Dementia with Lewy bodies is similar in some ways to the dementia resulting from Alzheimer's disease. It also is manifested in symptoms similar to those of Parkinson's disease as well as in early development of hallucinations and pronounced variation in intellectual function, attention, and alertness.
It is often confused in its early stages with Alzheimer's disease and vascular dementia (multi-infarct dementia). No cause has been identified.
Dementia with Lewy bodies is also known under a variety of other names – for example, senile dementia of Lewy type. All incorporate the name Lewy.