Changes in spectral EEG energies during sleep over the first 2 months of life in healthy neonatal cohorts
Two spectral EEG measures were compared from multiple-channel EEG-sleep 3-hr nap studies of 40 preterm and 31 fullterm infants from birth through 7 months of age. Spectral beta range EEG energies derived from fourteen cerebral channels decreased for both neonatal cohorts from 38 to 44 weeks gestational age; however, the preterm cohort had a greater decline in spectral beta range EEG energies than the fullterm cohort. Paradoxically, spectral EEG correlations between two pairs of homologous EEG channels (T3C3/C4T4) increased for both groups between 38 to 44 weeks conceptional age (CA) but the preterm group expressed a greater rate of increase during this time period. Declines in spectral beta range EEG energies and increases in spectral EEG correlations reflect functional reorganization of brain structures responsible for brain activity during sleep during later fetal and neonatal periods. Altered functional brain maturation, as expressed during sleep, is one physiological explanation for earlier occurrence of SIDS in a preterm population.
