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Updated: Sep 21, 2026
Application of Granger Causality Analysis of the Directed Functional Connection in Alzheimer's Disease and Mild Cognitive Impairment
Published on: August 7, 2017
Subregional Functional Connectivity of the Precuneus as a Preclinical Biomarker in Alzheimer's Disease
Claudia Aponte1,2, Antonio Jimenez-Marín3, Malen Razkin3
1Grupo Neuropsicología y Conducta, School of Medicine, Universidad de Antioquia, Medellín, Colombia, udea.edu.co.
Introduction:
The precuneus (Pc) is a central hub integrating diverse brain functions, and it is early involved in Alzheimer's disease (AD) pathophysiology, yet its subregional vulnerability remains poorly understood. This study aims to delineate the differential involvement and vulnerability of these subdivisions in the early stages of AD.
Methods:
We conducted a resting-state FC analysis of Pc subregions in 32 cognitively unimpaired carriers of the PSEN1 E280A mutation compared to 25 noncarriers using seed-based analyses.
Results:
As compared to noncarriers, we found that the group of asymptotic carriers had increased connectivity from the 7Am subregion toward the entorhinal cortex, superior temporal gyrus, insula-operculum, dlPFC, and somatosensory areas. Moreover, the POS2 subregion significantly decreased connectivity with the anterior insula and dlPFC. Higher MoCA scores correlated with increased connectivity within and between the Pc and frontoparietal networks.
Discussion:
These results reveal distinct patterns of early functional reorganization and support the subregional Pc analysis in identifying sensitive biomarkers for preclinical AD, often overlooked in conventional whole-region analyses.
