REM sleep behaviour disorder (RBD)

• What is REM Sleep Behaviour Disorder
• Statistics on REM Sleep Behaviour Disorder
• Risk Factors for REM Sleep Behaviour Disorder
• Progression of REM Sleep Behaviour Disorder
• Symptoms of REM Sleep Behaviour Disorder
• Clinical Examination of REM Sleep Behaviour Disorder
• How is REM Sleep Behaviour Disorder Diagnosed?
• Prognosis of REM Sleep Behaviour Disorder
• How is REM Sleep Behaviour Disorder Treated?
• REM Sleep Behaviour Disorder References

What is REM Sleep Behaviour Disorder

Rapid eye movement (REM) sleep behavior disorder (RBD) is a newly described disorder, recognized as a distinct clinical entity following a series of reports in 1986 of adults with RBD. RBD is the best studied REM sleep parasomnia. Clinically, RBD is characterized by loss of normal voluntary muscle atonia during REM sleep associated with complex behaviour while dreaming.

Statistics on REM Sleep Behaviour Disorder

The exact incidence and prevalence of the disorder are not conclusively known because of the inadequate and inaccurate nature of reporting and misdiagnosis. A recent telephone survey conducted in the US indicated a 2% overall prevalence of violent behaviours during sleep, 25% of which were likely to be due to RBD. This in turn provides us with a prevalence of 0.5% of RBD in the general population. There is not likely to be any international difference in prevalence.

Risk Factors for REM Sleep Behaviour Disorder

RBD may be idiopathic (no known cause) or it may occur in association with various neurologically based conditions. These may include brainstem neoplasm, multiple sclerosis affecting brain stem, olivopontocerebellar atrophy (OPCA), progressive supranuclear palsy (PSP), or Shy-Drager syndrome.
With Parkinson’s the incidence of RBD is increased and RBD may still precede the development of Parkinson’s by several years. This relationship between RBD and Parkinson disease, however, is complex as not all patients with RBD develop Parkinsonism and vice-versa.
Additional brainstem degeneration is beleived to play a significant role in controlling the condition.

How is REM Sleep Behaviour Disorder Diagnosed?

Imaging studies (such as MRI‘s) are not used in idiopathic cases. They are used if neurologically based dysfunction is indicated by history and neurologic examination.

Prognosis of REM Sleep Behaviour Disorder

The prognosis of RBD depends on aetiology (the cause or origin). In idiopathic (no known cause) cases, the symptoms are controlled with medications. In secondary cases, the prognosis depends on what the primary disease is.

How is REM Sleep Behaviour Disorder Treated?

Medical care
RBD is treated symptomatically by various medications; however, the response varies in individual cases. Therefore, all available medications should be tried before considering the patient’s RBD as intractable.

Environmental safety 
The other important aspect of management of patients with RBD is environmental safety. Potentially dangerous objects should be removed from the bedroom, and the mattress should be placed on the floor or a cushion should be put around the bed.
Consultations
The neurologist may consult a sleep specialist for proper diagnosis and treatment of RBD.
Diet
No special recommendations or restrictions of diet exist for RBD.

More Information

For more information about sleep, including how much is good for you, tips for getting more sleep, and sleep disorders, as well as some useful videos, see Sleep.

REM Sleep Behaviour Disorder References

1. Abad VC, Guilleminault C: Review of rapid eye movement behavior sleep disorders. Curr Neurol Neurosci Rep 2004 Mar; 4(2): 157-63
2. American Sleep Disorders Association: International Classification of Sleep Disorders, revised: Diagnostic and Coding Manual. Rochester, Minn: American Sleep Disorders Association; 1997:177-80.
3. eMedicine