Constantly discontinuous EEG patterns in full-term neonates with hypoxic-ischaemic encephalopathy

Objectives: Selected EEG features were evaluated in 21 constantly discontinuous tracings recorded on the same number of full-term neonates with hypoxic-ischaemic encephalopathy. Methods: The tracings were examined without using interval amplitude as the basis for distinguishing between burst-suppression and non-burst-suppression patterns. Results: The results were related to outcomes and other clinical parameters (severity of hypoxic-ischaemic encephalopathy, pO2 levels and drug intake). Conclusions: Features defining the grade of EEG discontinuity (i.e. maximum interval duration, minimum burst duration and interval amplitude) significantly related to outcome and, in most cases, to the grade of hypoxic-ischaemic encephalopathy. Other features (amplitude of slow waves within the burst and incidence of abnormal EEG transients) related to pO2 levels. The consumption of anticonvulsant drugs increased EEG discontinuity, but this effect did not seem dose-related. Finally, the persistence of a constantly discontinuous EEG pattern after the first week of life is a sign of unfavourable prognosis. In full-term neonates with hypoxic-ischaemic encephalopathy quantitative analysis of all constantly discontinuous EEGs seems more useful than only describing burst-suppression patterns on the basis of interval amplitude.