Dreams may herald the risk of developing dementia and Parkinson's disease up to 15 years before symptoms appear

A leading neuroscientist has revealed that the first signs of dementia and Parkinson's disease could lie in the content of nightmares that individuals have.

According to leading brain health expert Dr. Raul Jandial, dreaming of violent or threatening scenes, such as being chased, killed, or fleeing from danger, can indicate early brain deterioration that appears in a range of neurological conditions.

People most at risk are those whose disturbing dreams cause them to perform physical actions during their sleep, such as punching, kicking, and even choking their partner in some cases.

For example, studies show that 97% of people who exhibit these behaviors during sleep will develop Parkinson's disease or another neurological condition within 14 years.

One expert identifies the problem of these types of nightmares, which often cause physical actions, as REM sleep behavior disorder.

Dr. Jandial noted that those with REM sleep behavior disorder years later develop a type of brain disease called synucleinopathies, an umbrella term for neurodegenerative diseases characterized by the abnormal accumulation of clusters of the protein alpha-synuclein in neurons, nerve fibers, or glial cells. There are several diseases within Synucleinopathies, including Parkinson's disease and some types of dementia, including Lewy body dementia (DLB).

In cases of synucleinopathies, alpha-synuclein protein accumulates and forms clumps that can disrupt the normal functioning of cells and lead to damage to brain cells.

It is not known exactly how these clusters lead to dream acting behavior. But their ability to predict synucleinopathy is curious.

These disorders appear, on average, within 10 to 15 years after the onset of dream behavior disorder.

People with REM sleep behavior disorder often have vivid and violent dreams that involve an imminent physical threat to themselves or someone they love.

Case studies have described people becoming violent, hitting, kicking, and wrestling with their partners, and running in their sleep to escape the attacker in dreams.

Violence is not a good feature of the disorder. People with REM sleep behavior disorder have reported singing or clapping in their sleep and even engaging in peaceful activities such as fishing.

“Because dream representation and new onset nightmares are a clinical precursor to Parkinson's disease, arriving years, even decades, before the first motor symptoms of the neurodegenerative condition appear, paying attention to dreams and nightmares could provide clinicians with a rare window into dream analysis and early intervention,” Dr. Jandial said.

Experts say nightmares are common in the late stages of the disease. Nearly 80% of Parkinson's patients suffer from terrible nightmares.

It is noteworthy that neurological disorders are not the only types of disorders that can be predicted by behavioral REM sleep disorder.

In a study of heart patients, the types of dreams participants had indicated how well they would recover after a routine procedure to open narrowed arteries.