0942 PEDIATRIC REM SLEEP WITHOUT ATONIA MAY BE ASSOCIATED WITH BRAINSTEM ABNORMALITIES

Abstract

Introduction: The clinical significance of REM sleep without atonia (RSWA) in children remains unclear, especially if not associated with a clinical history or polysomnographic evidence of REM behavior disorder. Moreover, there is no universal criterion to define RSWA in children and many different parameters have been used in various studies. Methods: A retrospective chart review was conducted on patients observed to have RSWA during polysomnography (PSG) performed from years 2015 to 2016. These children were referred for symptoms of sleep-disordered breathing or sleepiness. RSWA was defined as an obvious increase in muscle tone on chin or leg electromyography with or without large body movements but without arousal during REM sleep. Data with regards to age, sex, medical history, family history, presenting symptoms, medication history, PSG and cranial imaging findings were collected. Results: Six patients were identified to have RSWA. Ages ranged from 3-15 years. There were 3 males and 3 females. Three had past history of migraines and one had achondroplasia. A family history of obstructive sleep apnea (OSA) was present in 4/6 patients and REM behavior disorder in one. The most common presenting non-sleep symptom was headache (3/6), while the most common sleep related symptoms were snoring (3/6) and excessive daytime sleepiness (3/6). Two patients had parasomnia (dream enactment and sleep walking). None of the patients were taking medications that could affect REM sleep. The most common associated PSG finding was an increased periodic limb movement index (4/6). One patient had mild OSA and another had a diagnosis of long sleep and two SOREM's, in observation for possible narcolepsy. Three out of five patients imaged after PSG had Chiari I malformations (two had symptoms of esotropia, hoarseness and dysphagia with aspiration). The sixth patient, diagnosed with achondroplasia, had narrowing of the foramen magnum and C1 ring hypoplasia in an MRI done two years prior. Conclusion: Our results suggest that patients presenting with RSWA and concurrent neurologic symptoms may have underlying structural or physiological abnormalities of the central nervous system. Further investigation is warranted in a larger population to accurately define the phenomenon of RSWA in children.