Characterizing the impact of advancing age on 500 Hz tone-burst evoked ocular-vestibular evoked myogenic potentials.

PURPOSE: Ageing is process that brings about steady decline in most of the systems, and vestibular system is no different. Although the effects of advancing age on the functioning of the semicircular canals and saccule has been well explored, its impact on the utricle remains the least studied component. While some researchers have investigated the effect of advancing age on the utricular functioning by virtue of studying ocular-vestibular evoked myogenic potentials (oVEMP), the use of smaller sample sizes would hamper the generalization of their results. Therefore, the present study aimed at investigating the effect of advancing age on oVEMP using a substantially larger sample size than the predecessors.

METHODS: A total of 480 individuals in the age range of 10-70 years were used as participants and were divided into six age groups, each one defined as a decade. Contralateral oVEMPs were elicited by 500-Hz tone-bursts and averaged over 200 sweeps to obtain the final waveform.

RESULTS: There was a significant decline in the response rates, prolongation of latencies and reduction of peak-to-peak amplitude of oVEMP with increasing age after 50 years (p < 0.05). However, there was no significant difference among the age groups until 50 years of age on any of these parameters (p > 0.05). Further, there was no significant change in inter-aural amplitude difference ratio with increasing age (p > 0.05).

CONCLUSION: The results of the study confirm significant impact of the ageing process on oVEMP after the age of 50 years and, therefore, age appropriate norms should be considered when using oVEMP for investigating utricular functioning in an individual, especially after the age of 50 years.