Normalization of poor auditory brainstem response in infants and children.

In these past 10 years, the usefulness of auditory brainstem response (ABR) has been demonstrated in the clinical evaluation of audiological or neurological disorders, and the absence of an ABR is commonly accepted as consistent with a peripheral hearing loss caused by middle or inner ear diseases. In this article, the authors report nine infants and children who had an absent or difficult to detect ABR at the first examination with subsequent normalization of ABR. Repeated otological examinations were always normal in these patients. The final diagnoses were delayed development, Waardenburg syndrome with congenital heart disease and epilepsy, healthy infant, infantile convulsion, mental retardation with history of low birth weight, in each case, and chromosomal aberration in four patients. The reason for normalization of ABR in our patients is not clear and is yet to be ascertained. However, the authors believe that neurological maturation rather than an improved primary peripheral disorder is responsible for the noted normalization of the ABR, because of the high incidence of neurological abnormalities in these patients.