Yu Lei, Dawe Robert J, Buchman Aron S, Boyle Patricia A, Schneider Julie A, Arfanakis Konstantinos, Bennett David A
Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA.
Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Diagnostic Radiology and Nuclear Medicine, Rush University Medical Center, Chicago, IL, USA.
Behav Brain Res. 2017 Mar 30;322(Pt B):233-240. doi: 10.1016/j.bbr.2016.09.001. Epub 2016 Sep 3.
Alterations of the transverse relaxation rate, R, measured using MRI, are observed in older persons with Alzheimer's (AD) dementia. However, the spatial pattern of these alterations and the degree to which they reflect the accumulation of common age-related neuropathologies are unknown. In this study, we characterized the profile of R alterations in post-mortem brains of persons with clinical diagnosis of AD dementia and investigated how the profile differs after accounting for neuropathologic indices of AD, cerebral infarcts, Lewy body disease, hippocampal sclerosis and transactive response DNA-binding protein 43. Data came from 567 post-mortem brains donated by participants in two cohort studies of aging and dementia. R was quantified using fast spin echo imaging. Voxelwise linear regression examined R alterations between subjects diagnosed with AD dementia at death and those with no cognitive impairment. Voxels showing significant R alterations were clustered into regions of interest (ROIs). Three R profiles were compared, which were adjusted for (1) demographics only; (2) demographics and AD pathology; (3) demographics, AD pathology and other common neuropathologies. R alterations were observed throughout the hemisphere, most commonly in white matter. Of the distinct ROIs identified, the largest region encompassed large portions of white matter in all lobes. This ROI became smaller in size but remained largely intact after adjusting for AD and other neuropathologic indices. Further, R alterations identify AD dementia with improved accuracy, above and beyond demographics and neuropathologic indices (p<0.0001). In conclusion, R alterations in AD dementia are not solely reflective of common age-related neuropathologies, suggesting that other mechanisms are at work.
使用磁共振成像（MRI）测量的横向弛豫率R的改变，在患有阿尔茨海默病（AD）痴呆的老年人中可以观察到。然而，这些改变的空间模式以及它们反映常见年龄相关神经病理学积累的程度尚不清楚。在本研究中，我们对临床诊断为AD痴呆患者的死后大脑中R改变的特征进行了描述，并研究了在考虑AD的神经病理学指标、脑梗死、路易体病、海马硬化和转录激活反应DNA结合蛋白43后，这种特征如何不同。数据来自两项衰老和痴呆队列研究参与者捐赠的567个死后大脑。使用快速自旋回波成像对R进行量化。体素线性回归检查了死亡时诊断为AD痴呆的受试者与无认知障碍受试者之间的R改变。显示出显著R改变的体素被聚类到感兴趣区域（ROI）。比较了三种R特征，分别针对（1）仅人口统计学因素；（2）人口统计学因素和AD病理学；（3）人口统计学因素、AD病理学和其他常见神经病理学进行了调整。在整个半球都观察到了R改变，最常见于白质。在确定的不同ROI中，最大的区域包括所有脑叶中的大部分白质。在调整AD和其他神经病理学指标后，这个ROI的大小变小，但基本保持完整。此外，R改变能够以高于人口统计学和神经病理学指标的准确性识别AD痴呆（p<0.0001）。总之，AD痴呆中的R改变并非仅仅反映常见的年龄相关神经病理学，这表明还有其他机制在起作用。
