title: Structural correlates of early and late onset Alzheimer's disease: voxel based morphometric study.
abstract: OBJECTIVE
  To examine the brain structural correlates of age at onset in patients with Alzheimer's disease.
  
  
  METHODS
  We studied nine patients with early onset (age < or =65 years), nine with late onset (age > 65) Alzheimer's disease (EOAD and LOAD, respectively) of mild-moderate severity, and 26 controls who were stratified into younger (YC, age < or =65, n = 9) and older (OC, age > 65, n = 17) subjects. The patients were closely matched for clinical severity: 3/2/3/1 patients had clinical dementia rating of 0.5/1/2/3, respectively, in both the groups. High resolution magnetic resonance images of the brain of the EOAD and YC groups and the LOAD and OC groups were compared on a voxel by voxel basis with statistical parametric mapping to detect areas specifically atrophic.
  
  
  RESULTS
  The patients with EOAD showed greater neocortical atrophy at the temporoparietal junction while the patients with LOAD showed greater hippocampal atrophy. The results could not be accounted for by the apolipoprotein E genotype.
  
  
  CONCLUSIONS
  Since genetic factors are believed to play a relevant pathogenetic role in EOAD and environmental factors in LOAD, genetic and environmental factors may differentially predispose the neocortical and limbic areas to the development of Alzheimer's neuropathology.
authors.affiliation: Laboratory of Epidemiology and Neuroimaging, IRCCS San Giovanni di Dio-FBF, via Pilastroni 4, I-25123 Brescia, Italy. papers@centroAlzheimer.it
authors.forename: G B
authors.initials: GB
authors.lastname: Frisoni
authors.forename: C
authors.initials: C
authors.lastname: Testa
authors.forename: F
authors.initials: F
authors.lastname: Sabattoli
authors.forename: A
authors.initials: A
authors.lastname: Beltramello
authors.forename: H
authors.initials: H
authors.lastname: Soininen
authors.forename: M P
authors.initials: MP
authors.lastname: Laakso
mesh_terms: D017668:Age of Onset; D000368:Aged; D000465:Algorithms; D000544:Alzheimer Disease / Q000473:pathology*; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged