Cortical Organization And Variability In Unilateral Auditory Neuropathy Spectrum Disorder: A Case Study

Objective: We examined 1) auditory cortical organization and functioning, and 2) variability in cortical responses in a paediatric patient with unilateral auditory neuropathy spectrum disorder (ANSD). Study design: Measures of high-density EEG (including cortical auditory evoked potentials (CAEPs)), dipole and current-density analyses, independent component analyses-stacked trials (ICA), inter-trial coherence, and the patient's performance on measures of speech perception were compared for the ear with normal hearing (NH) and the ear with ANSD. Results: Differences were observed between the NH ear and the ear with ANSD for all test measures. Conclusions: Our results suggest that for some patients, 1) congenital ANSD may result in abnormal auditory cortical organization, and 2) neural dys-synchrony in the central auditory system, which characterizes ANSD, may result in a high degree of variability in cortical responses. In this study, cortical auditory activation in ANSD was examined using high-density EEG. Our study also demonstrates use of single-trial and time-frequency EEG analyses in evaluating the effect of neural dys-synchrony on cortical variability in patients with ANSD.