Abstract:
Vestibular evoked myogenic potentials (VEMPs) are widely used to assess the otolith functioning. These responses are affected by a wide range of stimulus and recording parameters. Optimization of these parameters is essential for appropriate recording of VEMP responses. The objectives of this study were to compare the infra-orbital and belly-tendon electrode montages for bone conduction ocular VEMP (BC-oVEMP) for mastoid and forehead stimulation and examine their test-retest reliability. The study included 55 healthy young adult aged 18-39 years. BC-oVEMPs were recorded using simultaneous infra-orbital and belly-tendon electrode montages for mastoid and forehead stimulation separately. The stimuli used was rarefaction polarity tone-bursts of 500 Hz (124 dB peSPL with rise /fall time of 0 ms and plateau of 4 ms) delivered via B-71 bone vibrator. Recordings were taken in sitting position with gaze angle of more than 30 degrees. The study found no significant difference between infra-orbital and belly-tendon electrode montage for mastoid and forehead stimulation. The response rates, latencies, peak-to-peak amplitudes and thresholds were better for mastoid than forehead stimulation. The BC-oVEMP showed moderate to excellent test-retest reliability for almost all parameters. While the electrode montage might not significantly influence the BC-oVEMP responses, the mastoid stimulation might prove to be a better choice for obtaining robust responses than forehead when using B-71 bone vibrator.
