Comparison of Brainstem Auditory Evoked Response at Different Click Rates between Preterm Babies after Neonatal Necrotizing Enterocolitis and Healthy Preterm Babies

Abstract

Background: Neonatal necrotizing enterocolitis (NEC) is associated with an increased incidence of poor neurodevelopment. The knowledge of underlying neurophysiology is very limited, and the influence of NEC on the preterm brainstem is very poorly understood. Objective: To assess the effect of NEC on the immature auditory brainstem by excluding any possible confounding effect of preterm birth. Methods: We recorded and analyzed brainstem auditory evoked response (BAER) at different click rates in preterm babies (30-34 weeks gestation) after NEC. The results were compared with those in age-matched healthy preterm babies who had no NEC. Results: At click rate 21/s, the latencies of BAER waves I and III in the preterm NEC babies were similar to those babies without NEC. However, wave V latency was longer in the NEC babies than in those without NEC. The I-V interpeak interval was also longer in the NEC babies than in those without NEC. These abnormalities were persistent at higher click rates 51 and 91/s. Wave I amplitude in the preterm NEC babies did not differ significantly from that in those without NEC, but wave III and V amplitudes were smaller than in those without NEC at all 21-91/s clicks. Conclusions: Compared with healthy preterm babies, preterm babies after NEC showed a major increase in wave V latency and I-V interval at all 21-91/s clicks. Brainstem auditory function is impaired in preterm NEC babies after excluding the possible confounding effect of preterm birth. Neonatal NEC and associated perinatal conditions adversely affect the premature brainstem.