Neonatal Cortical Auditory Evoked Potentials Are Affected by Clinical Conditions Occurring in Early Prematurity.

PURPOSE: Cortical auditory evoked potentials may serve as an early indicator of developmental problems in the auditory cortex. The aim of the study was to determine the effect on neonatal cortical auditory processing of clinical conditions occurring in early prematurity.

METHODS

Sixty-seven preterm infants born at 29 weeks mean gestational age (range, 23-34 weeks) were recorded at a mean postconception age of 35 weeks, before discharge from the third level neonatal intensive care unit. The average of 330 responses to standard 1000 Hz pure tones delivered in an oddball paradigm was recorded at frontal location. Data of 45 of 67 recruited premature infants were available for analysis. Mean amplitudes calculated from the data points of 30 milliseconds centered on P1 and N2 peaks in the waveforms of each subject were measured. The effect of perinatal clinical factors on cortical auditory evoked responses was evaluated.

RESULTS

The amplitude of P1 component was significantly lower in infants with bronco-pulmonary dysplasia (P = 0.004) and retinopathy of prematurity (P = 0.03). The multivariate analysis, done to evaluate the relative weight of gestational age and bronco-pulmonary dysplasia and/or retinopathy of prematurity on cortical auditory evoked potentials components, showed an effect of clinical factors on P1 (P = 0.005) and of gestational age on N2 (P = 0.02).

CONCLUSIONS

Cortical auditory processing seems to be influenced by clinical conditions complicating extremely preterm birth.