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

Ziel/Aim To examine differences in dynamic functional connectivity (DFC) in cognitively normal subjects (CN), and patients with mild cognitive impairment (MCI) or Alzheimer’s disease (AD).

Methodik/Methods Resting-state functional magnetic resonance imaging (rsfMRI data of 76 participants (41 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 and education. rsfMRI data were pre-processed using the CONN toolbox. For data reduction purposes, spatial independent and principal component analyses were performed on the normalized rsfMRI using GIFT. Resulting meaningful independent components were clustered into 13 functional resting-state networks. Using GIFT, a sliding window approach was employed to determine dynamic functional connectivity states across the scan period of 9 minutes. Afterwards, non-parametric t-tests were performed comparing the groups in measures of DFC such as dwell time (i.e. staying in a state), number of transitions (i.e. switching between states) and fraction time (i.e. total time spent in a state).

Ergebnisse/Results The DFC analysis resulted in 4 distinct functional connectivity states, which were characterized by either global connectivity patterns or distinct connectivity patterns between certain rs-networks. Group comparisons yielded that one state was particularly more occupied by the AD group compared to the CN group (p=.02) and the MCI group (p=.001).

Schlussfolgerungen/Conclusions Network reorganization may influence dynamic functional connectivity patterns in pre- and clinical AD.

Publikationsverlauf

Artikel online veröffentlicht:
14. April 2022