Abstract:
Rett syndrome (RTT) is a neurodevelopmental disorder caused by loss-of-function variants in the MECP2 gene, currently with no cure. Neuroimaging is an important tool for obtaining non-invasive structural and functional information about the in vivo brain. Multiple approaches to magnetic resonance imaging (MRI) scans have been utilized effectively in RTT patients to understand the possible pathological basis. This study combined developmental evaluations with clinical severity, T1-weighted imaging, and diffusion tensor imaging, aiming to explore the structural alterations in cohorts of young girls with RTT, idiopathic autism spectrum disorder (ASD), or typical development. Voxel-based morphometry (VBM) was used to determine the voxel-wised volumetric characteristics of gray matter, while tract-based spatial statistics (SPSS) was used to obtain voxel-wised properties of white matter. Finally, a correlation analysis between the brain structural alterations and the clinical evaluations was performed. In the RTT group, VBM revealed decreased gray matter volume in the insula, frontal cortex, calcarine, and limbic/paralimbic regions; TBSS demonstrated decreased fractional anisotropy (FA) and increased mean diffusivity (MD) mainly in the corpus callosum and other projection and association fibers such as superior longitudinal fasciculus and corona radiata. The social impairment quotient and clinical severity were associated with these morphometric alterations. This monogenic study with an early stage of RTT may provide some valuable guidance for understanding the disease pathogenesis. At the same time, the pediatric-adjusted analytic pipelines for VBM and TBSS were introduced for significant improvement over classical approaches for MRI scans in children.
摘要:
Rett综合征(RTT)是由MECP2基因的功能丧失变异引起的神经发育障碍,目前没有治愈。神经成像是获得有关体内大脑的非侵入性结构和功能信息的重要工具。在RTT患者中已有效利用了多种磁共振成像(MRI)扫描方法,以了解可能的病理基础。这项研究将发展评估与临床严重程度相结合,T1加权成像,和扩散张量成像,旨在探索RTT年轻女孩队列的结构变化,特发性自闭症谱系障碍(ASD),或典型的发展。基于体素的形态计量学(VBM)用于确定灰质的体素特征,而基于道的空间统计(SPSS)用于获得白质的体素特性。最后,我们对脑结构改变和临床评价进行了相关性分析.在RTT组中,VBM显示脑岛灰质体积减少,额叶皮质,calcarine,和边缘/旁缘区域;TBSS表现出主要在call体和其他投影和缔合纤维中的分数各向异性(FA)降低,平均扩散率(MD)增加,例如上纵向束状和冠状辐射。社会损害商和临床严重程度与这些形态改变有关。这种具有早期RTT的单基因研究可能为理解疾病的发病机制提供一些有价值的指导。同时,引入了经儿科调整的VBM和TBSS分析管道,以显著改善儿童MRI扫描的经典方法.