To evaluate auditory activity patterns in premature infants (PT), we performed auditory brainstem evoked potentials (ABEP) in a group of 9 healthy PT. A group of 9 full-term (FT) infants acted as control Infant groups were paired by postconcepcional age, sex, weight, height and cranial perimeter. All infants belong to a study on evaluation of the effect of the diet on the development of the central nervous system, and were evaluated at 4 months of post-term age during a quiet sleep state (stimulation intensities: 85 and 75 uV). Lactancies and amplitudes of waves I, III, and V, as well as inter-wave intervals I-III, III-V, and I-V were measured. No significant differences concerning latencies, amplitudes and inter-wave intervals were observed between infant groups. The decrease in the stimulation intensity (fro, 85 to 75 dB) provoked and increase of latencies and a decrease of amplitudes of different waves in both groups. The inter-wave interval I-V (central conduction time), however, remains unchanged regardless of stimulation intensities in PT and FT groups. These results indicate that healthy PT infants do not show differences of auditory activity patterns compared with full-term infants at 4 months of post-term age. This could suggest that the early exposure to the extrauterine environment does not modify ABEP patterns studied at the intensities usually used in the pediatric evaluation.

(Supported: Fondecyt 1940467, INSERM/CONICYT, Fondecyt 1930820.)