Institute for Stroke and Dementia Research, University Hospital, LMU Munich, Munich, Germany.
Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
Alzheimers Dement. 2020 Nov;16(11):1504-1514. doi: 10.1002/alz.12150. Epub 2020 Aug 18.
Microstructural alterations as assessed by diffusion tensor imaging (DTI) are key findings in both Alzheimer's disease (AD) and small vessel disease (SVD). We determined the contribution of each of these conditions to diffusion alterations.
We studied six samples (N = 365 participants) covering the spectrum of AD and SVD, including genetically defined samples. We calculated diffusion measures from DTI and free water imaging. Simple linear, multivariable random forest, and voxel-based regressions were used to evaluate associations between AD biomarkers (amyloid beta, tau), SVD imaging markers, and diffusion measures.
SVD markers were strongly associated with diffusion measures and showed a higher contribution than AD biomarkers in multivariable analysis across all memory clinic samples. Voxel-wise analyses between tau and diffusion measures were not significant.
In memory clinic patients, the effect of SVD on diffusion alterations largely exceeds the effect of AD, supporting the value of diffusion measures as markers of SVD.
通过弥散张量成像（DTI）评估的微观结构改变是阿尔茨海默病（AD）和小血管疾病（SVD）的重要发现。我们确定了这些情况中的每一种对弥散改变的贡献。
我们研究了六个样本（N=365 名参与者），涵盖了 AD 和 SVD 的范围，包括基因定义的样本。我们从 DTI 和游离水成像中计算了弥散指标。简单线性、多变量随机森林和体素回归用于评估 AD 生物标志物（β淀粉样蛋白、tau）、SVD 成像标志物与弥散指标之间的关联。
SVD 标志物与弥散指标密切相关，在所有记忆诊所样本的多变量分析中，其贡献高于 AD 生物标志物。tau 与弥散指标之间的体素分析不显著。
在记忆诊所患者中，SVD 对弥散改变的影响远远超过 AD，支持弥散指标作为 SVD 标志物的价值。
