PMC

AD Alzheimer's disease, FDG-PET [18F]fluorodeoxyglucose positron emission tomography, MRI structural magnetic resonance imaging.

AD Alzheimer's disease, FDG-PET [18F]fluorodeoxyglucose positron emission tomography, MMSE Mini Mental State Examination.

AD Alzheimer's disease, MMSE Mini Mental State Examination, MRI structural magnetic resonance imaging.

FDG-PET [18F]fluorodeoxyglucose positron emission tomography, GM grey matter, MRI structural magnetic resonance imaging.

Only clusters are shown exceeding a significance threshold of p = 0.001 uncorrected on voxel level and p = 0.05 FWE-corrected on cluster level. AD Alzheimer's disease, FDG-PET [18F]fluorodeoxyglucose positron emission tomography, MRI structural magnetic resonance imaging.

a) Schematic representation of age-related changes in one voxel (in %) considering GM volume at the age of 50 years as baseline. b) Schematic representation of changes related to healthy aging (black line) and age-related differences in AD (red line) in one voxel. Intersection age (dotted line) represents the age at which healthy aging in this voxel becomes similar to changes observed in AD. The hinge in the red line (aging in AD) at the intersection point indicates that after the intersection age, according to our assumption of the additive impact of AD related processes to healthy aging, the healthy aging model would apply in AD patients as no pathological processes in terms of atrophy or glucose hypometabolism are longer observable after this time point. c) Decrease (in %) in GM volume observed in an exemplary voxel in AD depending on the constellation of age and symptom severity (MMSE) relative to the baseline provided by healthy aging (violet line). AD Alzheimer's disease, GM grey matter, MMSE Mini Mental State Examination.