Functional Hubs in Mild Cognitive Impairment

TL;DR

This study uses MEG to analyze how mild cognitive impairment alters brain network hubs, revealing changes in centrality that suggest a shift towards more random network structures, potentially indicating early Alzheimer's signs.

Contribution

It provides novel insights into the specific alterations in brain network topology associated with MCI using MEG and synchronization likelihood analysis.

Findings

MCI patients show decreased hub centrality in occipital regions.

MCI patients show increased hub centrality in central regions.

MCI leads to more random functional brain network structures.

Abstract

We investigate how hubs of functional brain networks are modified as a result of mild cognitive impairment (MCI), a condition causing a slight but noticeable decline in cognitive abilities, which sometimes precedes the onset of Alzheimer's disease. We used magnetoencephalography (MEG) to investigate the functional brain networks of a group of patients suffering from MCI and a control group of healthy subjects, during the execution of a short-term memory task. Couplings between brain sites were evaluated using synchronization likelihood, from which a network of functional interdependencies was constructed and the centrality, i.e. importance, of their nodes quantified. The results showed that, with respect to healthy controls, MCI patients were associated with decreases and increases in hub centrality respectively in occipital and central scalp regions, supporting the hypothesis that MCI modifies functional brain network topology, leading to more random structures.