Aging Effect on the Ocular Vestibular-Evoked Myogenic Potentials

Objective: This study applied ocular vestibular-evoked myogenic potential (oVEMP) tests in healthy subjects of various ages to measure the effect of aging on oVEMPs quantitatively. Study Design: Prospective study. Setting: University hospital. Subjects: Seventy healthy subjects with the ages ranging from 24 to 76 years were divided into 6 groups by decade. Each group consisted of 10 subjects in 1 decade except 20 subjects in the group of 60 to 69 years. Main Outcome Measures: All subjects underwent oVEMP tests using bone-conducted vibration stimuli. Results: All subjects in groups of 20-59 years showed 100% response rates of clear oVEMPs, while 22 (55%) of 40 eyes in group of 60-69 years and 8 (40%) of 20 eyes in group of Q 70 years had clear oVEMPs, exhibiting significant differences between those below and over 60 years of age. The mean nI and pI latencies also showed significantly prolonged in those over 60 years, whereas the mean nI-pI amplitude reduced significantly in subjects over 40 years. However, the asymmetry ratios of oVEMPs did not differ significantly among the age groups. Analyses between the age factor and characteristic parameters revealed that significant correlations existed between the age factor and the nI latency, pI latency and nI-pI amplitude, but not the nI-pI interval. Conclusion: Aging effect (9 60 years old) on the oVEMPs includes reduced response rate, prolonged nI and pI latencies, and decreased nI-pI amplitude. Thus, age factor should be taken into consideration when interpreting the oVEMP results.