Hippocampal Atrophy Patterns Across the Alzheimer's Disease Spectrum: A Voxel-Based Morphometry Analysis
This work provides incremental insights into brain atrophy patterns for Alzheimer's disease research, aiding biomarker development.
The study analyzed hippocampal atrophy patterns in Alzheimer's disease (AD) and mild cognitive impairment (MCI) using voxel-based morphometry on MRI scans from 249 participants, finding significant atrophy in AD with large effect sizes (Cohen's d = 2.03 and 1.61) and moderate predictive value for MCI-to-AD conversion (AUC = 0.66).
Alzheimer's disease (AD) and mild cognitive impairment (MCI) are associated with progressive gray matter loss, particularly in medial temporal structures. In this study, CAT12/SPM12 voxel-based morphometry was applied to baseline T1-weighted MRI scans from 249 ADNI participants (CN = 90, MCI = 129, AD = 30). Gray matter volume was analyzed using a general linear model, with the diagnostic group as primary predictor and age and total intracranial volume as covariates. Statistical maps were thresholded at p < 0.001 (voxelwise) and corrected for multiple comparisons at the cluster level using family-wise error (FWE) correction (p < 0.05). Significant hippocampal atrophy was observed in AD relative to CN and MCI (Cohen's d = 2.03 and 1.61, respectively). Hippocampal volume demonstrated moderate predictive value for conversion from MCI to AD (AUC = 0.66). Stratification by APOE4 status did not reveal significant genetic effects on cross-sectional hippocampal volume. These results support medial temporal degeneration as a key feature of AD progression and provide insights into predictive biomarkers and genetic influences.