What is Lewy body dementia? Robin Williams' illness explained

Robin Williams' post-death diagnosis of Lewy body dementia unknowingly put him in the company of more than one million Americans dealing with brain changes caused by the disease.

The star died by suicide in 2014 and his family didn't fully understand what he was going through until the results of his autopsy.

"I was relieved it had a name," Susan Schneider Williams, his widow, said of the illness as she shared her husband's story in the documentary "Robin's Wish," available Sept. 1 on demand and on digital platforms.

"Robin and I had gone through this experience together, really being chased by an invisible monster. And it was like whack-a-mole with the symptoms. I left there with a name of the disease, the thing that Robin and I had been searching for."

The condition reportedly caused the actor to experience anxiety attacks and motor-skill problems.

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Famed DJ Casey Kasem also died in 2014 after being diagnosed with Lewy body dementia.

Ted Turner revealed his diagnosis of Lewy body dementia in 2018. The business tycoon and cable news pioneer, now 81, said he had been feeling exhausted and forgetful.

While Alzheimer’s disease is the most common form of degenerative dementia, Lewy body dementia is the second-most common form, according to the Lewy Body Dementia Association. LBD is often misdiagnosed as Alzheimer’s, but the two conditions have different causes and symptoms, Dr. James E. Galvin, a professor of neurology at NYU Langone Medical Center, told NBC News.

What causes Lewy body dementia?

Lewy bodies, named after Dr. Friedrich Lewy who first discovered them in 1912, are deposits of abnormal proteins inside brain cells, according to the Lewy Body Society.

They affect chemicals in the brain, which can lead to problems with thinking, movement, behavior, and mood, the National Institute on Aging noted.

It’s not well understood why these changes happen, but age is considered the greatest risk factor, with most people diagnosed over 50.

An LBD patient can either have Parkinson’s disease dementia or dementia with Lewy bodies — the two are closely related.

What are the symptoms?

The warning signs can be mild at first, but worsen with time. They include:

  • Problems with cognitive ability, attention, alertness, memory, judgment and concentration

  • Behavior changes

  • Hallucinations and delusions

  • Slow movement, tremors, difficulty walking, or rigidity

  • Sleep problems, including acting out dreams

  • Problems with autonomic body functions, such as bladder and bowel function

How is LBD diagnosed?

The disease affects some 1.4 million people in the U.S., the Lewy Body Dementia Association estimated, but diagnosing it can be challenging.

Only an autopsy can provide a conclusive diagnosis, but doctors can recognize the symptoms with the help of physical and neurological examinations, mental status tests and brain imaging.

What is the treatment?

There is no cure, but medications developed to treat cognitive problems produced by Alzheimer’s disease are also given to LBD patients.

A patient goes on to live for an average of five to eight years after a diagnosis, the National Institute on Aging estimated.

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