Auditory Electrophysiology of an Adolescent with Both Language and Learning Disorders

TL;DR

This case study explores the auditory system of an adolescent with language and learning disorders using electrophysiological tests to uncover underlying neurobiological issues.

Contribution

The study provides novel electrophysiological evidence linking auditory processing dysfunction to language and learning disorders in adolescents.

Findings

Electrophysiological tests revealed subcortical processing dysfunction and auditory asymmetry in the adolescent.

P300 responses showed prolonged latency and absence in one ear, indicating impaired auditory processing.

FFR results demonstrated mismatch between stimuli and neurophysiological responses under different listening conditions.

Abstract

Background and Clinical Significance: developmental language disorder (DLD) and specific learning disorder (SLD) may coexist, resulting in significantly broader impairments to oral and written language skills. Understanding the neurobiological basis of these deficits is crucial, and electrophysiological assessment of the auditory system offers an objective approach not influenced by behavioral factors. The present study describes the audiological electrophysiology of an adolescent diagnosed with both DLD and SLD. Case Presentation: R.B., a 15-year-old adolescent with a history of SLD and DLD, presented with persistent deficits in oral language (syntax) and written (decoding) skills after 7 months of intensive therapy. Basic audiological tests confirmed hearing within normal limits. An electrophysiological battery, including the click-brainstem auditory evoked potential (c-ABR), medium latency auditory evoked potential (MLAEP), long-latency auditory evoked potential (P300), and frequency following response (FFR), was performed to investigate information processing in the auditory trajectory. The c-ABR confirmed the integrity of the auditory pathway up to the brainstem. MLAEP revealed a differential ear effect, with significant asymmetry in the Na-Pa interamplitude, pointing to a dysfunction in subcortical processing. The P300 showed a prolonged latency in the left ear (437 ms), and there was no response in the right. The FFRs under ideal and impaired listening conditions demonstrated impaired perception of speech and revealed that the neurophysiological responses did not correspond to the eliciting stimulus. Conclusions: The present case study showed that electrophysiological testing of the auditory system provided objective and quantitative evidence for a neurobiological basis of the language deficits of an adolescent with DLD and SLD. The work demonstrated that when comorbidities are present, a multidisciplinary investigation of both the linguistic and auditory systems can be helpful.

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