[Electroencephalographic maturation in preterm newborn infants].

We have studied 51 preterm infants [gestational age (GE) less than 32 weeks] by: a neurologic examination at 40 weeks of postconceptional age, serial cranial ultrasonographies, weekly electroencephalograms (EEG) until 42 weeks of postconceptional age, and Brunet-Lezine test of psychomotor developmental at 1 year old. Our objective is the longitudinal study of EEG maturation in preterm infants with or without neurologic injury. In preterm infants with the less gestational age are present the EEG characteristics reported for the older infants, the typical EEG pattern is the "sawtooth" (27-30 weeks GE). If these infants are "normal", the EEG maturation get adjusted to the previous reported pattern, except for the earlier presentation of transitory acute frontal waves and the disappearance of the preterm's discontinuous trace. The EEG maturation of preterm infants with perinatal neurologic injury are significantly delayed in contrast with "normal" preterm infants until 40 weeks of postconceptional age; this fact have a poor prognosis for these infants.