Aberrant functional connectivity network in subjective memory complaint individuals relates to pathological biomarkers

• Published in: Translational neurodegeneration Vol. 7; no. 1; pp. 27 - 10
• Main Authors: Li, Kaicheng, Luo, Xiao, Zeng, Qingze, Jiaerken, Yeerfan, Xu, Xiaojun, Huang, Peiyu, Shen, Zhujing, Xu, Jingjing, Wang, Chao, Zhou, Jiong, Zhang, Min-Ming
• Format: Journal Article
• Language: English
• Published: England BioMed Central 19.10.2018; BMC
• Subjects: Degree centrality; Eigenvector centrality; Functional connectivity; Graph theoretical analysis; Neuropathology; Subjective memory complaint; Functional connectivity; Graph theoretical analysis; Degree centrality; Neuropathology; Subjective memory complaint; Eigenvector centrality
• ISSN: 2047-9158; 2047-9158
• DOI: 10.1186/s40035-018-0130-z

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 tau . 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.