Delay in maturation of the auditory pathway and its relationship to language acquisition disorders

Abstract

We studied 81 children, mostly boys, who experienced language acquisition delay but whose audiometric thresholds were normal. We assessed the evolution of children with delayed maturation of auditory pathways by brainstem evoked response audiometry (BERA). We also used a questionnaire administered during diagnostic procedures to determine if there was a probable etiology in each patient. In addition, we further studied language evolution in 29patients by means of a second questionnaire that was administered approximately 2 years later. Finally, we studied the evolution of the I-V interwave interval and the I/V amplitude ratio in 16 patients by performing a second BERA after a mean interval of 3 years. We observed improvement in both brainstem transmission time and language acquisition in all 81 patients. However, only a few patients achieved normal range results. Morphologic alterations, which were most common in patients who had had perinatal jaundice, remained unchanged. The most common possible risk factors for the delayed maturation pattern observed on BERA were parental consanguinity, prematurity, perinatal anoxia and jaundice, and postnatal seizure and infection. Some patients had more than one of these possible risk factors. We conclude that high-risk newborns and 2-year-old children who have no primitive verbal language skills should undergo BERA as well as investigation of hearing thresholds, interwave intervals, and I/V amplitude ratios. The alteration of these parameters points out the need for early intervention if there is no favorable prognosis.