Neurophysiological findings of auditory evoked potentials in infants with a history of prematurity.

BACKGROUND

Auditory evoked potentials (AEPS) constitutes the most commonly used neurophysiological test to assess the functional development of the auditory brainstem in infants and allows the evaluation of hearing for high frequencies.

METHODS

An observational, descriptive, cross-sectional and retrospective study was conducted. The AEPS results for 186 infants (372 ears) with a history of prematurity were examined. The bioelectrical response, morphology, amplitude, latencies I, III and V, and intervals I-III, III-V and I-V were compared, as well as auditory thresholds between two groups of premature infants < 32 and ≥ 32 weeks of gestational age (WGA).

RESULTS

The bioelectrical response, latencies I, III and V, and intervals I-III and III-V were similar between the two groups of premature infants according to their corrected age; no statistically significant differences were found (p > 0.05) for these variables. The amplitude, morphology, and the I-V interval were more affected in the group of premature infants < 32 WGA (p < 0.05). Of the 372 ears evaluated, 275 showed normal hearing and 97 showed some degree of hearing loss for high frequencies, which was more frequent in patients < 32 WGA (p < 0.05).

CONCLUSIONS

The functional development of the auditory brainstem was similar between the groups of premature infants and within the normal range for the respective corrected age. Prematurity produced a directly proportional and statistically significant increase in the frequency of hearing loss for high frequencies.