Characterizing the Age and Stimulus Frequency Interaction for Ocular Vestibular-Evoked Myogenic Potentials

Objectives: The normal process of aging is mostly associated with global decline in almost all sensory aspects of the human body. While aging affects the 500-Hz tone burst-evoked ocular vestibular-evoked myogenic potentials (oVEMPs) by reducing the amplitudes and prolonging the latencies, its interaction with oVEMP responses at other frequencies has not been studied. Therefore, the present study aimed at investigating the impact of advancing age on the frequency tuning of oVEMP. Design: Using a cross-sectional research design, oVEMPs were recorded for tone burst frequencies of 250, 500, 750, 1000, 1500, and 2000 Hz from 270 healthy individuals divided into six age groups (10-20, 20-30, 30-40, 40-50, 50-60, and >60 years). Results: The results revealed significantly lower response rates and amplitudes in age groups above 50 years of age than all the other groups at nearly all the frequencies (p < 0.05). Further, the frequency tuning was obtained at 500 or 750 Hz in majority of individuals below 60 years of age and at >= 1000 Hz in most of the individuals above 60 years of age (p < 0.05). Thus, there was a significant shift in frequency tuning of oVEMP from 500 or 750 Hz in the younger and the middle-aged adults to >= 1000 Hz in older adults, especially above 60 years of age. Conclusions: The results of the study showed significantly higher prevalence of frequency tuning at 1000 Hz in older adults above 60 years of age. Because the shift in frequency tuning to >= 1000 Hz is frequently used for identification of Meniere's disease, it is suggested that age-related correction be used for the diagnosis of Meniere's disease when using frequency tuning of oVEMP.