1 Division of Informatics, Imaging and Data Sciences, University of Manchester, Wolfson Molecular Imaging Centre, Manchester, UK.
2 Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, UK.
J Cereb Blood Flow Metab. 2018 Oct;38(10):1796-1806. doi: 10.1177/0271678X17718436. Epub 2017 Jul 4.
Clinical variants of Alzheimer's disease (AD) include the common amnestic subtype as well as subtypes characterised by leading visual processing impairments or by multimodal neurocognitive deficits. We investigated regional metabolic patterns and networks between AD subtypes. The study comprised 9 age-matched controls and 25 patients with mild to moderate AD. Methods included clinical and neuropsychological assessment, high-resolution FDG PET and T1-weighted 3D MR imaging with PET-MR coregistration, grey matter segmentation, atlas-based regions-of-interest, linear mixed effects and regional correlation analysis. Regional metabolic patterns differed significantly between groups, but significant hypometabolism in the posterior cingulate cortex (PCC) was common to all subtypes. The most distinctive regional abnormality was occipital hypometabolism in the visual subtype. In controls, two large clusters of positive regional metabolic correlations were observed. The most pronounced breakdown of the normal correlation pattern was found in amnestic patients who, in contrast, showed the least regional focal metabolic deficits. The normal positive correlation between PCC and hippocampus was lost in all subtypes. In conclusion, PCC hypometabolism and metabolic correlation breakdown between PCC and hippocampus are the common functional core of all AD subtypes. Network alterations exceed focal regional impairment and are most prominent in the amnestic subtype.
阿尔茨海默病（AD）的临床变异型包括常见的遗忘型亚型以及以主要视觉处理损伤或多模态神经认知缺陷为特征的亚型。我们研究了 AD 亚型之间的区域代谢模式和网络。该研究包括 9 名年龄匹配的对照者和 25 名轻度至中度 AD 患者。方法包括临床和神经心理学评估、高分辨率 FDG PET 和具有 PET-MR 配准的 T1 加权 3D MR 成像、灰质分割、基于图谱的感兴趣区、线性混合效应和区域相关性分析。两组之间的区域代谢模式存在显著差异，但所有亚型均存在后扣带回皮层（PCC）的明显低代谢。最具特征性的区域异常是视觉亚型的枕叶低代谢。在对照组中，观察到两个大的区域代谢正相关簇。在遗忘型患者中发现了最明显的正常相关模式的破坏，而在遗忘型患者中，区域局部代谢缺陷最少。PCC 和海马之间正常的正相关在所有亚型中均丢失。总之，PCC 低代谢和 PCC 与海马之间代谢相关性的破坏是所有 AD 亚型的共同功能核心。网络改变超过了局部区域损伤，在遗忘型亚型中最为明显。
