title: Relationship of amyloid-β burden with age-at-onset in Alzheimer disease.
abstract: OBJECTIVE
  To investigate the relationship between in vivo brain amyloid-beta (Aβ) burden, measured by C-labeled Pittsburgh Compound B (C-PiB) retention, and age-at-onset in patients with Alzheimer disease (AD).
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  University Dementia Clinic.
  
  
  METHODS
  Twenty-two AD patients including 11 early-onset AD (EOAD: onset <65 years) and 11 late-onset AD (LOAD: onset ≥65years) cases with matched dementia severity, duration of illness, and apolipoprotein E ε4 allele number.
  
  
  METHODS
  C-PiB positron emission tomography scans.
  
  
  METHODS
  Both region of interest and voxel-based analyses were performed to compare C-PiB retention between EOAD and LOAD groups, and to test linear relationship between age-at-onset and C-PiB retention.
  
  
  RESULTS
  Both region of interest (ROI) and voxel-based analyses revealed that EOAD patients had significantly higher C-PIB retentions than LOAD patients in diffuse brain regions including frontal, lateral parietal, lateral temporal, and occipital cortex, and basal ganglia. Subgroup analyses showed that negative correlation between age-at-onset and C-PiB retention was significant in LOAD but not in EOAD.
  
  
  CONCLUSIONS
  Our finding of a heavier Aβ burden in the brain of living EOAD patients than LOAD patients is in agreement with those from postmortem studies. The inverse relationship between age-at-onset and Aβ burden is possibly associated with aging-related decrease of brain or cognitive reserve and with aging-related increase of brain vulnerability.
authors.affiliation: Department of Neuropsychiatry and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Il Han
authors.initials: IH
authors.lastname: Choo
authors.forename: Dong Young
authors.initials: DY
authors.lastname: Lee
authors.forename: Jee Wook
authors.initials: JW
authors.lastname: Kim
authors.forename: Eun Hyun
authors.initials: EH
authors.lastname: Seo
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
authors.forename: Yu Kyeong
authors.initials: YK
authors.lastname: Kim
authors.forename: Shin Gyeom
authors.initials: SG
authors.lastname: Kim
authors.forename: Shin Young
authors.initials: SY
authors.lastname: Park
authors.forename: Jong Inn
authors.initials: JI
authors.lastname: Woo
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Yoon
mesh_terms: D017668:Age of Onset; D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000503:physiopathology* / Q000523:psychology; D016229:Amyloid beta-Peptides / Q000378:metabolism* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography
chemical_list: D016229:Amyloid beta-Peptides