FREQUENCY SHIFT FROM 500 HZ TO 1000 HZ IN CERVICAL VESTIBULAR EVOKED MYOGENIC POTENTIALS IN MENIERE'S DISEASES
1Eskişehir Osmangazi Üniversitesi, Odyoloji Bölümü, Eskişehir, Türkiye2Selçuk Üniversitesi Sağlık Bilimleri Fakültesi, Odyoloji Bölümü, Konya, Türkiye
3Eskişehir Osmangazi Üniversitesi Tıp Fakültesi, Kulak Burun Boğaz Anabilim Dalı, Eskişehir, Türkiye
4Sağlık Bilimleri Üniversitesi Gülhane tıp Fakültesi, Tıp Bilişimi Anabilim Dalı, Ankara, Türkiye Introduction: Cervical vestibular evoked myogenic potentials (cVEMP) are important in evaluating saccular function and the inferior vestibular nerve. During this test, measurements are routinely performed using a 500 Hz tone burst (TB) stimulus. This study aimed to determine how different stimulus frequencies affect cVEMP responses in Meniere's disease (MD).
Materials and Methods: Twenty-five adults (18-60 years) with unilateral definite MD were included in the study. Individuals were evaluated by otological-examination, conventional-audiometry, and the cVEMP using 500 Hz and 1000 Hz TB stimuli. The presence and amplitudes of P1-N1 waves at 500 and 1000 Hz were compared between healthy and affected ears.
Results: In individuals with MD, 96% of affected ears had abnormal cVEMP responses at 500 Hz and 68% at 1000 Hz. 1000 Hz P1-N1 amplitude was significantly higher in affected ears, whereas 500 Hz P1-N1 amplitude was higher in healthy ears (p<0.001). According to ROC (receiver operating characteristic) analysis, wave amplitudes ≤ 61µV at 500 Hz and ≤ 44.5µV at 1000 Hz in the cVEMP test favour MD. The area under the ROC curve was 0.995 for 500 Hz cVEMP and 0.769 for 1000 Hz cVEMP (p<0.001).
Discussion and Conclusions: The higher P1-N1 amplitude at 1000 Hz compared to 500 Hz in the affected ears of individuals with MD showed that the cVEMP test in MD shifts towards high-frequency stimuli. According to these data, evaluating individuals with 1000 Hz stimulus in addition to 500 Hz stimulus in the cVEMP test is useful for the diagnosis and follow-up of MD.
Keywords : Meniere's disease, cVEMP, Frequency shift, Acoustic stimuli, 500 Hz, 1000 Hz