Abstract
Introduction
Central sleep apnea (CSA) syndrome is defined when five or more central apneas and/or hypopneas are present per hour of sleep, more than 50% of all respiratory events. CSA usually occur during NREM stage and rarely during REM. CSA is important to recognize because of complications ranging from frequent nighttime awakenings,sleepiness to adverse cardiovascular outcomes. We present a 40 year old female patient with rare CSA during REM sleep and dream enactment.
Report of Case
40yo African American female with history of loud snoring, witnessed sleep apnea, and daytime fatigue. She reported nightmares, sleep talking, and acting out her dreams without injury. Epworth sleepiness score was 5 /24. Her past medical history is significant for depression and anxiety. She has no history of head trauma, no neurologic or cardiovascular disorders. Her medications include fluoxetine and,quetiapine. She denied substance use, narcotic use, or alcohol use.
Her level 1 sleep study showed predominantly REM-associated central sleep apneas which is rare. She also was observed to have loss of REM sleep muscle atonia suggestive of REM Behavior disorder.
Her sleep architecture was atypical with decreased N3 sleep stage. REM sleep duration was adequate. She was noted to have loss of REM muscle atonia based on AASM guidelins elevated chin EMG, excessive transient muscle activity, and witnessed movement during REM stage via video monitoring.
During the study, she had an apnea/hypopnea index (AHI) of 13.1 per hour of sleep, Central apneas were predominantly noted during REM stage, 10 per hour, comprised of 50% of her respiratory events. The minimum SpO2 value with CSA was 94%. She had normal sinus rhythm.
Her sleep was fragmented. A total arousals were 28.4/hour,and 7.9/hour were respiratory arousals, and the rest were spontaneous arousals.
An echocardiogram showed normal left ventricular ejection fraction of 55 to 60 %. Her room air arterial blood gas was normal with PaC02 of 37 mmHg. MRI of the brain/brainstem was ordered given her atypical REM sleep. She had no acute intracranial abnormalities. There is a non specific finding of a low lying cerebellar tonsils without evidence of Chiari I malformation.
Conclusion
Our patient has rare idiopathic central apnea in REM stage and is third case reported. She also has loss of muscle atonia during REM with dream enactment which is also rare in her age group. Injury precaution advised.
Amelioration of sleep-disordered breathing with supplemental oxygen in older adults
