[The effect of chronic ototoxicity of gentamicin on the function of auditory efferents].

OBJECTIVE

To study the effect of chronic ototoxicity of gentamicin on the function of the cochlea and auditory efferents.

METHOD: The effect of chronic ototoxicity of gentamicin on the function of the cochlea was determined by recording thresholds of the compound action potentials (CAP) of the auditory nerves to tone pip at 4, 6, 8, 10 and 12 kHz. The function of the medial olivocochlear (MOC) system was determined, through the observation of the effect of the contralateral noise (CLN) on CAP, before and after gentamicin administration.

RESULT: The suppression effects of CLN on CAP were irreversibly eliminated, and the effects were most obvious at the 11th week after gentamicin (P < 0.01), and the response threshold of CAP was raised about 10 dB and 25 dB, respectively, at the 3rd and 11th week after the application of gentamicin. These results were most related to the morphological changes on cochlear efferents and hair cells.

CONCLUSION

The auditory efferents play an important role in the chronic ototoxicity of gentamicin.