Mohammad Hossein Harirchian1, Narges Karimi, Shahriar Nafisi, Shahram Akrami, Davod Ghanbarian, Shahriar Gharibzadeh. 1. Neurology Department, Iranian Center of Neurological Research, Tehran University of Medical Sciences, Tehran, ²Neurology Department, Mazandaran University of Medical Sciences, Sari, Iran3Department of Physical Medicine and Rehabilitation, Tehran University of Medical Sciences, Tehran, 4Neurologist, Shafa Center of Neuroscience Research, Khatamolanbia Hospital, Tehran; Iran, 5Neuromuscular System Laboratory, Biomedical Engineering Department, Amirkabir University of Technology, Tehran, Iran.
Abstract
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.
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 MSpatients 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 MSpatients, and VEMP could be recommended as a useful complementary neurophysiological method to evaluate the MSpatients.