original_query: What is the distinction between "diffuse Lewy body dementia" and the umbrella term "Lewy body dementia"?
query: What is the distinction between "diffuse Lewy body dementia" and the umbrella term "Lewy body dementia"?
answer: Diffuse Lewy body dementia (more commonly called diffuse Lewy body disease) refers to the underlying disease process, while the umbrella term "Lewy body dementia" encompasses both Parkinson's disease dementia (PD) and dementia with Lewy bodies (DLB).  In early PD, Lewy bodies are limited in distribution, but in DLB, they are spread widely throughout the brain, as was the case with Robin Williams.