What best differentiates Lewy body from Alzheimer's disease in early-stage dementia?

Brain. 2006 Mar;129(Pt 3):729-35. doi: 10.1093/brain/awh725. Epub 2006 Jan 9.


To determine which clinical feature(s) [among visual hallucinations (VH), extrapyramidal signs (EPS) and visuospatial impairment] in the earliest stages of disease best predicted a diagnosis of dementia with Lewy bodies (DLB) at autopsy, first-visit data of 23 pathologically proven DLB and 94 Alzheimer's disease cases were compared. There were no group differences with regard to age, gender, education or global severity of dementia at presentation (mean Mini-Mental State Examination: 24.0 versus 25.0, mean Dementia Rating Scale: 123.6 versus 125.7). DLB patients at initial presentation displayed an increased frequency of VH (P = 0.001), but not EPS (P = 0.3), compared to Alzheimer's disease patients. However, only a minority of DLB cases had either VH (22%), EPS (26%) or both (13%). In contrast, although not a core feature, visuospatial/constructional impairment was observed in most of the DLB cases (74%). Among clinical variables, presence/recent history of VH was the most specific to DLB (99%), and visuospatial impairment was the most sensitive (74%). As a result, VH at presentation were the best positive predictor of DLB at autopsy (positive predictive value: 83% versus 32% or less for all other variables), while lack of visuospatial impairment was the best negative predictor (negative predictive value: 90%). We conclude that the best model for differentiating DLB from Alzheimer's disease in the earliest stages of disease includes VH and visuospatial/constructional dysfunction, but not spontaneous EPS, as predictors. This suggests that clinical history plus a brief assessment of visuospatial function may be of the greatest value in correctly identifying DLB early during the course of disease.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Alzheimer Disease / diagnosis*
  • Alzheimer Disease / pathology
  • Alzheimer Disease / psychology
  • Diagnosis, Differential
  • Female
  • Hallucinations / etiology
  • Humans
  • Lewy Body Disease / diagnosis*
  • Lewy Body Disease / pathology
  • Lewy Body Disease / psychology
  • Male
  • Neuropsychological Tests
  • Orientation
  • Perceptual Disorders / etiology
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • Visual Perception