Use of evoked potentials in preterm neonates.

This paper has reviewed the techniques used for recording evoked potentials in the premature infant and the early developmental changes. The maturational changes in the evoked potentials, including morphological changes, and the very rapid latency changes within the first months of life, provide an invaluable means for assessing and monitoring development within the central nervous system. The maturational changes are such that normative values are requisite, and the norms must take into account both the infant's gestational age at birth as well as the postnatal age. These norms can then be used to aid in the assessment of gestational age, and whether there has or has not been normal maturational development, either in utero or during the postnatal preterm period. Evoked potentials are of increasing value clinically in preterm neonates, primarily because of the difficulty in obtaining reliable neurological evaluation of these infants. Median nerve SEPs may provide reliable information in preterm infants at risk of PVL, and when recorded in the second week of life, predict cerebral palsy. PTN SEPs seem to be even more reliable indicators of outcome, but the difficulty in obtaining them in preterm infants needs to be taken into consideration. Further study is needed in some areas, such as in apnoeic preterm babies clearly to establish the role that evoked potentials (in this case BAEPs) may have in understanding both the aetiology and the clinical course of this dysfunction. In other conditions, such as delayed intrauterine growth, that may lead to neurological sequelae, evoked potentials can provide objective CNS assessment. Evoked potentials may also prove useful in the monitoring of treatment modalities for preterm infants. The evoked potentials are a valuable adjunct in the assessment of preterm neonates and, as their value is recognised, we expect their use to increase.