title: Phenotypic differences based on staging of Alzheimer's neuropathology in autopsy-confirmed dementia with Lewy bodies.
abstract: The goal was to compare subgroups of dementia with Lewy Bodies (DLB) using neuropathological measures to differentiate 'pure' Lewy body (LB) dementia from 'mixed' DLB [co-occurring LB and Alzheimer's disease (AD) pathology] to facilitate diagnostic decision-making and future development of interventions based on predicted type(s) of neuropathology. Studies comparing these groups are rare relative to those differentiating 'pure' AD and all-cause DLB, and are limited by insufficient sample size, brief cognitive batteries, and/or absence of autopsy confirmation. To address these limitations, we assessed cognition and other features in a large, autopsy-confirmed DLB sample using an extensive neuropsychological battery.
  
  
  
  Subjects from an AD research center autopsy series satisfying DLB pathology criteria were divided by an AD neuropathology index into DLB-LB (Braak stage 0-3) (n = 38) and DLB-AD (Braak stage 4-6) (n = 41) and compared on baseline variables from chart reviews and standardized measures.
  
  
  
  DLB-LB subjects were more impaired on visuospatial constructions, visual conceptual reasoning, and speed of processing, but less impaired on verbal memory and confrontation naming. All-type hallucinations occurred more frequently in DLB-LB, while delusions were common in both groups. Groups were similar in education and age at onset, and in baseline age, dementia severity, and functional capacity.
  
  
  
  Salient findings included greater impairment on visual tasks and speed of processing and more frequent reports of all-type hallucinations in DLB-LB compared to DLB-AD. Relatively intact confrontation naming in DLB-LB and no differences in reported delusions were of note. Identifying differences in phenotypic features can improve prediction of underlying neuropathology.
authors.affiliation: Department of Neurosciences, University of California, San Diego, United States. Electronic address: gpeavy@ucsd.edu.
authors.forename: Guerry M
authors.initials: GM
authors.lastname: Peavy
authors.affiliation: Department of Neurosciences, University of California, San Diego, United States; Department of Family Medicine and Public Health, University of California, San Diego, United States.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Edland
authors.affiliation: Hahn School of Nursing and Health Science, University of San Diego, United States.
authors.forename: Belinda M
authors.initials: BM
authors.lastname: Toole
authors.affiliation: Department of Neurosciences, University of California, San Diego, United States; Department of Pathology, University of California, San Diego, United States.
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Hansen
authors.affiliation: Department of Neurosciences, University of California, San Diego, United States.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Galasko
authors.affiliation: Hahn School of Nursing and Health Science, University of San Diego, United States.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Mayo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000473:pathology* / Q000503:physiopathology*; D001344:Autopsy; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D004185:Disability Evaluation; D005260:Female; D006212:Hallucinations / Q000503:physiopathology; D006801:Humans; D020961:Lewy Body Disease / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D008297:Male; D000069338:Neuropathology; D009483:Neuropsychological Tests; D010641:Phenotype; D011569:Psychiatric Status Rating Scales
keywords: Alzheimer's disease; Behavior; Delusions; Dementia with Lewy bodies; Hallucinations; Neuropsychology; Parkinsonism