Quantitative study of vestibulotoxicity induced by gentamicin or cisplatin in the guinea pig.

Although aminoglycoside vestibulotoxicity is well established, the question of cisplatin vestibulotoxicity is controversial. The goals of this study were 1. to determine whether cisplatin induces vestibulotoxicity as measured histologically, and 2. to compare the vestibulotoxicity between gentamicin and cisplatin. Guinea pigs' vestibular end-organ hair bundles in control, gentamicin, and cisplatin groups were compared. In the lateral cristae of the cisplatin group, hair bundles decreased 21% on the central apex portion. In the gentamicin group, a slight decrease (17%) of hair bundles on the striola from the utricular maculae was observed, as was severe damage on the entire cristae, especially on the central apex (70%). These results indicate that gentamicin and cisplatin may not influence vestibular function of the otolithic membrane. However, gentamicin may severely damage and cisplatin may slightly damage the crista ampullaris hair bundles.