Auditory Neuropathy Spectrum Disorder: Genetic and Electrophysiological Testing for Predicting Rehabilitation Outcomes after Cochlear Implantation

Abstract

Reviling the etiology or at least pathophysiology of auditory neuropathy spectrum disorder is crucial for choosing rehabilitation pathway and predicting rehabilitation outcomes. Some patients with auditory neuropathy spectrum disorder undergo cochlear implantation, but it is not always possible to foresee the results of rehabilitation. Genetic testing, especially in cases without obviously perinatal hearing loss risk factors, might help to understand etiology and pathophysiology, whether it is synaptopathy or neuropathy; therefore, it becomes possible to predict rehabilitation outcomes. More than 20 genes related to auditory neuropathy spectrum disorder phenotype are known already. Modern genetic approaches, such as whole genome and whole exome sequencing, reveal etiology of auditory neuropathy spectrum disorder in many cases. But there are still auditory neuropathy spectrum disorder cases with unknown etiology and site of the lesion. Electrophysiological methods (electrocochleography, electrically evoked brainstem potentials) might help to localize the site of lesion in hearing system and therefore help to predict rehabilitation outcomes. Electrically evoked brainstem potential testing after cochlear implantation seems to be applicable and useable tool to predict potential CI outcomes and to choose optimal rehabilitation trace.