Vestibular evoked myogenic potentials are intact after sudden deafness

OBJECTIVE: To evaluate vestibular evoked myogenic potentials (VEMPs) in cases of sudden deafness, and to confirm the noncochlear origin of the VEMPs. STUDY DESIGN: Prospective study. VEMPs, which were evoked by short tone burst (95 dB nHL) stimulation, were recorded in 20 patients with unilateral, idiopathic sudden deafness. The results of the deaf ears were compared with those of the contralateral healthy ears and the normal control ears. The relations between VEMPs and the hearing level or caloric response were then investigated. RESULTS: All 20 of the deaf ears displayed normal biphasic VEMPs. The mean latencies of p13 and n23, as well as mean amplitude p13-n23, were 15.1 +/- 2.8 msec, 20.7 +/- 3.3 msec and 25.2 +/- 12.6 microV, respectively, not significantly different to either the contralateral healthy ears (p > 0.05) or the normal control ears (p > 0.05). Five deaf ears displayed canal paresis or absent caloric response, whereas the remaining 15 ears revealed normal caloric response. CONCLUSION: All the lesioned ears of patients with idiopathic sudden deafness exhibit normal biphasic VEMPs. Neither the hearing level nor the caloric response correlated to the VEMPs.     

Properties of binaural vestibular evoked myogenic potentials elicited with air-conducted and bone-conducted tone bursts

The purpose of this investigation was to compare the effects of monaural and binaural stimulation on unilaterally-measured vestibular evoked myogenic potential (VEMP) magnitude and latency. The subjects were eighteen normal-hearing adults with no history of vestibular disease. Monaural VEMPs were acquired with air-conducted (AC) and bone-conducted (BC) 500 Hz tone bursts presented at 95 dB nHL and 70 dB nHL, respectively. These stimuli were simultaneously paired with 95 dB nHL contralateral tone bursts at 250, 500, 750, or 1000 Hz during acquisition of binaural VEMPs. Results indicated that AC-VEMP relative magnitudes decreased in each of the binaural conditions compared to the monaural condition. However, no changes in relative magnitude between conditions occurred for BC-VEMPs. Similar latencies were observed for monaural and binaural VEMPs. Differences in bilateral interaction seen between the AC-VEMP and BC-VEMP conditions are consistent with modification of sound transmission through the ear during presentations of binaural sound.     

Properties of binaural vestibular evoked myogenic potentials elicited with air-conducted and bone-conducted tone bursts

The purpose of this investigation was to compare the effects of monaural and binaural stimulation on unilaterally-measured vestibular evoked myogenic potential (VEMP) magnitude and latency. The subjects were eighteen normal-hearing adults with no history of vestibular disease. Monaural VEMPs were acquired with air-conducted (AC) and bone-conducted (BC) 500 Hz tone bursts presented at 95 dB nHL and 70 dB nHL, respectively. These stimuli were simultaneously paired with 95 dB nHL contralateral tone bursts at 250, 500, 750, or 1000 Hz during acquisition of binaural VEMPs. Results indicated that AC-VEMP relative magnitudes decreased in each of the binaural conditions compared to the monaural condition. However, no changes in relative magnitude between conditions occurred for BC-VEMPs. Similar latencies were observed for monaural and binaural VEMPs. Differences in bilateral interaction seen between the AC-VEMP and BC-VEMP conditions are consistent with modification of sound transmission through the ear during presentations of binaural sound.     

The influence of clicks versus short tone bursts on the vestibular evoked myogenic potentials

OBJECTIVE: Vestibular evoked myogenic potential (VEMP) has become a diagnostic tool to evaluate the integrity of sacculo-collic reflex. To obtain a more consistent VEMP response in normal-hearing subjects, we examine whether clicks or short tone bursts are more effective in eliciting VEMP responses. DESIGN: Prospective study. Twenty-nine normal-hearing volunteers (58 ears) were given VEMP tests. Clicks and short tone bursts were presented alternately to evoke VEMPs. The latencies of peak p13 and n23, peak-to-peak interval and amplitude (p13-n23) were measured and compared. RESULTS: Click stimulation of 57 ears (98%) produced VEMPs (C-VEMPs), whereas 51 (88%) revealed positive short tone burst-evoked VEMPs (STB-VEMPs), exhibiting a significant difference (p < 0.05). Furthermore, C-VEMPs displayed shorter latency, longer interval and larger amplitude than STB-VEMPs, with a significant difference (p < 0.05), respectively. CONCLUSIONS: C-VEMPs had a higher response rate, shorter latency, and larger amplitude than STB-VEMPs. These findings suggest that click is superior to short tone burst to trigger VEMPs. Because C-VEMPs have a shorter p13 latency than STB-VEMPs, the interpretation of prolonged latency differs in each stimulus condition.     

Vestibular evoked myogenic potential induced by bone-conducted stimuli in patients with conductive hearing loss

CONCLUSIONS: Bone-conducted vestibular evoked myogenic potentials (B-VEMPs) showed high specificity for the presence of vertigo in patients with unilateral chronic otitis media (COM). These results suggest that vestibular function can be evaluated with B-VEMPs, even in patients with conductive hearing loss. OBJECTIVE: The purpose of this study was to investigate the VEMPs induced by bone-conducted stimuli (B-VEMPs) in patients with conductive hearing loss due to perforated COM. SUBJECTS AND METHODS: The subjects were 48 patients with unilateral perforated COM and conductive hearing loss. The disequilibrium group consisted of 25 patients, and the non-disequilibrium group consisted of 23 patients. The control group comprised 35 healthy volunteers. B-VEMPs were stimulated with tone burst sound of 60 dB nHL and 250 Hz delivered from a bone vibrator and were recorded for each subject. The results of B-VEMP were compared between disequilibrium and non-disequilibrium groups. RESULTS: The mean interaural ratio was 16.5+/-12.1% in the control group, thus the normal range was <40.7%. Abnormal results were not found in any subject in the non-disequilibrium group but were found in 13 patients (54.0%) in the disequilibrium group (p<0.001). The ear with COM showed lower responses than the intact ear in all subjects with abnormal results.     

前庭诱发肌源性电位的正常人群观察

目的:观察我国正常青年人群中前庭诱发肌源性电位(VEMP)出现的阳性率及各项参数指标。方法:选取52例(男31例,女21例)21~22岁正常健康人群,以短声为刺激声,单耳给声,同侧胸锁乳突肌(SCM)记录。结果:47例2耳均可引出VEMP,5例2耳均不能引出。总104耳中,94耳阳性,10耳阴性,阳性率90%。统计阳性耳各参数:p1潜伏期(15.97±3.22)ms、n2潜伏期(24.41±2.46)ms、p1n2间期(8.41±2.06)ms,幅值(33.27±14.37)μV,阈值(93.67±5.20)dB nHL。统计47例正常人同一个体耳内差异的各参数为p1潜伏期(0.97±1.31)ms,n2潜伏期(1.23±1.30)ms,p1n2间期(0.95±1.21)ms,幅值(10.04±11.88)μV,阈值(2.29±2.56)dB nHL。男女各参数比较差异无统计学意义。结论:绝大部分正常人可引出VEMP。VEMP的引出体现该侧耳球囊→前庭下神经→脑干前庭神经核→前庭脊髓通路→颈肌运动神经元这条反射途径的完整性。VEMP可能成为一种检测前庭终器及其传导通路完整性的方法。     

Sound-evoked myogenic potentials on the sternocleidomastoid muscle in monkeys

CONCLUSION: We recorded sound-evoked myogenic potentials of the sternocleidomastoid (SCM) muscle using awake monkeys. The characteristics of these potentials are similar to those of vestibular evoked myogenic potentials (VEMPs) in humans, suggesting that the sound-evoked myogenic potentials of the SCM muscle in monkeys may be utilized as an animal model of VEMPs. OBJECTIVE: The pathway of the VEMPs remains uncertain as no animal model has yet been used to record sound-evoked myogenic potentials in the SCM muscle. Therefore, the present study aimed to establish an animal model of VEMPs using macaque monkeys. MATERIALS AND METHODS: Four macaque monkeys were used. A pair of electrodes was attached on the SCM muscle ipsilateral side to the intense sound stimulation. RESULTS: The sound-evoked myogenic potentials of the SCM muscle exhibited a biphasic waveform. When a click at 125 dBSPL was applied, the peak latency of the first positive wave was 12.5 ms and was not delayed when the stimulating sound intensity was reduced. The thresholds of the myogenic potentials were 103 dBSPL, which were 43 dB higher than those of the auditory brainstem response (ABR). When a short tone burst was applied, the reactive optimal frequency of the myogenic potentials was relatively low (500-1000 Hz).     

Clinical investigation and mechanism of air-bone gaps in large vestibular aqueduct syndrome

OBJECTIVES: Patients with large vestibular aqueduct syndrome (LVAS) often demonstrate an air-bone gap at the low frequencies on audiometric testing. The mechanism causing such a gap has not been well elucidated. We investigated middle ear sound transmission in patients with LVAS, and present a hypothesis to explain the air-bone gap. METHODS: Observations were made on 8 ears from 5 individuals with LVAS. The diagnosis of LVAS was made by computed tomography in all cases. Investigations included standard audiometry and measurements of umbo velocity by laser Doppler vibrometry (LDV) in all cases, as well as tympanometry, acoustic reflex testing, vestibular evoked myogenic potential (VEMP) testing, distortion product otoacoustic emission (DPOAE) testing, and middle ear exploration in some ears. RESULTS: One ear with LVAS had anacusis. The other 7 ears demonstrated air-bone gaps at the low frequencies, with mean gaps of 51 dB at 250 Hz, 31 dB at 500 Hz, and 12 dB at 1,000 Hz. In these 7 ears with air-bone gaps, LDV showed the umbo velocity to be normal or high normal in all 7; tympanometry was normal in all 6 ears tested; acoustic reflexes were present in 3 of the 4 ears tested; VEMP responses were present in all 3 ears tested; DPOAEs were present in 1 of the 2 ears tested, and exploratory tympanotomy in 1 case showed a normal middle ear. The above data suggest that an air-bone gap in LVAS is not due to disease in the middle ear. The data are consistent with the hypothesis that a large vestibular aqueduct introduces a third mobile window into the inner ear, which can produce an air-bone gap by 1) shunting air-conducted sound away from the cochlea, thus elevating air conduction thresholds, and 2) increasing the difference in impedance between the scala vestibuli side and the scala tympani side of the cochlear partition during bone conduction testing, thus improving thresholds for bone-conducted sound. CONCLUSIONS: We conclude that LVAS can present with an air-bone gap that can mimic middle ear disease. Diagnostic testing using acoustic reflexes, VEMPs, DPOAEs, and LDV can help to identify a non-middle ear source for such a gap, thereby avoiding negative middle ear exploration. A large vestibular aqueduct may act as a third mobile window in the inner ear, resulting in an air-bone gap at low frequencies.     

Age-related changes in vestibular evoked myogenic potentials

Vestibular evoked myogenic potentials (VEMP) in response to sound stimulation (500 Hz tone burst, 129 dB SPL) were studied in 1000 consecutive patients. VEMP from the ear with the larger amplitude were evaluated based on the assumption that the majority of the tested patients probably had normal vestibular function in that ear. Patients with known bilateral conductive hearing loss, with known bilateral vestibular disease and those with Tullio phenomenon were not included in the evaluation. It was found that there was an age-related decrease in VEMP amplitude and an increase in VEMP latency that appeared to be rather constant throughout the whole age span. The VEMP data were also compared to an additional group of 10 patients with Tullio phenomenon. Although these 10 patients did have rather large VEMP, equally large VEMP amplitudes were observed in a proportion of unaffected subjects of a similar age group. Thus, the finding of a large VEMP amplitude in response to a high-intensity sound stimulation is not, per se, distinctive for a significant vestibular hypersensitivity to sounds.     

The effects of click and tone-burst stimulus parameters on the vestibular evoked myogenic potential (VEMP)

Vestibular evoked myogenic potentials (VEMP) are short latency electromyograms (EMG) evoked by high-level acoustic stimuli and recorded from surface electrodes over the tonically contracted sternocleidomastoid (SCM) muscle and are presumed to originate in the saccule. The present experiments examined the effects of click and tone-burst level and stimulus frequency on the latency, amplitude, and threshold of the VEMP in subjects with normal hearing sensitivity and no history of vestibular disease. VEMPs were recorded in all subjects using 100 dB nHL click stimuli. Most subjects had VEMPs present at 500, 750, and 1000 Hz, and few subjects had VEMPs present at 2000 Hz. The response amplitude of the VEMP increased with click and tone-burst level, whereas VEMP latency was not influenced by the stimulus level. The largest tone-burst-evoked VEMPs and lowest thresholds were obtained at 500 and 750 Hz. VEMP latency was independent of stimulus frequency when tone-burst duration was held constant.     

Ten-year longitudinal study of the effect of impulse noise exposure from gunshot on inner ear function

This longitudinal study investigated how chronic gunshot noise exposure affects cochlear and saccular function in police officers who engaged in regular target shooting practice using dual protection (ear plugs plus earmuffs) for >10 years. In 1997, 20 male police officers underwent audiometry before and two weeks after shooting. Twelve of the original subjects were re-examined by audiometry coupled with vestibular evoked myogenic potential (VEMP) test in 2007. Significant deterioration of mean hearing thresholds at frequencies of 500 Hz through 4000 Hz was noted ten years later, affecting both ears. However, only the frequencies of 4000 and 6000 Hz on the left ear revealed significant difference in mean hearing thresholds compared with healthy controls. Abnormal VEMP responses were evident in nine police officers (75%), including absent VEMPs 7 and delayed VEMPs 2. In conclusion, deterioration to hearing may occur after long term exposure to gunshots, even when double hearing protection is used. Further study is in progress regarding how to preserve both cochlear and saccular function during long term gunshot exposure.     

Effects of stimulus conditions on vestibular evoked myogenic potentials in healthy subjects

Background: Characteristics of vestibular evoked myogenic potentials (VEMPs) depend on stimulus conditions.

Objective: To determine the optimal stimulus conditions for cervical and ocular VEMPs.

Methods: Participants were 23 healthy subjects. We compared air-conducted cervical and ocular VEMPs elicited by various tone-burst conditions (frequencies 500–1,000?Hz, rise/fall times 1–2?ms, and plateau times 0–6?ms) with an intensity of 105?dB normal hearing level. Effects of simultaneous contralateral masking noise on VEMPs were also evaluated.

Results: The largest cervical VEMP amplitudes were elicited by 500–750?Hz and 2–6?ms plateau time-tone-bursts, and the largest ocular VEMP amplitudes by 750?Hz and 2–4?ms plateau time-tone-bursts. Repeatability of the latency was better at 1?ms than at 2?ms rise/fall time in both VEMPs. In both VEMPs, masking noise reduced amplitude, and in ocular VEMP, amplitudes were significantly larger at the left ear stimulation than the right.

Conclusion: Optimal tone-burst stimulation for both VEMPs seemed to be 500–750?Hz frequency and 1/2/1?ms rise/plateau/fall time without contralateral masking noise. Ocular VEMP amplitudes from left ear stimulation were originally larger than those from right ear stimulation.     

Vestibular evoked myogenic potential (VEMP) in patients with Ménière's disease with drop attacks

OBJECTIVE: In this retrospective study, we tested the hypothesis that vestibular evoked myogenic potential (VEMP) thresholds are more often elevated or absent in patients with Ménière's disease experiencing Tumarkin drop attacks than in other patients with Ménière's disease. METHODS: Subjects included normal subjects (n = 14) and patients with unilateral Ménière's disease by AAO-HNS (1995) diagnostic criteria with (n = 12) and without (n = 82) Tumarkin drop attacks at a large specialty hospital otology service. VEMP threshold testing was conducted using 250, 500, and 1,000 Hz tone burst stimuli. RESULTS: VEMP responses were present in at all frequencies in both ears of all normal subjects. In unaffected ears of patients with unilateral Ménière's disease, VEMPs were undetectable in 13% of measurements attempted. This number rose to 18% in affected ears of patients with unilateral Ménière's disease and to 41% in Meniere ears with Tumarkin drop attacks. Frequency tuning of the VEMP response in normal subjects showed lowest thresholds at 500 Hz. In Meniere ears, the tuning was altered such that the 500-Hz thresholds were higher than the 1,000-Hz thresholds. There was a gradient of threshold elevation and altered tuning that corresponded to the gradient of worsening disease. CONCLUSION: Our findings support the hypothesis that Tumarkin drop attacks arise from advanced disease involving the saccule and that VEMP may be a clinically valuable metric of disease severity or progression in patients with Ménière's disease.     

Characterization of age-related changes in vestibular evoked myogenic potentials.

A tone-burst stimulation of 500 Hz seems to be clinically most appropriate to elicit vestibular evoked myogenic potentials (VEMPs) because those VEMPs can be recorded at the lowest stimulus intensity possible. However, little is known about gender and age-related changes of the amplitude in tone-burst (500 Hz) evoked VEMPs. The aim of the present paper was therefore to investigate the influence of gender and age on VEMP amplitude in relation to the tonic muscle activity. VEMPs of 64 healthy subjects were recorded ipsilaterally during air- or bone-conducted tone burst stimulation. The EMG of the tonically activated sternocleidomastoid muscle was recorded ipsilaterally with surface electrodes. Averages were taken for P1/N1 amplitudes of male and female volunteers within 3 different age groups. Although the amplitude decreased with increasing age the tonic activity was not significant different between the age groups. Consequently the relation between VEMP amplitude and tonic muscle activity decreased with increasing age. The normative values of the age-dependent relation between VEMP amplitude and tonic muscle activity were described by the 90% confidence interval of the individual values. Normative thresholds were calculated. Normal saccular receptor function could be diagnosed if the VEMP amplitude is above (or equal to) the normative value at a given tonic muscle activity and age. Normative data as described above are required to diagnose isolated saccular defects, which are indicative of a vestibular disorder.     

Vestibular evoked myogenic potential induced by bone-conducted stimuli in patients with conductive hearing loss

Conclusions. Bone-conducted vestibular evoked myogenic potentials (B-VEMPs) showed high specificity for the presence of vertigo in patients with unilateral chronic otitis media (COM). These results suggest that vestibular function can be evaluated with B-VEMPs, even in patients with conductive hearing loss. Objective. The purpose of this study was to investigate the VEMPs induced by bone-conducted stimuli (B-VEMPs) in patients with conductive hearing loss due to perforated COM. Subjects and methods. The subjects were 48 patients with unilateral perforated COM and conductive hearing loss. The disequilibrium group consisted of 25 patients, and the non-disequilibrium group consisted of 23 patients. The control group comprised 35 healthy volunteers. B-VEMPs were stimulated with tone burst sound of 60 dB nHL and 250 Hz delivered from a bone vibrator and were recorded for each subject. The results of B-VEMP were compared between disequilibrium and non-disequilibrium groups. Results. The mean interaural ratio was 16.5±12.1% in the control group, thus the normal range was <40.7%. Abnormal results were not found in any subject in the non-disequilibrium group but were found in 13 patients (54.0%) in the disequilibrium group (p<0.001). The ear with COM showed lower responses than the intact ear in all subjects with abnormal results.     

The Effects of Plateau Time on Vestibular-evoked Myogenic Potentials Triggered by Tone Bursts

Vestibular-evoked myogenic potentials (VEMPs) can be triggered by acoustic, vibratory or galvanic stimuli. However, each method has drawbacks for studying if the vestibulocollic reflex is intact in the patients tested. We used air-conducted VEMPs as a screening test to examine the integrity of the sacculocollic reflex. In a previous study, we defined the optimal rise fall time of short tone bursts (STBs) to evoke VEMPs. In this paper, we studied the optimal plateau time of tone bursts to evoke VEMPs. Four different plateau times (1, 2, 5 and 10 ms) were used in a random order to test 26 normal ears. VEMP responses (p13 n23) triggered by the tone bursts were clearly observed in all ears. When the plateau time was increased in order from 1 to 10 ms, the latencies (p13, n23) and interval (p13-n23) were also increased in parallel, although significant differences were not observed between some plateau times. Considering the latencies and interval together for the four plateau times, the variances were smallest for the 2 ms plateau time, meaning that it caused the smallest interaural VEMP differences. The amplitude or relative amplitude in individual ears was lowest for the 1 ms plateau time, while it was comparable for the other three plateau times. In conclusion, we recommend that the ideal stimulation pattern for evoking STB VEMPs is as follows: frequency 500 Hz; stimulation repetition rate 5 Hz; rise fall time 1 ms; and plateau time 2 ms. The waveform morphology of the VEMP responses observed with this stimulation pattern was simultaneously the most constant and marked.     

Vestibular evoked myogenic potentials in acute acoustic trauma.

OBJECTIVES: Anatomical proximity of the saccule to the stapedial footplate points to the possibility of acoustic trauma associated with saccular dysfunction. Therefore, it was the authors' premise that abnormal vestibular evoked myogenic potential (VEMP) after acute acoustic trauma may be caused by saccular damage from very high intensity noise; consequently, irreversible hearing loss ensued. The aim of this study was to investigate the VEMP responses in those with acute acoustic trauma. STUDY DESIGN: A prospective study. SETTING: University hospital. PATIENTS: Twenty patients (29 ears) without previous ear disorders diagnosed as acute acoustic trauma were enrolled in this study. MAIN OUTCOME MEASURES: Before treatment, each patient underwent pure tone audiometry and caloric and VEMP tests. Correlations between the hearing outcome and mean hearing level, sources of noise, caloric responses, or VEMP results were investigated. RESULTS: After 3 months of medication, complete recovery was achieved in 4 ears and hearing improvement in 4 ears, whereas hearing in 21 ears (72%) remained unchanged. Eighteen ears presenting normal VEMPs revealed hearing improvement in eight ears (44%) and unchanged hearing in ten ears (56%). However, hearing loss remained unchanged in all 11 ears (100%) with absent or delayed VEMPs, exhibiting a significant relationship between VEMP results and hearing outcome. Thus, VEMP test can predict the hearing outcome after acute acoustic trauma with a sensitivity of 44% and a specificity of 100%. CONCLUSION: The greater the noise intensity, the severer damage on the cochlea and saccule is shown. Absent or delayed VEMPs in ears after acute acoustic trauma may indicate poor prognosis with respect to hearing improvement, whereas normal VEMP is not a powerful indicator for expectation of hearing improvement.     

Vestibular evoked myogenic potentials in delayed endolymphatic hydrops

OBJECTIVE/HYPOTHESIS: Vestibular evoked myogenic potential (VEMP) has become an established test to explore the sacculo-collic reflex. The study aims to investigate the VEMPs in cases of delayed endolymphatic hydrops because greatly dilated saccule was observed in histopathological specimens of delayed endolymphatic hydrops. STUDY DESIGN: Prospective study. METHODS: Twenty patients with delayed endolymphatic hydrops were subjected to pure-tone audiometry, caloric testing, and VEMP test. Delayed VEMP was defined as the latency of peak I exceeding 22.6 milliseconds or of peak II exceeding 33.1 milliseconds. Interaural amplitude difference over the sum of amplitudes of both ears was measured, and when the ratio exceeded 0.36, it was identified as augmented VEMP or depressed VEMP depending on whether the amplitude of the lesioned side was greater or less than the opposite side. RESULTS: The VEMP test revealed that 9 patients (45%) were normal, 6 (30%) exhibited absent VEMPs, and 5 (25%) displayed abnormal VEMPs, including delayed VEMPs in 2, depressed VEMPs in 2, and augmented VEMPs in 1. The caloric test indicated that 9 (47%) of the 19 ears exhibited normal caloric response, whereas 10 ears displayed abnormal caloric responses including canal paresis in 8 and absent caloric response in 2. Six ears had preserved both the caloric response and the VEMPs, whereas no ear demonstrated both absent caloric response and absent VEMPs. CONCLUSIONS: The residual caloric as well as saccular functions after ear insult may determine whether delayed endolymphatic hydrops will occur. These findings suggest that patients with sudden deafness or juvenile unilateral total deafness should undergo caloric testing and VEMP test to predict the occurrence of delayed endolymphatic hydrops in the future.     

Effect of the middle ear status on the recording of vestibular evoked myogenic potential--VEMP

The aim of this study was to assess the effect of the middle ear status on the recording of air- and bone-conducted vestibular evoked myogenic potential. Forty eight children were included in the study, ranging in age from 4 to 10 years. All of the children underwent otoscopy, pure tone audiometry, tympanometry and air- and bone-conducted VEMP in response to click. There were 3 groups according to the condition of the middle ear: group I--52 ears (type A and C1 tympanogram, pure tone average < or = 20 dB), group II--23 ears (type C2 and B tympanogram, pure tone average < or = 20 dB), group III--21 (type B tympanogram, pure tone average > 20 dB). The threshold, presence of correct waveform morphology of the response and latency was evaluated. The condition of the middle ear has no significant effect on the recording of VEMP and mean level of the response threshold with bone stimulation, based on the performed studies. However, with air stimulation it has effect on the recording of VEMP, increase of the mean threshold response and shortening of latency p13 and n23.     

VEMP responses are not affected in non-insulin-dependent diabetes mellitus patients with or without polyneuropathy

CONCLUSION: Vestibular evoked myogenic responses (VEMPs) are not affected in non-insulin-dependent diabetes mellitus (NIDDM) patients with or without polyneuropathy. OBJECTIVE: To compare VEMP responses of NIDDM patients and healthy subjects. SUBJECTS AND METHODS: VEMP responses were collected from 25 NIDDM patients with polyneuropathy (PNP), 13 NIDDM patients without PNP and 21 healthy subjects using click stimulation. After excluding ears with hearing loss (HL) (worse than 25 dB) the VEMP responses (p13 and n21 latencies and amplitude) recorded in 105 dB stimulus intensity were compared. RESULTS: There was no statistically significant difference between groups. VEMP responses were found to be normal in NIDDM patients with or without PNP.