Hideya Kodama
University of Akita, Japan
Title: Assessment of nocturnal sleep architecture by actigraphy and one-channel electroencephalography in early infancy
Biography
Biography: Hideya Kodama
Abstract
Objective: To elucidate characteristic sleep architecture of different nocturnal sleep patterns　in early infancy.　Methods: Participants were 27 infants at the same conceptional age of 3-4 months. Nocturnal sleep of　these infants was monitored at home by simultaneously using actigraphy and a one-channel portable　EEG device. According to the infants' activity for 6 hours from sleep onset, each night's sleep pattern　was classified into three categories: sleeping through the night (STN), sleeping with weak signals　(crying/fuss episodes <10 minutes or fed), and sleeping with strong signals (crying/fuss episodes≧10　minutes). Associations of sleep patterns with sleep variables (percentage of time in sleep stages,　pattern of slow-wave sleep (SWS) recurrence, etc.) were investigated.　Results： Analysis was conducted in 95 nights. STN pattern (n=36) was characterized by suppressed　body movements while EEG represented a state of wakefulness. Weak signal pattern (n=27) tended to　indicate rich and regular distributions of SWS across the night. Strong signal pattern (n=32) was　characterized by reduced sleep time, although the amount of SWS was not reduced to that degree.　Exclusively breastfed infants accounted for 78% of weak signal patterns, whereas formula-feeding　infants, 67% of STN patterns. In several nights with STN or strong signal pattern, SWS did not occur in　>50% of the sleep cycles. Multiple regression analysis showed that exclusive breastfeeding may　increase the proportion of SWS in non-REM sleep.　Conclusions: Each nocturnal sleep pattern was associated with some sleep architecture, part of which would be attributed to infant's feeding methods.