1370 Multiple Sclerosis Associated Rapid Eye Movement Sleep Behavior Disorder

Abstract Introduction Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by muscle atonia during REM sleep and dream enactment behavior1,2. RBD may be idiopathic, drug-induced, or secondary to other medical conditions. Idiopathic RBD is frequently associated with neurodegenerative disorders, while secondary RBD has been linked to genetic disorders, brainstem lesions, and conditions such as multiple sclerosis (MS)3. Sleep disorders are more frequent in patients with MS than in the general population4. We present a case of RBD in a patient with MS. Report of case(s) A 44-year-old male with MS on natalizumab was referred for chronic insomnia, poor sleep, and excessive daytime sleepiness. He reported dream enactment behaviors two or three nights weekly, including jumping, running, and talking during sleep. A prior home sleep apnea test was negative for obstructive sleep apnea. Polysomnography with electromyography demonstrated REM sleep without atonia, confirming RBD. Previous brain magnetic resonance imaging revealed demyelinating lesions in the parietal/pericallosal white matter, periventricular left parietal white matter, and periventricular right temporal lobe, dorsal pons and dorsal medulla. The patient was counseled on bedroom safety and started on nightly melatonin and cognitive behavioral therapy for insomnia. At three-month follow-up, dream enactment behaviors had resolved and overall sleep quality improved. Conclusion Sleep disorders, including RBD, are common in MS and contribute to impaired quality of life through effects on pain, depression, and fatigue5. RBD is characterized by abnormal motor activity during REM sleep due to failure of muscle atonia. The pontine tegmentum and medial medulla play central roles in regulating this process. Demyelinating plaques in this region have been implicated in secondary RBD associated with MS7-11. In this case, similar lesions likely contributed to the development of RBD. Treatment of RBD focuses on ensuring safety during sleep. Melatonin and clonazepam are first-line pharmacologic treatments for RBD in adults1,3,12. In patients with RBD associated with MS, management of MS activity may improve RBD symptoms4. This case highlights the importance of recognizing RBD in patients with MS who report dream enactment or disrupted sleep, as early recognition and treatment can markedly improve safety and quality of life. Support (if any)