Differences in dynamic functional connectivity across the Alzheimer’s disease spectrum

Background To examine differences in dynamic functional connectivity (DFC) cognitively normal subjects (CN), and patients with mild cognitive impairment (MCI) or Alzheimer’s disease (AD). Method Resting-state magnetic resonance imaging (rsfMRI data of 76 participants (40 CN, 24 MCI, 11 AD) from the ADNI database (http://adni.loni.usc.edu/) was used for analysis. Groups were matched according to age, sex education. rsfMRI pre-processed using CONN toolbox. For reduction purposes, spatial independent principal component analyses performed on normalized GIFT. Resulting meaningful components clustered into 13 resting-state networks. Using GIFT, a sliding window approach employed determine states across scan period 9 minutes. Afterwards, non-parametric t-tests comparing groups measures DFC such as dwell time (i.e. staying state), number transitions switching between states), fraction total spent meta state characteristics. Result The analysis resulted 4 distinct states, which characterized by either global patterns certain rs-networks. Group comparisons yielded that one particularly more occupied AD group compared CN (p = .02) MCI .001). showed lower span compares groups. Conclusion Network reorganization may influence pre- clinical AD.