Can Obstructive Sleep Apnea (OSA) present with symptoms similar to Rapid Eye Movement Sleep Behavior Disorder (RBD)?

Obstructive Sleep Apnea Can Present with Symptoms Mimicking REM Sleep Behavior Disorder

Yes, Obstructive Sleep Apnea (OSA) can present with symptoms that mimic REM Sleep Behavior Disorder (RBD), and polysomnography is essential to differentiate between these conditions.

How OSA Can Mimic RBD

• Vigorous arousals during respiratory events in OSA can produce behaviors that clinically resemble RBD, with patients exhibiting dream-enactment behaviors and unpleasant dreams 1
• These abnormal behaviors in OSA occur specifically during apnea-induced arousals, rather than due to loss of REM atonia as seen in true RBD 2
• Severe OSA can particularly mimic RBD symptoms, with patients reporting dream-enactment behaviors that resolve with CPAP therapy 2

Distinguishing Features

• In true RBD, polysomnography shows loss of normal electromyographic (EMG) atonia during REM sleep (REM sleep without atonia - RSWA) 1
• In OSA mimicking RBD, polysomnography shows preserved REM atonia but demonstrates abnormal behaviors occurring only during respiratory event-related arousals 2
• Video-polysomnography (VPSG) is the gold standard for correctly differentiating between RBD and OSA-related behaviors 3

Clinical Implications

• When patients present with dream-enactment behaviors, clinicians should consider both RBD and OSA in their differential diagnosis 1, 3
• Proper diagnosis is crucial as:
  • RBD often heralds neurodegenerative disorders (particularly synucleinopathies) 1
  • OSA has significant cardiovascular and metabolic consequences if left untreated 1
• The conditions can also coexist, complicating diagnosis and treatment decisions 3

Diagnostic Approach

• A comprehensive sleep evaluation is essential when OSA is suspected, to identify or exclude other comorbid sleep complaints 1
• Polysomnography is mandatory to establish the diagnosis of RBD and identify or exclude other causes of dream-enacting behaviors 1
• The STOP-BANG questionnaire can help screen for OSA, while specific questions about dream enactment behaviors can help identify possible RBD 1

Treatment Considerations

• In cases where OSA is mimicking RBD, continuous positive airway pressure (CPAP) therapy typically eliminates the abnormal behaviors, unpleasant dreams, and daytime sleepiness 2
• If RBD is confirmed, referral to neurology is recommended, particularly given the association with neurodegenerative disorders 1
• When both conditions coexist, treating the OSA component may improve overall sleep quality and potentially reduce RBD symptoms 4

Special Considerations

• Patients with atypical parkinsonism and RBD (particularly multiple system atrophy and dementia with Lewy bodies) have higher vulnerability to OSA compared to other RBD groups 5
• These patients tend to sleep more in the supine position, which may contribute to their higher apnea-hypopnea indices 5
• Non-breathing sleep disorders including RBD and periodic limb movement disorder can coexist with OSA in patients with neurological conditions such as stroke 6

Remember that while OSA can mimic RBD symptoms, they are distinct disorders with different pathophysiologies and treatment approaches. Polysomnography is essential for accurate diagnosis and appropriate management.