Map of Brain Networks Extracting from Resting- State fMRI in Alzheimer’s Disease, Amnestic Mild Cognitive Impairment, and Normal Aging Subjects

Abstract

Purpose:
Evaluation of the resting-state brain networks map in Alzheimer’s disease, amnestic mild cognitive impairment, and normal aging subjects.

Methods:
The resting-state functional Magnetic Resonance Imaging data of 13 patients with Alzheimer’s disease, 16 patients with amnestic mild cognitive impairment, and 14 normal aging subjects were evaluated using functional
connectivity analysis. Preprocessing steps were realignment, slice timing correction, segmentation, co-registration, normalization, and functional smoothing. In the second-level measurement, ROI-ROI/seed-based analysis using bivariate correlation coefficient and Fisher z-transformation was performed.

Results:
Using parametric statistics (cluster threshold: p < 0.05 p-False Discovery Rate corrected; voxel threshold: p < 0.001 p-uncorrected) group differences were found between Alzheimer’s disease and normal aging and also between Alzheimer’s disease and amnestic mild cognitive impairment. Using parametric multivariate statistics (cluster threshold: p < 0.05 p-False Discovery Rate corrected; connection threshold: p < 0.05 p-uncorrected), differences were found in the map of the three groups. No significant difference was found between the two groups of normal and amnestic mild cognitive impairment.

Conclusions:
The map of statistical correlation in the resting-state brain network (matrix display) of the three groups was different (The number of positive and negative correlations and the strength of connections between the nodes of the resting-state networks differed). Also, seed- based functional connectivity analysis and the resulting spatial map showed differences between Alzheimer’s disease – amnestic mild cognitive impairment and Alzheimer’s disease
– normal aging groups.