Ocular vestibular evoked myogenic potentials in normal-hearing adults

Ocular vestibular-evoked myogenic potential (oVEMP) is a novel vestibular function test. This short-latency response can be recorded through contracting extraocular muscles by high-intensity acoustic stimulation and can be used to evaluate contralateral ocular-vestibular reflex. The aim of this study was to record and compare the amplitude، latency، asymmetry ratio and occurrence percentage of oVEMP (n10) and cervical VEMP (p13) responses in a group of normal adult subjects. We carried out a cross-sectional study on 20 adult subjects'' mean age 22. 18 years، SD=2. 19 with normal hearing sensitivity and no history of vestibular diseases. oVEMP and cVEMP responses in both ears were recorded using air conducted stimuli 500 Hz short tone burst، 95 dB nHL via insert earphone and compared. cVEMP was recorded in all subjects but oVEMP was absent in two subjects. Mean amplitude and latency were 140. 77 μv and 15. 56 ms in p13; and 3. 18 μv and 9. 32 ms in n10. There were statistically significant differences between p13 and n10 amplitudes (p<0. 001). This study showed that occurrence percentage and amplitude of oVEMP were less than those of cVEMP. Since these two tests originate from different sections of vestibular nerve، we can consider them as parallel vestibular function tests and utilize them for evaluation of vestibular disorders.