Longitudinal Study of Impaired Intra- and Inter-Network Brain Connectivity in Subjects at High Risk for Alzheimer's Disease

• Published in: Journal of Alzheimer's disease Vol. 52; no. 3; p. 913
• Main Authors: Zhan, Yafeng, Ma, Jianhua, Alexander-Bloch, Aaron F, Xu, Kaibin, Cui, Yue, Feng, Qianjin, Jiang, Tianzi, Liu, Yong
• Format: Journal Article
• Language: English
• Published: Netherlands 23.05.2016
• Subjects: Aged; Aged, 80 and over; Alzheimer Disease - diagnostic imaging; Alzheimer Disease - pathology; Analysis of Variance; Brain - pathology; Canada; Cognitive Dysfunction - diagnostic imaging; Cognitive Dysfunction - pathology; Disease Progression; Female; Humans; Image Processing, Computer-Assisted; Longitudinal Studies; Magnetic Resonance Imaging; Male; Mental Status Schedule; Neural Pathways - diagnostic imaging; Neural Pathways - pathology; Neuropsychological Tests; Oxygen - blood; United States; Default mode network; resting-state network; late mild cognitive impairment; salience network; early mild cognitive impairment
• ISSN: 1875-8908
• DOI: 10.3233/JAD-160008

Alzheimer's disease (AD) is associated with abnormal resting-state network (RSN) architecture of the default mode network (DMN), the dorsal attention network (DAN), the executive control network (CON), the salience network (SAL), and the sensory-motor network (SMN). However, little is known about the disrupted intra- and inter-network architecture in mild cognitive impairment (MCI). Here, we employed a priori defined regions of interest to investigate the intra- and inter-network functional connectivity profiles of these RSNs in longitudinal participants, including normal controls (n = 23), participants with early MCI (n = 26), and participants with late MCI (n = 19). We found longitudinal alterations of functional connectivity within the DMN, where they were correlated with variation in cognitive ability. The SAL as well as the interaction between the DMN and the SAL were disrupted in MCI. Furthermore, our results demonstrate that longitudinal alterations of functional connectivity are more profound in earlier stages as opposed to later stages of the disease. The increased severity of cognitive impairment is associated with increasingly altered RSN connectivity patterns, suggesting that disruptions in functional connectivity may contribute to cognitive dysfunction and may represent a potential biomarker of impaired cognitive ability in MCI. Earlier prevention and treatment may help to delay disease progression to AD.