Effects of selective cochlear toxicity and vestibular deafferentation on vestibular evoked myogenic potentials in guinea pigs

Conclusion: The findings suggest that sound-evoked myogenic potentials on the guinea pig sternocleidomastoid muscle (SM) originate from the vestibular end organ and not from the cochlea of the inner ear. Objective: Studies in animals of the sound evoked vestibular myogenic potentials on the SM should aid in elucidating the pathway of the vestibular-evoked myogenic potential (VEMP). However, details of the pathway of the VEMP remain to be elucidated. This study aimed to clarify aspects of this pathway. Materials and methods: In the present study, short latency biphasic myogenic potentials on the SM in guinea pigs were induced by an intense brief sound. Results: The thresholds of the potentials were 67 dB SPL above those of the auditory brainstem response (ABR). The potentials were eliminated by a vestibular deafferentation, but were observed after selective cochlea toxicity using an amikacin injection.