Lewy Body Dementia: What is the condition which Robin Williams' wife blames for his death?

After he died, coroners found the actor had the disease

Robin Williams, who died in August 2014 (Getty Images )

Robin Williams was unwittingly suffering from a rare form of dementia, and had three years to live, the actor’s widow has revealed.

Susan Schneider said that following her husband’s suicide, a coroner found signs of Lewy Body Dementia (LBD) during his autopsy.

The rare form of the dementia likely contributed to the anxiety and depression which Williams was treated for as he reached the end of his life, and likely lead to his suicide in August 2014, she said.

Speaking to the US broadcaster ABC, she said that Williams began suffering from a range of symptoms, including urinary trouble and sleeplessness. As his condition worsened, he would suddenly lose his lucidity.

“It's one minute, totally lucid. And then, five minutes later, he would say something that wasn't — it didn't match," she said.

In what would be the final weeks of his life, doctors were planning to check him into a facility for neurocognitive testing. Schneider recalled how her husband was “disintegrating before my eyes," during that time.

Schneider said she believed that by taking his life, Williams was saying: "'No.' And I don't blame him one bit."

What is LBD?

Dementia is an umbrella term used to describe an individual’s loss of mental ability. This is caused by the gradual death of nerve cells and the loss of brain tissue, and can take years to develop and show severe symptoms.

Similarly to people with Alzheimer’s disease – the most common type of dementia – the judgement and memory of those with LBD becomes diminished.

However, symptoms can also include difficulty concentrating and identifying objects, as well as a lack spacial awareness. How quickly a person thinks, their use of language, understanding, and judgment can be affected, too.

Depression is another symptom which sufferers can face, as well as a loss of facial expression.

Slower movement, becoming unsteady and stiff, and tremors can also suggest that a person has LBD.

Hallucinations can also affect patients, leading them to believe they are being persecuted; that strangers are living in their home; or their partner has been replaced by an identical imposter. This can make caring for an LBD patient extremely distressing.

As described by Schneider, those with the condition can suddenly become drowsy or stare off in the distance.

Around 10 per cent of people diagnosed with dementia will have LBD, according to the Alzheimer’s Society.

What causes LBD?

The condition is named after Lewy bodies – collections of protein inside the brain’s nerve cells, in the area of the organ which controls movement and memory.

Such deposits are also believed to be the main feature of Parkinson’s disease, which is why it is sometimes called a Lewy body disorder.

Scientists believe that the build-up of protein inhibits chemical signals in the brain – particularly acetylcholine and dopamine - but it is uncertain why the protein develops.

Unlike early onset Alzheimers disease, the condition is not believed to run in the family.

How is it diagnosed?

Those concerned that they have the disease should visit a doctor. They may then be referred to a specialist who will carry out physical assessments, as well as brain scans, and memory and blood tests.

It is most common is those over the age of 65, however some cases in under 65s have been recorded.