Individuals with subjective memory complaints (SMC) feature a higher risk of cognitive decline and clinical progression of Alzheimer’s disease (AD). However, the pathological mechanism underlying SMC remains unclear. We aimed to assess the intrinsic connectivity network and its relationship with AD-related pathologies in SMC individuals. We included 44 SMC individuals and 40 normal controls who underwent both resting-state functional MRI and positron emission tomography (PET). Based on graph theory approaches, we detected local and global functional connectivity across the whole brain by using degree centrality (DC) and eigenvector centrality (EC) respectively. Additionally, we analyzed amyloid deposition and tauopathy via florbetapir-PET imaging and cerebrospinal fluid (CSF) data. The voxel-wise two-sample T-test analysis was used to examine between-group differences in the intrinsic functional network and cerebral amyloid deposition. Then, we correlated these network metrics with pathological results. The SMC individuals showed higher DC in the bilateral hippocampus (HP) and left fusiform gyrus and lower DC in the inferior parietal region than controls. Across all subjects, the DC of the bilateral HP and left fusiform gyrus was positively associated with total tau and phosphorylated tau181. However, no significant between-group difference existed in EC and cerebral amyloid deposition. We found impaired local, but not global, intrinsic connectivity networks in SMC individuals. Given the relationships between DC value and tau level, we hypothesized that functional changes in SMC individuals might relate to pathological biomarkers.

中文翻译：

---

主观记忆投诉个体的异常功能连接网络与病理生物标志物有关

具有主观记忆障碍 (SMC) 的个体具有较高的认知能力下降和阿尔茨海默病 (AD) 临床进展的风险。然而，SMC 的病理机制仍不清楚。我们旨在评估 SMC 个体的内在连接网络及其与 AD 相关病理的关系。我们纳入了 44 名 SMC 个体和 40 名正常对照，他们接受了静息状态功能 MRI 和正电子发射断层扫描 (PET)。基于图论方法，我们分别使用度中心性（DC）和特征向量中心性（EC）检测整个大脑的局部和全局功能连接。此外，我们通过 florbetapir-PET 成像和脑脊液 (CSF) 数据分析了淀粉样蛋白沉积和 tauopathy。体素双样本 T 检验分析用于检查内在功能网络和脑淀粉样蛋白沉积的组间差异。然后，我们将这些网络指标与病理结果相关联。与对照组相比，SMC 个体在双侧海马 (HP) 和左侧梭状回中表现出更高的 DC，而在下顶叶区域表现出更低的 DC。在所有受试者中，双侧 HP 和左梭状回的 DC 与总 tau 和磷酸化 tau181 呈正相关。然而，EC和脑淀粉样蛋白沉积没有显着的组间差异。我们在 SMC 个体中发现受损的本地而非全球内在连接网络。鉴于 DC 值和 tau 水平之间的关系，