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

Abstract

Objectives: The 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.

Methods: Charts 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.

Results: Thirty-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).

Conclusion: In 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.