REM Sleep Behavior Disorder

What Causes REM Sleep Behavior Disorder?

Scientists don’t know precisely what causes RBD. The underlying cause is likely a problem with neurotransmitters, biochemicals that allow the brain to send signals to the muscles via nerve cells. In the case of RBD, an imbalance of neurotransmitters probably results in improper signaling from the brain to the muscles during sleep. However, scientists don’t yet know which neurotransmitters are at fault or what causes the chemical imbalances in the first place.

Some factors increase the risk of RBD, including:

• Sex. Men are more likely than women to experience the disorder.
• Age. RBD is most common in people over 50.
• Smoking
• Medications, including some antidepressants
• Alcohol or drug use or withdrawal
• Neurological disorders, including Parkinson’s disease, Lewy body dementia, head injuries, and stroke
• Narcolepsy, a sleep disorder that causes excessive sleepiness
• Exposure to certain chemicals

Is REM Sleep Behavior Disorder Hereditary?

Most of the time, RBD is probably caused by external factors, medical disorders, or other underlying conditions other than genetics. However, studies have suggested that some people may have a genetic predisposition to RBD, and the predisposition may be inherited. For example, one study found that people with RBD were about three times more likely to have a family history of the disorder. This suggests that a genetic component plays at least some role in developing the disorder.

Researchers have not identified any specific gene or genetic mutation associated with RBD.

How Is REM Sleep Behavior Disorder Detected?

Since its symptoms occur during sleep, RBD may go unnoticed if the person sleeps alone or their partner is asleep during episodes. RBD movements are sometimes minor twitches in the arms or legs, but they can evolve into broader, more complex movements that could injure the person or their partner.

Because of the risk of injury and the possibility that RBD can be a sign of serious neurological disorders, you should consult a doctor if you experience any of the disorder’s symptoms.

How Is REM Sleep Behavior Disorder Diagnosed?

Doctors may take several different diagnostic steps when a patient is experiencing difficulty staying awake.

• Physical and neurological exams. These basic exams will screen for indications of medical conditions that could be causing the sleep problems.
• Sleep diary. Your doctor may ask you or your partner to keep a log of your sleep over two weeks, or so, to look for patterns in your sleep behavior. You may also be asked to track other habits that could impact your sleep, such as your caffeine use.
• Sleep study. A study of your sleep patterns, which may be conducted at a sleep center, may be recommended if your doctor suspects that a condition such as sleep apnea could be the cause of your RBD. The study can also identify the pattern of muscle activity characteristic of RBD.

The International Classification of Sleep Disorders, Third Edition (ICSD-3) includes diagnostic criteria providers can use to diagnose RBD. The criteria include:

• The patient experiences episodes of arousal during sleep in which they move or make sounds, usually in connection with dream imagery.
• The patient can remember the dreams associated with episodes.
• The patient is alert if awakened during the episode.
• A sleep study shows increased muscle activity during episodes.
• The symptoms are not caused by another sleep disorder, medication, substance use, or a mental health disorder.

PLEASE CONSULT A PHYSICIAN FOR MORE INFORMATION.

How Is REM Sleep Behavior Disorder Treated?

Treatment of underlying conditions can sometimes improve RBD symptoms. In cases where RBD appears to be a side effect of medication, changing dosages or medications may help.

Doctors will typically recommend changing the sleep environment to minimize the danger to the patient and their sleeping partner. These changes can include:

• Putting padding on the floor and on bedside furniture to prevent injuries
• Removing hazardous items (e.g., sharp objects, weapons) from the bedroom
• Blocking access to windows
• Sleeping separately from your partner

Doctors may also prescribe medications to control symptoms, such as:

• Clonazepam. This sedative acts to inhibit muscle movement and can lessen symptoms. However, long-term use can cause side effects.
• Melatonin. This naturally occurring chemical is sometimes used to treat RBD and other sleep disorders. Research into its effectiveness has shown mixed results, but it causes fewer side effects than clonazepam and may be better suited to some patients.

How Does REM Sleep Behavior Disorder Progress?

Untreated RBD often becomes more frequent and more severe over time. It can lead to complications, including:

• Injuries to yourself or your partner
• Relationship difficulties
• Social isolation

How Is REM Sleep Behavior Disorder Prevented?

There is no known way to prevent RBD. Lifestyle factors such as stress which can sometimes cause other sleep disorders, do not appear to cause RBD. However, in the absence of proven preventive measures, doctors encourage good sleep habits and a healthy lifestyle to lessen RBD risk. Steps you can take to ensure better sleep include:

• Stick to a regular sleep schedule (even on weekends)
• Don’t eat or drink close to bedtime
• Avoid stimulating activities (e.g., watching TV, using electronics) 30 minutes before bedtime
• Use your bedroom only for sleep
• Keep your bedroom dark and cool
• Get plenty of exercise
• Limit consumption of caffeine and alcohol
• Quit smoking
• Don’t take naps
• Try meditation or relaxation techniques

REM Sleep Behavior Disorder Caregiver Tips

Some people with RBD also suffer from other brain and mental health-related issues, a condition called co-morbidity. Here are a few of the disorders commonly associated with RBD:

• RBD is sometimes associated with neurodegenerative diseases such as Lewy body dementia, multiple system atrophy, or Parkinson’s disease.
• RBD is also sometimes associated with narcolepsy.
• Brain tumors, brain injuries, and stroke may increase RBD risk.

REM Sleep Behavior Disorder Brain Science

Scientists are not sure what causes RBD, but research has suggested that it is likely the result of a problem related to brain chemicals called neurotransmitters. Neurotransmitters allow nerve cells to send signals to each other. Some of them increase cell-to-cell signals, allowing, for example, a signal for muscle movement to travel from the brain to the muscle cells, causing the muscles to move. Other neurotransmitters inhibit signaling, preventing unwanted or unnecessary signals from traveling from cell to cell.

During REM sleep, a part of the brain called the ventromedial medulla, and the spinal cord, increase their output of inhibitory neurotransmitters. The resulting high level of these chemicals prevents nerve-cell signaling and effectively paralyzes the skeletal muscles, creating a state called atonia.

RBD is likely caused by a disruption in this process, creating an imbalance of inhibitory and excitatory neurotransmitters. However, scientists are not yet sure in what part of the brain the imbalance originates or precisely which neurotransmitters are involved.

REM Sleep Behavior Disorder Research

Title: Treatment of REM Sleep Behavior Disorder (RBD) With Sodium Oxybate

Stage: Recruiting

Contact: Emmanuel During, MD

Stanford University

Palo Alto, CA

Rapid eye movement sleep behavior disorder (RBD) is a condition resulting in violent dream-enactment during sleep, affecting millions of individuals in the United States. However, therapies for RBD are limited and cause significant side effects. As a result, despite using a combination of drugs, many patients with RBD continue to act out violent dreams causing severe self-injuries or injuries to their bed partners. Prior studies and our experience have shown that sodium oxybate can be effective in these cases of treatment-resistant RBD. Therefore, this study would evaluate the efficacy and tolerance of sodium oxybate in this patient population.

This study is an 8-week trial comparing sodium oxybate versus placebo randomly assigned to patients with treatment-resistant RBD, i.e., individuals who have insufficiently responded or tolerated melatonin and clonazepam. The study uses a double-blind design (participants, staff, and investigators will not know which drug between active drug and placebo is given to participants) and will measure treatment efficacy based on patients, partners, and clinicians’ reports, and objective outcomes based on in-home actigraphy and in-lab polysomnography before and after the intervention.

Title: Sleep Profiles in REM Sleep Behavior Disorder

Stage: Recruiting

Principal investigator: Aleksandar Videnovic, MD

Massachusetts General Hospital

Boston, MA

Rapid eye movement (REM) sleep behavior disorder (RBD) is a sleep disorder in which you act out dreams during REM sleep. Sleep disturbances are very common in RBD, where they negatively impact patients’ quality of life and safety. One of the known causes of sleep disturbance is the impairment of the “circadian rhythm,” or the human sleep/wake cycle. This study aims to examine the role of disruption of the circadian rhythm in the development of RBD.

Title: Extended-Release Melatonin in Patients With Rapid Eye Movement Sleep Behavior Disorder

Stage: Recruiting

Principal investigator: Emir Festic, MD, MS

Mayo Clinic Florida

Jacksonville, FL

This research aims to compare the efficacy of immediate versus extended-release melatonin as a supplement affecting the sleep cycle in patients with Parkinson’s disease and Rapid Eye Movement Sleep Behavior Disorder.

Enrolled patients with Parkinson’s disease and previously diagnosed rapid eye movement sleep behavior disorder, who are being treated at Mayo Clinic in Florida, will be randomized to receive either immediate-release melatonin or extended-release melatonin and then will be crossed over to receive the opposite intervention. The study will consist of two treatment periods of 4 weeks separated by a washout period of 2 weeks.