Interhemispheric asynchrony of NREM EEG at the beginning and end of sleep describes evening vigilance performance in patients undergoing diagnostic polysomnography.

Objective: Obstructive Sleep Apnea (OSA) is associated with deficits in vigilance. This work explored the temporal patterns of OSA-related events during sleep and vigilance levels measured by the Psychomotor Vigilance Test (PVT) in patients undergoing Polysomnography (PSG) for suspected OSA. Approach: The PVT was conducted prior to in-laboratory PSG for 80 patients suspected of having OSA. Three groups were formed based on PVT-RT-outcomes and participants were randomly allocated into Training (n=55) and Test (n=25) samples. Sleep epochs of non-rapid-eye movement (NREM) Electroencephalographic (EEG) asynchrony data, and REM and NREM data for respiratory, arousal, limb movement and desaturation events were analysed. The data were segmented by sleep stage, by Sleep Blocks (SB) of stable Stage N2, Stage N3, mixed-stage NREM sleep, and, by Time of Night (TN) across sleep. Models associating this data with PVT groups were developed and tested. Main Results: A model using NREM EEG asynchrony data segmented by SB and TN achieved 81.9% accuracy in the Test Cohort. Models based on interhemispheric asynchrony SB data and OSA data segmented by TN achieved 80.6% and 79.5% respectively. Significance: Novel data segmentation methods via blocks of NREM sleep and TN have improved our understanding of the relationship between sleep, OSA and vigilance. .