Hippocampal and amygdala volumetry by MRI in elderly with normal or mildly impaired cognition using FreeSurfer software

Abstract

Introduction. Decreased hippocampal and amygdala volume has been associated with cognitive impairment. This study compared hippocampal and amygdala volumes in older adults with normal cognition and mild cognitive impairment (MCI) using magnetic resonance imaging (MRI) with FreeSurfer software. Material and Methods. This cross-sectional study analyzed clinical information and MRI scans obtained from the ADNI-GO and ADNI-2 databases. Participants with normal cognition or MCI were enrolled based on the Clinical Dementia Rating (CDR) and Mini-Mental State Examination (MMSE) scales. Older adults were categorized by cognitive status (normal and MCI) and age (60-75 and 76-90 years). Hippocampal and amygdala volumes were compared with cerebral MRI using FreeSurfer software. Results. Older adults, 62 with normal cognition and 62 with MCI, were included. Hippocampal volume was significantly lower in the MCI group (right hippocampus 3166 ± 605 mm3 and left hippocampus 3121 ± 515 mm3) than in the normal cognition group (right hippocampus 3685 ± 456 mm3 and left hippocampus 3550 ± 437 mm3) (p < 0.001). The amygdala was significantly smaller in the MCI group (right amygdala 1340 ± 322 mm3 and left amygdala 1149 ± 262 mm3) than the older adults with normal cognition group (right amygdala 1573 ± 249 mm3 and left amygdala 1514 ± 221 mm3) (p = 0.001). The hippocampal and amygdala volumes were significantly lower in the MCI group, regardless of age. Conclusion. In our study, decreased hippocampal and amygdala volumes in older adults were associated with MCI. MRI assessment in older adults may be a useful tool to monitor cognitive status.

Keywords

• Hippocampal volume. Amygdala volume. Elderly. Normal cognition. Mild cognitive impairment. Cerebral MRI.