[Changes in the early auditory evoked potentials during premature infancy, infancy and early childhood]

We report on the derivation of the early acoustic evoked potentials (EAEP) in 498 healthy normotrophic infants between the 32nd post-conceptional week and the end of the 3rd year of life. The changes of the wave latencies and interpeak intervals in different age periods until they reached the constant values found in adults are followed by 1528 potential derivations. The varying rate of maturation of the auditory pathway in the brain stem can be followed up well by the potential patterns. The time around the 34th post-conceptional week is characterized by a maturation episode of central and peripheral auditory pathway portions. The extrauterine matured normotrophic preterm infant shows statistically significantly longer latencies of waves III and V and a longer interpeak interval I-V in comparison with normotrophic term neonates. Gestational age, birth weight and Apgar score of the preterm infant had no influence on the behaviour of the EAEP. After the 38th post-conceptional week practically only the maturation of the central auditory pathway portion takes place: the main portion of the latency shortenings of III and V and IPI I-V is applicable to the 1st year of life. The maturation is an individually characterized progressive process of varying speed with no fixed age for its completion. Thus the adult wave V latency was reached in 8% of the 4- to 6-month-old children, and in 57% by the end of the 1st year of life. The adult IPI I-V values were reached in 42% of the 10- to 12-month-old children.(ABSTRACT TRUNCATED AT 250 WORDS)