Dementia with Lewy bodies: reliability and validity of clinical and pathologic criteria.

Clinical criteria for dementia with Lewy bodies (DLB) have been proposed, but their formulation, reliability, and validity require further study. Pathologic criteria for DLB are also undergoing evolution. Two studies were conducted with the goal of identifying the components of these evolving criteria that may benefit from further refinement; one study evaluated the components of the clinical criteria and another study operationalized the pathologic criteria for DLB. Twenty-four patients with a premorbid diagnosis of probable or possible Alzheimer's disease (AD) (n = 18), Parkinson's disease (PD) (n = 5), or progressive supranuclear palsy (PSP) (n = 1) were studied. Inter-rater reliability and validity of the clinical criteria were determined by a retrospective chart review, done by five neurologists, and a blinded pathologic evaluation. The Consortium on dementia with Lewy bodies (CDLB) pathologic criteria were operationalized to compare past criteria and test the validity of the evolving clinical criteria on the dementia patients. Three or more cortical fields (at 250 x magnification) with many (four or more) Lewy bodies (LBs) on ubiquitin immunoreactive sections were required to meet the CDLB neocortical score of > 6. Fifteen of the AD patients had at least one LB in a cortical section, four had many LBs, while three had no LBs; all patients with movement disorder had at least one LB in a cortical section. The sensitivity/specificity ratio of the CDLB probable DLB clinical criteria based upon many LBs being present was 75%/79%. Reformulated clinical criteria that require the presence of extrapyramidal signs significantly predicted those patients with many LBs versus those with few or no LBs (chi 2 = 5.48, p = 0.02) and increased clinical specificity to 100%. This preliminary study identifies components of the evolving clinical and pathologic criteria for DLB that require further refinement.