Recovery of hearing following cisplatin ototoxicity in the guinea pig.

BACKGROUND: To report a spontaneous recovery of hearing, following cisplatin ototoxicity in the guinea pig. The findings are related to the animal and human literature on recovery from hearing loss following cisplatin ototoxicity. MATERIALS AND METHODS: Hearing was measured from compound action potentials (CAP) evoked by acoustic tones, which were monitored daily from an electrode implanted onto the round window of the inner ear. Cisplatin was administered at 2 mg/kg/day intraperitoneally until a hearing loss occurred. RESULTS: A hearing loss occurred suddenly across the frequency range and recovered over the period 2-14 days after treatment. The endocochlear potential was significantly lower than normal before hearing recovery and normal following recovery. CONCLUSION: These findings suggest a pivotal role for the endocochlear potential in the hearing loss from cisplatin ototoxicity and its recovery, and a plausible mechanism for the hearing recovery sometimes reported in patients following cisplatin ototoxicity.