- Background: The modulation of delta-alpha phase-amplitude cross-frequency coupling (PACFC) may influence information processing throughout the human cerebral cortex. We investigated whether this frequency band-specific modulation is impaired in patients with obstructive sleep apnea (OSA).
Patients & Methods: In this study, the C3- and C4- electroencephalographic recordings of 170 participants (86 in main dataset: age 27-84 years, 44 subjects had moderate or severe OSA with respiratory disturbance index RDI>15/h; 84 in validation dataset: age 35 -75 years, 42 subjects with RDI>15/h) who underwent full-night polysomnography (PSG) were evaluated. We tested if the delta-alpha PACFC modulation index (MI) at the sensorimotor cortex differs between OSA patients with RDI>15/h and those with RDI≤15/h in distinct sleep stages. Further, by making use of a Support Vector Machine (SVM) algorithm, we tested if the sleep stage – specific MIs could predict RDI values of OSA patients.
Results: InBackground: The modulation of delta-alpha phase-amplitude cross-frequency coupling (PACFC) may influence information processing throughout the human cerebral cortex. We investigated whether this frequency band-specific modulation is impaired in patients with obstructive sleep apnea (OSA).
Patients & Methods: In this study, the C3- and C4- electroencephalographic recordings of 170 participants (86 in main dataset: age 27-84 years, 44 subjects had moderate or severe OSA with respiratory disturbance index RDI>15/h; 84 in validation dataset: age 35 -75 years, 42 subjects with RDI>15/h) who underwent full-night polysomnography (PSG) were evaluated. We tested if the delta-alpha PACFC modulation index (MI) at the sensorimotor cortex differs between OSA patients with RDI>15/h and those with RDI≤15/h in distinct sleep stages. Further, by making use of a Support Vector Machine (SVM) algorithm, we tested if the sleep stage – specific MIs could predict RDI values of OSA patients.
Results: In both datasets, in OSA patients with RDI >15/h, the delta-alpha CFC-MI was significantly (p< 0.05) reduced at the sensorimotor cortex during REM and NREM1 stages, while increased during NREM2 compared to patients with RDI ≤15/h. In addition, the delta-alpha MI in REM sleep stage could provide with use of an SVM algorithm a quite reliable (82% accuracy) prediction of the RDI in OSA patients.
Conclusions: This increase in disconnection at the cortical sensorimotor areas with increasing respiratory distress during sleep further supports the concept of a cortical sensorimotor dysfunction in OSA patients. Additionally, the delta – alpha MI during REM sleep may provide an objective neurophysiologic surrogate marker of respiratory distress in OSA patients.…
