Department of Radiology, The 2nd Affiliated Hospital of Zhejiang University, School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou, 310009, China.
Department of Neurology, The 2nd Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.
Brain Imaging Behav. 2018 Feb;12(1):188-200. doi: 10.1007/s11682-017-9680-4.
Amnestic mild cognitive impairment can be further classified as single-domain aMCI (SD-aMCI) with isolated memory deficit, or multi-domain aMCI (MD-aMCI) if memory deficit is combined with impairment in other cognitive domains. Prior studies reported these clinical subtypes presumably differ in etiology. Thus, we aimed to explore the possible mechanisms between different aMCI subtypes by assessing alteration in brain activity and brain vasculature, and their relations with CSF AD biomarkers. 49 healthy controls, 32 SD-aMCI, and 32 MD-aMCI, who had undergone structural scans, resting-state functional MRI (rsfMRI) scans and neuropsychological evaluations, were identified. Regional homogeneity (ReHo) was employed to analyze regional synchronization. Periventricular white matter hyperintensities (PWMH) and deep WMH (DWMH) volume of each participant was quantitatively assessed. AD biomarkers from CSF were also measured. SD-aMCI showed decreased ReHo in medial temporal gyrus (MTG), and increased ReHo in lingual gyrus (LG) and superior temporal gyrus (STG) relative to controls. MD-aMCI showed decreased ReHo, mostly located in precuneus (PCu), LG and postcentral gyrus (PCG), relative to SD-aMCI and controls. As for microvascular disease, MD-aMCI patients had more PWMH burden than SD-aMCI and controls. Correlation analyses indicated mean ReHo in differenced regions were related with memory, language, and executive function in aMCI patients. However, no significant associations between PWMH and behavioral data were found. The Aβ level was related with the ReHo value of STG in SD-aMCI. MD-aMCI displayed different patterns of abnormal regional synchronization and more severe PWMH burden compared with SD-aMCI. Therefore aMCI is not a uniform disease entity, and MD-aMCI group may show more complicated pathologies than SD-aMCI group.
遗忘型轻度认知障碍可进一步分为单域遗忘型轻度认知障碍（SD-aMCI），表现为孤立性记忆缺陷，或多域遗忘型轻度认知障碍（MD-aMCI），如果记忆缺陷伴有其他认知域的损伤。先前的研究报告称，这些临床亚型可能在病因学上有所不同。因此，我们旨在通过评估大脑活动和血管的改变，以及它们与 CSF AD 生物标志物的关系，来探讨不同 aMCI 亚型之间的可能机制。共纳入 49 名健康对照者、32 名 SD-aMCI 和 32 名 MD-aMCI，他们接受了结构扫描、静息态功能磁共振成像（rsfMRI）扫描和神经心理学评估。采用局部一致性（ReHo）分析来分析局部同步性。定量评估每位参与者的脑室周围白质高信号（PWMH）和深部白质高信号（DWMH）体积。还测量了 CSF 中的 AD 生物标志物。与对照组相比，SD-aMCI 患者的内侧颞叶（MTG）区域的 ReHo 降低，舌回（LG）和颞上回（STG）的 ReHo 增加。MD-aMCI 患者的 ReHo 降低，主要位于楔前叶（PCu）、LG 和中央后回（PCG），与 SD-aMCI 和对照组相比。至于微血管疾病，MD-aMCI 患者的 PWMH 负担比 SD-aMCI 和对照组更重。相关分析表明，aMCI 患者不同区域的平均 ReHo 与记忆、语言和执行功能有关。然而，未发现 PWMH 与行为数据之间存在显著相关性。Aβ 水平与 SD-aMCI 患者的 STG 的 ReHo 值相关。与 SD-aMCI 相比，MD-aMCI 表现出不同的异常区域同步模式和更严重的 PWMH 负担。因此，aMCI 不是一个单一的疾病实体，MD-aMCI 组可能比 SD-aMCI 组表现出更复杂的病理。
