Int. Adv. Otol. 2010; 6(2); 211-215

Comparison of vestibular evoked myogenic potential responses between binaural versus monaural logon stimulation.
Ali Ozdek, Emine Metin, Hakan Korkmaz
Ministry of Health, Ankara Diskapi Yildirim Beyazit Research and Training Hospital, Ankara, Turkey

Objective: To compare VEMP response characteristics between binaural and monaural stimulation and to determine normative data for logon stimulus in adults.

Subjects and Methods: Twenty-two healthy adults were involved in the study. Two set types of VEMP recordings were performed for each subject. One is simultaneous binaural logon stimulation with bilateral recordings (B-VEMP) and the other one is monaural logon stimulation of each ear separately with two sequential ipsilateral recording (M-VEMP). Subjects were divided into two groups involving 11 participants in each group. In the first group all participants underwent initial B-VEMP test and subsequent M-VEMP test; while in the second group all participants underwent initial M-VEMP test and subsequent BVEMP test. Logon type stimulus with 120 dB HL intensity was used to trigger VEMPs in both methods.

Results: There was no statistical difference between B-VEMP and M-VEMP recordings in respect to P1 and N1 latencies, P1- N1 interval and P1-N1 amplitude in any of the groups. When the VEMP responses of 2 groups were combined (42 ears), we have found that the mean P1 latency was 14.9 ± 1.5 msec, the mean N1 latency was 22.3 ± 2.3 msec, the mean P1-N1 interval was 7.6 ± 2.4 msec, and the mean P1-N1 amplitude was 14.1 ± 6.1 µV for B-VEMP recordings. These values were 15.1 ± 1.6 msec, 22.2 ± 1.6 msec, 7.0 ± 1.9 msec, and 14.8 ± 6.0 µV respectively for M-VEMP recordings.

Conclusion: Binaural stimulation with simultaneous bilateral recording gives similar results with monaural stimulation with a separate recording for each site. B-VEMP recording can be a more convenient way of VEMP testing especially in those subjects who have difficulty to maintain a constant muscular effort during test procedure.