[The study of factors affecting ABR in high risk newborn infants].

A.B.R. was employed to examine auditory pathways in a group of 78 newborn infants at risk and one of 20 normal infants. The impaired newborn group suffered of various risk factors or pathologies: 20 premature infants, 12 undersize (small for date), 12 with breathing distress, 11 hiv positive, 5 with neonatal jaundice, 4 suffered of convulsion, 4 at risk for hereditary deafness, 4 born by mothers with mellitus diabetes, 2 with dolichocefalia, 1 with the Albers-Schomberg syndrome, 1 with congenital heart disease and 1 with congenital glycogenosis. The results of A.B.R. of the risk group were compared statistically employing the "t Student's test" with those of the group of normal infants. The influence of risk factors in the first group on alterated A.B.R. parameters was then examined using a step-by-step logistic regression analysis method. The result showed a significant increase in a latency of waves V and III and inter-waves I-V and III-V in risk infants, while wave I and I-III internals were normal. These findings appear to demonstrate that in infants at risk, brainstem acoustic pathways are more sensitive to damage than the cochlea and acoustic nerve. This could be explained by the different degree of maturation that exists between the central acoustic pathways and the coclea and acoustic nerve. Analysis of the influence of pathologies and risk factors on A.B.R. indicate that birth weight followed by chronological age and length of the gestation period are significant in the development of A.B.R. alterations. The Albers-Schomberg syndrome, dolicocephalia, microcephalia, congenital glicogenosys, hiv infection, breathing difficulty and neonatal jaundice proved to be the main pathologies responsible for bringing about A.B.R. alterations.