Vestibular evoked myogenic potential for diagnoses of multiple sclerosis: is it beneficial?

AIM

To determine the sensitivity of the vestibular evoked myogenic potential (VEMP) in multiple sclerosis (MS) patients as well as its relation to clinical signs and symptoms, course of the disease and other evoked potentials.

METHODS

This case-control study was conducted on 40 subjects (20 MS patients and 20 healthy participants). Participants were selected from Imam Khomeini Hospital, Tehran, Iran. Two hundred stimuli (clicks of 0.1 ms of duration and 2 Hz frequency) were applied to each ear. These stimuli were repeated in two consecutive cycles. In order to evaluate the reproducibility the stimulation intensity of 95dBNHL was applied. During the test, individuals were requested to be seated on a chair and rotate their head to the opposite side of the stimulated ear to activate the ipsilateral sternocleidomastoid muscle (SCM).

RESULTS

A biphasic, initially positive, p13-n23 wave pattern was found in all patients. All of the parameters, including latencies and amplitudes fit the normal Kolmogorov-Smirnov (KS) distribution. Fourteen (70%) patients reported abnormal results, and VEMP abnormality was significantly related to disease duration also. In addition, there was a significant correlation between abnormality of VEMP and abnormality of visual evoked potential (VEP) as well as the abnormality of VEMP and brainstem auditory evoked potential (BAEP).

CONCLUSION

Vestibular evoked myogenic potential has a high sensitivity (70%) in MS patients, and VEMP could be recommended as a useful complementary neurophysiological method to evaluate the MS patients.