Speech evoked auditory brainstem response in learning disabled children

Abstract

Background: Children with learning disability (LD) are thought to have deficits of neural origin. Speech evoked auditory brainstem responses (ABR) can objectively assess the biological processes underlying auditory processing of complex signals, not revealed using standard ABR responses to clicks. Objective: To assess central auditory processing functions in children with learning disability through electrophysiological testing. Methods: The present study comprised 60 normal hearing children of both genders. Cases included 30 learning disabled children and the controls included 30 healthy children without a learning disability. Each group was further subdivided into three subgroups according to age: subgroup age ranging from 6 to 8 years, > 8 to 10 years and > 10 to 12 years. All subjects were submitted to full history taking, otological examination, basic audiological evaluation, and Speech ABR testing. Parameters measured were latencies and amplitudes of the onset response and the steady state response waves. Results: This study showed that all subjects demonstrated identifiable and repeatable waves. The reliability of the response peaks was generally very good. All LD children showed statistically significant delayed latencies of waves V, A and F in both ears in all tested subgroups, compared to their controls. There was a statistically significant diminished amplitude of wave F in all tested subgroups in both ears compared to their controls. There was a statistically significant decreased amplitudes of waves D and E in 6–8 years subgroup and waves C and D in 8–10 years subgroup compared to their controls. In addition, compared to the controls, the amplitude of waves D and E were statistically significantly decreased in the 6-8 years subgroup, and waves C and D in the 8-10 years subgroup. Conclusion: Speech evoked ABR response parameters are affected in LD children, reflecting abnormalities in brainstem encoding of speech signals.

Key words::

• central auditory processing disorders
• learning disability
• speech evoked auditory brainstem response

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.