Auditory Neuropathy Accompanying Bilateral Vestibular Hypofunction

Auditory neuropathy is a term used to describe the auditory neural pathway abnormality in the presence of cochlear outer hair cellfunctions. It is reported that 9 of 14 auditory neuropathy patients had abnormal findings in the caloric test. The authors present acase of auditory neuropathy accompanying bilateral vestibular loss. The patient was a 33-year-old female who had a familyhistory of her mother having bilateral hearing loss. Auditory brain stem response (ABR) and otoacoustic emission (OAE) werechecked and the results were compatible with auditory neuropathy. To evaluate her vestibular function, bithermal caloric test,rotatory chair, fundus photograph, vestibular evoked myogenic potential (VEMP), oculomotor test were checked. Laboratoryfindings were compatible with bilateral vestibular loss involving both superior and inferior division of vestibular nerve territory.Though bilateral vestibular hypofunction was substantial, she did not report any subjective discomfort from bilateral vestibularloss. Considering the presence of OAE and the abnormal findings in ABR in this patient, the pathologic lesion seems to be inthe vestibular neural pathway rather then in the vestibular end organs. Routine vestibular evaluation seems to be necessary forcomprehensive evaluation of the auditory neuropathy patients.