■一系列成像模式报告了在经历主观认知能力下降(SCD)的个体中与阿尔茨海默病相关的异常。然而,在SCD的多种神经影像学检查中,未发现一致的局部异常.
■我们旨在研究淀粉样β(Aβ)沉积的趋同局部改变,葡萄糖代谢,和SCD中的静息态功能MRI(RS-fMRI)指标。
■50名SCD患者(66.4±5.7岁,19名男性[38%])和15名正常对照(NC)(66.3±4.4岁,5名男性[33.3%])同时用[18F]-florbetapirPET和[18F]-氟代脱氧葡萄糖PET进行扫描,以及2018年2月至2018年11月的同时RS-fMRI。对体素指标进行了回顾性分析,包括Aβ沉积,葡萄糖代谢,低频波动幅度(ALFF),区域同质性(ReHo),和学位中心性(DC)。
■SCD组显示Aβ沉积和葡萄糖代谢增加(p<0.05,校正),以及降低ALFF,ReHo,和DC(p<0.05,未校正)在左背前肌(dPCu)。此外,dPCu说明了与默认模式网络的负静息状态功能连接。关于全球Aβ沉积阳性,左侧dPCu中的Aβ沉积呈梯度变化,即,Aβ阳性SCD>Aβ阴性SCD>Aβ阴性NC。此外,Aβ阳性SCD和Aβ阴性SCD均显示dPCu中糖代谢增加和RS-fMRI指标降低.
■背前肌,与公元早期有牵连的区域,显示SCD的神经影像学改变,并且可能与其他认知功能更相关(例如,注意力不集中)而不是情景记忆。
UNASSIGNED: A range of imaging modalities have reported Alzheimer\'s disease-related abnormalities in individuals experiencing subjective cognitive decline (SCD). However, there has been no consistent local abnormality identified across multiple neuroimaging modalities for SCD.
UNASSIGNED: We aimed to investigate the convergent local alterations in amyloid-β (Aβ) deposition, glucose metabolism, and resting-state functional MRI (RS-fMRI) metrics in SCD.
UNASSIGNED: Fifty SCD patients (66.4±5.7 years old, 19 men [38%]) and 15 normal controls (NC) (66.3±4.4 years old, 5 men [33.3%]) were scanned with both [18F]-florbetapir PET and [18F]-fluorodeoxyglucose PET, as well as simultaneous RS-fMRI from February 2018 to November 2018. Voxel-wise metrics were retrospectively analyzed, including Aβ deposition, glucose metabolism, amplitude of low frequency fluctuation (ALFF), regional homogeneity (ReHo), and degree centrality(DC).
UNASSIGNED: The SCD group showed increased Aβ deposition and glucose metabolism (p < 0.05, corrected), as well as decreased ALFF, ReHo, and DC (p < 0.05, uncorrected) in the left dorsal
precuneus (dPCu). Furthermore, the dPCu illustrated negative resting-state functional connectivity with the default mode network. Regarding global Aβ deposition positivity, the Aβ deposition in the left dPCu showed a gradient change, i.e., Aβ positive SCD > Aβ negative SCD > Aβ negative NC. Additionally, both Aβ positive SCD and Aβ negative SCD showed increased glucose metabolism and decreased RS-fMRI metrics in the dPCu.
UNASSIGNED: The dorsal
precuneus, an area implicated in early AD, shows convergent neuroimaging alterations in SCD, and might be more related to other cognitive functions (e.g., unfocused attention) than episodic memory.