Brainstem auditory abnormality in extremely premature babies and the impact of neonatal bronchopulmonary dysplasia.

INTRODUCTION: Extremely premature babies, particularly those who have neonatal bronchopulmonary dysplasia, are at risk of brain damage and neurodevelopmental impairment. This study aimed to examine functional status of the brainstem auditory pathway in extremely premature babies and assess the impact of bronchopulmonary dysplasia on function.

MATERIAL AND METHODS: Brainstem auditory evoked response was studied at term in babies born at ≤27 weeks of gestation with or without neonatal bronchopulmonary dysplasia. The normal controls were term babies without perinatal problems.

RESULTS: Compared with the normal controls, the extremely premature babies showed an elevated response threshold, increased latencies of waves I, III and particularly V. They also showed significantly increased I-V and III-V intervals. The amplitudes of waves I and V were moderately reduced. These abnormalities were clearly more significant in those with bronchopulmonary dysplasia than those without bronchopulmonary dysplasia. A direct comparison between the two groups of extremely premature babies revealed that wave V latency, and I-V and particularly III-V intervals were significantly longer in the babies with bronchopulmonary dysplasia than those without bronchopulmonary dysplasia.

CONCLUSIONS: Extremely premature babies have functional impairment of the brainstem auditory pathway. The impairment is clearly more significant in those with bronchopulmonary dysplasia than those without bronchopulmonary dysplasia. Neonatal bronchopulmonary dysplasia and associated unfavorable conditions are major contributors to brainstem auditory impairment in extremely premature babies.