Validity of clinical criteria for the diagnosis of dementia with Lewy bodies

Objective: To assess the clinical validity of clinical diagnostic criteria for dementia with Lewy bodies (DLB). Methods: We assessed the sensitivity, specificity, and positive and negative predictive values of the clinical cr iteria of the Consortium on dementia with Lewy Bodies (CDLB) in 18 patients with autopsy-proven DLB and in 76 patients with dementia not associated wi th Lewy bodies, using postmortem diagnosis as a gold standard. Results: CDL B criteria had either high sensitivity or high specificity, but no set of c riteria simultaneously provided both high sensitivity and high specificity. Clinical criteria had higher predictive validity in patients with pure DLB than in patients with DLB and AD. Seventy-eight percent of patients with p ure DLB had two or more major criteria, compared with 44% of patients with DLB and AD (p < 0.02). If the nine patients with DLB and AD were excluded f i om the DLB group, the CDLB criteria for probable DLB had sensitivity of 7 8% and specificity of 85%. CDLB criteria for probable DLB (two or more majo r criteria) distinguished DLB from AD with a sensitivity of 78% and a speci ficity of 64%. Conclusions: The proposed CDLB criteria have high negative p redictive value and thus do well at excluding patients with DLB. Positive p redictive value of 75% can be achieved by a combination of any three major or minor criteria, providing the analysis is confined to patients with mild to moderate dementia. Criteria were most accurate if confined to patients with pure DLB who had mild to moderate dementia.