Sleeping Disorders

Rapid Eye Movement Behavior Disorder (RBD)

Rapid Eye Movement Behavior Disorder (RBD) is a parasomnia sleep disorder characterized by the acting out of violent or dramatic dreams while in REM sleep.
RBD involves a dissociation between the various stages of sleep.
The average age of the onset of RBD is estimated to be around 60 years of age.
RBD was first described by Schenck et al. in 1986 in a research paper titled "Chronic Behavioural Disorders Of Human REM Sleep: A New Category Of Parasomnia" [Sleep 9:293-309].

Symptoms

The major, and arguably only, abnormal feature or symptom of Rapid Eye Movement Behavior Disorder (RBD) is the loss of muscle atonia, that is the loss of muscle paralysis, during otherwise normal sessions of REM sleep.  REM sleep is the stage of sleep during which the most vivid dreaming occurs, and the loss of muscle paralysis by RBD sufferers can lead to a wide range of behavioral releases during sleep.  This extends from simple limb twitches to more complex integrated movements where RBD sufferers appear to be unconsciously acting out their dreams.
The resulting behaviors and movements are often violent in nature and commonly result in injury to either the patient or their bed partner.  Such injuries range from bruises and cuts to fractures, subdural haematoma, and other serious injuries.
In contrast, all other aspects of an RBD sufferer's sleep appear normal.

Causes

Approximately 60% of Rapid Eye Movement Behavior Disorder (RBD) cases are idiopathic (that is, they have no known cause).
However, the following are suspected or known causes for RBD:
· Sex: RBD is far more common in males.  Most studies report that only around a 10% of sufferers are female.
Please Note: This imbalance may be due to a referral bias, as violent activity carried out by men is more likely to result in harm and injury and is far more likely to be reported than injury caused to male bed partners by women.  Or the imbalance may reflect a true difference in the prevalence of RBD as a result of genetic or androgenic factors.
· Linked or Related Medical Conditions: It is now known that RBD appears in association with a variety of different injuries or medical conditions, such as:
o Narcolepsy: this link is hardly surprising, as both RBD and Narcolepsy involve dissociation of sleep states probably arising from a disruption to the sleep control mechanisms.
o Brain Injuries: RBD has also been reported following cerebrovascular accidents and neurinoma, indicating that damage to the brainstem area may precipitate RBD.
o Drug or Alcohol Withdrawal: RBD may be acute and have a sudden onset if it is triggered by or associated with a drug treatment or withdrawal or with alcohol withdrawal.
o Neurodegenerative Diseases: This includes RBD that is found in association with conditions such as Parkinson’s disease and dementia with Lewy bodies, where it is often seen to precede the onset of neurodegenerative disease.

Diagnosis

Various conditions are very similar to Rapid Eye Movement Behavior Disorder (RBD) in that sufferers exhibit excessive sleep movement and potentially violent behavior.  Such disorders include Sleep Walking and Sleep Terrors, which are associated with N-REM sleep, Nocturnal Seizures, and Obstructive Sleep Apnea (OSA) which can induce arousals from REM sleep associated with complex behaviors.
Because of the similarities between the conditions, polysomnography plays an important role in confirming or otherwise a diagnosis for RBD or some other sleep disorder.  A Polysomnogram is a device that continuously records the brain waves and a number of other nerve and muscle functions during nighttime sleep, the results of which can be used to detect and distinguish between a range of possible sleep disorders.

Complications / Issues

The main complication and issue related toe Rapid Eye Movement Behavior Disorder (RBD) is injuries to either the RBD sufferer or their bed partner.
The treatment described in section 4.10.5 Treatment below can successfully reduce and even eliminate the chances of RBD related complications and issues.

Treatment

Rapid Eye Movement Behavior Disorder (RBD) is a treatable condition.
The standard therapy is the anti-convulsant drug clonazepam, and works well in restoring REM Atonia (muscle paralysis) during REM sleep in RBD sufferers.  How this drug works to restore REM Atonia is unclear, however it is thought to suppress muscle activity, rather than directly restoring atonia.

Prevention

The chances of developing Rapid Eye Movement Behavior Disorder (RBD) can be reduced by avoiding the causes and triggers for RBD, such as brain injuries, drug and alcohol addiction, and so on.  See section 4.10.2 Causes above.
If the RBD is caused, triggered, or aggravated by existing medical condition(s), then treatment of these conditions can reduce or eliminate the symptoms of RBD.
In addition, treating the RBD can prevent or reduce the onset of the symptoms, especially in severe cases.  See section 4.10.5 Treatment above.

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