University of Toronto researchers suggest that people who act out their dreams have a sleep disorder that may cause brain diseases such as Alzheimer's, Parkinson's and other forms of dementia in the future.

The rapid-eye-movement sleep behavior disorder (RBD) happens during a person's rapid-eye-movement (REM) phase while sleeping, causing him or her to act out dreams that may even result to harming themselves or their bed partner. The new study shows that RBD is not only a precursor to brain disease, it is also a critical warning sign of neurodegeneration.

"It's important for clinicians to recognize RBD as a potential indication of brain disease in order to diagnose patients at an earlier stage," University of Toronto associate professor and study researcher John Peever, MD said. "This is important because drugs that reduce neurodegeneration could be used in RBD patients to prevent (or protect) them from developing more severe degenerative disorders." Peever considers sleep disorders as the best way to predict the beginning of a brain disease.

According to Peever, around 80 to 90 percent of people who suffer from RBD will develop a degenerative brain disease soon. The research shows that neurodegeneration targets other areas of the brain involved in sleep first before it attacks brain areas that cause other common diseases such as Parkinson's and Alzheimer's.

People with RBD usually act out their dreams during the rapid-eye-movement stage of sleep. They often kick, hit, scream, yell and leap out of bed. These are the people who grab and/or punch their bed partner and sometimes hurt them. They usually fall out of bed. This disorder is often associated with sleep walking but it is a completely different thing. The difference is that sleepwalkers can find it hard to wake up, often confused and groggy after waking up. People with RBD are completely awake and conscious as soon as they wake up.

The Centers for Disease Control and Prevention reported that insufficient sleep is actually a public health pandemic. People who do not get enough sleep are prone to chronic diseases such as diabetes, hypertension, obesity, depression and even more complicated ones such as increased mortality, cancer and an overall reduced quality of productivity and life.

90 percent of people who develop RBD are men and most are above 50 years old. RBD patients are usually treated with a muscle relaxant such as clonazepam among other medications that can delay or slow down the progression of Alzheimer's, Parkinson's and other forms of dementia and brain disorders.

The study appears in the journal Trends in Neuroscience.