title: Re-evaluation of clinical dementia diagnoses with pittsburgh compound B positron emission tomography.
abstract: OBJECTIVE
  There is an overlap regarding Pittsburgh compound B (PIB) retention in patients clinically diagnosed as Alzheimer's disease (AD) and non-AD dementia. The aim of the present study was to investigate whether there are any differences between PIB-positive and PIB-negative patients in a mixed cohort of patients with neurodegenerative dementia of mild severity regarding neuropsychological test performance and regional cerebral glucose metabolism measured with [(18)F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET).
  
  
  METHODS
  Eighteen patients clinically diagnosed as probable AD or frontotemporal dementia were examined with PIB PET, FDG PET and neuropsychological tests and followed for 5-9 years in a clinical setting.
  
  
  RESULTS
  The PIB-positive patients (7 out of 18) had slower psychomotor speed and more impaired visual episodic memory than the PIB-negative patients; otherwise performance did not differ between the groups. The initial clinical diagnoses were changed in one third of the patients (6 out of 18) during follow-up.
  
  
  CONCLUSIONS
  The subtle differences in neuropsychological performance, the overlap of hypometabolic patterns and clinical features between AD and non-AD dementia highlight the need for amyloid biomarkers and a readiness to re-evaluate the initial diagnosis.
authors: Department of Public Health/Geriatrics, Uppsala University, Uppsala, Stockholm, Sweden.
authors: M
authors: M
authors: Degerman Gunnarsson
authors: Department of Public Health/Geriatrics, Uppsala University, Uppsala, Stockholm, Sweden ; Department of Psychology, Stockholm University, Stockholm, Stockholm, Sweden.
authors: M
authors: M
authors: Lindau
authors: Geriatric Psychiatry, Department of Clinical Medicine, Lund University, Lund, Stockholm, Sweden.
authors: A F
authors: AF
authors: Santillo
authors: Section of Nuclear Medicine and PET, Department of Radiology, Oncology and Radiation Sciences, Uppsala University, Uppsala, Stockholm, Sweden.
authors: A
authors: A
authors: Wall
authors: Faculty of Medicine and Faculty of Science, University of the Republic Uruguay, Montevideo, Uruguay.
authors: H
authors: H
authors: Engler
authors: Department of Public Health/Geriatrics, Uppsala University, Uppsala, Stockholm, Sweden.
authors: L
authors: L
authors: Lannfelt
authors: Department of Public Health/Geriatrics, Uppsala University, Uppsala, Stockholm, Sweden ; BioArctic Neuroscience AB, Stockholm, Sweden.
authors: H
authors: H
authors: Basun
authors: Department of Public Health/Geriatrics, Uppsala University, Uppsala, Stockholm, Sweden.
authors: L
authors: L
authors: Kilander
keywords: Alzheimer's disease; Amyloid biomarker; Dementia with Lewy bodies; Episodic memory; Frontotemporal dementia; Neuropsychological tests; Pittsburgh compound B positron emission tomography; Trail Making Test, part A; [18F]Fluoro-2-deoxy-D-glucose positron emission tomography; β-Amyloid