Robin Williams was diagnosed with a form of dementia in his final months, but did not know it, according to a new biography.
Mr Williams’ autopsy report showed he had severe Lewy body dementia; doctors who reviewed the report say it was one of the worst cases they had seen.
However, in the months before he died Mr Williams was diagnosed with Parkinson’s disease.
Lewy body dementia is the second-most common form of dementia after Alzheimer’s disease. The illness causes protein deposits in the brain that affect thinking, memory, emotions, and body movements.
The disease is notoriously hard to diagnose because its symptoms are similar to those of Alzheimer’s disease, Parkinson’s disease, and psychiatric illnesses.
One of the key differences between the diseases can be that Lewy body dementia progresses more quickly than the others.
In his book, Robin, author Dave Itzkoff says that in the months before he died, Mr Williams struggled to remember lines, had trouble controlling his emotions, developed a slight tremor in his hand, was anxious, had trouble sleeping, and lost his sense of smell.
His symptoms first began appearing in 2013; he died in 2014.
While all these symptoms can now be attributed to Lewy body dementia, at the time they were attributed to Parkinson’s disease.
Would a correct diagnosis have helped: “We will never have the answer”
After he died, his third wife, Susan Schneider Williams, wrote an article for the journal Neurology, describing her husband before he died and calling for further research.
“I am writing to share a story with you, specifically for you. My hope is that it will help you understand your patients along with their spouses and caregivers a little more,” she wrote.
Mrs Williams wrote that her husband battled all 40 of the symptoms of Lewy body dementia, but questioned if a diagnosis would have helped them before he died.
“We will never know the answer to this,” she wrote.
Robin Williams won academy awards in 1987 for his portrayal of a Vietnam radio host in Good Morning, Vietnam, and in 1997 for Good Will Hunting. In the 1970s he became a household name for his role as Mork in Mork & Mindy, which reached 60 million viewers. He was also known for his roles in Dead Poets Society, Mrs. Doubtfire, and Jumanji, among many others.