ABSTRACT INTRODUCTION We performed a systematic review and meta-analysis of the Alzheimer’s disease (AD) literature to examine consistency of functional connectivity alterations in AD dementia and mild cognitive impairment (MCI), using resting-state functional magnetic resonance imaging (rsfMRI). METHODS Studies were screened using a standardized procedure. Multiresolution statistics were performed to assess the spatial consistency of findings across studies. RESULTS Thirty-four studies were included (1,363 participants, average 40 per study). Consistent alterations in connectivity were found in the default-mode, salience and limbic networks in patients with AD dementia, MCI, or in both groups. We also identified a bias in the literature towards specific examination of the default-mode network. DISCUSSION Convergent evidence across the literature supports the use of resting-state connectivity as a biomarker of AD. The locations of consistent alterations suggest that metabolically expensive hub regions in the brain might be an early target of AD.

Resting-state network dysfunction in Alzheimer’s disease: a systematic review and meta-analysis