前庭诱发肌源性电位检查的点评

借由气导声刺激或骨导振动刺激可成功诱发前庭诱发肌源性电位(vestibular-evoked myogenic potential, VEMP)。从颈部胸锁乳突肌表面记录得到的VEMP称为颈肌前庭诱发肌源性电位(cVEMP),从眼外肌表面记录得到的VEMP称为眼肌前庭诱发肌源性电位(oVEMP)。这两项新兴的耳神经科学功能检查开启了科学家探索耳石器官(球囊与椭圆囊)的纪元,分别用来检测“球囊-颈肌反射”和“椭圆囊-眼肌反射”神经通路。内耳功能检查序列,包括听力检查、cVEMP检查、oVEMP检查、温度试验检查等,可以对内耳终末器官诸如耳蜗、球囊、椭圆囊及半规管的功能进行全面检测,目前已经广泛应用于动物及人体。这一系列内耳功能检测项目将有助于描绘内耳终末器官受侵犯的范围、厘清过去医学上的盲点,进一步阐明内耳及中枢前庭系病变的机制。     

Acute hearing loss in patients with hematological disorders

Objective: This study adopted an inner ear test battery to investigate the causes of acute sensorineural hearing loss in patients with hematological disorders. Methods: During the past 20 years, the authors have experienced 14 patients with hematological disorders, i.e. leukemia or aplastic anemia, having acute sensorineural hearing loss. An inner ear test battery comprising audiometry and cervical vestibular-evoked myogenic potential (cVEMP), ocular VEMP (oVEMP), and caloric tests was performed. Results: Diagnoses comprised of sudden sensorineural hearing loss in 12 patients and endolymphatic hydrops in four patients (two patients had one ear with sudden sensorineural hearing loss while the other ear had endolymphatic hydrops). Percentages of recruitment phenomenon showed a significant difference between endolymphatic hydrops and sudden sensorineural hearing loss. Abnormal percentages for mean hearing level (86%), cVEMP test (71%), oVEMP test (25%), and caloric test (14%) exhibited a significant sequential decline in these patients. Conclusion: Acute sensorineural hearing loss in a patient with leukemia or aplastic anemia may be related to either sudden sensorineural hearing loss or endolymphatic hydrops. A significant sequential decline in the function of the cochlea, saccule, utricle, and semicircular canals indicates that the pars inferior is more vulnerable to blood insult than the pars superior.     

Sequence of vestibular deficits in patients with noise-induced hearing loss

This study utilized audiometry, and cervical vestibular-evoked myogenic potential (cVEMP), ocular VEMP (oVEMP) and caloric tests to investigate the sequence of vestibular deficits in patients with noise-induced hearing loss (NIHL). Thirty patients with NIHL underwent an inner ear test battery. Another 30 normal controls with age- and sex-matched were included for comparison. The abnormal percentages of the audiometry, and cVEMP, oVEMP and caloric tests were 100, 70, 57 and 33 % in NIHL patients, which showed significant differences from 13, 13, 7 and 3 % in normal controls, respectively. A significantly decreasing trend among the four tests, with the sequence of damage from the cochlea, followed by the saccule, utricle, and semicircular canals was noted in NIHL patients, but not in normal controls. In conclusion, the decreasing order of abnormal percentages in the function of the cochlea, saccule, utricle and semicircular canals after chronic noise exposure further supports that the pars inferior (cochlea and saccule) is more vulnerable to noise exposure than the pars superior (utricle and semicircular canals).     

Inner ear deficits after chronic otitis media

Investigation of the causes of vestibular symptoms in patients with chronic otitis media (COM) faces frustration, mainly because the bithermal caloric test using tap water is generally contraindicated in perforated ears. This study utilized audiometry, ocular vestibular-evoked myogenic potential (oVEMP) test, and cervical VEMP (cVEMP) test to evaluate inner ear deficits after COM. A total of 85 COM patients (117 ears) underwent otoscopy, image study, audiometry, oVEMP test, and cVEMP test. Mean bone-conducted (BC) hearing threshold ≤25 dB was observed in 74 ears, 26–40 dB in 30 ears, and >40 dB in 13 ears. Restated, abnormal BC hearing threshold was identified in 43 ears (37 %). Percentages of abnormal cVEMP test, oVEMP test, and BC hearing threshold in 117 COM ears were 65, 62, and 37 %, respectively, exhibiting a significantly declining sequence in inner ear function. Furthermore, cVEMP/oVEMP test results were significantly correlated with BC hearing threshold, whereas no correlation existed between the cVEMP and oVEMP test results. In conclusion, the sequence of inner ear deficits after COM runs from the saccule/utricle to the cochlea and semicircular canals. Restated, in addition to BC hearing test, the cVEMP/oVEMP test may serve as a supplementary tool for early detection of inner ear involvement in COM patients.     

Evolution of Meniere’s Disease from MD 1.0, via MD 1.5, to MD 2.0

Abstract

Background: Elder Meniere’s disease (MD) patients ultimately lose their vestibular function.

Objective: This study utilized an inner ear test battery to investigate evolution of MD.

Methods: Total 278 elder MD patients aged >65 years were divided into three groups. Ninety-four patients with bilateral MD (188 ears) were assigned to Group A. The remaining 184 patients with unilateral MD were further divided into two groups. Group B consisted of 20 affected ears with normal vestibular function on the opposite ears, while Group C indicated 184 unaffected ears. All patients underwent an inner ear test battery.

Results: Inner ear deficits in Group B declined from the cochlea via the saccule, utricle to semicircular canals. In contrast, Groups A and C did not significantly differ in the abnormality rates of cervical vestibular-evoked myogenic potential (cVEMP), ocular VEMP and caloric tests, indicating that Group C (unaffected ears) may partly share the same mechanism like Group A (affected ears), namely aging and hydropic effects.

Conclusion and significance: Evolution of MD may progress from unilateral MD (MD 1.0), via unilateral MD coupled with asymptomatic hydrops on opposite ear (MD 1.5), toward bilateral MD (MD 2.0), where the number 1.0-2.0 means the number of clinically affected ears.     

Superior canal dehiscence reveals concomitant unilateral utricular loss (UUL)

Conclusion: We report enhanced symmetrical cervical vestibular evoked myogenic potential (cVEMP) but asymmetrical ocular VEMP (oVEMP) responses in a patient with CT-verified bilateral superior semicircular canal dehiscence (SCD) but with acute vestibular syndrome. This implies that absence of unilateral utricular macula function alone is sufficient to cause symptoms of acute vertigo. Acute vertigo should not automatically be presumed to originate from semicircular canal dysfunction. Objectives: To identify the cause of an acute vertigo attack in a patient with bilateral SCD. Methods: The functional state of all peripheral vestibular sense organs was tested using the video head impulse test (vHIT) for all semicircular canals and VEMPs to air-conducted sound (ACS) or bone-conducted vibration (BCV) to test all otolith organs. The cVEMP tested mainly saccular function and the oVEMP mainly utricular function. Results: All semicircular canals showed normal function. The cVEMPs showed enhanced, but symmetrical saccular function. In contrast, oVEMPs showed an enhanced but asymmetric n10 component – it was greatly reduced beneath the left eye, implying decreased function in the right utricular macula. That result was confirmed using very high frequency stimuli which are effective in SCD: 4000 Hz BCV stimuli showed that oVEMP n10 was present beneath the right eye but absent beneath the left eye.     

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.     

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。     

Comparison of cervical vestibular evoked potentials evoked by air-conducted sound and bone-conducted vibration in vestibular Schwannoma patients

Abstract

Objective: The vestibular evoked myogenic potential (VEMP) is associated with otolithic afferents and can be used to evaluate the function of the saccule and utricle. In this study, we compared cervical VEMP evoked by stimulation with Air-conducted sound (ACS) and bone-conducted vibration (BCV) to the forehead and investigated whether BCV can be used as a substitute for ACS.

Methods: Data were obtained from 33 patients with vestibular schwannoma. Vestibular examinations were performed preoperatively. VEMP was obtained upon stimulation with ACS (ACS cVEMP) and BCV to the forehead using a minishaker (BCV cVEMP). Vestibular function was also analyzed using the caloric test and ocular VEMP (oVEMP) testing. oVEMP was measured using bone-conductive vibration to the forehead. The results of BCV cVEMP, ACS cVEMP, and oVEMP were compared by the caloric test.

Results: Rates of patients with abnormal ACS cVEMP, BCV cVEMP, oVEMP, and caloric test results were 78.8%, 75.8%, 78.8%, and 69.7%, respectively. BCV cVEMP did not correlate with ACS cVEMP, but correlated with oVEMP and caloric test results.

Conclusion: BCV cVEMP did not correlate with ACS cVEMP. Therefore, BCV cVEMP cannot be used as a substitute for ACS cVEMP.     

同步检测眼性和颈性前庭诱发肌源性电位的可行性研究

目的 探讨同步检测眼性前庭诱发肌源性电位(ocular vestibular-evoked myogenic potential,oVEMP)和颈性前庭诱发肌源性电位(cervical vestibular-evoked myogenic potential,cVEMP)的可行性.方法 对20例正常人及23例梅尼埃病患者分别进行oVEMP和cVEMP同步检测和单独检测,两种检测方式所用仪器和坐姿相同,检测参数设置相同,分别比较两种检测方式下两组对象oVEMP和cVEMP的振幅、潜伏期、波间期及双侧耳不对称比.结果 正常人左、右耳的oVEMP及cVEMP的引出率、振幅、潜伏期、波间期与不对称比在两种形式同步检测与各方式单独检测之间无显著差异;两种方式同步检测时梅尼埃病患者的患耳及对侧耳的oVEMP及cVEMP引出率、振幅、潜伏期、波间期及不对称比与各方式单独检测的结果也无显著差异.结论 对正常人和梅尼埃病患者,oVEMP和cVEMP检测可同步进行,但检测参数应与单独检测时设置一致.     

全聋型突发性耳聋患者的预后与前庭症状及前庭功能关系的回顾性分析

目的 探讨全聋型突发性耳聋患者的预后与前庭症状及前庭功能的关系。 方法 回顾性分析52例单侧全聋型突发性耳聋患者的前庭症状,以及眼肌前庭诱发肌源性电位(oVEMP)、颈肌前庭诱发肌源性电位(cVEMP)、视频头脉冲试验(vHIT)和冷热试验结果,观察这些患者的听力结果与前庭症状及前庭功能的关系。 结果 在52例单侧全聋型突发性耳聋患者中,有前庭症状、前庭功能异常的全聋型患者与无前庭症状者、功能正常者相比疗效差异有统计学意义。oVEMP、cVEMP、vHIT和冷热试验四项结果异常的全聋型患者显示出更低的治疗总有效率,oVEMP、cVEMP、vHIT和冷热试验正常的突发性耳聋患者有更高的听力恢复数值。 结论 有前庭症状、前庭功能异常的全聋型突发性耳聋患者疗效较差,oVEMP、cVEMP、vHIT和冷热试验正常的全聋型突发性耳聋患者有更好的听力恢复。前庭功能异常提示突发性聋患者的内耳病变范围较大、程度较重。     

梅尼埃病前庭功能分级的探讨

目的 建立一种新的梅尼埃病患者前庭功能分级方法,初步探索其临床意义及与梅尼埃病听力分期的相关性。 方法 收集112例单侧梅尼埃病患者资料,所有患者均完成包括纯音测听、cVEMP、oVEMP、vHIT以及冷热试验检查。冷热试验和vHIT的结果中任一项异常均视为半规管功能异常。cVEMP结果异常视为球囊功能异常,oVEMP结果异常视为椭圆囊功能异常。球囊、椭圆囊、半规管功能均正常的患者为前庭功能I级,球囊、椭圆囊、半规管功能其中1项异常者为前庭功能Ⅱ级,2项异常者为前庭功能Ⅲ级,3项均异常者为前庭功能Ⅳ级。 结果 根据听力分期,符合入组标准的95例梅尼埃病患者中Ⅰ期13例、Ⅱ期13例、Ⅲ期52例、Ⅳ期17例。患耳平均听阈为(51.86±21.70)dB HL。前庭功能检测结果cVEMP异常率63.2%,oVEMP24异常率74.7%,vHIT异常率33.7%,冷热试验异常率52.6%。前庭功能分级Ⅰ级9例、Ⅱ级28例、Ⅲ级39例、Ⅳ级19例。前庭功能分级与患者的听力差异有统计学意义(P<0.01, r=0.35)。前庭功能分级与患者梅尼埃病分期差异有统计学意义(P<0.01, r=0.35)。前庭功能分级与患者的病程差异有统计学意义(P=0.02, r=0.24)。前庭功能分级与患者的年龄差异无统计学意义(P=0.084)。 结论 梅尼埃病患者随着病程的进展,耳石器功能和半规管功能检测异常率会逐渐增加。通过对球囊、椭圆囊、半规管低频和高频功能的精细化检测,能够对梅尼埃病患者前庭功能进行精准评估。听力分期与前庭功能分级的同步评估能够反映患者疾病的进展状态,同时能够对患者治疗方案的选择和术后康复的预判起到参考作用。     

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.     

Bilateral Meniere’s disease assessed by an inner ear test battery

Conclusion: An inner ear test battery may suggest bilateral involvement and aid in ‘grading’ of potential disease in a patient with actively symptomatic Meniere’s disease (MD). Objectives: This study applied an inner ear test battery in patients with bilateral MD to map the inner ear deficits in each ear. Methods: From 2009 to 2012, 100 (20%) of 498 MD patients were diagnosed with bilateral involvement, which was defined as established MD in one ear, and the opposite ear had inner ear symptoms combined with documented hearing loss. Each patient underwent audiometry, and ocular vestibular-evoked myogenic potential (oVEMP), cervical VEMP (cVEMP), and caloric tests. Results: Grading of inner ear deficits was based on the number of abnormal results in the inner ear test battery. Of 100 patients with bilateral MD, 54% had the same grade and 46% had different grades in their 2 ears. On the other hand, based on four-tone average, 79% had the same Meniere stage and 21% had different stages in their two ears. The difference between ears with asymmetric grades (46%) and ears with asymmetric stages (21%) accounts for 25% of bilateral MD patients, which may be caused by the saccular hydrops in the opposite ear.     

Input–Output Functions of Vestibular Afferent Responses to Air-Conducted Clicks in Rats

Sound-evoked vestibular myogenic potentials recorded from the sternocleidomastoid muscles (the cervical vestibular-evoked myogenic potential or cVEMP) and the extraocular muscles (the ocular VEMP or oVEMP) have proven useful in clinical assessment of vestibular function. VEMPs are commonly interpreted as a test of saccular function, based on neurophysiological evidence showing activation of saccular afferents by intense acoustic click stimuli. However, recent neurophysiological studies suggest that the clicks used in clinical VEMP tests activate vestibular end organs other than the saccule. To provide the neural basis for interpreting clinical VEMP testing results, the present study examined the extent to which air-conducted clicks differentially activate the various vestibular end organs at several intensities and durations in Sprague–Dawley rats. Single unit recordings were made from 562 vestibular afferents that innervated the otoliths [inferior branch otolith (IO) and superior branch otolith (SO)], the anterior canal (AC), the horizontal canal (HC), and the posterior canal (PC). Clicks higher than 60 dB SL (re-auditory brainstem response threshold) activated both semicircular canal and otolith organ afferents. Clicks at or below 60 dB SL, however, activated only otolith organ afferents. Longer duration clicks evoked larger responses in AC, HC, and SO afferents, but not in IO afferents. Intra-axonal recording and labeling confirmed that sound sensitive vestibular afferents innervated the horizontal and anterior canal cristae as well as the saccular and utricular maculae. Interestingly, all sound sensitive afferents are calyx-bearing fibers. These results demonstrate stimulus-dependent acoustic activation of both semicircular canals and otolith organs, and suggest that sound activation of vestibular end organs other than the saccule should not be ruled out when designing and interpreting clinical VEMP tests.     

N-acetylcysteine as a single therapy for sudden deafness

Conclusion: Like NAC ameliorates hearing loss from acoustic trauma in the inner ear, NAC may also rescue hearing loss from sudden deafness confined to the inner ear.

Objective: This study assesses the effect of N-acetyl-L-cysteine (NAC) as a single therapy for sudden deafness.

Methods: Thirty-five sudden deafness patients with neither systemic disorders nor central signs in electronystagmography were treated with NAC alone and assigned to Group A. For comparison, another 35 sudden deafness patients treated by corticosteroids and plasma expander were assigned to Group B. There were no significant differences between the two groups in terms of age, sex, laterality, and pre-treatment mean hearing level. All patients underwent an inner ear test battery comprising audiometry, and ocular vestibular-evoked myogenic potential (oVEMP), cervical VEMP (cVEMP), and caloric tests.

Results: Groups A and B did not significantly differ in the pre-treatment mean hearing level, and percentages of abnormal oVEMP, cVEMP, and caloric tests, indicating that the involvement severity of sudden deafness between the two groups was similar. However, Group A (43?±?27?dB) showed significantly greater mean hearing gain than Group B (21?±?28?dB), and Group A (91%) revealed better improved rate of hearing than Group B (57%).     

前庭诱发肌源性电位预测突聋患者疗效的临床价值

目的 分析单侧突发性耳聋患者的疗效,探讨前庭功能与预后的关系。 方法 回顾性分析59例(59耳)突发性耳聋患者的临床资料,观察临床疗效,根据前庭功能结果探讨对预后的影响。 结果 59例突发性耳聋患者在治疗前共进行了183项前庭功能检查,眼性前庭诱发肌源性电位(oVEMP)和颈性前庭诱发肌源性电位(cVEMP)异常的突聋患者显示出更低的治疗总有效率;oVEMP和cVEMP正常的突聋患者受损频率听力提高更明显。冷热试验(Caloric Test)和视频头脉冲试验(vHIT)的正常与否对突聋患者的总有效率和受损听力的提高无影响。cVEMP和oVEMP都异常的患者治疗无效率比仅其中一项异常的患者高,受损听力恢复程度也比仅其中一项异常的患者差。 结论 oVEMP和cVEMP异常的突聋患者疗效较差,oVEMP和cVEMP正常的突聋患者有更好的听力恢复。oVEMP和cVEMP功能可能是预测突发性聋患者预后的有效指标。前庭功能异常提示突发性聋患者的内耳病变范围较大、程度较重。     

气导声刺激前庭诱发肌源性电位在正常儿童中的表现

目的 探讨研究正常儿童中气导声刺激诱发的眼性前庭诱发肌源性电位(oVEMP)和颈性前庭肌源性诱发电位(cVEMP)的各项参数指标,并对正常值进行统计学处理分析。 方法 选择4~10岁听力正常健康儿童52例,以500 Hz短纯音作为刺激音,分别行 oVEMP和cVEMP检测,记录左、右耳引出率及波形参数,并采用SPSS统计软件进行统计学处理分析。 结果 双耳皆未引出oVEMP 2例,单耳可引出oVEMP4例,oVEMP总体引出率为92%。双耳皆未引出cVEMP 2例,cVEMP总体引出率为96%。oVEMP与cVEMP的P1潜伏期分别为(17.07±0.89)ms、(15.55±1.58)ms;N1潜伏期分别为(12.39±0.91)ms、(23.10±2.29)ms;N1P1间期分别为(4.68±0.88)ms、(7.83±1.56)ms;oVEMP与cVEMP的振幅分别为(7.24±4.79)μV、(197.40±118.37)μV。双耳间oVEMP及cVEMP振幅不对称比分别为(19.03±12.50)%、(22.16±18.64)%。患儿左右耳的潜伏期,P1N1间期及振幅差异无统计学意义(P>0.05)。 结论 绝大部分正常儿童经气导声刺激可引出oVEMP与cVEMP。该检测患儿依从性高,可用来评估儿童前庭功能。此研究结果可为我国的儿童气导VEMP提供正常参考值范围。     

Otolith dysfunction in recurrent benign paroxysmal positional vertigo after mild traumatic brain injury

Background: The pathogenesis of recurrence of traumatic benign paroxysmal positional vertigo (BPPV) is poorly understood by far.

Objectives: To evaluate the value of secondary otolith dysfunction using vestibular evoked myogenic potential (VEMP) test in the pathogenesis of recurrence of BPPV after mild traumatic brain injury (mTBI).

Material and methods: We reviewed 42 patients with BPPV after mTBI. According to recurrence, patients were divided into two groups. Both cervical VEMP (cVEMP) and ocular VEMP (oVEMP) tests were performed on all of them.

Results: We detected abnormal cVEMP responses in four (26.7%) patients in the recurrent BPPV group after mTBI and five (18.5%) patients in the non-recurrent BPPV group after mTBI, and there was no significant difference between both groups. We detected abnormal oVMEP responses in nine (60.0%) patients in the recurrent BPPV group after mTBI and six (22.2%) patients in the non-recurrent BPPV group after mTBI, and there was a significant difference between both groups.

Conclusions and significance: Our study shows that oVEMP abnormalities in recurrent BPPV group after mTBI are significantly higher than those in non-recurrent BPPV group after mTBI. Therefore, we can conclude that secondary utricular dysfunction may be a potential pathogenesis of recurrence of traumatic BPPV.