Characteristics of the default mode functional connectivity in normal ageing and Alzheimer's disease using resting state fMRI with a combined approach of entropy-based and graph theoretical measurements.

摘要: Cognitive decline in normal ageing and Alzheimer's disease (AD) emerges from functional disruption the coordination of large-scale brain systems sustaining cognition. Integrity these can be examined by correlation methods based on analysis resting state magnetic resonance imaging (fMRI). Here we investigate connectivity within default mode network (DMN) AD using fMRI. Images young elderly controls, patients with were processed spatial independent component to identify DMN. Functional was quantified integration indices derived graph theory. Four DMN sub-systems identified: Frontal (medial superior), parietal (precuneus-posterior cingulate, lateral parietal), temporal temporal), hippocampal (bilateral). There a decrease antero-posterior interactions (lower global efficiency), but increased frontal (higher local clustering) compared controls. This decreased more pronounced particularly precuneus-posterior cingulate region. Conjoint knowledge measures same data helps interpretation results, as comprehension one measure improves understanding other. The approach allows for complete characterisation changes could applied other networks different pathologies.