Auditory brain stem responses of kernicterus infants.

Auditory brainstem evoked responses (ABRs) and behavioral audiometry in 25 infants with kernicterus were studied to determine the level of the lesion causing their hearing disorders. ABR thresholds, peak latencies of wave I and V, and interwave latency of wave V-I were measured; behavioral audiometric thresholds were determined through conditioned orientation reflex audiometry (COR). Eighty-eight per cent of infants with kernicterus who showed ABR threshold elevation with respect to age-matched normals, were found to show ABR abnormalities associated with peripheral hearing loss, and 84% of these were found to have COR threshold elevation. The ABR abnormalities were threshold elevation of wave V, prolonged latency of wave I and V, and the absence of ABRs. However, no brainstem lesion pattern was found in our cases. Our results suggested that at least some lesions which produce hearing disorders in kernicterus occur in the cochlea or auditory nerve.