These criteria are proposed as being able to predict with high likelihood that dementia is associated with cortical Lewy bodies. They represent a refinement of earlier criteria proposed for Lewy body dementia. They are potentially applicable to patients with idiopathic Parkinson's disease who subsequently develop dementia. These criteria do not exclude the presence of concomitant Alzheimer pathology and many patients may simultaneously meet guidelines for the clinical diagnosis of Alzheimer's disease.

1. The central feature required for a diagnosis of DLB is progressive cognitive decline of sufficient magnitude to interfere with normal social or occupational function. Prominent or persistent memory impairment may not necessarily occur in the early stages, but is usually evident with progression. Deficits on tests of attention and of frontal-subcortical skills and visuospatial ability may be especially prominent.

2. […]