Demonstrating the diagnostic value of brain maturation in preterm amplitude-integrated electroencefalography

Background: Amplitude-integrated electroencephalogram (aEEG) is becoming more common in Neonatal Intensive Care Units (NICUs) for monitoring infants after perinatal asphyxia. aEEG is a valuable tool for the continuous evaluation of functional brain maturation in infants.Objective: The aim of this study is to evaluate and characterize amplitude-integrated electroencephalogram tracings in preterm infants at varying postmenstrual age (PMA).Methods: Infants with a PMA of <37 weeks admitted to the neonatal intensive care unit of the Celal Bayar University Hospital were studied prospectively by using aEEG. Clinically stable infants without clinical or sonographic evidence of neurologic abnormalities were eligible for inclusion in the study. The distribution of 3 background aEEG activity patterns (discontinuous low-voltage, discontinuous high-voltage, and continuous), presence of sleep-wake cycles, and amplitude of the lower border were determined by visual analysis. Furthermore, CFM recordings were evaluated using the scoring system for record continuity, presence of cyclic changes in electrical activity and amplitude of the lower border.Results: 33 aEEG recordings were obtained in 24 infants. Amplitude of the lower border increased with increasing PMA. With advanced PMA the aEEG becomes more continuous and it displays mature sleep?wake cycles. Discontinuous low voltage pattern and discontinuous high voltage pattern showed an inverse correlation to PMA. With advanced PMA, scores for each variable as well as total scores progressively increased with maturation.Conclusion: The older PMA of infants, the more mature the aEEG pattern, manifested as increased continuity and sleep-wake cycle, the higher low bound voltage.