title: Age of onset and brain atrophy in Alzheimer's disease.
abstract: Using magnetic resonance imaging-based planimetry, we measured cortical and cerebral (cortical and ventricular) atrophy in 26 patients with Alzheimer's disease (AD) (age, 72.2 +/- 7.0) according to NINCDS-ADRDA criteria and 22 control subjects (age, 71.5 +/- 5.4). AD patients exhibited greater cerebral atrophy (p < .05) than control subjects. Cerebral atrophy was significantly correlated with age (r = .72, p < .0005) in healthy volunteers but not in AD patients. In AD patients, age of onset was negatively correlated with the estimated rate of disease-attributed cerebral degeneration ([observed atrophy--atrophy in normal aging calculated from the regression equation derived from the control group]/[duration of illness]) (r = -.54, p < .005). Multiple regression with interaction analysis demonstrated that age, age of onset, and their interaction successfully explained cerebral (R2 = .51, p < .05) and cortical (R2 = .64, p < .05) atrophy in patients with probable AD. Age of onset may be a strong predictor of the rate of cerebral degeneration in AD, and our results suggest that controlling age and the age of onset is essential in the quantitative study of AD.
authors.affiliation: Department of Psychiatry, Seoul National University College of Medicine, Korea.
authors.forename: J I
authors.initials: JI
authors.lastname: Woo
authors.forename: J H
authors.initials: JH
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000453:epidemiology; D001284:Atrophy; D002540:Cerebral Cortex / Q000473:pathology*; D002552:Cerebral Ventricles / Q000473:pathology; D005260:Female; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D012016:Reference Values