Sleep-wake cycling on amplitude-integrated electroencephalography in term newborns with hypoxic-ischemic encephalopathy

Objective. The objective of this amplitude-integrated electroencephalography (aEEG) study was to evaluate the influence of perinatal hypoxia-ischemia on sleep-wake cycling (SWC) in term newborns and assess whether characteristics of SWC are of predictive value for neurodevelopmental outcome. Methods. From a consecutive series of newborns born during a 10-year period, the aEEG tracings of 171 term newborns with hypoxic-ischemic encephalopathy were assessed for the presence, time of onset, and quality of SWC. SWC patterns were categorized with regard to the background pattern on which they presented, as normal or abnormal SWC. Results. SWC was seen in 95.4% of the surviving newborns and in 8.1% of those who died. The median time intervals from birth to onset of SWC were significantly different in newborns with hypoxic-ischemic encephalopathy grades I, II, and III (7, 33, and 62 hours, respectively). Newborns with seizure discharges developed SWC with a delay of 30.5 hours. Good outcome was associated with earlier onset of SWC and normal SWC pattern. The difference in the median Griffiths' developmental quotients in newborns who started SWC before/after 36 hours was 8.5 points. The good/poor neurodevelopmental outcome was predicted correctly by the onset of SWC before/after 36 hours in 82% of newborns. Conclusions. The presence, time of onset, and quality of SWC reflected the severity of the hypoxic-ischemic insult to which newborns were exposed. The time of onset of SWC has a predictive value for neurodevelopmental outcome.