title: Amyloid deposition in semantic dementia: a positron emission tomography study.
abstract: Pittsburgh compound B ([11C]-PIB) identifies amyloid-β (Aβ) deposition in vivo. Asymptomatic Aβ deposition has been reported consistently in some healthy older subjects. Of patients with frontotemporal dementia, those who have later onset have a higher potential for Aβ deposition.
  
  
  
  Comparison of Aβ deposition in Alzheimer's disease (AD), healthy older controls, and patients with early- and late-onset semantic dementia (SD), a subtype of frontotemporal dementia.
  
  
  
  Subjects were recruited from tertiary academic care centers specializing in assessment and management of patients with neurodegenerative disease. We used the radiotracer [11C]-PIB in a high-resolution positron emission tomography scanner to evaluate 11 participants with SD (six with onset before age 65 and five with later onset), 9 with probable AD, and 10 controls over age 60. The main outcome measures were frontal, temporal, parietal, and total [11C]-PIB standardized uptake value ratios to establish PIB-positive (PIB+) cutoff.
  
  
  
  The five patients with late-onset SD were PIB-negative. Two of six with early-onset SD, seven of nine with AD, and 1 of 10 controls were PIB+. The SD participants who were PIB+ did not have memory or visuospatial deficits that are typical in AD.
  
  
  
  Aβ deposition does not seem to be associated with late-onset SD. Future larger studies might confirm whether a significant minority of early-onset SD patients exhibit Aβ deposition. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Eric E
authors.identifier: 0000-0002-1575-2606
authors.initials: EE
authors.lastname: Brown
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.|Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, Ontario, Canada.
authors.forename: Ariel
authors.initials: A
authors.lastname: Graff-Guerrero
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.|Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, Ontario, Canada.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Houle
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.|Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, Ontario, Canada.
authors.forename: Romina
authors.initials: R
authors.lastname: Mizrahi
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.|Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, Ontario, Canada.
authors.forename: Alan A
authors.initials: AA
authors.lastname: Wilson
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.|Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, Ontario, Canada.
authors.forename: Bruce G
authors.initials: BG
authors.lastname: Pollock
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.|Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, Ontario, Canada.
authors.forename: Benoit H
authors.initials: BH
authors.lastname: Mulsant
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Felsky
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.|Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, Ontario, Canada.
authors.forename: Aristotle N
authors.initials: AN
authors.lastname: Voineskos
authors.affiliation: University Health Network, Toronto, Ontario, Canada.
authors.forename: David F
authors.initials: DF
authors.lastname: Tang-Wai
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.|Baycrest Health Sciences, Toronto, Ontario, Canada.
authors.forename: Nicolaas P L G
authors.initials: NP
authors.lastname: Verhoeff
authors.affiliation: Baycrest Health Sciences, Toronto, Ontario, Canada.|Rotman Research Institute, Baycrest Health Sciences, Toronto, Ontario, Canada.|Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.|Department of Medicine, Division of Neurology, Mt. Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Morris
authors.initials: M
authors.lastname: Freedman
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.|Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, Ontario, Canada.|Departments of Psychiatry and Neurology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Zahinoor
authors.initials: Z
authors.lastname: Ismail
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.|Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, Ontario, Canada.|Baycrest Health Sciences, Toronto, Ontario, Canada.|Rotman Research Institute, Baycrest Health Sciences, Toronto, Ontario, Canada.|Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tiffany W
authors.initials: TW
authors.lastname: Chow
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000814:Aniline Compounds; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000378:metabolism*; D005260:Female; D057180:Frontotemporal Dementia / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019636:Neurodegenerative Diseases / Q000378:metabolism; D049268:Positron-Emission Tomography / Q000379:methods; D013844:Thiazoles
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D013844:Thiazoles
keywords: Alzheimer disease; Pittsburgh compound B; amyloid; frontotemporal dementia; positron emission tomography; semantic dementia