Heartbeat evoked potential assessment in moderate and severe obstructive sleep apnea patients

Sleep apnea disorder is defined as more than five apnea events per hour or more than 10 seconds of respiratory airflow ceasing during sleep. Obstructive sleep apnea (OSA) manifests as recurrent attacks of the upper respiratory tract, with an unaltered breathing rhythm. However, it remains unclear if brain responses to cardiac impulses relate with the severity of OSA. In this paper, we aimed to assess heartbeat evoked potentials (HEPs) during non-rapid eye movement (non-REM) and rapid eye movement (REM) sleep stages in moderate and severe OSA patients. The HEP signal is a cerebral reaction to the heartbeat and a measure of brain-body interactions like interoceptive processing and intrinsic arousal levels. We identified significant clusters over the central region (i.e., C4 electrode) only during non-REM sleep when comparing the amplitude of HEPs between moderate and severe OSA patients independently during non-REM and REM periods. These results show that interoceptive processing impairments may be most prevalent during non-REM sleep.