title: Amyloid deposition in early onset versus late onset Alzheimer's disease.
abstract: BACKGROUND
  Patients with early-onset Alzheimer's disease (EOAD) may differ from those with late-onset Alzheimer's disease (LOAD) in cognitive impairment profiles and clinical course. Postmortem studies also reported that EOAD has a greater pathologic burden than LOAD. We examined the effects of age at onset on the burden and distribution of amyloid plaques in patients with AD, using a statistical parametric mapping (SPM) and regions of interest (ROIs) analyses of the Pittsburgh compound B (PiB)-PET.
  
  
  METHODS
  We initially recruited 72 patients with AD who had completed the [11C] PiB-PET scan, but four patients were excluded due to familial AD or incomplete MRI data. Of the 68 patients, 61 were classified as PiB-positive (PiB+) and seven as PiB-negative (PiB-) using the measured global PiB uptake ratio values. Of the 61 patients with PiB+ AD, in order to maximize the effect of onset age, we excluded 20 patients in their 60 s. Thus among the remaining 41 patients, the amyloid deposition of only 17 patients with EOAD (age onset <60 years) and 24 patients with LOAD (onset age ≥70 years) were compared.
  
  
  RESULTS
  There were no significant differences in the global mean PiB index between EOAD and LOAD patients, whereas SPM and ROIs analyses showed that those with EOAD retained higher levels of PiB in the bilateral basal ganglia, bilateral thalamus, left superior temporal cortex, and left cuneus compared to those with LOAD.
  
  
  CONCLUSIONS
  Our findings demonstrated that EOAD patients differed from those with LOAD in the topography of amyloid deposition, which may partly account for the findings from previous studies that extrapyramidal symptoms and frontal dysfunction are more common in EOAD than in LOAD patients.
authors.affiliation: Samsung Medical Center, Department of Neurology, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hanna
authors.initials: H
authors.lastname: Cho
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Seo
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Mee Kyung
authors.initials: MK
authors.lastname: Suh
authors.forename: Jae-Hong
authors.initials: JH
authors.lastname: Lee
authors.forename: Yearn Seong
authors.initials: YS
authors.lastname: Choe
authors.forename: Kyung-Han
authors.initials: KH
authors.lastname: Lee
authors.forename: Jae Seung
authors.initials: JS
authors.lastname: Kim
authors.forename: Geon Ha
authors.initials: GH
authors.lastname: Kim
authors.forename: Young
authors.initials: Y
authors.lastname: Noh
authors.forename: Byoung Seok
authors.initials: BS
authors.lastname: Ye
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Cindy W
authors.initials: CW
authors.lastname: Yoon
authors.forename: Juhee
authors.initials: J
authors.lastname: Chin
authors.forename: Duk L
authors.initials: DL
authors.lastname: Na
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000378:metabolism*; D000682:Amyloid / Q000378:metabolism*; D000814:Aniline Compounds; D053327:Apolipoprotein E4 / Q000235:genetics; D003627:Data Interpretation, Statistical; D005260:Female; D005838:Genotype; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D011597:Psychomotor Performance / Q000502:physiology; D019275:Radiopharmaceuticals; D018401:Sample Size; D013844:Thiazoles
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D000682:Amyloid; D000814:Aniline Compounds; D053327:Apolipoprotein E4; D019275:Radiopharmaceuticals; D013844:Thiazoles