We investigated the associations between Boston Naming and the animal fluency tests and cortical atrophy in 19 probable AD and 5 multiple domain amnestic mild cognitive impairment patients who later converted to AD. We applied a surface-based computational anatomy technique to MRI scans of the brain and then used linear regression models to detect associations between animal fluency and Boston naming test (BNT) performance and cortical atrophy. The global permutation-corrected significance for the maps associating BNT performance with cortical atrophy was p=0.0124 for the left and p=0.0196 for the right hemisphere and for the animal fluency maps p=0.055 for the left and p=0.073 for the right hemisphere. The degree of language impairment correlated with cortical atrophy in the left temporal and parietal lobes (BA 20, 21, 37, 39, 40, 7), bilateral frontal lobes (BA 8, 9, 44) and the right temporal pole (BA 38). Using a novel 3D mapping technique, we demonstrated that in AD language abilities are strongly influenced by the integrity of the perisylvian cortical regions.

The Mini-mental State Examination (MMSE) is a brief cognitive screening instrument frequently used to track Alzheimer disease (AD) progression. We investigated the structural neuroimaging correlates of MMSE performance in patients with clinical and preclinical AD. We analyzed structural magnetic resonance imaging data from 29 probable AD and 5 MCI patients who later converted to probable AD using an advanced 3D cortical mapping technique. MMSE scores were entered as covariates in a general linear model that predicted the gray matter density at each cortical surface point. The results were corrected for multiple comparisons by permutation testing. The global permutation-corrected significance for the maps linking gray matter loss and cognitive decline was P=0.005 for the left and P=0.012 for the right hemisphere. Strongest correlations between MMSE score and gray matter integrity were seen in the entorhinal, parahippocampal, precuneus, superior parietal, and subgenual cingulate/orbitofrontal cortices. Significant correlations were also seen bilaterally in the temporal, the middle frontal and the left angular and supramarginal gyri. As a global cognitive measure, MMSE depends on the integrity of widely distributed cortical areas in both brain hemispheres with left-sided predominance.

PurposeThe aim of this study was to investigate the longitudinal positron emission tomography (PET) metabolic changes in the elderly.ProceduresNineteen nondemented subjects (mean Mini-Mental Status Examination 29.4 ± 0.7 SD) underwent two detailed neuropsychological evaluations and resting 2-deoxy-2-[F-18]fluoro-d-glucose (FDG)-PET scan (interval 21.7 ± 3.7 months), baseline structural 3T magnetic resonance (MR) imaging, and apolipoprotein E4 genotyping. Cortical PET metabolic changes were analyzed in 3-D using the cortical pattern matching technique.ResultsBaseline vs. follow-up whole-group comparison revealed significant metabolic decline bilaterally in the posterior temporal, parietal, and occipital lobes and the left lateral frontal cortex. The declining group demonstrated 10–15% decline in bilateral posterior cingulate/precuneus, posterior temporal, parietal, and occipital cortices. The cognitively stable group showed 2.5–5% similarly distributed decline. ApoE4-positive individuals underwent 5–15% metabolic decline in the posterior association cortices.ConclusionsUsing 3-D surface-based MR-guided FDG-PET mapping, significant metabolic changes were seen in five posterior and the left lateral frontal regions. The changes were more pronounced for the declining relative to the cognitively stable group.