[Clinical and electrophysiological studies of the organ of hearing in newborn infants. II. Study of maturity of the auditory pathway by brain stem responses (ABR) in newborn infants].

In a group of 130 tested children, 102 of whom a property had evaluated on brain stem responses, we tested the influence of newborn maturation on values of response parameters, their configuration and threshold values. It was shown that newborn maturation lowers in a statistically significant way the threshold values of acoustic stimulus. Also, the configuration of the monitoring changes with age of child tested. Newborn maturation increases the frequency of occurrence of waves II, IV, V and VI though decreases of incidence IV/V complex. In the group of the youngest pre-term babies IV/V complex were present in 50% of cases, whereas in the group of newborns carried to term its present could be verified only in 5-11% of cases. Newborn maturity also influences in an essential way the average latent time consecutive waves as well as central conduction time determined by interpeak latency I-V. Coefficient correlation values for these parameters shows a negative statistical significance correlation. That is, a decreasing of average values of these parameters with maturation of the newborn. It was also shown that structures of the hearing pathway responsible for generation of early and late components of brain stem responses nature at different periods. Peripheral structures of the hearing pathway are significantly more mature at birth than are central structures.