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A Closer Look at the Disease That Devastated Robin Williams' Life

Lewy body dementia, as shown in new documentary, is a common and often misdiagnosed condition

spinner image Actor and comedian Robin Williams
Reed Saxon/AP Photo

More than 1.4 million Americans have Lewy body dementia (LBD), the second-most common form of progressive dementia after Alzheimer's disease. It struck mogul Ted Turner, actresses Dina Merrill and Estelle Geddes, DJ Casey Kasem, and actor Robin Williams, whose widow Susan Schneider Williams says his last wish was this: “I want to help people be less afraid."

Williams was afraid because he never knew what disease he had. His widow fulfills his last request in a moving, enlightening new documentary about his illness, Robin's Wish, available to stream on Amazon Prime. “During the last year of his life, Robin was confronted with anxiety, paranoia, insomnia, scary altered realities and a roller coaster of hope and despair,” she says. “It wasn't until after Robin's passing, in autopsy, that the source of his terror was revealed: He had diffuse Lewy body disease."

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The hidden threats of Lewy body dementia

"Robin struggled with getting the right diagnosis,” says Norma Loeb, who founded the Lewy Body Dementia Resource Center after her mother got the disease; she also consulted on Robin's Wish. “That parallels the experience we hear from people with LBD and their loved ones who call our helpline."

LBD, which generally affects people over 60, is tricky to diagnose because its multiple symptoms resemble those attributed to other diseases. “Susan [Williams] compares LBD to ‘whack-a-mole,’ because symptoms pop up and disappear,” says Loeb. Without knowing why, Robin Williams had mysterious sleep disturbances, thrashing while dreaming. He also experienced a sudden onslaught of memory issues. “When Robin was doing Night at the Museum III, he couldn't remember his very few lines,” says Loeb. “And he had just done Broadway twice a day with hundreds and hundreds of lines and didn't make a single mistake. He thought, ‘What the heck is going on?'"

For Loeb, her mother's LBD first manifested in her having trouble balancing her checkbook. Next, she developed Capgras syndrome, mistaking loved ones for impostors. The world her mother knew became suddenly foreign, says Loeb: “She'd say, ‘How did they get this apartment to look exactly like my other one? All the furniture is the same.'"

RELATED: Dementia's gender disparity: Report uncovers unique challenges facing women

In other patients, LBD can also cause motor issues, Loeb says, and frightening hallucinations. “The lamp in a room will look like a monster,” she says. “Caregivers make sure to put knives away.”

The dangers of misdiagnosis

According to Loeb, LBD is often misdiagnosed as Alzheimer's, Parkinson's or other illnesses. “Being misdiagnosed can be dangerous,” she says, “because people with LBD are sensitive to medications, and the wrong drugs may cause severe reactions, such as hallucinations or worse. The correct diagnosis is crucial to a better quality of life.”

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Help for caregivers

She hopes the film and her organization can help people who do develop LBD as well as their caregivers, who need and deserve a range of coping strategies. “One big piece of advice is, do not argue with [someone with LBD],” Loeb says, “because they need to feel that they still have some sense of control. If they make a request that doesn't make sense, are having a scary hallucination, or get angry, always try to change the topic. Soothing music is a big help. You can show them old pictures — anything to distract."

Loeb has another piece of advice for those whose loved ones have LBD: Since there will be good days and bad ones, seize the good. “My advice is to really be so thankful for those blessings on a good day, those moments everyone else takes for granted. Be grateful if you see that smile, when the light switches on. Try to stay in this moment.” Even when LBD robs someone of rational cognition, there can still be moments of deep emotional connection. “Some people just didn't understand how I could connect with my mother, who could no longer talk. But I did. It's connecting really on a different level. There's a communication that isn't intellectual — it's spiritual.”

The Lewy Body Dementia Resource Center is the only organization in the United States that offers a live helpline for LBD at 516-218-2026, and more than 8,000 supportive resources on its website at

8 Differences Between Lewy Body Dementia, Alzheimer's and Parkinson's

Lewy Body Dementia Resource Center founder and executive director Norma Loeb offers these tips on distinguishing three illnesses often mistaken for each other. For more information on dementia, consult the AARP Disrupt Dementia page.

1. The most prominent symptom in Alzheimer’s disease is memory loss. In Lewy body dementia (LBD), problems with planning, judgment and visual perception are more typical, though memory problems will occur as the disease progresses.

2. Movement problems (motor skills and Parkinson’s symptoms) are predominant in Parkinson’s disease and generally evident in LBD, versus walking and balance issues in later-stage Alzheimer’s.

3. Hallucinations and misidentification of people and objects are much more typical in LBD.

4. The REM sleep disorder occurring in LBD (and some people with Parkinson’s) is much less common in Alzheimer’s.

5. People with LBD may also have issues with their autonomic nervous system, where they experience changes in blood pressure and incontinence. This is not typically an Alzheimer’s issue, though incontinence certainly is in later-stage Alzheimer’s.

6. Unlike early Parkinson’s disease, people with LBD will exhibit cognitive impairment (particularly executive dysfunction) and behavior issues, and have fluctuations in alertness. Depression is also a symptom of the disease in connection with all the others.

7. People with LBD have many of the same symptoms of Parkinson’s disease (slowness of movement, a shuffling gait, rigidity in the arms and legs), though many individuals with LBD don’t have the hand tremor. 

8. People with LBD are extremely sensitive to medications.

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