Prediction of lower developmental performances of healthy neonates by neonatal EEG-sleep measures

Abstract

Previous neurophysiologic studies from our laboratory have demonstrated altered EEG-sleep behavior at conceptional term ages in healthy preterm infant compared with a term cohort. Developmental assessments at 12 and 24 months of age of 16 children in each cohort were compared using MANOVA. Differences were detected on MANOVA between each cohort on Bayley mental and motor performance scores, while social skills (Vineland) and temperament (Carey) were similar. Healthy preterm infants had lower scores at 12 months of age ( P < .0001) and 24 months ( P < .04) than term infants before adjustment for prematurity. No group differences were observed after adjustment. For the combined cohort of 32 healthy neonates, specific neonatal EEG-sleep measures were included as predictor variables in regression analyses with Bayley mental scores as outcome variables. Lower Bayley mental scores at 12 and 24 months were associated with higher spectral EEG correlations, lower spectral EEG energies in the beta frequency ranges, fewer arousals per minute, lower rapid eye movements per minute, and shorter sleep latencies from awake state to active sleep. Significant associations were observed before adjustment for prematurity at both 12 and 24 months, and after adjustment at 12 months of age for lower spectral beta EEG energies. Lower socioeconomic class also correlated with lower developmental scores. Even in the absence of major neonatal illnesses, brain adaptation to prematurity influences later developmental outcome. Adjustment for “age equivalency” may be required up to at least 24 months of age even in a healthy preterm population.