Rapid eye movement (REM) sleep behavior disorder is a sleep disorder in which you physically act out vivid, often unpleasant dreams with vocal sounds and sudden, often violent arm and leg movements during REM sleep — sometimes called dream-enacting behavior.

You normally don't move during REM sleep, a normal stage of sleep that occurs many times during the night. About 20 percent of your sleep is spent in REM sleep, the usual time for dreaming, which occurs primarily during the second half of the night.

The onset of REM sleep behavior disorder is often sudden, and episodes may occur occasionally or several times a night. The disorder can get worse with time.

REM sleep behavior disorder often may be associated with other neurological conditions, such as Lewy body dementia (also called dementia with Lewy bodies), Parkinson's disease or multiple system atrophy.

With REM sleep behavior disorder, instead of experiencing the normal temporary paralysis of your arms and legs (atonia) during REM sleep, you physically act out your dreams.

Symptoms of REM sleep behavior disorder may include:

  • Movement, such as kicking, punching, arm flailing or jumping from bed in response to the content of action-filled or violent dreams, such as being chased or defending yourself from an attack
  • Noises, such as talking, laughing, shouting, emotional outcries or even profanity
  • Being able to recall the dream if you are woken up during the episode

Nerve pathways in the brain that prevent muscles from moving are active during normal REM or dreaming sleep, resulting in temporary paralysis of your body. In REM sleep behavior disorder, these pathways no longer work and you may physically act out your dreams.

Factors associated with the development of REM sleep behavior disorder include:

  • Being male and over 50 years old — however, more women are now being diagnosed with the disorder, especially under age 50, and young adults and children can develop the disorder, usually in association with narcolepsy, antidepressant use or brain stem tumors
  • Having a certain type of neurodegenerative disorder, such as Parkinson's disease, multiple system atrophy or dementia with Lewy bodies — in fact, REM sleep behavior disorder can be the first indication of future development of a neurodegenerative disease
  • Having a chronic sleep disorder characterized by overwhelming daytime drowsiness and sudden attacks of sleep (narcolepsy)
  • Taking certain medications, especially newer antidepressants, or the use or withdrawal of drugs or alcohol

Recent evidence has suggested that there may also be several specific environmental or personal risk factors for REM sleep behavior disorder, including occupational pesticide exposure, farming, previous head injury or smoking.

Complications caused by REM sleep behavior disorder can include:

  • Injury to yourself or your sleeping partner
  • Distress to your sleeping partner or other people living in your home

You may start out by seeing your primary care doctor. Your doctor may refer you to a sleep specialist.

Here's some information to help you get ready for your appointment.

What you can do

To prepare for your appointment:

  • Bring a family member or friend along, if possible. Someone who accompanies you can help you remember what the doctor says.
  • Make a list of all medications, vitamins or other supplements you're taking, as well as dosages and any recent changes.
  • Make a note of any symptoms you're experiencing, including any that may seem unrelated to the reason for the appointment.
  • Note key personal information, including any major stresses or recent life changes.
  • Keep a sleep diary. Keeping a sleep diary for two weeks before your appointment can help your doctor understand what's happening. In the morning, record as much as you know of your (or your partner's) sleep issues that occurred the previous night.
  • Prepare questions to ask your doctor to make the most of your time together.

Some basic questions to ask include:

  • What is likely causing my symptoms or condition?
  • What are other possible causes?
  • What kinds of tests do I need?
  • Is my condition likely temporary or long term?
  • What's the best course of action?
  • What are the alternatives to the primary approach you're suggesting?
  • Should I see a specialist?
  • Are there any brochures or other printed material that I can have? What websites do you recommend?

Don't hesitate to ask other questions that occur to you.

What to expect from your doctor

Your doctor is likely to ask you several questions, such as:

  • When did you begin experiencing symptoms?
  • If you have a sleeping partner, what sleep behavior has he or she observed?
  • Have you or your sleeping partner ever been injured by your sleep behaviors?
  • In addition to your dream-enacting behaviors, have you ever experienced sleepwalking?
  • Are you having any motor symptoms, such as handwriting problems, drooling, unsteadiness when walking or dizziness when standing up, or a tremor in your chin, hand, foot or ankle?
  • Are you having any problems with your memory?
  • Have you had sleep problems in the past?
  • Does anyone else in your family have sleep problems?
  • What medications are you taking?

Your doctor may ask your sleeping partner whether he or she has ever seen you appear to act out your dreams while sleeping, such as punching, flailing your arms in the air, shouting or screaming. Your doctor may also ask your partner to fill out a questionnaire about your sleep behaviors.

To diagnose your condition, your doctor will review your medical history and your symptoms. Your evaluation may include tests such as:

  • Physical and neurological exam. Your doctor will conduct a physical and neurological exam and evaluate you for REM sleep behavior disorder and other sleep disorders. REM sleep behavior disorder may have symptoms similar to other sleep disorders, or it may coexist with other sleep disorders such as obstructive sleep apnea or narcolepsy.
  • Nocturnal sleep study (polysomnogram). Doctors may evaluate your condition during an overnight study in a sleep laboratory. During this test, sensors monitor your heart, lung and brain activity, breathing patterns, arm and leg movements, and blood oxygen levels while you sleep. You also will be videotaped to document your behavior during REM sleep cycles.

Diagnostic criteria

To diagnose REM sleep movement behavior disorder, sleep medicine physicians typically use the symptom criteria in the International Classification of Sleep Disorders — Third Edition (ICSD-3).

For a diagnosis of REM sleep behavior disorder, criteria include the following:

  • You have repeated times of arousal during sleep where you talk, make noises or perform complex motor behaviors, such as punching, kicking or running movements that often parallel the content of your dreams
  • You recall dreams associated with these movements or sounds
  • If you awaken during the episode, you are alert and not confused or disoriented
  • A sleep study shows you have increased muscle activity during REM sleep
  • Your sleep disturbance is not caused by another sleep disturbance, a mental disorder, medication or substance abuse

Treatment for REM sleep behavior disorder may include physical safeguards and medications.

Physical safeguards

Your doctor may recommend that you make changes in your sleep environment to make it safer, including:

  • Padding the floor near the bed
  • Removing dangerous objects, such as sharp items and weapons
  • Placing barriers on the side of the bed
  • Moving furniture away from the bed
  • Protecting windows

Medications

Examples of treatment options for REM sleep behavior disorder include:

  • Melatonin. Your doctor may prescribe a dietary supplement called melatonin, which may help reduce or eliminate your symptoms. Melatonin may be as effective as clonazepam and is usually well-tolerated with few side effects, but it may cause some grogginess in the morning.
  • Clonazepam (Klonopin). This prescription medication, often used to treat anxiety, is also the traditional choice for treating REM sleep behavior disorder, appearing to effectively reduce symptoms. Clonazepam may cause side effects such as daytime sleepiness, decreased balance and worsening of sleep apnea.

Doctors continue to study several other medications that may treat REM sleep behavior disorder. Talk with your doctor to determine the most appropriate treatment option for you.

Jul. 11, 2014