Cerebral lesions in early prematurity: EEG prognostic value in the neonatal period

The new radiological technics show the incidence of intraventricular hemorrhage (IVH), intraparenchymal hemorrhage (IPH), or of porencephaly (PL), in the neonatal period. Discrepancies between the initial extent of lesions and the outcome have been observed. We tried to appreciate the EEG value in infants having had such lesions during the first month of life. We studied serial EEGs and neuroradiological exams in 34 babies: with IVH (group I, 17 cases), with IPH and/or PL (group II, 17 cases). Their gestational age (GA) was between 27 and 34 weeks; they all had a neurological follow-up between one and five years. Infants with favourable outcome (76% in gr. I, 47% in gr. II) had normal or slightly abnormal EEGs, whatever the extent of lesions. Nine babies had very abnormal EEGs (numerous positive rolandic spikes (PRSs) and/or EEG background without physiological rhythms); one developed moderate sequelae, the other 8 major sequelae (2 with infantile spasms). In gr. II, babies with major sequelae had a higher GA than babies with good outcome. The PRSs were more often observed with periventricular lesions than with IVH only and in babies with higher GA; they lasted up to 12 weeks on serial EEGs in one case with porencephaly (major sequelae with infantile spasms); they appeared before scan abnormality in another case which developed later porencephaly (major sequelae). Thus, EEGs give valuable information on brain function and help to forecast outcome in premature babies.