Auditory brainstem response: reference-values for age.

PURPOSE To study the absolute latencies of waves I , III and V and interpeak I-III , III-V and I-V of Auditory brainstem responses obtained in preterm newborns in relation to post-conceptual age, term newborns and six months of age infants, establishing reference values ​​for each age group. METHODS Retrospective study realized through the analysis of tests performed on 80 infants divided into four groups, being the group one composed per newborns assessed between 35 and 36 weeks post-conceptual age; group two by newborns assessed between 37 and 38 weeks; group three with newborns reviewed between 39 to 40 weeks; and group four with infants evaluated with six months. RESULTS The wave I absolute latency in the group one was 1.81 ms, decreasing to 1.79 ms in groups two and three, and to 1.70 ms in group four. The wave III latency in group one was 4.74 ms, decreasing to 4.62 ms in group two, to 4.56 ms in the group three and to 4.37 ms in the group four. The wave V latency in group one was 7.14 ms, in the group two it was 7.05 ms, in the group three 6.90 ms; and in the group four it was 6.50 ms. Interpeak latencies were also decreased in all groups. CONCLUSION The latencies studied decreased with the increasing age and were similar values ​​with the international literature.