Table 1

Classification of EEG background activity

GA, gestational age; IBI, interburst intervals.
1Normal/mild abnormalitiesNormal pattern for GA, including slightly abnormal activity, e.g. mild asymmetries, mild voltage depression
2Moderate abnormalitiesDiscontinuous activity with IBI too long for GA. Clear asymmetry or asynchrony. Absence of age appropriate EEG features, e.g. delta brushes
3Major abnormalitiesSevere discontinuity in EEG for GA. Burst suppression pattern. No appropriate wake–sleep cycles for GA. Multi focal sharp waves or positive rolandic sharp waves
4Inactive EEGBackground activity <10 μV