Jiang Lanli, Zhao Shaokun, Li Ting, Liu Jiawen, Zhang Junyin, Zhang Zhanjun, Li Xin
State Key Laboratory of Cognitive Neuroscience and Learning, Faculty of Psychology, Beijing Normal University, Beijing, 100875, China.
Beijing Aging Brain Rejuvenation Initiative (BABRI) Centre, Beijing Normal University, Beijing, 100875, China.
BMC Geriatr. 2025 Jul 2;25(1):452. doi: 10.1186/s12877-025-06072-8.
The occurrence of worry in subjects with Subjective Cognitive Decline(SCD) confers a greater risk of future AD and cognitive decline. However, it is not known whether these individuals have distinct memory and neuroimaging profiles. Therefore, we aimed to identify brain imaging characteristics associated with episodic memory in elderly adults with subjective cognitive decline and related worry (SCD+) in a population-based cohort.
A total of 418 individuals from the BABRI cohort underwent structural MRI (n = 418) and episodic memory-related task-based fMRI (n = 153) scans. The subjects were classified into Mild Cognitive Impairment (MCI), SCD+ , SCD, and Normal Control (NC) groups. A brain structure-function-episodic memory pathway model was constructed to investigate potential compensatory mechanisms.
Cognitively, SCD+ group did not perform significantly worse than SCD group on episodic memory tasks. For the structural T1-weighted MRI results, gray matter integrity in SCD+ group exhibited altered atrophy patterns compared to SCD, mainly in the posterior hippocampus and parahippocampal cortex. Using PsychoPhysiological Interactions (PPI) to investigate task-based functional connectivity, we found that the SCD+ group exhibited significantly stronger functional connectivity (FC) in the Default Mode Network (DMN) and other networks than SCD. Using moderation model analysis, we found that stronger FC between the DMN and Visual Network (VN) moderated the relationship between gray matter volume (GM) of the posterior hippocampus and episodic memory encoding accuracy within SCD+ group.
Stronger DMN-VN connectivity may reflect early cognitive reserve processes supporting episodic memory in SCD+ despite structural vulnerability, although such adaptations may vunerable as Alzheimer's disease progresses. Task-based fMRI may serve as a sensitive tool for detecting these processes before clinical decline.
主观认知衰退（SCD）患者出现担忧会使其未来患阿尔茨海默病（AD）和认知衰退的风险更高。然而，尚不清楚这些个体是否具有独特的记忆和神经影像学特征。因此，我们旨在确定基于人群的队列中患有主观认知衰退及相关担忧（SCD+）的老年人的情景记忆相关脑成像特征。
共有418名来自BABRI队列的个体接受了结构MRI扫描（n = 418）和基于情景记忆相关任务的功能MRI扫描（n = 153）。受试者被分为轻度认知障碍（MCI）组、SCD+组、SCD组和正常对照组（NC）。构建了一个脑结构-功能-情景记忆通路模型来研究潜在的代偿机制。
在认知方面，SCD+组在情景记忆任务上的表现并不比SCD组显著更差。对于结构T1加权MRI结果，与SCD组相比，SCD+组的灰质完整性呈现出改变的萎缩模式，主要位于海马后体和海马旁皮质。使用心理生理交互作用（PPI）来研究基于任务的功能连接性，我们发现SCD+组在默认模式网络（DMN）和其他网络中的功能连接性（FC）比SCD组显著更强。使用调节模型分析，我们发现在SCD+组中，DMN与视觉网络（VN）之间更强的FC调节了海马后体灰质体积（GM）与情景记忆编码准确性之间的关系。
尽管存在结构脆弱性，但更强的DMN-VN连接性可能反映了支持SCD+组情景记忆的早期认知储备过程，尽管随着阿尔茨海默病的进展，这种适应性可能会变得脆弱。基于任务的功能MRI可能是在临床衰退之前检测这些过程的敏感工具。
