[Seizures in premature neonates and in full-term neonates (author's transl)].

Normal EEG rhythms depend on conceptional age (CA), i.e., gestational age plus legal age. To assess whether pathological rhythms are also related to the level of maturation. EEG seizures have been compared in 26 premature neonates (PN) - 16 from 26 to 32 weeks of CA, 10 from 33 to 36 weeks of CA - and in 20 full-term neonates (FTN). The amplitude, the frequency, the polarity, the duration of paroxysmal discharges, the presence of variations in localization and the presence of clinical seizures are not related to CA. In FTN, the discharges during seizures, display a more complex pattern; the foci of spike discharges are more often on the rolandic area; spikes or delta waves are more often asynchronous than in PN. In PN less than 32 weeks of CA, seizures occur more often in females than in males. The prognosis of seizures is more severe in PN than in FTN. The prognosis is also more severe in FTN with brief discharges (less than 3 min) than in those with long-lasting discharges. The seizures are mainly related to extensive intraventricular haemorrhage in PN, to cortical lesions in FTN.