Early Abnormal Amplitude-integrated Electroencephalography (aEEG) is Associated with Adverse Short-term Outcome in Premature Infants

Background: In preterm infants with IVH the electrocortical background activity is affected and there is a correlation between the severity of cerebral injury to the degree of depression, however the usefulness of the early aEEG recordings has hardly been determined.

Aim: To identify early aEEG features that could be used as prognostic markers for severe brain injury in prematures.

Methods: In 115 infants, 25-32 wk GA, aEEG recordings during the first 72 h of life were correlated with head ultrasound findings. Continuity (Co), sleep-wake cycling (Cy) and amplitude of the lower border (LB) of the aEEG were evaluated by semi-quantitative analysis.

Results: The infants were divided into four groups based on head ultrasound findings: A (n=72, normal), B [n=16, grades 1-2 intraventricular hemorrhage (IVH)], C (n=21, grades 3-4 IVH) and D (n=6, periventricular leukomalacia). 18 infants (16 of group C and 2 of group D) died during hospitalization. Significantly lower values of all aEEG features were found in group C infants. The presence of pathological tracings (burst-suppression, continuous low-voltage, flat trace) or discontinuous low-voltage (DLV), the absence of Cy and LB<3 μV in the initial aEEG displayed a sensitivity of 88.9%, 63% and 51.9% respectively, for severe brain injury. Logistic regression of aEEG features and GA to the presence or absence of severe injury revealed that only Co was significantly correlated to outcome. Using this feature 83.19% of cases were correctly classified.

Conclusion: Pathological tracings or DLV in the initial aEEG is predictive for poor short-term outcome in premature neonates.