Prognostic value of electroencephalogram in hypoxic-ischemic encephalopathy (HIE)

Abstract

In order to check the prognostic implications of EEG tracings in hypoxic-ischemic encephalopathy (HIE), we carried out prospective EEG recordings in 116 newborn babies (65 term and 51 premature) admitted to our neonatal intensive care unit as a result of perinatal asphyxia. Forty term neonates were found to have critical and/or intercritical epileptiform EEG alterations; the developmental results of 23 of these cases (57.5%) were adverse and were favorable in 17 cases (42.5%). Given that unfavorable results occurred in only 4 of the other 25 term neonates, the epileptiform EEG alterations were statistically significant for adverse developmental results (p < 0.005). Of the premature neonates, 29 were found to have critical and/or intercritical epileptiform EEG alterations. The developmental results were adverse in 19 of these children (65.5%) and favorable in 10 cases (34.8%). The statistical evaluation in this case showed a barely significant difference (p < 0.005) between epileptiform EEG alterations and poor developmental outcome when uncorrected age was used, and no statistically significant difference when corrected age was used. Thus, we conclude that although epileptiform EEG anomalies may serve as markers for neurological development impairments, they must be considered in conjunction with the background EEG tracing.