quantitative neuroimaging study using neurite orientation dispersion and density imaging, a multishell diffusion-weighted magnetic resonance imaging technique that distinguishes white matter fiber arrangement and geometry from changes in neurite density. Fractional anisotropy (FA) and mean diffusivity images were also derived. Tract-based spatial statistics compared white matter structure between patients and control subjects and tested associations with age, symptom severity, and medication.RESULTS: Patients with first-episode psychosis had lower regional FA in multiple commissural, corticospinal, and association tracts. These abnormalities predominantly colocalized with regions of reduced neurite density, rather than aberrant fiber bundle arrangement (orientation dispersion index). There was no direct relationship with active symptoms. FA decreased and orientation dispersion index increased with age in patients, but not control subjects, suggesting accelerated effects of white matter geometry change.CONCLUSIONS: Deficits in neurite density appear fundamental to abnormalities in white matter integrity in early psychosis. In the first application of neurite orientation dispersion and density imaging in psychosis, we found that processes compromising axonal fiber number, density, and myelination, rather than processes leading to spatial disruption of fiber organization, are implicated in the etiology of psychosis. This accords with a neurodevelopmental origin of aberrant brain-wide structural connectivity predisposing individuals to psychosis.