REM sleep behavior disorder in 703 sleep-disorder patients: The importance of eliciting a comprehensive sleep history

ObjectivesThe aim of our study was to evaluate the frequency of REM sleep behavior disorder (RBD) in a mixed sleep laboratory population and to assess potential associations. Moreover, we investigated referral diagnoses of patients subsequently diagnosed with RBD and assessed the frequency of incidental RBD.MethodsCharts and polysomnographic reports of 703 consecutive patients comprising the full spectrum of ICSD-2 sleep disorders [501 males, 202 females; mean age, 51.0 ± 14.1 years (range: 10–82 years)] were carefully reviewed. The vast majority of patients were adults (98.7%). Patients were categorized into those with and without RBD. For associations, all concomitant sleep and neurological diagnoses and medications were evaluated.ResultsThirty-four patients (4.8%) were diagnosed with RBD (27 men; 7 women, mean age, 57.7 ± 12.3 years). RBD was idiopathic in 11 patients (1.6%; 9 men) and symptomatic in 23 patients (3.3%; 18 men) secondary to Parkinsonian syndromes (n = 11), use of antidepressants (n = 7), narcolepsy with cataplexy (n = 4), and pontine infarction (n = 1). Six out of 34 patients were referred for suspected RBD, 20 reported RBD symptoms only on specific questioning, and 8 patients had no history of RBD but showed typical RBD behavioral manifestations in the video-polysomnography. Logistic regression analysis revealed significant associations between RBD and the presence of Parkinsonian syndromes (odds ratio [OR] 16.8, 95%CI: 6.4–44.1; P < 0.001), narcolepsy with cataplexy (OR 10.7, 95%CI: 2.9–40.2; P < 0.001), SSRI use (OR 3.9, 95%CI: 1.6–9.8; P = 0.003), and age (OR 1.5/10-year increase, 95%CI: 1.0–2.0; P = 0.039).ConclusionIn this population of 703 consecutive sleep-disorder patients, RBD was uncommon. Its etiology was predominantly symptomatic. The majority of RBD patients reported RBD symptoms on specific questioning only, underlining the importance of eliciting a comprehensive sleep history for the diagnosis of RBD.