Inner ear deficits after chronic otitis media

Abstract

Investigation of the causes of vestibular symptoms in patients with chronic otitis media (COM) faces frustration, mainly because the bithermal caloric test using tap water is generally contraindicated in perforated ears. This study utilized audiometry, ocular vestibular-evoked myogenic potential (oVEMP) test, and cervical VEMP (cVEMP) test to evaluate inner ear deficits after COM. A total of 85 COM patients (117 ears) underwent otoscopy, image study, audiometry, oVEMP test, and cVEMP test. Mean bone-conducted (BC) hearing threshold ≤25 dB was observed in 74 ears, 26-40 dB in 30 ears, and >40 dB in 13 ears. Restated, abnormal BC hearing threshold was identified in 43 ears (37 %). Percentages of abnormal cVEMP test, oVEMP test, and BC hearing threshold in 117 COM ears were 65, 62, and 37 %, respectively, exhibiting a significantly declining sequence in inner ear function. Furthermore, cVEMP/oVEMP test results were significantly correlated with BC hearing threshold, whereas no correlation existed between the cVEMP and oVEMP test results. In conclusion, the sequence of inner ear deficits after COM runs from the saccule/utricle to the cochlea and semicircular canals. Restated, in addition to BC hearing test, the cVEMP/oVEMP test may serve as a supplementary tool for early detection of inner ear involvement in COM patients.