Background and Aim: Vestibular evoked myogenic potentials (VEMP) originate from the saccule and the inferior vestibular nerve. In this study, the prevalence of VEMP and latency of the p13 and n23 were compared between three groups of individuals, including symptomatic and asymptomatic Meniere's disease cases and normal participants.

Methods: This study was conducted on 42 cases with the mean age of 40.48 years thirty were Meniere's disease patients, of which 19 were symptomatic and 11 were asymptomatic twelve were normal participants. The VEMP were recorded with 500 Hz tone bursts at 120 dBpeSPL. Then the prevalence and latency of the waves were analyzed and compared in the three above mentioned groups.

Results: The prevalence of VEMP in symptomatic Meniere's disease patients (52.6%) was significantly less than asymptomatic individuals (90.9%) and also normal subjects (100%)(p<0.05). There was no significant difference between latencies of the waves in these three groups (p>0.05). The latency of p13 for symptomatic, asymptomatic and normal participants was 16.41, 15.20 and 14.14 ms, respectively and the latency of n23 for these groups was 20.25, 18.77 and 18.50 ms, respectively.

Conclusion: In Meniere's disease, after medical management, the succule probably regains normal function resulting in re-existence of VEMP. It seems that there is no change in the latency of the waves, most likely due to involvement of the inner ear and intactness of the nerve. VEMP may be a useful test for diagnosis of Meniere's disease and additionally for monitoring the trend of medical management.

Background and Aim: Vestibular evoked myogenic potential in response to click or short tone burst stimuli have been used as a clinical test for distinguish saccule and inferior vestibular nerve diseases. Different studies show that cochlear implant could have inverse effects on vestibular structures. We aimed to investigate vestibular evoked myogenic potential in unilateral cochlear implanted individuals in compare to normal individuals.
Methods: Thirty-three unilateral cochlear implanted patients (mean age 19.96 years) and 30 normal hearing individuals (mean age 24-27 years) as control group were enrolled in this cross- sectional study. Absolute latencies and amplitudes of myogenic potential responses were measured and compared in both groups.
Results: Myogenic potential recorded in both ears of all controls were normal. No response could be recorded in 16 patients (48.48%) from both ears. In three patients, responses were recorded in both ears though the amplitude of waves was reduced in implanted ear. Unilateral response could be recorded in 14 patients only in their non-implanted ear.
Conclusion: Vestibular evoked myogenic potential test is a useful tool for assessing saccular function in cochlear implant patients. Damages of osseous spiral lamina and basilar membrane after cochlear implantation could result in dysfunctions of vestibular organs specially saccule. It seems that saccule could be easily damaged after cochlear implantation. This would cause absence or reduced amplitudes in myogenic potential.

Background and Aim: Patients with migraine commonly show vestibular symptoms. However, abnormal neurotological test findings during the inter-attack intervals, even in the absence of vestibular symptoms, are suggestive of subclinical vestibular dysfunction in migraine. This study aimed to compare the vestibular evoked myogenic potentials between migraine patients and normal individuals.
Methods: Subjects included 25 patients with migraine and 26 healthy volunteers with an age range of 20-53 years old. The vestibular evoked myogenic potentials were recorded with 500 Hz tone bursts at 95 dB nHL.
Results: Mean of absolute amplitude and p13 latency values in the migraine group were significantly less and more than the normal group, respectively (p=0.001 for absolute amplitude in right and left ears p=0.004 for p13 latency in right ears and p=0.02 in left ears). There was no statistically significant difference between the two groups in mean of the n23 latency and also the amplitude ratio (p>0.05).
Conclusion: According to the prolonged latency of vestibular evoked myogenic potentials response, vestibulospinal tract in brainstem is probably involved in migraine patients. However, due to small sample size, for generalizing this result to all patients with migraine, further researches are needed.

Background and Aim: Vestibular evoked myogenic potentials and acoustically evoked short latency negative response are two non-cochlear responses with probably saccular origin. The present study was conducted to determine the percentage of presence and the relation between these two responses in children with hearing loss.
Methods: Thirty children with profound congenital sensorineural hearing loss were studied.  Vestibular evoked myogenic potentials ellicitedby tone burst stimuli and acoustically evoked short latency negative response ellicited by click stimuli were recorded. Both responses were recorded at air conduction threshold level monaurally via an internal receiver.
Results: Vestibular evoked myogenic potentials in 53.3% of children and acoustically evoked short latency negative response in 40.0% of cases were recorded. There was a significant correlation between the percentage of recording these two responses (p=0.005). Gender and the stimulated ear had no effect on the results.
Conclusion: In almost half of these disabled children, both vestibular evoked myogenic potentials and acoustically evoked short latency negative response were recoreded. This finding may both indicate that hearing loss has no effect on the function of otolith organs in some children and vestibular deficits probably exist along with hearing impairment in others. This findng reiterates the importance of evaluation of vestibular system as part of standard auditory evaluations.

Background and Aim: Patients with systemic lupus erythematosus (SLE) may develop hearing and balance disorders as a result of the immune-mediated inner ear damage. Vestibular evoked myogenic potential (VEMP) is a new vestibular test assesses the vestibulospinal tract. Balance disorders such as endolymphatic hydrops may occur as a result of perisaccular deposition of immune complexes in these patients. Although the vestibular system abnormality in the patients has been demonstrated, the function of the part of vestibular system including vestibulospinal tract has not been investigated so far. This study aimed to compare the vestibular evoked myogenic potentials between patients with inactive stage of systemic lupus erythematosus and normal individuals.

Methods: In this cross-sectional study, vestibular evoked myogenic potential was recorded between 26 healthy subjects and 20 patients with lupus erythematosus in inactive stage of disease aged 20 to 50 years old, using 500 Hz-tone bursts at 95 dB nHL.

Results: Vestibular evoked myogenic potentials responses were present in all (100%) of the participants. There was no significant difference in mean peak to peak amplitude and assymetry ratio between two groups. The mean p13 and n23 latencies were significantly higher in patients (p<0.05). Duration of disease had no effect on test parameters.

Conclusion: According to the prolonged latency of vestibular evoked myogenic potentials response in patients with lupus erythematosus , lesions in the retrolabyrinthine, especially in the vestibulospinal tract is suspected. Due to small sample size, there is no possibility for generalizing this result to all patients with lupus lupus erythematosus .

Background and Aim: Patients with type I diabetes mellitus commonly complain about dizziness, floating sensation, tinnitus, weakness, and sweating. The aim of this study was comparing vestibular evoked myogenic potentials (VEMPs) between these patients and normal people.

Methods: Twenty-four patients with type I diabetes mellitus and twenty-four healthy volunteers with the age range of 15-40 years were enrolled in this study. A tone burst of 500 Hz, with the intensity of 95 dB nHL, was delivered through a insert earphone and vestibular evoked myogenic potential was recorded. The t-test was used to compare the results between the two groups. To investigate the effect of glycated hemoglobin (HbA1c) on VEMP responses (latency, absolute and relative amplitude), the regression analysis was used.

Results: The mean p13 and n23 latency were significantly more in patients with type Ι diabetes mellitus (for P13 latency, p=0.013 in right and p=0.010 in left ear, and for n23 latency, p<0.001 in right and p=0.005 in left ear). There was no significant difference between two groups in absolute and relative amplitude and prevalence of the VEMP (p>0.050). There was no correlation between VEMPs and HbA1c in patients with type 1 diabetes mellitus (p>0.05).

Conclusion: Prolonged latencies of the VEMP in patients with type 1 diabetes mellitus suggest lesions in the retrolabyrinthine, especially in the vestibulospinal tract. Nevertheless, due to the limited number of examined samples, further investigation with more patients should be performed.

Background and Aim: The cochlea and vestibule are related developmentally. Therefore individuals with severe to profound sensourineural hearing loss have additional risk for vestibular dysfunction. The aim of this study was to assess saccular function using vestibular evoked myogenic potentials (VEMP) in children with severe to profound sensorineural hearing loss (SNHL) who are candidates for cochlear implant.

Methods: Thirty children (17 males and 13 females) with bilateral severe to profound sensorineural hearing loss in the age range of 3-15 years participated in this study. 17 children (9 males and 8 females) with normal hearing in the age range of 3-13 years participated as the control group. All children in each group were evaluated for saccular function by performing vestibular-evoked myogenic potentials in both ears.

Results: Comparison of mean threshold values between the two groups revealed statistically significant difference (p<0.05). In addition, comparison of mean amplitude values between the two groups revealed statistically significant difference (p<0.05). However, comparison of p1 3 and n23 latency values between the two groups revealed no significant difference (p>0.05). Out of the 30 children with bilateral severe to profound sensorineural hearing loss eight children (26.66%) had absent VEMP responses in both ears.

Conclusion: Children with severe to profound sensorineural hearing loss who are candidates for cochlear implant ha d more potential for saccular abnormalities compared to normal-hearing children. Therefore, assessment of vestibular function is very important in this population.