Moderate Unconjugated Hyperbilirubinemia Causes a Transient but Delayed Suppression of Amplitude-Integrated Electroencephalographic Activity in Preterm Infants

Abstract

Background: Unconjugated hyperbilirubinemia occurs frequently in preterm infants and may result in bilirubin encephalopathy. Amplitude-integrated electroencephalography (aEEG) is used to evaluate brain function in newborns. Objectives: To investigate the influence of total serum bilirubin (TSB) on the aEEG amplitude of preterm infants and to evaluate aEEG as a noninvasive method to identify acute bilirubin encephalopathy. Methods: We performed a prospective observational study of 34 infants with a gestational age (GA) of 26–31 6/7 weeks. Infants had aEEG recordings on the 1st–5th, 8th and 15th day after birth. Infants with asphyxia, intraventricular hemorrhage >grade I or circulatory insufficiency were excluded. aEEG was evaluated by calculating the mean 5th, 50th and 95th centiles of the aEEG amplitudes. Results: TSB peaked on the 4th day after birth. There was no synchronous relationship between TSB and aEEG amplitudes. The 5th, 50th, and 95th aEEG amplitude centiles on the 8th day correlated negatively with the TSB peak value (r = –0.37, p = 0.048; r = –0.60, p = 0.001; r = –0.44, p = 0.017, respectively), irrespective of GA. The 5th and 50th aEEG amplitude centiles increased with increasing GA (r = 0.45, p < 0.001, and r = 0.26, p < 0.001, respectively) and postnatal age (r = 0.25, p < 0.001, and r = 0.16, p = 0.023, respectively). Conclusions: TSB had no direct effect on aEEG amplitudes in preterm infants. There is, however, a delayed effect on electrocerebral activity in the 2nd week after birth.

Fully automated simultaneous peripheral arteriovenous exchange transfusion not seen to aggravate brain function and the disorder of the internal environment in neonates with severe hyperbilirubinemia

“…23 The abnormality of aEEG correlated positively with the TSB value. 24,25 In our study, most neonates without bilirubin encephalopathy had continuous normal amplitude, mature SWC and no seizures, while all the neonates with bilirubin encephalopathy had the abnormal aEEG, with discontinuous abnormal amplitude and with immature and delayed SWC or with electrographic seizures. Little research has focused on the effects of some clinical procedures on electrocortical activities.…”

Early Amplitude-Integrated Electroencephalography Predicts Long-Term Outcomes in Term and Near-Term Newborns With Severe Hyperbilirubinemia

“…neurons is not uncommon among newborns with jaundice. [22][23][24][25][26]44 Our results suggest that early severe abnormalities in aEEG recordings are correlated with neurological deficits in newborns with severe jaundice, although its sensitivity was only 35.7%, which was very low compared with abnormal ABR with a sensitivity of 83.3%. One reason for this result might be that ABE might be reversible with rapid and aggressive intervention.…”

“…12,14 In our study design, aEEG was performed before the exchange transfusion, whereas ABR was carried after the intervention when the patients had stabilized. Another possible explanation for the difference is that hyperbilirubinemia only affects the cerebrocortical electrical activity for a limited time, 23,25 whereas aEEG mainly reflects cortical signal changes. Last but not least, the auditory system is the most sensitive neural system to bilirubin toxicity 8 and might be damaged in isolation regardless of other common regions of the brainstem, 3 thus leading to earlier subtle changes in ABR recordings as an indicator of bilirubin neurotoxicity.…”

“…22 However, studies on the predictive role of aEEG in jaundice patients have yielded conflicting results. 25,26 Here, we report the potential contribution of aEEG to the prediction of prognosis of ABE.…”

Hyperbilirubinemia Influences Sleep-Wake Cycles of Term Newborns in a Non-Linear Manner

“…From this point of view, although SWC cannot provide information on location, it may have a high sensitivity to subtle nerve damages with different degrees of exposure. Recently, Horst et al[31] also used aEEG to study preterm children (26–31 6/7 weeks gestational age) suffering from hyperbilirubinemia (TSB 124–291 μ mol/l), but did not find an association between SWC and TSB. The author believed this may be related to low bilirubin exposure.…”