Auditory Neuropathy: A Report of Three Cases / 대한이비인후과학회지

ABSTRACT

Auditory neuropathy is a hearing disorder characterized by an absent or severely abnormal auditory brainstem response, with preservation of the cochlear microphonics and otoacoustic emissions. This suggests that outer hair cell (OHC) function is normal but that auditory function proximal to the OHCs is impaired. These patients demonstrate mild to severe hearing loss for pure tones and impaired word discrimination out of proportion to pure tone loss. Hearing aid alone is of little or no benefit in patients with auditory neuropathy. Visual support via cued speech or signed language can be a fail-safe method for insuring language development. Recently, there are some reports that cochlear implantation is highly successful in patients with auditory neuropathy. We report three cases (two children and one woman) with auditory neuropathy. Each patient was tested with cochlear microphonics, otoacoustic emissions, auditory brainstem response and middle latency response, etc. All three patients had normal cochlear microphonics or otoacoustic emissions with absent auditory brainstem response. Two of them had evidence of a peripheral neuropathy. We should be aware of auditory neuropathy and implications for its management, which differs from treatment of sensorineural hearing loss. Auditory neuropathy also raises a concern about the risk of false-negative findings when newborn hearing screening is restricted to otoacoustic emissions.