From the Stroke Research Group (A.J.L., H.S.M.), Clinical Neurosciences, University of Cambridge; Neurosciences Research Centre (E.A.Z., P.B., C.P.L., T.R.B.), Molecular and Clinical Sciences Research Institute (E.A.Z., P.B., C.P.L., T.R.B.), St George's University of London; and Department of Psychology (R.G.M.), King's College Institute of Psychiatry, Psychology and Neuroscience, London, UK.
Neurology. 2018 May 22;90(21):e1898-e1910. doi: 10.1212/WNL.0000000000005551. Epub 2018 Apr 25.
To determine whether longitudinal change in white matter structural network integrity predicts dementia and future cognitive decline in cerebral small vessel disease (SVD). To investigate whether network disruption has a causal role in cognitive decline and mediates the association between conventional MRI markers of SVD with both cognitive decline and dementia.
In the prospective longitudinal SCANS (St George's Cognition and Neuroimaging in Stroke) Study, 97 dementia-free individuals with symptomatic lacunar stroke were followed with annual MRI for 3 years and annual cognitive assessment for 5 years. Conversion to dementia was recorded. Structural networks were constructed from diffusion tractography using a longitudinal registration pipeline, and network global efficiency was calculated. Linear mixed-effects regression was used to assess change over time.
Seventeen individuals (17.5%) converted to dementia, and significant decline in global cognition occurred ( = 0.0016). Structural network measures declined over the 3-year MRI follow-up, but the degree of change varied markedly between individuals. The degree of reductions in network global efficiency was associated with conversion to dementia (B = -2.35, odds ratio = 0.095, = 0.00056). Change in network global efficiency mediated much of the association of conventional MRI markers of SVD with cognitive decline and progression to dementia.
Network disruption has a central role in the pathogenesis of cognitive decline and dementia in SVD. It may be a useful disease marker to identify that subgroup of patients with SVD who progress to dementia.
确定脑小血管病（SVD）患者白质结构网络完整性的纵向变化是否可预测痴呆症和未来认知能力下降。研究网络中断是否在认知能力下降中起因果作用，并介导 SVD 的常规 MRI 标志物与认知能力下降和痴呆症之间的关联。
在前瞻性纵向 SCANS（圣乔治中风认知和神经影像学）研究中，对 97 名无痴呆症状性腔隙性卒中患者进行了为期 3 年的年度 MRI 随访和 5 年的年度认知评估。记录向痴呆症的转化。使用纵向配准管道从弥散张量成像构建结构网络，并计算网络全局效率。线性混合效应回归用于评估随时间的变化。
17 名患者（17.5%）转为痴呆症，且整体认知能力显著下降（ = 0.0016）。结构网络测量值在 3 年的 MRI 随访中下降，但个体间的变化程度差异很大。网络全局效率降低的程度与向痴呆症的转化有关（B = -2.35，优势比 = 0.095， = 0.00056）。网络全局效率的变化很大程度上介导了 SVD 的常规 MRI 标志物与认知能力下降和向痴呆症进展的关联。
网络中断在 SVD 认知能力下降和痴呆症的发病机制中起核心作用。它可能是一种有用的疾病标志物，可识别 SVD 患者中向痴呆症进展的亚组。
