Age-related changes in ocular vestibular-evoked myogenic potentials via galvanic vestibular stimulation and bone-conducted vibration modes.

CONCLUSION: The age-related changes in ocular vestibular-evoked myogenic potentials (oVEMPs) elicited by galvanic vestibular stimulation (GVS) and bone-conducted vibration (BCV) might be attributed to the morphological degeneration of the vestibular system.

OBJECTIVE: This study employed GVS and BCV modes for eliciting oVEMPs in healthy subjects to explore the effect of aging on the vestibulo-ocular reflex (VOR) pathway.

METHODS: Sixty-nine healthy subjects (aged 22-69 years) were divided into 5 groups of 12-19 subjects by decades of age. All subjects underwent oVEMPs using GVS and BCV modes. The prevalence and parameters of oVEMPs, including nI latency, pI latency, nI-pI interval, and nI-pI amplitude were measured and compared.

RESULTS: The prevalences of GVS-oVEMPs had nonsignificant differences among all age groups, whereas that of BCV-oVEMPs in the over-60 group was significantly lower than those in the under-60 groups. In GVS-oVEMPs, the group over 60 years had significantly longer nI, pI latencies, and smaller amplitudes when compared with those under 60 years. In BCV-oVEMPs, the nI and pI latencies in the over-60 group were significantly longer than those of the under-60 groups, while the nI-pI amplitudes of groups over 50 years were significantly smaller than those of groups under 50 years. All oVEMP parameters exhibited significant differences between GVS- and BCV-oVEMPs in each age group.