Two Cases of REM Sleep Behavior Disorder Combined with Severe Obstructive Sleep Apnea: Misdiagnosed as “Pseudo-REM Sleep Behavior Disorder” by Diagnostic Polysomnography

Abstract

Received September 16, 2013 Revised December 8, 2013 Accepted December 9, 2013 Address for correspondence Sang-Ahm Lee, MD, PhD Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea Tel: +82-2-3010-3445 Fax: +82-2-474-4691 E-mail: salee@amc.seoul.kr REM sleep behavior disorder (RBD) is a sleep disorder characterized by loss of normal voluntary muscle atonia during REM sleep associated with complex motor behavior while dreaming. Dream-enacting behaviors can also occur in patients with other sleep disorders such as obstructive sleep apnea (OSA). This clinical situation has been termed “pseudo-RBD”. In contrast, OSA causes frequent arousal, which may consequently result in masking of RBD symptoms. We reported two patients with severe OSA, who were initially diagnosed with “pseudo-RBD” but on continuous positive airway pressure (CPAP) titration, rediagnosed with “true-RBD”. When RBD is clinically suspected but is not confirmed by diagnostic overnight polysomnography, we have to keep in mind that RBD could be detected during CPAP titration. J Korean Sleep Res Soc 2013;10:62-65