AIMS We performed quantitative diffusion tensor imaging and brain tractography to distinguish clinical severity in a series of 35 patients with hypomyelinating PLP1-related disorders classified using the Motor Developmental Score according to the best motor function acquired before the age of 5 years and the gross motor function measure (GMFM) at the time of magnetic resonance imaging acquisition. METHODS We calculated fractional anisotropy and diffusivity values in 26 regions of interest and the numbers of fibers and volumes of hemisphere tractograms. Fiber bundles on tractograms were characterized according to 3 criteria: size, direction of main-stream fibers, and connectivity of bundles (extratelencephalic projections, commissural fibers, and intrahemispheric connections). RESULTS Age-adjusted multivariate analysis in 3 severity groups revealed increased isotropic diffusion in the superior cerebellar peduncle and grey matter in the most severe group, and larger tractogram volumes and increased numbers of fibers in the least severely affected group. Tractogram patterns showed preserved extratelencephalic projections and a main anterior-posterior aspect of intrahemispheric fibers in most patients, whereas interhemispheric connectivity was variable. The most severely affected and intermediate patients had less intrahemispheric connectivity, with a frequent predominant anterior-posterior direction of main-stream fibers. INTERPRETATION Diffusion tensor imaging and tractographic parameters can operate as biomarkers to distinguish clinical severity in PLP1-related disorders and could improve our understanding of hypomyelinating leukodystrophies.

中文翻译：

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脑扩散成像和脑电图以区分人类PLP1相关疾病的临床严重程度。

目的我们进行了定量扩散张量成像和脑束描记术，以根据35岁之前获得的最佳运动功能和总体运动功能，根据运动发育评分对35例与髓鞘增生性低下的PLP1相关疾病进行分类，以区分临床严重程度磁共振成像采集时的测量值（GMFM）。方法我们计算了26个感兴趣区域的分数各向异性和扩散率值以及半球体束图的纤维数量和体积。根据3个标准​​对硬皮图上的纤维束进行了表征：尺寸，主流纤维的方向和束的连通性（脑前外侧投影，连合纤维和半球内连接）。结果在3个严重程度组中，经过年龄调整的多元分析显示，在最严重的组中，小脑上侧足柄和灰质的各向同性扩散增加，在受影响最轻的组中，更大的束带图体积和纤维数量增加。牵引图显示大多数患者保留了脑外投射和半球内纤维的主要前后位置，而半球间的连通性却是可变的。受影响最严重的中级患者半球内连通性较低，主流纤维的前后方向频繁。