“Lewy bodies are clumps of abnormal protein particles that, for reasons that are not fully understood, accumulate in the brain. These deposits cause a form of dementia called Lewy body dementia, or LBD — which is what the late actor and comedian Robin Williams suffered from.

LBD is not the same as Parkinson’s, but the two are closely related: LBD causes some or all of the motor symptoms of Parkinson’s. More than 1 million people in the U.S. are affected by Lewy body dementia, according to the Lewy Body Dementia Association.”

John Hopkins Medicine