Severe Central Sleep Apnea/Hypopnea Syndrome Mimicking Rapid Eye Movement Sleep Behavior Disorder

Abstract

Rapid eye movement sleep behavior disorder (RBD) is a sleep disorder characterized by loss of muscle atonia during rapid eye movement (REM) sleep associated with dream enactment. However, these complex behaviors can also occur in other sleep disorders, a clinical situation termed as “pseudo-RBD”. Anecdotal reports of obstructive sleep apnea syndrome simulating the clinical features of RBD have been reported. It has been suggested that “pseudo-RBD” is a form of a confusional arousal caused by a combination of severe oxyhemoglobin desaturations and other unknown factors. However, there have been no previous reports of RBD-like behaviors associated with central sleep apnea. Here, we describe two patients who reported complex motor and vocal behavior mimicking RBD, but REM sleep without atonia was not observed in video-polysomnography (VPSG). Furthermore, VPSG demonstrated severe central sleep apnea-hypopnea inducing abnormal motor and vocal behaviors.