Use of amplitude-integrated electroencephalography (aEEG) and near infrared spectroscopy findings in neonates with asphyxia during selective head cooling

Background: Amplitude-integrated electroencephalogram (aEEG) at <6 h is the best single outcome predictor in term infants with perinatal asphyxia at normothermia. Hypothermia treatment has changed the cutoff values for outcome prediction by using time at onset of normal trace and SWC. Cerebral hemodynamics and oxygenation changes detected by near infrared spectroscopy (NIRS) during hypothermia treatment in aphyxiated neonates are not a well known issue. Aim: The aim of this study was to investigate the correlations between brain monitoring (amplitude integrated EEG and NIRS) and outcome in asphyxiated full-term infants with moderate/severe hypoxic-ischemic encephalopathy before, during and after hypothermia treatment. Method: Ten neonates were recruited for hypothermia treatment by using the cool cap entry criteria. aEEG and NIRS were applied in 10 and 8 patients, respectively with moderate and severe hypoxic-ischemic encephalopathy before, just after brain cooling and rewarming periods. Patterns and voltages of aEEG backgrounds sleep-wake cycles (SWC) and NIRS values (TOI% and FTOE) were recorded. During the follow up their outcomes were assessed by using the Bayley Scales of Infant Development II. Conclusion: Hypothermia changes the predictive value of early aEEG. Normalization of a baby's aEEG and the appearance of SWCs while being cooled occurs later. In our study one patient had normal aEEG background pattern at 80 and imminent SWC at 90 h after birth and still had normal Bayley scores at 24 months. Time to normal aEEG and SWC appearance should be carefully evaluated during the cooling period. NIRS values were different due to the clinical presentations of the patients. 2011 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.