[The significance of the interaural latency difference of VEMP].

OBJECTIVE

To investigate the significance of the interaural latency (IAL) difference of the latency of VEMP and to raise the sensitivity of the test.

METHOD: Vestibular evoked myogenic potentials (VEMP) were tested in 20 healthy subjects; 13 patients with acoustic neuromaor cerebellopontile angle occupying lesions and 1 patient with multiple sclerosis. IAL differences of the wave p13,n23 and p13-n23 (abbreviatd as /delta p13/, /delta n23/ and /delta p13-n23/, respectively) were analysed to determine the normal range and the upper limit of the norm data. Four illustrative cases with the abnormality of the IAL difference were given as examples.

RESULT: The upper limit of the IAL of /delta p13/ was 1.13 ms; that of the /delta n23/ was 1.38 ms and that of /delta p13-n23/ was 1.54 ms. The /p13-n23/ latency between the right and left side had no significant difference (P > 0.05).

CONCLUSION

/delta p13/, /delta n23/ and /delta p13-n23/, especially /delta p13/ of VEMP can suggest abnormality in the neural pathway and it may be applicable in practice.