Normative values of ocular vestibular evoked myogenicpotentials induced by bone-conducted sound in healty adultsubjects

Objective: The aim of this study is to determine the normative values of ocular vestibular evoked myogenic potentials induced by bone-conducted sound in healthy adults Design: Prospective, clinical study. Settings: Baskent University Deparment of Otorhinolaryngology Method: The study was carried out with 42 healthy volunteers (84 ears). Audiological evaluation and positional tests were applied to the subjects after a thorough otorhinolaryngologic examination. The volunteers that had pure tone average of better than 20 dB and that have no nystagmus during the positional tests were involved. Ocular vestibular evoked myogenic potentials were measured using air-conducted and bone-conducted sound. The demographic characteristics of the volunteers were determined; the latency and amplitude values of the n1 and p1 waves were recorded and the results were compared with each other. Results: Eighteen volunteers were male and twenty-four volunteers were female. The mean age of the volunteers was 39,74±11.28 (20-60) years. n1 latency for the right and left bone conducted stimuli was 9,9±1,94 msec, and 10,08±1,82, respectively (p=0,66). p1 latency for the right and left bone conducted stimuli was 12,69±1,44 msec, and 12,81±1,4, respectively (p=0,69). Amplitude values for bone-conducted stimuli were found as 5,05±1,98 μV for the right, and 5,08±1,99 μV for the left ear (p= 0,95). There was statistically no significant difference between male and female patients, in terms of the latency and amplitude values (p>0,05). There was no correlation between the age and both n1 and p1 latencies and amplitudes (p>0,05). Since the age and side tested did not interfere with the results, test parameters of 84 ears were calculated. Thus, overall n1 latency was 9,9±1,87 (6,33-15,00) msec and p1 latency was 12,75±1,41 (9,67-15,67) msec. The mean amplitude was found as 5,06±1,97 (2,93-11,12) μV. Conclusion: Ampliitude and latency values of the oVEMP waves that were evoked by bone-conducted sound stimuli were determined in healthy adults. Our results were consistent with the literature. The data obtained will be accepted as normative values for healthy adults and will construct a basis for the future studies. Key Words: Vestibulo-ocular reflex, vestibular evoked myogenic potentials, ocular vestibular myogenic response, air conduction, bone conduction, n1 wave, p1 wave, amplitude, latency