Neonatal necrotizing enterocolitis adversely affects neural conduction of the rostral brainstem in preterm babies

Necrotizing enterocolitis (NEC) is a devastating neonatal disease, often leading to long term neurodevelopmental impairment. The effect of NEC on the immature brain remains not fully understood. We test the hypothesis that NEC adversely affects functional integrity, particularly neural conduction, of the preterm brainstem.

Thirty-two preterm NEC babies (30-36weeks gestation) were recruited at term age. Maximum length sequence brainstem auditory evoked response was recorded and analysed with click rates 91-910/s at term age. The results were compared with normal term babies and age-matched healthy preterm babies.

Wave V latency, I-V and III-V intervals, and III-V/I-III interval ratio differed significantly among the three groups of babies at all click rates 91-910/s. Compared with normal term babies, preterm NEC babies showed significant increase in all these MLS BAER variables at all rates, with no apparent abnormalities in wave I and III latencies and I-III interval. All these abnormalities were more significant at higher than at lower click rates. No notable abnormalities were seen in wave amplitudes. Compared with age-matched healthy preterm babies, NEC babies showed similar abnormalities, although the abnormalities were relatively less significant.

MLS BAER components that mainly reflect neural conduction in the more central regions of the auditory brainstem were abnormal in preterm NEC babies, although those components that mainly reflect peripheral function were generally normal.

Neonatal NEC adversely affects myelination of the more rostral or central regions of the immature brainstem, resulting in delayed or impaired neural conduction, but spares the more peripheral regions.