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.     

Improving vestibular evoked myogenic potential reliability by using a blood pressure manometer

OBJECTIVE/HYPOTHESIS: To improve the reliability of vestibular evoked myogenic potentials (VEMP), we propose a feedback method making use of a readily available blood pressure manometer with inflatable cuff to control the sternocleidomastoid muscle (SCM) contraction. STUDY DESIGN: Prospective study. MATERIALS AND METHODS: The feedback method for SCM contraction consisted of subjects pushing with their jaw against the hand-held inflated cuff to generate a specified cuff pressure. This pressure level was monitored by subject and investigator. First, we tested in a group of healthy subjects whether there was a learning or fatigue effect during four successive SCM contraction runs when making use of the feedback method. Then, we investigated the mean rectified voltage (MRV) values of the SCM. Next, we examined the hypothesis that the MRV values of the SCM contraction measured before and simultaneously with the VEMP test were equal when using this feedback method. Finally, we compared the VEMP amplitude variability in two circumstances: with and without the feedback method. RESULTS: There was no learning or fatigue effect, and the MRV values measured before the VEMP were not significantly different from those measured during the VEMP test. The VEMP amplitude variability was significantly lower when applying the feedback method than when no feedback method was used. CONCLUSION: This feedback method improves significantly the VEMP amplitude reliability.     

Effects of cochlear implants on otolith function as evaluated by vestibulo-ocular reflex and vestibular evoked myogenic potentials

ObjectiveThe aim of this study was to investigate whether the insertion of an implant into the cochlea is accompanied by a deterioration in otolith function. Cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) and linear vestibulo-ocular reflex (lVOR) during eccentric rotation were assessed before and after cochlear implantation (CI) to evaluate otolith function.MethodsTwelve patients with bilateral severe sensorineural hearing loss who had undergone CI surgery in our hospital between May 2016 and November 2017 were included in this study. cVEMP and oVEMP were assessed using the asymmetry ratio (AR), calculated with the following formula: [(peak-to-peak amplitude calculated as the sum of the p13 and n23 amplitudes in the non-operated side) − (that in the operated side)]/[(that in the non-operated side) + (that in the operated side)]. The ratio of VOR gain during eccentric rotation against VOR gain during center rotation was used to assess lVOR. For eccentric rotation, patients were rotated while displaced from the axis of rotation. At the same time, linear acceleration stimulated the utricle and induced lVOR. All patients underwent cVEMP and oVEMP tests and center and eccentric rotation tests before and about 30 days after CI surgery.ResultsThree patients with absent cVEMP responses before surgery were excluded, leaving pre-surgery cVEMP results for 9/12 patients. In five of these patients, the AR of cVEMP increased after CI, indicating that saccular function, as evaluated by cVEMP, did not deteriorate significantly postoperatively. One patient with an absent oVEMP response before CI was excluded, leaving pre-surgery oVEMP results for 11/12 patients. In 10 of these patients, the AR of oVEMP increased after CI surgery, indicating that utricular function, as evaluated by oVEMP, deteriorated significantly postoperatively. However, because the ratio of VOR gain during eccentric rotation against VOR gain during center rotation did not become worse after CI, utricular function, as evaluated by lVOR, did not deteriorate significantly postoperatively. Symptoms of vertigo became worse after CI in two of the 12 patients.ConclusionCI does not cause a deterioration in saccular function, as evaluated by cVEMP. Although CI does cause a deterioration in utricular function in oVEMP tests, this is not consistent in lVOR tests. These results indicate that CI causes a slight deterioration in utricular function that is insufficient to cause vertigo or deterioration of lVOR.     

Effect of head position on vestibular evoked myogenic potentials with toneburst stimuli

Conclusion. The present study demonstrated the robustness of VEMP testing with toneburst stimuli, since it is hardly affected by head position, i.e. base or tonic excitation levels of the saccule and inferior vestibular nerve. However, the small but highly significant difference found in latency should not be neglected: the gravitational axis in the upright position may have some special effect on tonic excitation of the saccule. Objectives. To evaluate the effect of head positions on vestibular evoked myogenic potentials (VEMPs) with toneburst stimuli. Materials and methods. VEMPs were recorded with short tonebursts of 500 Hz in 14 normal subjects in 5 head positions (upright, nose up, ear up, nose down, and ear down). The three parameters analyzed were: 1) latency of p13, 2) latency of n23, and 3) corrected amplitude of p13-n23 (CA p13-n23). Results. One-way repeated measures ANOVA showed significant effects on both p13 (p=0.0245) and n23 (p<0.0001) latencies, but not on CA p13-n23. Bonferroni's post hoc test demonstrated that there were significant differences in n23 latency between the upright position and all other head positions leaning on the bed.     

Ocular vestibular evoked myogenic potential in patients with myasthenia gravis: A prospective clinical study

Objective

Myasthenia gravis (MG) is an archetypic disorder of neuromuscular junctions (NMJs) and autoantibody-mediated disease causing fatigable weakness of skeletal muscles with an ocular onset in up to 85%. The aim of this study was to detect extra ocular muscles (EOMs) abnormalities in MG patients using ocular vestibular evoked myogenic potential (oVEMP) n10 response.

大前庭水管综合征患者的听力学及前庭诱发肌源性电位检测的特点

目的:探讨大前庭水管综合征(LVAS)患者的听力学、前庭诱发肌源性电位(VEMP)检测的特点及诊断意义。方法:对30例(60耳)LVAS患者行纯音测听、声导抗、ABR、畸变产物耳声发射(DPOAE)、VEMP及冷热实验检测,分析其诊断意义。结果:30例(60耳)LVAS患者均呈进行性、波动性听力下降,16例在听力波动性下降时伴眩晕。纯音测听主要呈感音神经性聋,但47耳(94.0%)在中耳功能正常的情况下于低频250、500Hz分别出现(43±17)dBHL及(33±18)dBHL骨气导差,呈混合性聋。ABR检测18耳(64.3%)于(3.06±0.52)ms引出声诱发短潜伏期负反应。42耳VEMP振幅均值为(147.10±107.55)μV,19耳反应阈为75dBnHL,7耳反应阈为65dBnHL。结论:根据进行性波动性听力减退、感音神经性聋在中耳功能正常的情况下出现低频骨气导差,ABR测试引出声诱发短潜伏期负反应及VEMP呈现高振幅低阈值的特征性提示,有助于临床医生得出LVAS的初步印象,可进一步行影像学检查以确诊。     

Idiosyncratic compensation of the subjective visual horizontal and vertical in 60 patients after unilateral vestibular deafferentation

Objective To investigate long-term compensation mechanisms of utricular function after translabyrinthine surgery for vestibular schwannoma. Correlations between the subjective visual horizontal (SVH) and subjective visual vertical (SVV) and other parameters of vestibular compensation were studied. The correlation between the SVH and SVV was also investigated to see whether these measurements are compatible for patients.

Material and Methods Sixty consecutive patients were investigated 3 months before and 6 months after surgery by means of electronystagmography and SVH and SVV tests. Tumor size was measured using MRI.

Results The SVH and SVV increased significantly towards the ipsilesional side postoperatively. Preoperative tilt correlated with age. Postoperative tilt correlated weakly with preoperative caloric sensitivity and inversely with tumor size. The correlation between the SVH and SVV was high both before and after surgery (r_s>0.74; p<0.001).

Conclusions The long-term compensation of static tilt perception was dependent on age and not on dynamic canal functions. We propose an idiosyncrasy in the SVH and SVV compensation after unilateral vestibular deafferentation, incongruous with the general course of vestibular compensation. The results suggest a probable dependence on non-vestibular information, i.e. proprioception, in facilitating compensation of static vestibular deficits. The similarity between the SVH and SVV measurements confirms that either test can be used clinically for patients with vestibular lesions.     

The clinical utility of vestibular autorotation test in patients with vestibular migraine

Objective: To investigate the characteristics and clinical utility of vestibular autorotation test (VAT) in patients with vestibular migraine.

Methods: This study included two groups, an experimental group (441 patients) and a control group (65 healthy subjects). Both groups undertook VAT; the parameters evaluated were horizontal gain/phase, vertical gain/phase and asymmetry. The differences in VAT results between the two groups were investigated.

Results: There were no statistical differences between the VAT data of the control group when compared to the reference value from the manufacturer (p?>?.05). There were statistically significant differences in VAT results between the experimental and control group, namely elevated horizontal gain at frequency 2, 3, 4 and 5?Hz, horizontal phase delay at frequency 2, 4, 5 and 6?Hz, elevated vertical gain at frequency 2?6Hz and vertical phase delay at frequency 4?6Hz.

Conclusion: The results of this study using VAT in VM patients demonstrate elevated horizontal gain, vertical gain and delay in horizontal phase, vertical phase. We suggest the application of VAT as a diagnostic tool which may provide objective evidence that can contribute to the diagnosis of VM and also in differential diagnosis.     

Recovery of vestibular evoked myogenic potentials after a vertigo attack due to vestibular neuritis

Conclusions. Inferior vestibular nerve functions could recover in patients with vestibular neuritis (VN).

Objectives. Although the recovery of superior vestibular nerve functions has been reported, there is little information about the recovery of inferior vestibular nerve functions in patients with VN. This study was done to clarify if inferior vestibular nerve functions recover after an attack of VN.

Methods. Neuro-otological tests including vestibular evoked myogenic potential (VEMP) testing and caloric testing were sequentially performed in 13 patients with VN, who showed absence of VEMP on the affected side at the initial examination (7 men and 6 women, 28–82 years of age). VEMPs to click stimulation (95 dBnHL) were recorded with surface electrodes over each sternocleidomastoid muscle.

Results. Among the 13 patients, 5 patients (4 men and 1 woman) showed recovery of VEMP responses. Four of the five patients (three men and one woman) showed recovery of VEMP to the normal range. It takes 6 months to 2 years to recover within the normal range. On the other hand, caloric responses recovered to the normal range only in one patient.     

Appearance of ocular vestibular evoked myogenic potential elicited by bone-conducted vibration in a patient with CHARGE syndrome with aplasia of all semicircular canals

We report VEMP results in a patient with aplasia of bilateral semicircular canals and a small vestibular cavity. The patient was a 27-year-old male. The computed tomograph showed absolutely no formation of his semicircular canals, together with hypoplasia of his vestibular cavity and cochlea in both ears. His oVEMP was recorded near the extraocular muscles on the left side when elicited by BCV in the Fz. The clinical profile of this patient suggested that oVEMP elicited by BCV recorded near the extraocular muscles originated from otolithic end organs, and not from semicircular canal afferents.     

Vestibular evoked myogenic potentials in young children: test parameters and normative data

OBJECTIVE: The vestibular evoked myogenic potential (VEMP) is a test of the vestibulocollic reflex that has been extensively studied in adults. Much is known about the normal values in adults as well as their changes with age. In children, the expected test values and their possible changes in development have not yet been described nor has the feasibility of reliable testing in this group. The aim of this prospective study is to accumulate normative data and to verify the viability of testing in young children. The study focused on optimal test parameters, reproducibility, and subject compliance in a pediatric population. METHODS: Thirty normal-hearing children (60 ears) ages 3 to 11 completed VEMP testing and audiograms for analysis. VEMP testing was performed with alternating clicks at three intensities (80-, 85-, and 90-dB normalized hearing level) using averaged, unrectified electromyograms recorded by surface electrode on the sternocleidomastoid muscle ipsilateral to the stimulus. VEMP latencies, amplitude, compliance, and length of testing were recorded for each patient, as well as their feedback on the testing session. The subjects were divided into four age groups for analysis. RESULTS: All but one of the subjects attempting VEMP testing was able to finish. Of 30 children completing VEMP tests, bilateral reflexes were recorded for all subjects with symmetric responses in 28 of 30 subjects (93%). The mean peak latencies (+/- standard deviation [SD]) of pI and nII were 11.3 msec (1.3 ms) and 17.6 msec (1.4 ms), respectively. The mean pI-nII amplitude (+/- SD) was 122 muV (68 muV). There was a significantly shorter nII mean peak latency of group I (ages 3-5) left ear in comparison to other groups, with an absolute shorter mean latency nII in the right ear of group I (not significant). Average test time was 15 minutes with two researchers testing, and subjects were highly compliant. CONCLUSIONS: VEMP is a well-tolerated test for screening vestibular function in young children, performed with minimal test time and reproducible results. Mean latencies in this study suggested a shorter initial negative peak (nII) than in adult studies, consistent with prolongation seen in previous research on the effects of age. Ninety-decibel normalized hearing level clicks were adequate for uniform response rates. Expected latency and amplitude values in single-channel VEMP-unrectified electromyograms were established. This is the first study describing expected latencies and optimal testing parameters in children.     

原发性良性阵发性位置性眩晕患者前庭诱发肌源性电位检测的意义

目的：探讨检测眼肌前庭诱发肌源性电位（oVEMP）和颈肌前庭诱发肌源性电位（cVEMP）对单侧原发性良性阵发性位置性眩晕（BPPV）患者进行可能发病部位的定位诊断价值。方法：对52例单侧原发性BP-PV患者（BPPV组）和38例正常人（对照组）分别进行气导短纯音诱发的oVEMP和cVEMP检测,分析两种反射的引出率、潜伏期、振幅等数据。结果;BPPV组患侧oVEMP的引出率为46．15％,cVEMP的引出率为67．31％;其健侧oVEMP的引出率为48．08％,cVEMP的引出率为65．38％。对照组左侧oVEMP的引出率84．21％,cVEMP的引出率92．11％;右侧oVEMP的引出率为81．58％,cVEMP的引出率为94．74％。对照组双侧cVEMP和oVEMP的P1、N1潜伏期及N1-P1振幅值差异均无统计学意义。BPPV组和对照组cVEMP和oVEMP耳间振幅比及不对称率差异有统计学意义（P〈0．05）。结论：单侧原发性BPPV患者双侧前庭耳石器传导通路功能受损状况,可以通过oVEMP和cVEMP检测进行客观评估,并且oVEMP的异常率比cVEMP高。     

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.     

Large vestibular evoked myogenic potentials in response to bone-conducted sounds in patients with superior canal dehiscence syndrome

Dehiscence of the superior semicircular canal is a 'new' vestibular entity. Among these patients, the vestibular evoked myogenic potentials (VEMP) in response to air-conducted sounds are large. In the present study, VEMP in response to bone-conducted sounds were studied in 5 normal subjects, in 3 patients after (unilateral) labyrinthectomy and in 4 patients with (unilateral) superior canal dehiscence syndrome. The bone-conducted sound stimulus was a 250- and a 500- tone burst delivered monaurally on the mastoid using standard bone conductors. Among the normals, bone-conducted sounds delivered monaurally caused VEMP bilaterally. There was, however, a transcranial attenuation for the 500-Hz stimulus, but less so for the 250-Hz stimulus. Among the patients with labyrinthectomy there were VEMP on the healthy side, but not on the lesioned side, irrespective of whether the bone-conducted sounds were presented behind the healthy or the operated ear. Among the patients with superior canal dehiscence syndrome, the VEMP on the affected side were larger than on the healthy side. This suggests that there is also vestibular hypersensitivity for bone-conducted sounds in these patients.