REM Sleep Behavior Disorder: Diagnosis, Clinical Implications, and Future Directions

Area of Science:

• Neurology
• Sleep Medicine
• Neurodegeneration

Background:

• Rapid eye movement sleep behavior disorder (RBD) is characterized by dream enactment and loss of muscle atonia during REM sleep.
• RBD is strongly linked to synucleinopathies, including Parkinson disease, dementia with Lewy bodies, and multiple system atrophy.
• RBD can precede overt motor, cognitive, or autonomic symptoms by years or decades, indicating it may be an early manifestation of neurodegeneration.

Purpose of the Study:

• To review the diagnostic criteria, clinical associations, and management of RBD.
• To highlight RBD as a prodromal marker for neurodegenerative diseases.
• To emphasize the need for further research into prognosis and neuroprotective strategies.

Main Methods:

• Clinical history of dream enactment.
• Polysomnography to confirm REM sleep without atonia.
• Assessment of prodromal neurodegenerative signs (e.g., hyposmia, constipation, orthostatic hypotension).
• Review of neuroimaging, neurophysiological, and autonomic testing findings.

Main Results:

• Idiopathic RBD is associated with a high risk (up to 90.9%) of developing a defined neurodegenerative disease.
• Prodromal signs of neurodegeneration are common in RBD patients.
• Melatonin (3-12 mg) or clonazepam (0.5-2.0 mg) are recommended for symptom management to prevent injury.

Conclusions:

• RBD serves as a significant early indicator of underlying neurodegenerative processes, particularly synucleinopathies.
• Symptomatic treatment can mitigate injury risk in RBD patients.
• Further prospective studies are crucial for refining prognosis and developing effective therapies, including neuroprotection.