Sensitivity and specificity of three clinical criteria for dementia with Lewy bodies in an autopsy-verified sample

Objective. To evaluate the sensitivity and specificity of the clinical feat ures of three published diagnostic criteria for diffuse Lewy body disease ( DLBD) using autopsy-confirmed Alzheimer's (AD), DLBD and AD + DLBD (mixed) dementia cases. Design. Retrospective chart review of an autopsy series of 56 patients sele cted from the State of Florida Brain Bank on the basis of a pathological di agnosis of either pure AD, DLBD (pure and common forms) or AD + DLBD (mixed ) dementia. Clinical features were assessed by three raters blind to the pa thological diagnosis. Results. The existing criteria for a clinical diagnosis of DLBD were highly specific (90- 100 %) but not very sensitive (49-63%) in the differential d iagnosis of DLBD versus AD; sensitivity did improve (61-74%) when mixed AD + DLBD cases were eliminated. Clinical features that occur more frequently in DLBD than in AD were unspecified hallucinations, unspecified EPS, fluctu ating course and rapid progression. Post-hoc analysis also indicated that h allucinations and EPS were more common early in the disease course of DLBD than in AD. Empirically derived criteria, formulated using the most prevale nt clinical features, demonstrated sensitivity values of 57-96% for pure fo rms and 43-91% for mixed forms. Conclusions. This study demonstrated that additional improvements in the es tablished criteria for DLBD are needed. Our empirically derived criteria en hanced the distinction of DLBD from AD while allowing the clinician the cho ice of maximizing sensitivity with acceptable specificity, and vice versa. Copyright (C) 1999 John Wiley & Sons, Ltd.