Abstract：
White matter hyperintensities (WMH) are associated with cortical thinning. Although they are primarily detected in older participants, these lesions can appear in younger and midlife individuals. Here, we tested whether WMH are associated with cortical thinning in relatively younger (26-50 years) and relatively older (58-84) participants who were free of dementia, and how these associations are moderated by WMH localization. WMH were automatically quantified and categorized according to the localization of three classes of white matter tracts: association, commissural and projection fibers. Mediation analyses were used to infer whether differences in cortical thickness between younger and older participants were explained by WMH. Our results revealed that total WMH explained between 20.6 % and 65.5 % of the effect of age on cortical thickness in AD-signature regions including the lateral temporal lobes and supramarginal gyrus, among others. This mediation was slightly stronger for projection WMH, although it was still significant for association and commissural WMH. These results suggest that there is an interplay between vascular and AD causes of cognitive impairment that starts at younger ages.
摘要：
白质高强度（WMH）与皮质变薄有关。虽然它们主要在年龄较大的参与者中检测到，这些病变可出现在年轻人和中年人身上。这里,我们测试了WMH是否与相对年轻（26-50岁）和相对年长（58-84）的无痴呆参与者的皮质变薄有关，以及这些关联是如何通过WMH本地化来调节的。WMH根据三类白质束的定位自动量化和分类：关联，连合和投射纤维。中介分析用于推断年轻和老年参与者之间的皮质厚度差异是否由WMH解释。我们的结果表明，总WMH解释了年龄对AD特征区域（包括颞叶外侧和上脑回）皮质厚度的影响的20.6％至65.5％，在其他人中。对于投影WMH，这种调解稍强，尽管这对协会和委员性WMH仍然很重要。这些结果表明，血管性和AD之间存在相互作用的认知障碍的原因，从年轻的年龄开始。
