Frequency-Amplitude Ratio of Ocular Vestibular-Evoked Myogenic Potentials for Detecting Meniere's Disease: A Preliminary Investigation.

OBJECTIVE: Several parameters of ocular vestibular-evoked myogenic potential (oVEMP) have been used to identify Meniere's disease. Nonetheless frequency-amplitude ratio (FAR), which is the ratio of amplitude between two frequencies, is one among the parameters that has failed to attract researchers' attention despite proving its worth in diagnosis of Meniere's disease when used in conjunction with cervical VEMP. Thus, the present study aimed at investigating the utility of FAR of oVEMP in identifying Meniere's disease and finding out an optimum frequency pair for its diagnosis.

DESIGN: Using a case-control design, oVEMPs were recorded for tone bursts of 500, 750, 1000, and 1500 Hz from 36 individuals with unilateral definite Meniere's disease in the age range of 15 to 50 years. For comparison purposes, oVEMP at the above frequencies were also obtained from an equal number of age- and gender-matched healthy individuals. The amplitudes of 750, 1000, 1500 Hz and tuned frequency, which was the frequency with the largest peak to peak amplitude among the above-mentioned frequencies, were divided by the amplitude of 500 Hz to obtain FARs for 750/500, 1000/500, 1500/500, and tuned frequency/500 frequency pairs.

RESULTS: The results revealed significantly higher FAR in the Meniere's disease group than the healthy controls for all the frequency pairs (p < 0.05). The sensitivity of almost 90% and the specificity 100% was obtained for 1000/500 and 750/500, whereas the other frequency pairs produced a sensitivity of about 56% while still showing a specificity of 100%.

CONCLUSIONS: High sensitivity and specificity, coupled with considerably lowered test duration when using only two frequencies, makes the use of FAR a more attractive prerogative, with 1000/500 as the frequency pair of choice.