Department of Neurology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
Department of Radiology, the Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
J Alzheimers Dis. 2021;81(3):1285-1294. doi: 10.3233/JAD-201244.
Cognitive reserve (CR) is an important protective factor for Alzheimer's disease (AD), yet its mechanism has not been fully elucidated.
To explore the effect of CR on resting and dynamic brain intrinsic activity in patients with mild cognitive impairment (MCI).
65 amyloid-β PET-negative (Aβ-) normal controls (NC) and 30 amyloid-β PET-positive (Aβ+) MCI patients underwent resting-state functional magnetic resonance imaging were included from Alzheimer's Disease Neuroimaging Initiative. According to the years of education, the subjects were divided into high education group and low education group. A two-way analysis of variance was employed for the fractional amplitude of low-frequency fluctuation (fALFF) and dynamic fALFF (dfALFF) comparisons among the four groups. Moreover, the interaction effect of neuroimaging×pathology on clinical cognitive function was tested with linear regression analysis.
The value of fALFF in the left prefrontal lobe was increased in Aβ+ MCI patients compared to Aβ- NC. The significant interactive effect between disease state and education (binary factor) was observed in the right parahippocampal gyrus (PHG) for fALFF, the right PHG and the right inferior parietal lobule for dfALFF. While no significant results between education (continuous factor) and brain activity was found in voxel-by-voxel analysis. For MCI patients, a significant fluorodeoxyglucose hypometabolic convergence index×right PHG dfALFF interaction was found, indicating the maintenance of executive function at higher levels of dfALFF in the right PHG.
High CR can alleviate the impairment of hypometabolism on executive function in MCI patients, which is partially achieved by regulating the dynamic brain activity in the right PHG.
认知储备（CR）是阿尔茨海默病（AD）的重要保护因素，但它的机制尚未完全阐明。
探讨认知储备对轻度认知障碍（MCI）患者静息和动态脑内在活动的影响。
从阿尔茨海默病神经影像学倡议中纳入 65 名淀粉样蛋白-β PET 阴性（Aβ-）正常对照（NC）和 30 名淀粉样蛋白-β PET 阳性（Aβ+）MCI 患者进行静息态功能磁共振成像。根据受教育年限，将受试者分为高教育组和低教育组。采用双因素方差分析比较四组间低频振幅（fALFF）和动态 fALFF（dfALFF）的差异。此外，采用线性回归分析检验神经影像学与病理学对临床认知功能的交互作用。
与 Aβ- NC 相比，Aβ+ MCI 患者左前额叶的 fALFF 值增加。fALFF 时观察到疾病状态与教育（二分类因素）之间的显著交互作用，dfALFF 时观察到右海马旁回（PHG）、右 PHG 和右顶下小叶。而在体素水平分析中，教育（连续因素）与脑活动之间无显著相关性。对于 MCI 患者，发现氟脱氧葡萄糖低代谢融合指数×右 PHG dfALFF 交互作用有显著意义，表明右 PHG 中 dfALFF 水平较高时执行功能保持较高水平。
高认知储备可以减轻 MCI 患者低代谢对执行功能的损害，这部分是通过调节右 PHG 的动态脑活动来实现的。
