Impact of Advancing Age on Frequency Tuning of Ocular Vestibular Evoked Myogenic Potential

Abstract

Normal aging is mostly associated with global decline in almost all aspects. While aging affects the 500 Hz tone burst evoked ocular vestibular evoked myogenic potentials (oVEMP) by reducing the amplitudes and prolonging the latencies, its interaction with oVEMP responses at other frequencies has sparingly been explored. Therefore the present study aimed at investigating the impact of advancing age on the frequency tuning of oVEMP. The oVEMPs were recorded from 50 healthy individuals divided under five age groups (20-30, 30-40, 40-50, 50-60, &> 60 years) for tone-burst frequencies of 250, 500, 750, 1000, 1500 and 2000 Hz. The results revealed significantly lower response rates for age groups above 50 years than all the other groups at almost all the frequencies (p< 0.05). Although there was a trend towards lower peak-to-peak amplitudes in age groups above 50 years, the differences were not statistically significant (p> 0.05). Further, the frequency tuning was obtained at 500 Hz or 750 Hz in majority of individuals below 60 years and at e” 1000 Hz in most of the individualsabove 60 years. The proportion of ears showing frequency tuning at e” 1000 Hz was significantly higher in the above 60 years age groups than below it (p <0.05). Thus, there was a significant shift in frequency tuning of oVEMP from 500 Hz or 750 Hz in the younger and the middle-aged adults to e” 1000 Hz in older adults, especially above 60 years of age. Since the shift in frequency tuning to e” 1000 Hz is popularly used for identification of Meniere’s disease, it is suggested that age-related correction be used for diagnosis of Meniere’s disease when using frequency tuning of oVEMP for doing so.