[Ocular vestibular evoked myogenic potential elicited by different types of stimulus among normal young Chinese people].

OBJECTIVE

To observe waveform differences among ocular vestibular evoked myogenic potentials (ACS-oVEMP) elicited by different types of air conducted sound in normal young Chinese subjects.

METHOD

Twenty-two adult volunteers (44 ears) were recruited as research subjects including 12 males and 10 females aged between 18 and 35. Five hundred Hz tone burst, 125 Hz tone burst and click were employed as stimulus for conventional ACS-oVEMP examinations in bilateral ears of each subject. The response rate, threshold, n I latency, p I latency, n I-p I latency interval, amplitude and inter-aural asymmetry were recorded and compared among groups.

RESULT

The response rate was 100% (44/44) in 500 Hz tone burst group, 40.9% (18/44) in 125 Hz tone burst group and 29.6% (12/44) in click group There were statistical significant differences between the 500 Hz tone burst group and the other groups (P < 0.05). Waveform amplitude was the largest in the 500 Hz tone burst group (7.3 +/- 5.5) muV than that in the 125 Hz tone burst group (3.8 +/- 1.5) muV and that in the click group (5.8 +/- 1.3) muV, which had statistically significant differences between the former and the later two groups (P < 0.05). Other waveform parameters presented similar differeces.

CONCLUSION

ACS-oVEMP waveforms could be largely affected by different stimulus. 500 Hz tone burst was the best stimulus with highest response rate, biggest amplitude and therefore most easily recognizable waveform in ACS-oVEMP examination.