title: Clinical features of Pittsburgh compound-B-negative dementia.
abstract: OBJECTIVE
  We previously found that some cases of clinically diagnosed Alzheimer's disease (AD) were rated as Pittsburgh compound B (PiB) negative by amyloid imaging (i.e. cases of PiB-negative dementia). The present study was designed to analyze the clinical features of PiB-negative dementia patients in detail.
  
  
  METHODS
  Of the 64 cases of clinically diagnosed AD, 14 were rated PiB negative. Eleven of these were further analyzed using CSF biomarker levels and findings from MRI, FDG-PET, (123)I-MIBG myocardial scintigraphy and voxel-based morphometry (VBM).
  
  
  RESULTS
  When examined by (123)I-MIBG myocardial scintigraphy, the heart/mediastinum ratio was significantly higher in the PiB-negative dementia group than in the dementia with Lewy bodies (DLB) group. Analyses of CSF biomarkers and MRI and FDG-PET findings suggested argyrophilic grain disease (AGD) in 3 cases, frontotemporal lobar degeneration (FTLD) in 3 cases, neurofibrillary tangle-predominant dementia (NFTD) in 1 case, and AD in 2 cases. In the VBM data analysis, the PiB-positive AD group showed significant atrophy of both hippocampi compared with the healthy control group, while the PiB-negative dementia group presented with significant atrophy of the left precuneus.
  
  
  CONCLUSIONS
  PiB-negative dementia is unlikely to include DLB, while it most likely includes diseases of tauopathy, such as FTLD, AGD and NFTD. A better understanding of PiB-negative dementia is expected to further improve the accuracy of the clinical AD diagnosis.
authors.affiliation: Department of Geriatrics and Neurology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Takeuchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shimada
authors.forename: Suzuka
authors.initials: S
authors.lastname: Ataka
authors.forename: Joji
authors.initials: J
authors.lastname: Kawabe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mori
authors.forename: Kei
authors.initials: K
authors.lastname: Mizuno
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Wada
authors.forename: Susumu
authors.initials: S
authors.lastname: Shiomi
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Takami
authors.initials: T
authors.lastname: Miki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D000814:Aniline Compounds / Q000378:metabolism*; D016022:Case-Control Studies; D003704:Dementia / Q000175:diagnosis / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007457:Iodine Radioisotopes; D020961:Lewy Body Disease / Q000175:diagnosis / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D013844:Thiazoles / Q000378:metabolism*; D016875:tau Proteins / Q000134:cerebrospinal fluid
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D013844:Thiazoles; D016875:tau Proteins; D019788:Fluorodeoxyglucose F18