Fig. 1.

Cortical atrophy in aMCI. (A) Regions of the default mode network tested in this study. Right and left side thickness and volumes were combined. The green area near the temporal lobe is representative of the hippocampus. (B) The middle temporal lobe and the parahippocampal gyrus showed significant thinning in the aMCI phenotype compared with the cognitively normal individuals. (C) The thickness reductions in the aMCI subjects were observed regardless of disease origins. Amnestic MCI subjects from ADNI and PPMI both show decreased cortical thickness in the middle temporal gyrus and parahippocampal gyrus. (D) Although hippocampal atrophy was not significant, the slope of the relationship between hippocampal volume and age was significantly steeper in the aMCI individuals (golden ⋄) compared with the cognitively normal group (black •). (E) This relationship in (D) was maintained even when the cohort was refined to include only amyloid-negative controls, and amyloid-positive AD-MCI subject and amyloid-negative PD-MCI subjects. ∗ Denotes mean values for each group, Normal, AD, and PD. Abbreviations: AD, Alzheimer's disease; ADNI, Alzheimer's Disease Neuroimaging Initiative; aMCI, amnestic mild cognitive impairment; MCI, mild cognitive impairment; PD, Parkinson's disease; PPMI, Progressive Parkinson's Markers Initiative.