梅尼埃病眼肌前庭诱发肌源性电位的临床研究

目的通过对梅尼埃病(Meniere disease,MD)患者眼肌前庭诱发肌源性电位(ocular vestibular-evoked myogen-ic potential,o VEMP)结果进行分析,进一步探讨梅尼埃病患者o VEMP的临床特征。方法对66例梅尼埃病患者及27例年龄、性别与之匹配的健康人进行o VEMP测试,分析对比oVEMP的引出率及各参数指标。结果 oVEMP在病例组患侧的引出率为41.7%、健侧为55%,对照组为100%;患侧与健侧比较差异无统计学意义(P>0.05),患侧、健侧与对照组比较差异均有统计学意义(P<0.05)。病例组患侧、健侧及对照组间o VEMP的振幅及不对称比均有统计学差异(P<0.05),然各波潜伏期相比无统计学意义。整体来讲,梅尼埃病患者oVEMP引出率随听力学分期升高而呈逐渐下降趋势。结论梅尼埃病患者无论健侧还是患侧,其oVEMP异常均较显著,且以患侧变化显著,提示MD患者的椭圆囊功能受损,oVEMP可用于评估MD患者椭圆囊功能,且进一步对其诊疗作出指导。     

Assessing the stage of Meniere's disease using vestibular evoked myogenic potentials

BACKGROUND: The staging of Ménière's disease that was proposed by the American Academy of Otolaryngology-Head and Neck Surgery in 1995 was based on the arithmetic mean of the pure-tone thresholds at 0.5, 1.0, 2.0, and 3.0 kHz using the worst audiogram during the 6-month interval before treatment. The stages were classified as follows: stage I, a 4-tone average of less than 26 dB; stage II, 26 to 40 dB; stage III, 41 to 70 dB; and stage IV, more than 70 dB. OBJECTIVE: Because the saccule, next to the cochlea, is the second most frequent site of hydrops formation, we wanted to find out whether vestibular evoked myogenic potential (VEMP) responses can reflect the stage of Ménière's disease. DESIGN: Prospective study. SETTING: Tertiary university hospital. PATIENTS: Forty patients (23 men and 17 women; mean +/- SD age, 43 +/- 12 years) with unilateral definite Ménière's disease were enrolled in the study. MAIN OUTCOME MEASURES: The interaural amplitude difference (IAD) ratio, which was defined as the difference of the amplitudes of peak p13 to peak n23 (p13-n23) in the right (R) and left (L) ears divided by the sum of p13-n23 in both ears (R-L/R + L), was measured, and the stages of the disease were compared with the types of hearing loss, the percentage of unilateral weakness of caloric response, and the IAD ratio, respectively. RESULTS: Six ears were classified as stage I: the VEMPs were normal in 5 and augmented in 1, with a mean +/- SD IAD ratio of -0.02 +/- 0.20. Twelve ears were classified as stage II: the VEMPs were normal in 7, augmented in 2, depressed in 1, and absent in 2, with an IAD ratio of -0.12 +/- 0.39. Seventeen ears were classified as stage III: the VEMPs were normal in 10, depressed in 4, and absent in 3, with an IAD ratio of -0.30 +/- 0.30. Five ears were classified as stage IV: the VEMPs were normal in 2, depressed in 1, and absent in 2, with an IAD ratio of -0.54 +/- 0.43. A comparison of the IAD ratio and the stage of Ménière's disease demonstrated a significant relationship (P<.05, 1-way analysis of variance test), whereas there was no significant relationship noted between the percentage of unilateral weakness of caloric response and the stage of disease. CONCLUSION: The IAD ratio of VEMPs correlates with the stage of Ménière's disease and can be used as another aid to assess the stage of Ménière's disease.     

Vestibular evoked myogenic potentials versus vestibular test battery in patients with Meniere's disease.

OBJECTIVE: The present study was undertaken to assess the sensitivity of vestibular evoked myogenic potentials testing to side-of-disease in Meniere's disease patients and to test the hypothesis that information supplied by vestibular evoked myogenic potentials is complementary to that provided by a conventional vestibular test battery. STUDY DESIGN: Prospective cohort study. SETTING: Large specialty hospital, department of otolaryngology. SUBJECTS: Twenty consenting adults (9 men and 11 women) with unilateral Meniere's disease by American Academy of Otolaryngology-Head and Neck Surgery diagnostic criteria. INTERVENTIONS: All subjects underwent bilateral vestibular evoked myogenic potentials testing using ipsilateral broadband click and short-toneburst stimuli at 250, 500, and 1,000 Hz. All subjects also underwent electronystagmography and sinusoidal vertical axis rotation testing. MAIN OUTCOME MEASURES: Accuracy of side-of-disease assignment by vestibular evoked myogenic potentials, caloric asymmetry, and multivariate analysis. RESULTS: Side-of-disease assignment was most accurate using caloric asymmetry with a 5% interaural difference criterion, achieving 85% correct assignment. The next best method was vestibular evoked myogenic potentials using 250-Hz toneburst stimuli, achieving 80% correct assignment. The least accurate method was caloric asymmetry using a traditional 30% interaural difference limen, achieving 55% correct assignment. Comparison of 5% interaural difference criterion and vestibular evoked myogenic potentials using 250-Hz toneburst stimuli showed discordant results, but in no case did both 5% interaural difference criterion and vestibular evoked myogenic potentials using 250-Hz toneburst stimuli make an incorrect assignment. CONCLUSION: Vestibular evoked myogenic potentials threshold was shown to be highly sensitive to side-of-disease in unilateral Meniere's disease. We observed instances of discordance in side-of-disease assignment by caloric asymmetry and vestibular evoked myogenic potential methods but no case in which both methods were incorrect. This supports the hypothesis that vestibular evoked myogenic potentials supplies information complementary to that provided by other components of the vestibular test battery.     

Evaluation of vestibular evoked myogenic potentials

In previous studies, electromyographic potentials, recorded in response to auditory clicks, have been attributed to stimulation of the otolith (saccule) and have been termed vestibular evoked myogenic potentials (VEMPs). In this study, we assessed the VEMPs in subjects with normal auditory brainstem evoked responses, with no history of vestibular symptoms or neck and other skeletal muscle abnormalities. To this effect, 32 subjects (64 ears), after ethics committee approval, were exposed to 75, 150, and 300 clicks at 100 dB, and the responses were averaged. Electromyographic activity was recorded by applying surface electrodes over the sternocleiodomastoid muscle under the following three conditions: no muscle contraction/no clicks, muscle contraction/no clicks, and muscle contraction/clicks. Our findings suggest that electromyographic responses have to be obtained, during muscle contraction, first without and then with clicks. Our data also suggest that comparison of these two recordings is necessary for meaningful results.     

Laterality of vestibular evoked myogenic potentials

To clarify the laterality of acoustically evoked vestibulocollic reflexes with a short latency (vestibular evoked myogenic potentials, VEMPs), responses on the bilateral sternocleidomastoid muscles (SCMs) to unilateral acoustic stimulation were studied. Twenty-one healthy volunteers were enrolled. Surface electrodes were placed on the upper half of each SCM (active) and on the lateral end of the upper sternum (reference). Clicks and 500-Hz tone-bursts (95 dB nHL) were used. All subjects showed positive-negative biphasic responses on the ipsilateral SCM by clicks and tone-bursts. Click-stimulation of 41 of the 42 ears did not evoke any response on the contralateral SCM. However, in one ear, positive-negative biphasic responses were evoked on the contralateral SCM. Recordings on the contralateral SCM by tonebursts showed no response in 32 ears, small positive-nega-tive biphasic responses in four ears, and small negative-positive biphasic responses in six ears. These findings show that VEMPs are ipsilateral-dominant, basically consistent with the hypothesis that they are of saccular origin.     

Laterality of vestibular evoked myogenic potentials

To clarify the laterality of acoustically evoked vestibulocollic reflexes with a short latency (vestibular evoked myogenic potentials, VEMPs). responses on the bilateral sternocleidomastoid muscles (SCMs) to unilateral acoustic stimulation were studied. Twenty-one healthy volunteers were enrolled. Surface electrodes were placed on the upper half of each SCM (active) and on the lateral end of the upper sternum (reference). Clicks and 500-Hz tone-bursts (95dB nHL) were used. All subjects showed positive-negative biphasic responses on the ipsilateral SCM by clicks and tone-bursts. Click-stimulation of 41 of the 42 ears did not evoke any response on the contralateral SCM. However, in one ear, positive-negative biphasic responses were evoked on the contralateral SCM. Recordings on the contralateral SCM by tone-bursts showed no response in 32 ears, small positive-negative biphasic responses in four ears, and small negative-positive biphasic responses in six ears. These findings show that VEMPs are ipsilateral-dominant, basically consistent with the hypothesis that they are of saccular origin.     

Cervical vestibular evoked myogenic potentials in children

IntroductionCervical vestibular evoked myogenic potential is a test used in neurotological examination. It verifies the integrity of vestibular function through a muscular response evoked by an acoustic stimulation which activates the saccular macula. Normal standards in adults have been established, however, there are few published data on the normal responses in children.ObjectiveTo establish normal standards for vestibular myogenic responses in children without neurotological complaints.MethodsThis study's design is a cohort with cross-sectional analysis. The sample consisted of 30 subjects, 15 females (50%) and 15 males (50%).ResultsThe age of the subjects ranged between 8 and 13 years, with a mean of 10.2 (± 1.7). P1 peak showed an average latency of 17.26 (± 1.78) ms and a mean amplitude of 49.34 (± 23.07) μV, and the N2 peak showed an average latency of 24.78 (± 2.18) ms and mean amplitude of 66.23 (± 36.18) μV. P1–N2 mean amplitude was 115.6 (± 55.7) μV. There were no statistically significant differences when comparing by gender or by laterality.ConclusionWe established normal values of cervical myogenic vestibular responses in children between 8 and 13 years without neurotological complaints.     

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.     

前庭诱发的肌源性电位临床应用

前庭诱发的肌源性电位（Vestibular evoked myogenic potentials，VEMP）可用于评价球囊功能及其对称性。本文总结VEMP在神经耳科学中的应用情况。首先建立VEMP的临床适用的检查方法，这些方法包括：刺激声的选择、刺激强度及给声方式，建立VEMP在振幅、阈值、潜伏期和耳间潜伏期的正常值。临床上常用于：梅尼埃病和迟发性膜迷路积水、前庭神经炎、听神经瘤、前半规管裂综合征和听神经病的诊断定位。VEMP的振幅变化较大．潜伏期的变化较大，而阈值较稳定。梅尼埃病和迟发性膜迷路积水、前庭神经炎、听神经瘤可以出现振幅的异常或引不出；梅尼埃病、迟发性膜迷路积水和听神经瘤可见振幅和潜伏期异常。听神经瘤还可见耳间潜伏期延长。听神经病主要表现为振幅的异常，振幅减低或引不出。VEMP是一种稳定的肌源性电位，双侧声刺激较为适宜。VEMP的阈值检查主要用于压力或声音敏感性眩晕；耳间潜伏期的异常主要见于桥一小脑角占位病变：振幅和潜伏期的异常一般没有特异性．可见于累及前庭下神经的病变。     

Age-related differences in parameters of vestibular evoked myogenic potentials

Conclusions. The statistically significant correlations between vestibular evoked myogenic potential (VEMP) parameters and age may be due to hair cell loss of the otolith organ and/or to degenerative changes of the vestibular neural pathway. These findings indicate that age should be taken into account when interpreting VEMP results. It is also important to determine a standard method for performing VEMP and a universal index for comparison among laboratories. Objectives. VEMP, which measures the surface electric potential from the cervical muscle evoked by sufficiently loud sounds, is a useful tool to evaluate vestibule-colic reflex function. We have assayed the effect of age on VEMP results. Subjects and methods. After excluding subjects with a previous history of dizziness, middle ear pathology, or other inner ear symptoms, a total of 97 healthy volunteers (194ears) were included. All VEMP parameters were analyzed to find differences related to side and gender, as well as the relationship between age and each VEMP parameter. Results. Age was correlated with all VEMP parameters. Latency of p13, n23 showed a negative correlation and amplitude of p13-n23 showed a positive correlation with age. Differences between the right and left sides were not significant.     

Side-difference of vestibular evoked myogenic potentials in healthy subjects

The aim of this study was to investigate the side-difference of vestibular evoked myogenic potentials (VEMPs) in relation to the provocation rates, latencies and amplitudes using binaural acoustic stimulation with bilateral recording. Fourteen healthy volunteers underwent a serial VEMP testings elicited binaurally by a sequence of alternating stimulus intensities, that is, 95-95 (right-left), 85-95, 95-85, and 85-85 dBHL tone burst, respectively. The provocation rates as well as the mean latencies of p13 and n23 for the VEMPs demonstrated no significant side-difference despite using 95-95, 85-95, 95-85 and 85-85 dBHL binaural acoustic stimulation. In contrast, nine (64%) of the 14 subjects showed side-difference of absolute p13-n23 amplitude, including right side dominant in five subjects, and left side dominant in four subjects. However, there was no significant side-difference in terms of relative amplitude despite using 95-95, 85-95, 95-85 and 85-85 dBHL binaural acoustic stimulation. Furthermore, the relative amplitude or interaural amplitude difference (IAD) ratios between those with and without side-difference of p13-n23 amplitude did not differ significantly. Hence, this study provides a potentially important method for adjusting the side difference of p13-n23 amplitudes by using a relative amplitude or IAD ratio adjustment. It also adds confidence to the successful use of binaural stimulation and recording of VEMPs under conditions of bilateral SCM muscular contractions.     

Changes in vestibular evoked myogenic potentials after Meniere attacks

OBJECTIVES: The aim of this study was to apply videonystagmography (VNG) and vestibular evoked myogenic potential (VEMP) tests to patients with Meniere attacks, to explore the mechanics of where saccular disorders may affect the semicircular canals. METHODS: From January 2001 to December 2003, 12 consecutive patients with unilateral definite Meniere's disease with vertiginous attacks underwent VNG for recording spontaneous nystagmus, as well as VEMP tests. RESULTS: At the very beginning of the Meniere attack, the spontaneous nystagmus beat toward the lesion side in 5 patients (42%) and toward the healthy side in 7 patients (58%). Twenty-four hours later, only 6 patients (50%) showed spontaneous nystagmus beating toward the healthy side. Nevertheless, spontaneous nystagmus subsided in all patients within 48 hours. The VEMP test was performed within 24 hours of a Meniere attack; the VEMPs were normal in 4 patients and abnormal in 8 patients (67%). After 48 hours, 4 patients with initially abnormal VEMPs had resolution and return to normal VEMPs, and the other 4 patients still had absent VEMPs. CONCLUSIONS: Most patients (67%) with Meniere attacks revealed abnormal VEMPs, indicating that the saccule participates in a Meniere attack. This is an important idea that stimulates consideration of the mechanism of Meniere attacks.     

Development of vestibular evoked myogenic potentials in preterm neonates

Our recent study successfully recorded vestibular evoked myogenic potential (VEMP) responses in full-term newborns. However, when VEMP responses are elicited in preterm neonates remains unclear. This study employed the VEMP test in 27 low-risk preterm and 25 healthy full-term neonates without sedation to investigate the development of VEMP response after birth. Fourteen (26%) of 54 ears in preterm neonates exhibited VEMP responses, a response rate significantly lower than that of full-term neonates (72%). The mean latencies of peaks p13 and n23 in the preterm group were significantly longer than those in the full-term group. Analysis of variable parameters for present VEMPs in pre- and full-term neonates revealed that the cutoff values of body weight were 2.26 and 2.82 kg, and that those of postmenstrual age were 37.1 and 38.4 weeks, respectively. Both body weight and postmenstrual age were significantly negatively correlated with p13 and n23 latencies but not with p13-n23 amplitude. In conclusion, present VEMPs can be anticipated when the body weight of pre- and full-term neonates reaches >2.26 and 2.82 kg, respectively. It indicates that the sacculocollic reflex develops in the same manner, but the difference in response rate between full- and pre-term neonates may, at least in part, correlate with muscle bulk and strength, relative to the body weight adequate for the VEMP response.     

Reliability of the vestibular evoked myogenic potential test in assessing intratympanic gentamicin therapy in Meniere's disease

CONCLUSIONS: The results of this preliminary study demonstrate that with regard to determining the efficacy of intratympanic (IT) gentamicin treatment in patients with Meniere's disease, the reliability of testing for vestibular evoked myogenic potentials (VEMPs) is comparable to that of caloric tests. Compared with caloric tests, VEMP measurements are more comfortable and take less time. The results of VEMP and caloric testing do not correlate with the results of hearing tests. OBJECTIVE: To test the reliability of VEMP testing to monitor the results of IT gentamicin therapy in patients with Meniere's disease. SUBJECTS AND METHODS: Twelve patients with unilateral Meniere's disease were evaluated with pure tone audiometry (PTA), bithermal caloric tests, and VEMP tests. Patients with measurable caloric and VEMP results before IT gentamicin treatment were included in the study. IT gentamicin (0.5 ml) at a concentration of 40 mg/ml was administered to the patients. Reinjection was performed 10 days later depending on patients' complaints. Patients were re-evaluated with short- and long-term VEMP, hearing, and caloric test results. RESULTS: Caloric responses and VEMPs changed following gentamicin therapy in 9 patients and 12 patients, respectively. Long-term results of caloric and VEMP tests in patients receiving IT gentamicin treatment changed in 7 patients and 10 patients, respectively.     

The results of vestibular evoked myogenic potentials, with consideration of age-related changes, in vestibular neuritis, benign paroxysmal positional vertigo, and Meniere's disease

CONCLUSION: We interpreted VEMP findings in patients with the three major peripheral vertigo diseases, taking age-related changes into consideration. We found different abnormal VEMP rates among the three diseases, as well as differences in the proportion of parameters that were abnormal, according to the type of disease. OBJECTIVES: Vestibular neuritis, benign paroxysmal positional vertigo (BPPV), and Meniere's disease, common diseases that cause peripheral vertigo, often affect the saccule or inferior vestibular nerve, which are pathways of vestibular evoked myogenic potential (VEMP). Also, aging could have a primary effect on diminished VEMP responses. Our study investigated VEMP the findings in patients with the diseases in relation to their age. PATIENTS AND METHODS: A total of 134 patients with vestibular neuritis, 62 with BPPV, and 29 with Meniere's disease were enrolled in this study. The VEMP findings in patients within the three disease groups were interpreted using our own normative ranges according to age. RESULTS: Abnormal VEMP rates in the vestibular neuritis, BPPV, and Meniere's disease groups were 36.6%, 25.8%, and 69%, respectively. The proportion of prolonged p13 latency in BPPV patients with abnormal VEMP responses was relatively high compared with the other two diseases. VEMP asymmetry in the patients with Meniere's disease was relatively high.