Resting-state network dysfunction in Alzheimer's disease: A systematic review and meta-analysis-

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 mildcognitive impairment, using resting-state functional magnetic resonance imaging.Methods: Studies were screened using a standardized procedure. Multiresolution statistics wereperformed to assess the spatial consistency of findings across studies.Results: Thirty-four studies were included (1363 participants, average 40 per study). Consistentalterations in connectivity were found in the default mode, salience, and limbic networks in patientswith AD dementia, mild cognitive impairment, or in both groups.We also identified a strong tendencyin the literature toward specific examination of the default mode network.Discussion: Convergent evidence across the literature supports the use of resting-state connectivityas a biomarker of AD. The locations of consistent alterations suggest that highly connected hubregions in the brain might be an early target of AD. 2017 The Authors. Published by Elsevier Inc. on behalf of the Alzheimer’s Association. This is anopen access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Keywords: Resting-state fMRI; Functional connectivity; Alzheimer’s disease; Mild cognitive impairment; Meta-analysis1. IntroductionAlzheimer’s disease (AD) exists on a continuumcomprising a