While inducing experimental sinusitis in 38 rabbits, five animals (13.2%) with impairment in the inner ear were observed. From the findings of their posture it was assumed that the impairment was considered to be bilateral in three cases and unilateral in two. As regards ABR examination, the sound level of 80dB (SPL) applied to the affected side did not evoke any clear response, indicating a high degree of auditory disturbance. From ENG of the same rabbits that were used in ABR tests, remarkable findings of spontaneous nystagpius was shown toward normal side. Histological examination of temporal bone specimens revealed that there were organ of Corti damaged in most of the coils, markedly injured Reissner's membrane and lamina tectoria. In the round window membrane and tympanic cavity, however, no signs of inflammatory lesions were seen. From these findings, it would be suggested that the pathological changes in the inner ear may be caused by allergic mechanism.
