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Updated: Oct 2, 2025
Identification of Disease-related Spatial Covariance Patterns using Neuroimaging Data
Published on: June 26, 2013
Decoupling of regional neural activity and inter-regional functional connectivity in Alzheimer's disease: a
Somayeh Maleki Balajoo1,2,3, Farzaneh Rahmani4, Reza Khosrowabadi5
1Institute of Medical Science and Technology, Shahid Beheshti University, Tehran, Iran.
Purpose:
Alzheimer's disease (AD) and mild cognitive impairment (MCI) are characterized by both aberrant regional neural activity and disrupted inter-regional functional connectivity (FC). However, the effect of AD/MCI on the coupling between regional neural activity (measured by regional fluorodeoxyglucose imaging (rFDG)) and inter-regional FC (measured by resting-state functional magnetic resonance imaging (rs-fMRI)) is poorly understood.
Methods:
We scanned 19 patients with MCI, 33 patients with AD, and 26 healthy individuals by simultaneous FDG-PET/rs-fMRI and assessed rFDG and inter-regional FC metrics (i.e., clustering coefficient and degree centrality). Next, we examined the potential moderating effect of disease status (MCI or AD) on the link between rFDG and inter-regional FC metrics using hierarchical moderated multiple regression analysis. We also tested this effect by considering interaction between disease status and inter-regional FC metrics, as well as interaction between disease status and rFDG.
Results:
Our findings revealed that both rFDG and inter-regional FC metrics were disrupted in MCI and AD. Moreover, AD altered the relationship between rFDG and inter-regional FC metrics. In particular, we found that AD moderated the effect of inter-regional FC metrics of the caudate, parahippocampal gyrus, angular gyrus, supramarginal gyrus, frontal pole, inferior temporal gyrus, middle frontal, lateral occipital, supramarginal gyrus, precuneus, and thalamus on predicting their rFDG. On the other hand, AD moderated the effect of rFDG of the parietal operculum on predicting its inter-regional FC metric.
Conclusion:
Our findings demonstrated that AD decoupled the link between regional neural activity and functional segregation and global connectivity across particular brain regions.
Insights
Alzheimer's disease (AD) disrupts the connection between brain activity and functional connectivity. This study reveals how AD alters these relationships in key brain regions, impacting neural communication.
Area of Science:
- Neuroscience
- Medical Imaging
- Cognitive Science
Background:
- Alzheimer's disease (AD) and mild cognitive impairment (MCI) exhibit altered regional neural activity and disrupted functional connectivity (FC).
- The interplay between regional neural activity (rFDG) and inter-regional FC (rs-fMRI) in AD/MCI remains unclear.
Purpose of the Study:
- To investigate the coupling between regional neural activity and inter-regional functional connectivity in Alzheimer's disease (AD) and mild cognitive impairment (MCI).
- To examine how disease status (AD/MCI) moderates the relationship between regional fluorodeoxyglucose uptake (rFDG) and functional connectivity (FC) metrics.
Main Methods:
- Simultaneous FDG-PET/rs-fMRI scans were performed on 19 MCI patients, 33 AD patients, and 26 healthy controls.
- Regional FDG uptake (rFDG) and inter-regional FC metrics (clustering coefficient, degree centrality) were assessed.
- Hierarchical moderated multiple regression analysis examined the moderating effect of disease status on the rFDG-FC link.
Main Results:
- Both rFDG and inter-regional FC were disrupted in MCI and AD patients.
- Alzheimer's disease significantly altered the relationship between rFDG and inter-regional FC metrics in multiple brain regions, including the caudate, parahippocampal gyrus, and thalamus.
- AD also moderated the predictive effect of parietal operculum rFDG on its inter-regional FC.
Conclusions:
- Alzheimer's disease decouples the relationship between regional neural activity and functional connectivity.
- These findings highlight specific brain regions where AD disrupts the integration of neural activity and network organization.
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