Why acting out in dreams may signal a health issue
Wes Mills has a peculiar nighttime ritual that both stunned and amused his wife when they began to live together a decade ago. He would act out his dreams in dramatic fashion.
Some of the episodes involved him running in bed to escape an attacker, beckoning a little raccoon to eat out of his hand, and strategizing with fellow inmates in the midst of a prison riot.
“I used to laugh about it and call it ‘The Wes Show,’” said Eileen Mills, 49, of Taos, N.M.
But she doesn’t find it funny anymore. Wes Mills, a contemporary artist with work at The Whitney and MOMA, hasn’t been able to hold a pencil still for over a year. His tremor started on one side of the body and now affects both sides. In January, at age 63, he was diagnosed with Parkinson’s disease.
Researchers say that dream enactment can indicate health issues, one of the most common and serious being the future onset of Parkinson’s disease. Wes Mills started acting out his dreams more than 10 years before his first tremor appeared. Other common conditions that can lead to dream enactment are obstructive sleep apnea and post—traumatic stress disorder (PTSD).
Those who regularly act out their dreams should see a physician and undergo a sleep study to uncover the underlying reason for their behavior, experts say.
When shifting into rapid eye movement (REM) sleep, where dreaming occurs, the body normally enters a state of almost total paralysis to prevent dream enactment. But some people — approximately 1 percent of those over 50 — lose this paralysis.
This chronic sleep condition, known as REM sleep behavior disorder, or RBD, appears most often in late middle—aged men, researchers have found.
“The brainstem has two linked nuclei that generate the protective paralysis of REM sleep, and when one of them, or their connecting pathway, becomes damaged, that releases muscle tone,” said Carlos Schenck, a psychiatrist at the Minnesota Regional Sleep Disorders Center. “People can then act out their dreams.”
In 1986, Schenck and his colleagues first described RBD in four men and one woman, ages 60 or older. Most had long histories of injuring themselves or their bed partners with aggressive behaviors while asleep. One patient had attempted to strangle his wife while dreaming of fighting a bear, while another knocked over furniture during his dream of being a football player. The researchers noted that RBD is distinct from sleepwalking, which originates from non—rem sleep.
Dream enactment behavior has also been documented in severe obstructive sleep apnea, as it causes people to abruptly stop breathing for brief periods during sleep and partially awaken. Since these breathing cessations are most common and severe in REM sleep, they may act out their dreams, mimicking the symptoms of RBD, Schenck said.
About 39 million U.S. adults have obstructive sleep apnea, according to the National Council of Aging, but how many of these adults enact their dreams is not known.
Similarly, those with PTSD may show signs of reliving their trauma through dream enactment. Approximately 70 percent of patients with PTSD report sleep disturbances, and up to 70 percent have recurrent nightmares. However, no data exists on the prevalence of dream enactment behavior in PTSD, Schenck said.
For those with RBD, the risk of Parkinson’s is staggeringly high. Individuals ages 50 and older with idiopathic RBD — that occurs spontaneously with no other health complaints or recent medication changes — have a 130 times greater likelihood of developing Parkinson’s disease compared with someone without the sleep condition.
“There’s nothing like this. … 80 percent of people who have this condition develop Parkinson’s disease 15 to 20 years later,” said Ronald Postuma, director of neurology at Mcgill University Health Centre.
RBD is 10 times better than any other clinical marker — for example, abnormal motor exam or loss of sense of smell — at predicting the eventual onset of Parkinson’s. RBD is strongly associated with other synucleinopathies, too, a group of diseases that includes Lewy body dementia and multiple system atrophy.
Misfolded alpha—synuclein, a protein, is considered to play a role in both idiopathic RBD, and Parkinson’s and other synucleinopathies. When the misfolded protein accumulates into large, toxic clumps in the brain, it can disrupt nerve cell function and causesymptoms of Parkinson’s such as tremor and stiffness.
The brains of people with idiopathic RBD have enough of misfolded alpha—synuclein to affect their REM sleep, but the harmful protein hasn’t spread farther in the brain, experts say.
More rarely, RBD can be brought on by a stroke, a tumor, or medications such as certain antidepressants.
RBD presents a unique opportunity for researchers to study early Parkinson’s disease, its progression and preventive therapies. For instance, Michele Hu, professor of clinical neuroscience at the University of Oxford, is co—leading a randomized placebo—controlled trial in patients who have RBD that tests whether a drug can reduce brain inflammation, an early feature of Parkinson’s.