Monitoring of cerebral function after severe asphyxia in infancy.

Abstract

SUMMARY Thirty nine infants with severe asphyxia (28 affected perinatally and 11 later) were studied by electrophysiological cerebral function monitoring (CFM) for periods varying from a half to 49 days. Nineteen infants died while still in intensive care and two died later from sequelae. Eighteen survived and were followed up when aged between 8 and 36 months. The initial electroencephalogram (EEG) and the first 12 hours of CFM tracing correlated well. The type of background activity, whether continuous or interrupted, proved to be of high prognostic importance unlike the presence of seizure activity, which bore no distinct correlation to outcome in these severely asphyxiated infants.

Prognostic Significance of Amplitude-Integrated EEG during the First 72 Hours after Birth in Severely Asphyxiated Neonates

“…There was a good agreement between conventional EEG and aEEG recordings, similar to previous studies (8,12,14). Conventional EEG provided additional information in only two infants, showing focal EA that was not identified on aEEG.…”

“…When aEEG background patterns were of normal voltage (CNV, DNV) or normalized before the age of 24 h, prognosis was fair, whereas severely abnormal aEEG patterns that persisted beyond that age were related to adverse outcomes. Previous studies have shown that, already several hours after birth, aEEG recording is a reliable method for early prediction of neurologic outcome in asphyxiated infants, with accuracy between 70 and 85% (8,11,12,26). Our findings indicate that extension of the recording period up to 48 h after birth adds to the prognostic value.…”

“…Previous studies have shown that this might occur in a small number of infants (7,11). However, the suppressive effects of antiepileptic drugs on aEEG in most studies is reported as relatively short lasting, several hours at most (10), or absent (12). In the present study, none of the infants with normal voltage patterns developed severely abnormal patterns after antiepileptic treatment.…”

“…brain cooling (16,17) and oxygen radical scavenging (18). There are, however, only a few studies that investigated the longitudinal course of aEEG tracings during the first few days after severe perinatal asphyxia in the absence of such interventions (7,12). It therefore is necessary to obtain data on the "natural" course, i.e.…”

“…The aEEG records a single-channel EEG from biparietal electrodes; frequencies Ͻ2Hz and Ͼ15Hz are filtered selectively, and the amplitude of the signal is integrated. The processed signal is recorded semilogarithmically onto a printer with a low paper speed (12). Previous studies have shown that aEEG correlates well with conventional EEG (13,14).…”