Chapter 2 - Patterns of gray matter loss in different manifestations of Alzheimer ’ s disease

We assessed patterns of grey matter atrophy according to age-at-onset in a large sample of 215 AD patients and 129 controls with voxel-based morphometry using 3Tesla 3DT1 magnetic resonance imaging. Local grey matter amounts were compared between lateand early-onset AD patients and older and younger controls, taking into account the effect of APOE. Additionally, combined effects of age and diagnosis on volumes of hippocampus and precuneus were assessed. Compared to age-matched controls, late-onset AD patients exhibited atrophy of hippocampus, right temporal lobe and cerebellum, whereas early-onset AD patients showed GM atrophy in hippocampus, temporal lobes, precuneus, cingulate gyrus, and inferior frontal cortex. Direct comparisons between lateand early-onset AD revealed more pronounced atrophy of precuneus in early-onset AD patients and more severe atrophy in medial temporal lobe in late-onset AD patients. Age and diagnosis independently affected hippocampus; moreover, the interaction between age and diagnosis showed that precuneus atrophy was most prominent in early-onset AD. Our results suggest that patterns of atrophy may vary in the spectrum of AD.