title: Pathology and temporal onset of visual hallucinations, misperceptions and family misidentification distinguishes dementia with Lewy bodies from Alzheimer's disease.
abstract: OBJECTIVE
  To determine whether the temporal onset of visual phenomena distinguishes Lewy body disease (LBD) from Alzheimer's disease (AD), and to characterize the extent Lewy bodies and neurofibrillary tangles are associated with these clinical features.
  
  
  METHODS
  Consecutive cases of autopsy-confirmed LBD (n = 41), AD (n = 70), and AD with amygdala-predominant Lewy bodies (AD-ALB) (n = 14) with a documented clinical history of dementia were included. We mailed questionnaires to next-of-kin asking about symptoms during life. Lewy pathology and neurofibrillary tangle pathology were assessed.
  
  
  RESULTS
  The occurrence of visual hallucinations, misperceptions and family misidentification did not distinguish LBD from AD or AD-ALB, but the onset was earlier in LBD compared to AD and AD-ALB. When visual hallucinations developed within the first 5 years of dementia, the odds were 4-5 times greater for autopsy-confirmed LBD (or intermediate/high likelihood dementia with Lewy bodies) and not AD or AD-ALB. In LBD, limbic but not cortical Lewy body pathology was related to an earlier onset of visual hallucinations, while limbic and cortical Lewy body pathology were associated with visual misperceptions and misidentification. Cortical neurofibrillary tangle burden was associated with an earlier onset of misidentification and misperceptions in LBD and AD, but only with earlier visual hallucinations in AD/AD-ALB.
  
  
  CONCLUSIONS
  When visual hallucinations occur within the first 5 years of the dementia, a diagnosis of LBD was more likely than AD. Visual hallucinations in LBD were associated with limbic Lewy body pathology. Visual misperceptions and misidentification delusions were related to cortical Lewy body and neurofibrillary tangle burden in LBD and AD/AD-ALB.
authors.affiliation: Mayo Clinic, Jacksonville, FL 32224, USA. ferman.tanis@mayo.edu
authors.forename: T J
authors.initials: TJ
authors.lastname: Ferman
authors.forename: Z
authors.initials: Z
authors.lastname: Arvanitakis
authors.forename: H
authors.initials: H
authors.lastname: Fujishiro
authors.forename: R
authors.initials: R
authors.lastname: Duara
authors.forename: F
authors.initials: F
authors.lastname: Parfitt
authors.forename: M
authors.initials: M
authors.lastname: Purdy
authors.forename: C
authors.initials: C
authors.lastname: Waters
authors.forename: W
authors.initials: W
authors.lastname: Barker
authors.forename: N R
authors.initials: NR
authors.lastname: Graff-Radford
authors.forename: D W
authors.initials: DW
authors.lastname: Dickson
mesh_terms: D017668:Age of Onset; D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000473:pathology* / Q000523:psychology*; D001344:Autopsy; D001921:Brain / Q000473:pathology*; D003702:Delusions / Q000209:etiology; D005260:Female; D006212:Hallucinations / Q000209:etiology*; D006801:Humans; D020961:Lewy Body Disease / Q000150:complications / Q000473:pathology* / Q000523:psychology*; D008297:Male; D016874:Neurofibrillary Tangles / Q000473:pathology