Age effects on frequency amplitude ratio of cVEMP

Abstract

Background

The vestibular system can perceive sound at high intensity levels. The recording of vestibular evoked myogenic potentials (VEMPs) is one of the clinical techniques that capture the vestibular system when activated by sound. In healthy individuals, it has been demonstrated that VEMP thresholds are lower when using low-frequency stimuli, particularly 500 Hz tone burst. Aging affects frequency tuning, causing shift to higher frequencies.

Methods

This study was cross-sectional, which included 80 normal healthy individuals. Each participant in the study were subjected to cervical vestibular evoked myogenic potential (cVEMP) testing using air and bone conduction as a mode of stimulation. The following cVEMP parameters were assessed: cVEMP inter-frequency peak amplitude ratio (FAR): the ratio of peak-to-peak amplitude between 500 Hz and 1000 Hz in the same ear (1000 Hz/500 Hz FPA). Also, rectified FAR is a method of normalizing the amplitude of the VEMP response to the degree of muscle contraction as determined by EMG.

Results

There were differences among the 5 age groups that were statistically different regarding FAR and rFAR of cVEMP when using air and bone conduction stimuli.

Conclusion

In this study, we provided age norms for frequency amplitude ratio (FAR) (1000/500 Hz) of cVEMP using AC and BC stimuli. Participants above the 50 years age group showed significantly larger FAR and rectified FAR than the younger age groups in both the cVEMP. Air and bone conduction stimuli yielded similar FAR results and can be both used in testing.