Effect of Degree of Acquired Cochlear Hearing Loss on Ocular Vestibular Evoked Myogenic Potential

Abstract

Vestibular deficits frequently co-exist with hearing loss and there could be a possibility of one having an impact on the other. However, effect of hearing loss on ocular vestibular evoked myogenic potential (oVEMP) has sparsely been explored. Even the studies that have investigated this aspect, have mainly concentrated on the congenital and only severe to profound degree of hearing loss, notwithstanding the fact that the vestibular pathologies are quite often acquired in origin. Thus the present study aimed at examining the effect of the degrees of acquired cochlear hearing loss on oVEMP response parameters. Ocular VEMPs elicited by 500 Hz tone-bursts were recorded from 50 ears of adults with hearing loss ranging from mild to profound degree (sub-grouped into mild, moderate to moderately severe & severe to profound) and 50 ears of individuals with normal hearing. The results revealed significant reduction in response rate, prolongation of latencies and decrease in peak-to-peak amplitude of oVEMP with increase in severity of hearing loss (p < 0.05). Further, there was significant correlation of hearing thresholds and duration since the onset of hearing loss with oVEMP response parameters (p < 0.05). Thus, the use of a correction factor for the degree of hearing loss is reommended when interpreting the results of oVEMP.