EEG Depression and Germinal Layer Haemorrhage in the Newborn

Abstract

Amplitude integrated EEG (aEEG) recordings from 32 mechanically ventilated infants, gestational age 32 weeks or less, were analysed. All recordings were started within 24 h of birth and continued for at least 50 h. Germinal layer haemorrhage (GLH) was diagnosed by repeated ultrasonography. In six infants neither GLH nor hypocalcaemia were diagnosed; aEEG in these infants rapidly became more active after birth: at 30 h of age continuous background activity was present for more than 20% of the time, and a seizure-like pattern was exceptional. In seven infants without GLH but with hypocalcaemia and other signs of metabolic derangement, continuous background activity appeared later and seizure-like activity was frequent. In the infants with GLH, depression of the background activity was apparent. This finding was particularly distinct in the presence of severe haemorrhages. Four infants developed GLH after 30 h of age. All these infants had depressed aEEG before the development of GLH, with less than 20% continuous activity at 30 h of age. In ten infants an analysis of the aEEG during the occurrence of GLH was possible. In six of these, cortical electrical activity decreased. Due to the limitation of GLH timing, it was not possible to decide whether this decrease closely preceded or followed GLH. We suggest that GLH primarily occurs in brains with a preceding metabolic and neurophysiologic abnormality, and that further functional deterioration is caused by the most severe haemorrhages.

Decreased aEEG Continuity and Baseline Variability in the First 48 Hours of Life Associated With Poor Short-Term Outcome in Neonates Born Before 29 Weeks Gestation

“…The association between P/IVH and changes in the EEG and aEEG in extremely premature neonates has been seen in previous studies (19,22,24,29). Many of these studies have been performed after the first day of life in neonates who had already developed a P/IVH.…”

“…Only a few studies have assessed the EEG or aEEG before the onset of the P/IVH (24,29). In our study, head ultrasound examinations were performed on all neonates before commencement of the aEEG recording.…”

“…The general immaturity of the EEG trace in the extremely premature neonate results in difficulty distinguishing between a "normal" and "abnormal" aEEG trace in these neonates. A number of studies have assessed aEEG recordings of premature neonates during the first few weeks of life (18 -23); however, few studies have assessed extremely premature neonates in the first 48 h after birth (24,25). Quantitative aEEG analysis has been performed in some recent studies, which have shown associations between quantitative measures and outcome (20,23,25).…”

Electroencephalography and brain damage in preterm infants

“…Although the EEG/aEEG is of little diagnostic value it is a good predictor of outcome. The degree of background depression correlates with best with the extent of brain injury and also with the grade of IVH 18,19,20,21 .…”

“…Electrographical seizure activity, often subclinical, is common and affects approximately 60-70 % of infants during the development of IVH 20,21,22 . Although many previous studies indicated that an association between PRSW and IVH, some studies showed that PRSW did not seem to be associated with IVH and were more often observed with white matter injury PVL 20 .…”