Amplitude modulated vestibular evoked myogenic responses: a study of carrier and modulating frequencies

Abstract

Conclusion: Responses with greater amplitude were recorded when carrier frequencies were modulated at 37, 40, and 43 Hz. These responses can be recorded even in patients with significant sensorineural hearing loss, from the sternocleidomastoid (SCM) muscle for a 500 Hz tone, 100% modulated at 40 Hz. Objective: To determine the best carrier and modulating frequencies to evoke steady-state myogenic responses. Methods: The present study investigated 156 ears of 78 normal-hearing young adults, with carrier frequencies of 250, 500, and 1000 Hz, modulated at 20, 37, 40, 43, 70, 77, and 80 Hz, with an intensity of 95 dBA. Furthermore, we observed responses evoked by stimulus carrier frequency of 500 Hz, modulated at 40 Hz, with an intensity of 95 dBA in a group of five subjects with severe sensorineural loss. Results: Responses were found for all stimuli studied (p < 0.01). Modulated stimuli at frequencies of 37, 40, and 43 Hz evoked better steady-state vestibular evoked myogenic potential (S-VEMP) (p < 0.05). No statistically significant differences were found between the group of normal hearers and the group of subjects with hearing loss (p = 0.431), for the stimulus used.

Keywords::

• Evoked potentials
• vestibule
• labyrinth
• vestibular nerve
• amplitude modulation
• evoked responses
• electromyography

Acknowledgment

This work received financial support from CNPq (National Council for Scientific and Technological Development). ClinicalTrials.gov Identifier: NCT01260077.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.