title: Extremely Low Prevalence of Amyloid Positron Emission Tomography Positivity in Parkinson's Disease without Dementia.
abstract: Most cases of dementia with Lewy bodies (DLB) show Alzheimer's disease pathology-like senile plaques and neurofibrillary tangles. Several studies have also revealed a high prevalence of positive amyloid imaging with positron emission tomography (PET) in DLB and moderate prevalence in Parkinson's disease (PD) with dementia. However, it remains unclear in PD without dementia as to when the brain β amyloid (Aβ) burden begins and progresses. Our study aimed to determine the prevalence of Aβ deposition in PD without dementia using amyloid PET.
  
  
  
  This was a cross-sectional study on 33 patients with PD without dementia, of whom 21 had normal cognition and 12 met the criteria for PD-mild cognitive impairment. All subjects underwent neuropsychological assessment and [18F] florbetaben (FBB) PET.
  
  
  
  All subjects had Lewy body-related disorders, displaying a significantly reduced myocardial [123I] metaiodobenzylguanidine uptake. The cortical FBB-binding pattern in all subjects, including APOE e4 carriers, suggested negative Aβ deposition.
  
  
  
  Patients with PD without dementia exhibit an extremely low prevalence of Aβ positivity compared with those reported in cognitively normal elderly controls. Further longitudinal imaging studies and long-term follow-up are needed; however, our findings provide novel insights for understanding Aβ metabolism in PD.
authors.affiliation: Department of Neurology, Keio University School of Medicine, Tokyo, Germany.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Mashima
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ito
authors.forename: Masashi
authors.initials: M
authors.lastname: Kameyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Osada
authors.forename: Hajime
authors.initials: H
authors.lastname: Tabuchi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nihei
authors.forename: Takahito
authors.initials: T
authors.lastname: Yoshizaki
authors.forename: Eri
authors.initials: E
authors.lastname: Noguchi
authors.forename: Mariko
authors.initials: M
authors.lastname: Tanikawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Iizuka
authors.forename: Yugaku
authors.initials: Y
authors.lastname: Date
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ogata
authors.forename: Tadaki
authors.initials: T
authors.lastname: Nakahara
authors.forename: Yu
authors.initials: Y
authors.lastname: Iwabuchi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Jinzaki
authors.forename: Koji
authors.initials: K
authors.lastname: Murakami
authors.forename: Norihiro
authors.initials: N
authors.lastname: Suzuki
mesh_terms: D000368:Aged; D000682:Amyloid / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D049268:Positron-Emission Tomography; D015995:Prevalence
chemical_list: D000682:Amyloid
keywords: Alzheimer’s disease; Amyloid imaging; Dementia; Florbetaben; Mild cognitive impairment; Parkinson’s disease; Positron emission tomography; β amyloid