Prader-Willi综合征(PWS)是一种基因组印记的神经发育障碍,表现出特有的暴饮暴食障碍,轻度至中度智力残疾,以及可变范围的社会和行为困难。因此,预计神经结构、发育和成熟轨迹会发生广泛的变化。迄今为止,关于PWS的脑形态学的定量和系统研究很少,尽管已经报道了体积和皮质组织的改变。本研究旨在调查,在细节上,在匹配良好的病例对照分析中,患有PWS的年轻成年人的大脑灰质和皮质结构。20名患有PWS的年轻人,19-27岁,接受了多参数映射磁共振成像序列,灰质体积的度量,皮质厚度和磁化转移饱和度,作为髓鞘形成的替代量度,进行了检查。与40名通常正在发育的年轻人的对照组相比,研究了这些变量,年龄和性别相匹配。基于体素的形态计量学分析确定了PWS中大脑中灰质体积增加和减少的大型和广泛的双侧簇。特别是,体积增加的广泛区域包括前额叶皮层的一部分,尤其是中介,大部分扣带回皮质,从前部到后部,岛皮层,顶叶和颞叶皮质的区域。据报道,尾状中的体积也增加,壳核和丘脑。最腹内侧的前额区,相比之下,显示体积减少,内侧颞叶的部分也是如此,双侧颞极,和一个位于右侧前额叶皮层的小簇。对皮质结构的分析表明,PWS组中体积增加的区域很大程度上是由更大的皮质厚度驱动的。相反,使用磁化转移饱和度分析髓鞘含量表明,PWS和对照组的皮质髓鞘形成大致相似,除了高度本地化的地区,包括脑岛.这些异常的双侧性质表明是全身性生物学原因,讨论了可能的发育和成熟机制,并可能提供有关印迹基因对神经发育的贡献的见解。
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder of genomic imprinting, presenting with a characteristic overeating disorder, mild to moderate intellectual disability, and a variable range of social and behavioral difficulties. Consequently, widespread alterations in neural structure and developmental and maturational trajectory would be expected. To date, there have been few quantitative and systematic studies of brain morphology in PWS, although alterations of volume and of cortical organisation have been reported. This study aimed to investigate, in detail, the structure of grey matter and cortex in the brain in a sample of young adults with PWS in a well-matched case-controlled analysis. 20 young adults with PWS, aged 19-27 years, underwent multiparameter mapping magnetic resonance imaging sequences, from which measures of grey matter volume, cortical thickness and magnetisation transfer saturation, as a proxy measure of myelination, were examined. These variables were investigated in comparison to a control group of 40 typically developing young adults, matched for age and sex. A voxel-based morphometry analysis identified large and widespread bilateral clusters of both increased and decreased grey matter volume in the brain in PWS. In particular, widespread areas of increased volume encompassed parts of the prefrontal cortex, especially medially, the majority of the cingulate cortices, from anterior to posterior aspects, insula cortices, and areas of the parietal and temporal cortices. Increased volume was also reported in the caudate, putamen and thalamus. The most ventromedial prefrontal areas, in contrast, showed reduced volume, as did the parts of the medial temporal lobe, bilateral temporal poles, and a small cluster in the right lateral prefrontal cortex. Analysis of cortical structure revealed that areas of increased volume in the PWS group were largely driven by greater cortical thickness. Conversely, analysis of myelin content using magnetisation transfer saturation indicated that myelination of the cortex was broadly similar in the PWS and control groups, with the exception of highly localised areas, including the insula. The bilateral nature of these abnormalities suggests a systemic biological cause, with possible developmental and maturational mechanisms discussed, and may offer insight into the contribution of imprinted genes to neural development.