Abnormal characterization of dynamic functional connectivity in Alzheimer's disease

Numerous studies have shown abnormal brain functional connectivity in individuals with Alzheimer’s disease(AD) or amnestic mild cognitive impairment(a MCI). However, most studies examined traditional resting state functional connections, ignoring the instantaneous connection mode of the whole brain. In this case-control study, we used a new method called dynamic functional connectivity(DFC) to look for abnormalities in patients with AD and a MCI. We calculated dynamic functional connectivity strength from functional magnetic resonance imaging data for each participant, and then used a support vector machine to classify AD patients and normal controls. Finally, we highlighted brain regions and brain networks that made the largest contributions to the classification. We found differences in dynamic function connectivity strength in the left precuneus, default mode network, and dorsal attention network among normal controls, a MCI patients, and AD patients. These abnormalities are potential imaging markers for the early diagnosis of AD.