Reversible cochlear disorders with normal vestibular functions in three cases with Wegener's granulomatosis

Patients with Wegener's granulomatosis (WG) often suffer from hearing loss, but its precise mechanisms have not been well understood. We experienced 3 WG cases whose initial symptoms were bilateral progressive mixed (both conductive and sensorineural) hearing loss, followed by systemic symptoms one year later. They were diagnosed as WG based on positive serology of anti-neutrophil cytoplasmic antibodies (ANCAs) and pathologic findings of affected lesions in addition to systemic symptoms. Although they were different in the type of ANCAs and systemic lesions, all showed considerably reversible cochlear disorders with normal vestibular functions. Moreover, their initial otologic manifestations shared same characteristic features, (1) thick ear drums with pulsatile serous intratympanic effusion, (2) poor speech discrimination ability, and (3) steroid-dependent changes of hearing levels (HLs). They exhibited no significant vestibular abnormalities in chair vestibule-ocular reflex (VOR) testing and cold air caloric tests even when they had severe hearing loss. On the basis of these results, we hypothesized that vasculitis of stria vascularis which generates endocochlear potential might cause these reversible cochlear-specific dysfunctions.