Auditory brainstem responses and ultrasound changes in a high-risk infants population.

Abstract

50 neonates were selected in a high perinatal risk population and examined by means of cerebral ultrasound (US) and auditory brainstem responses (ABR). They were allocated in 5 groups according to their US diagnosis (normal scans, isolated peri-intraventricular haemorrhage, large haemorrhage with associated lesions, hypoxic-ischaemic lesions in term neonates, miscellaneous disorders). ABR abnormalities were found in 40% of the infants. They were more frequent in neonates with cerebral lesions. Furthermore, the more extensive the cerebral lesions, the more severe the ABR abnormalities. Most of the ABR changes were of audiological type (severe: threshold greater than 80 dB [14%]; moderate: threshold less than or equal to 80 dB [20%]), whereas neurological abnormalities were rare (6%). The prognostic value of ABR appears in this study to depend on the possible recovery in the neonatal period. Severe hearing loss was associated either with an early death or with major handicaps. ABR represent the method of first choice for the detection of hearing loss in the Neonatal Unit, while they seemed to be of limited value in assessing brainstem function.