Thrashing about in your sleep is a sign of dementia

Thrashing about in your sleep may be an early warning sign of Parkinson’s and dementia, new research suggests.

Moving around in bed, and seeming to ‘act out’ dreams is a characteristic of a condition called rapid eye movement sleep behaviour disorder (RBD).

People who suffer from this were shown to have inflammation in the area of the brain where the chemical dopamine is produced, which is involved in sending messages.

Parkinson’s and dementia patients are known to have diminished supplies of dopamine because nerve cells that make it have died. 

RBD affects around five per cent of people and includes talking, laughing, shouting and swearing while sleeping.

It adds to research published two years ago which discovered about half of people with RBD will develop Parkinson’s disease or another neurological disorder within a decade of being diagnosed.

Thrashing about in your sleep may be an early warning sign of Parkinson’s and dementia, research suggests (stock image)

An estimated seven to 10 million people worldwide are living with Parkinson’s disease – one million Americans and 127,000 people in the UK. 

Dementia affects 850,000 the UK and 5.4 million in US – figures expected to rise substantially to place huge pressures on health and social care services.


For most people, dreaming is purely a ‘mental’ activity: dreams occur in the mind while the body is at rest.

But people who suffer from REM behavior disorder (RBD) act out their dreams.

They physically move limbs or even get up and engage in activities associated with waking. Some engage in sleep talking, shouting, screaming, hittting or punching.

Some even jump out of bed while sleeping.

RBD is usually noticed when it causes danger to the sleeping person, their bed partner, or others they encounter.

People with RBD move around during the rapid eye movement period of sleep, when most dreaming occurs but the body’s muscles are usually paralysed by the brain stem.

Those with the condition are believed to have a malfunction in their brain-stem which allows them to move around during REM sleep, and therefore act out their dreams.

RBD is not curable, but it can be treated with high doses of the sleep aid or low doses of the anti-anxiety drug clonazepam.

Source: National Sleep Foundation


Sleep disorder patients are at risk of other conditions 

Study author Dr Morten Gersel Stokholm from Aarhus University Hospital in Denmark, said: ‘These patients have an inflammation of the brain in the area where the dopamine-producing nerve cells are found.

‘With this study, we have gained new knowledge about the disease processes in the brain in the early initial stages of the disease development.

‘The idea is for this knowledge to be used to determine which patients with the sleep disorder will later develop Parkinson’s disease.’  

The findings were published in the journal The Lancet Neurology. 

Previous research

Previously, the University of Minnesota reviewed 500 studies published between 1986 and 2014 that explored the link between RBD and Parkinson’s. 

The team found that ultimately, between 81 and 91 per cent of patients with RBD developed a degenerative brain disorder during their lifetimes.

They suggest that it could be that RBD results from the early stages of the breakdown of the proteins in the brain cells.

It is a different condition from sleepwalking, lead author Professor Howell explained, as sleepwalkers are confused when they wake up. 

However, not everyone who develops Parkinson’s will have RBD first.

Nevertheless, the findings could help doctors find a way to catch Parkinson’s early and treat Parkinson’s disease while it is in its early stages, Professor Howell added.