Functional abnormality of the auditory brainstem in high-risk late preterm infants

ObjectiveTo examine whether late preterm infants with perinatal problems are at risk of brainstem auditory impairment. Methods: 68 high-risk late preterm infants (gestation 33-36 weeks) with perinatal problems or conditions were studied at term using maximum length sequence brainstem auditory evoked response. The controls were 41 normal term infants and 37 low-risk late preterm infants. Results: Compared with normal term infants, the high-risk late preterm infants demonstrated a significant abnormal increase in MLS BAER variables that mainly reflect more central function of the brainstem auditory pathway, including wave V latency, III-V and I-V interpeak intervals, and III-V/I-III interval ratio. The abnormalities were more significant at higher than at lower click rates. The slopes of MLS BAER-rate function for these variables were increased. Compared with low-risk late preterm infants, the high-risk infants showed similar, though slightly less significant, abnormalities, mainly a significant increase in III-V and I-V intervals. Conclusions: Maximum length sequence brainstem auditory evoked response components that mainly reflect central function of the auditory brainstem were abnormal at term in high-risk late preterm infants. Significance: More central regions of the auditory brainstem are impaired in high-risk late preterm infants, which is mainly caused by associated perinatal problems or conditions. (C) 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.