Quantifying Cortical Maturational Aspects During Different Vigilance States in Preterm Infants by Advanced  EEG Analysis

Preterm birth is a significant risk factor for atypical neurodevelopment, yet early electrophysiological markers of brain maturation are still lacking. Non‐invasive electroencephalographic (EEG) monitoring of cortical maturation in these patients holds promise as a tool for neurodevelopmental prediction. However, its clinical application is limited by technical challenges in maintaining stable, long‐term electrode placement on very small neonate scalps and by the highly specialised, multi‐level expertise required to care for these fragile patients. Using video‐polysomnographic EEG recordings in very low birth weight (VLBW, < 1500 g) preterm infants, we characterised large‐scale neuronal dynamics during distinct vigilance states and tested whether they could serve as indicators of early cortical maturation. We analysed EEG recordings obtained at 33.9 ± 1.4 weeks postmenstrual age (PMA), during active sleep (AS), sleep onset active sleep (SOAS), quiet sleep (QS), and quiet wakefulness (QW). For each vigilance state, we assessed large‐scale neuronal dynamics in terms of phase synchronisation, neuronal bistability, and local phase‐amplitude coupling (PAC), both globally and separately for anterior and posterior regions, and correlated them with PMA. We found that phase synchronisation peaked in the δ band during QS and in the θ band during more active states (QW, SOAS, AS). δ‐band bistability was lower in posterior regions across all states, while δ‐PAC was lower posteriorly during sleep but reversed during wakefulness. Also, bistability and PAC decreased with advancing PMA. These findings suggest that vigilance‐state‐dependent neuronal dynamics capture aspects of early cortical maturation—even with low‐density EEG cap—offering novel candidate biomarkers to monitor neurodevelopment in infants born preterm.