Vestibular-evoked myogenic potentials in three patients with large vestibular aqueduct

An enlarged vestibular aqueduct (LVA) is a common congenital inner ear anomaly responsible for some unusual vestibular and audiological symptoms. Most of the cases show bilateral early onset and progressive hearing loss in children. The gross appearance on CT scan of the inner ear is generally normal. However, precise measurements of the inner ear components reveal abnormal dimensions, which may account for the accompanying auditory and vestibular dysfunction. Despite extensive studies on hearing and the vestibular apparatus, saccular function is not studied. To our knowledge this is the first report of saccular malfunction in three patients with LVA by means of vestibular evoked myogenic potentials. Conventional audiograms revealed bilateral severe sensorineural hearing loss in two patients and mixed type hearing loss in one patient. Two of the patients complained about vertigo and dizziness but vestibular assessments of the patients showed normal results. The diagnosis had been made by high-resolution CT scans and MR images of the skull that showed LVA in the absence of other anomalies. The VEMP threshold measured from the ear with LVA in two patients with unilateral enlargement of the vestibular aqueduct was 75–80 dB nHL whereas the threshold from normal ears was 95 dB nHL. The third patient with mixed type hearing loss and bilateral LVA had VEMP responses despite a big air–bone gap in the low frequency range. The VEMP in this patient was greater in amplitude and lower in threshold in the operated ear (the patient had a tympanoplasty which did not improve her hearing). These findings and results of other patients with Tullio phenomenon and superior semicircular canal dehiscence, who also showed lower VEMP threshold, confirmed the theory of a ‘third window’ that allows volume and pressure displacements, and thus larger deflection of the vestibular sensors, which would cause the vestibular organ to be more responsive to sound and pressure changes.     

Vestibular evoked myogenic potential in vestibular neuritis

This study wants to show the diagnostic value of vestibular evoked myogenic potential (VEMP) in the diagnosis of vestibular neuritis (VN), independently of the caloric test results. Twenty patients were enrolled with acute vertigo caused by VN. VEMP was tested with the binaural simultaneous stimulation method. Surface electromyographic activity was recorded in the supine patients from symmetrical sites over the upper half of each sternocleidomastoid muscle, with a reference electrode on the lateral end of the upper sternum. During the acute attack, 8 days, 1 month and 3 months after the beginning of the acute attack, all the patients underwent the following examinations: Dix–Hallpike manoeuvre, Pagnini–McClure manoeuvre, head shaking test, pure-tone audiometry, tympanometry, caloric labyrinth stimulation according to the Fitzgerald–Hallpike method and VEMP. At the last visit, the 11 patients diagnosed with superior branch vestibular neuritis did not show any improvement at the caloric labyrinth stimulation and presented VEMP on both sides with normal amplitude and latency; in the 9 cases diagnosed with inferior branch vestibular neuritis, there was an improvement of the VEMP reflex and normal caloric test. Our experience highlights that VEMP recording is applicable for patients with VN as a screening test.     

Vestibular neuritis: three-dimensional videonystagmography and vestibular evoked myogenic potential results

Eight patients diagnosed with vestibular neuritis received the newly developed three-dimensional videonystagmography (3D VNG) and vestibular evoked myogenic potential (VEMP) examination in order to localize the lesion site. Two (25%) of the 8 patients exhibited spontaneous nystagmus with 3 components, indicating that both the horizontal semicircular canal (HSCC) and anterior semicircular canal (ASCC) were affected. The remaining 6 patients (75%) displayed only horizontal nystagmus, meaning that only the HSCC was involved. Seven (88%) of the 8 patients had bilateral normal VEMPs, revealing sparing of the posterior semicircular canal (PSCC). In a comparative study, another seven patients with vestibular neuritis 1 year post-treatment also received the caloric test, 3D VNG and VEMP examination. Only one patient exhibited spontaneous nystagmus. An absent caloric response of the lesioned side persisted in 5 (71%) of the 7 patients. However, all patients showed normal VEMPs bilaterally. 3D VNG and VEMP examination indicates that vestibular neuritis mainly affects the superior division of the vestibular nerve, which innervates the HSCC and ASCC. Meanwhile, the function of the PSCC and saccule, innervated by the inferior vestibular nerve, is preserved.     

Vestibular evoked myogenic potential in unilateral vestibular hypofunction

Conclusions. The data collected in this study indicated that first Neural Response Imaging (NRI) thresholds had a better correlation with HiResolution? most comfortable loudness (M) levels than tNRI thresholds. Electrically evoked auditory reflex thresholds (EARTs) had a higher correlation with HiResolution M levels than tNRI thresholds and a lower correlation than first NRI thresholds. NRI is a very useful method for programming the cochlear implants of young children who cannot demonstrate a reliable judgment of loudness. Objective. To investigate how HiResolution sound processing, designed to deliver high-rate stimuli, relates to EARTs and electrically evoked compound action potential measurements produced by low-rate stimuli. Material and methods. Nine profoundly hearing-impaired children and adults aged 6–29 years participated in the study. NRI responses were elicited using pulse trains consisting of biphasic pulses at a pulse width per phase of 32 µs delivered at a frequency of 30 Hz using SoundWave programming software. Stimuli were delivered to the odd electrodes (1, 3, 5, 7, 9, 11, 13 and 15) along the array. tNRI (NRI threshold) and first NRI thresholds were recorded for each stimulating electrode. “Speech bursts” stimuli used in EARTs recording were delivered to four electrodes at a time and stapedial reflexes were recorded from the impedance bridge. The M levels used were those used by each patient in their everyday HiResolution programs. Results. For 8 patients (53 stimulating electrodes) the correlation between tNRI threshold and M level was r?=?0.675 (p?=?0.000) and that between first NRI thresholds and M level was r=0.741 (p?=?0.000). On average the M-level value was 20 CU (Current Unit) lower than the first NRI threshold value and 12 CU higher than the tNRI threshold value. The M-level patterns across the electrode array overall were similar to the tNRI or first NRI threshold patterns. For 7 patients (112 stimulating electrodes) the correlation between EART and M levels was r=0.710 (p?=?0.000). On average the EART value was 14 CU higher than the M-level value.     

前庭诱发肌源性电位对于耳硬化患者的骨导声反应

目的：使用前庭诱发肌源性电位对骨导声反应（BC-VEMP）阐明耳硬化症患者平衡问题的起源。方法：受试者包括25例非进展性的耳硬化症患者（9例男性,16例女性）,依据平衡问题的类型被分为两组。对两个组的耳蜗前庭功能的结果包括纯音测听、温度试验和BC-VEMP测试进行对比。结果：10例患者曾抱怨头晕和（或）眩晕（失调组）,其他15例患者没有这种症状（非失调组）。失调组中9例患者在BC-VEMP测试中结果异常,而非失调组中1例患者结果异常（P〈0．01）。结论：耳硬化症患者平衡问题的一个主要原因是球囊功能障碍。BC-VEMP的测试对于这些患者的诊断是有用的。     

Vestibular evoked myogenic potential (VEMP) in patients with acoustic neuromas

Objective: To study the utility of VEMP (vestibular-evoked myogenic potential) in the diagnosis of acoustic neuromas.Methods: Eighteen patients with unilateral acoustic neuromas were subjected to this study. Myogenic potential responding to loud click stimuli was recorded at ipsilateral sternocleidomastoid muscle. A normal range of VEMP was obtained from 20 controls. VEMP responses were compared with both, clinical symptoms and results of caloric tests.Result: Thirteen out of 18 patients showed decreased responses of VEMP at the affected side. VEMP responses seemed to have little relation with dysequilibrium, spontaneous nystagmus, canal paresis and pure-tone hearing.Conclusion: VEMP is useful for detecting dysfunction of inferior vestibular nerve in patients with acoustic neuromas.     

前庭诱发肌源性电位对前庭下神经炎的诊断价值

目的　探讨前庭诱发肌源性电位（VEMP）对前庭下神经炎的诊断价值。方法　回顾分析我科眩晕门诊18例前庭下神经炎的临床资料,尤其是VEMP检测结果。结果　18例患者中,15例表现为旋转性眩晕,3例为平衡障碍,所有患者纯音测听、冷热试验及眼性前庭诱发肌源性电位（oVEMP）正常而颈性前庭诱发肌源性电位（cVEMP）异常。其中14例cVEMP检查不能引出,4例振幅低下。3个月后复诊10例患者症状消失,复查cVEMP 9例恢复正常,1例振幅低下;半年复诊18例患者症状全部消失,复查cVEMP只有2例振幅低下,其余均恢复正常。结论　VEMP检查对前庭下神经炎的精准诊断及判断预后有重要临床价值,值得临床推广。     

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.     

Vestibular evoked myogenic potentials in response to skull taps for patients with vestibular neuritis

In recent years it has been demonstrated that loud clicks generate short latency vestibular evoked myogenic potentials (VEMP). It has also been demonstrated that skull tap stimulation evokes similar VEMP. In the present study, the differences between the click-induced and the skull-tap induced VEMP were studied in 18 patients at onset of vestibular neuritis. Gentle skull taps were delivered manually above each ear on the side of the skull and on the forehead midline. The muscular responses were recorded over both sternocleidomastoid muscles using skin electrodes. Abnormal skull tap VEMP were found in the majority of the patients (10/18, 56%). However, only 4/18 (22%) showed asymmetry in the click-induced VEMP. The high percentage of abnormal skull tap VEMP might suggest that this response is not only dependent on the inferior division of the vestibular nerve, because the inferior division of this nerve is usually spared in vestibular neuritis. Moreover, the patients with abnormal skull tap VEMP differed from those with normal VEMP in their settings of the subjective visual horizontal with static head tilt in the roll plane. This might suggest that skull tap VEMP are (also) related to utricular function.     

Preserved vestibular evoked myogenic potentials (VEMP) in some patients with walking-induced oscillopsia due to bilateral vestibulopathy

Bilateral vestibulopathy, i.e. decreased peripheral vestibular function affecting both ears, is characterized by unsteadiness of gait, particularly in darkness and by motion-induced oscillopsia. We have recently seen a few patients with severely impaired semicircular canal function albeit with rather normal vestibular evoked myogenic potentials (VEMP) suggesting normal saccular function. The five young patients, mean age 27 years (range 15-45), 4 males and 1 female, had severely impaired balance in darkness and they all reported walking-induced vertical oscillopsia. Hence, these patients with incomplete vestibular lesions had symptoms that were indistinguishable from the typical patient with bilateral vestibulopathy. Further, the findings in these patients suggest that saccular function probably contributes little to prevent walking-induced vertical oscillopsia.     

Vestibular evoked myogenic potential (VEMP) with galvanic stimulation in normal subjects

IntroductionThe vestibular evoked myogenic potential (VEMP) generated by galvanic vestibular stimulation (GVS) is related to the vestibulo-spinal pathway. The response recorded from soleus muscle is biphasic with onset of short latency (SL) component around 60 ms and medium latency (ML) component around 100 ms. The first component reflects otolith function (sacule and utricle) and the last deals with semicircular canals.AimTo describe VEMP generated by GVS.MethodsIn this cross-sectional clinical study, VEMP was generated by 2 mA/400 ms binaural GVS, frequency of 5–6 ms that was recorded from soleus muscles of 13 healthy adults, mean age 56 years. The subjects remained standing, head turned contralateral to the GVS applied to the mastoid. Thirty GVS were applied to the mastoid in the position cathode right anode left, followed by 30 in inverted position. SL and ML were measured.ResultsSL and ML components were recorded from both legs of all participants and were similar. The average of SL component was 54 ms and of ML was 112 ms.ConclusionThe components SL and ML of the VEMP response in soleus were reproducible and are useful measures of vestibular-spinal function.© 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.     

Relation of video-head-impulse test and caloric irrigation: a study on the recovery in unilateral vestibular neuritis

The head-impulse test (HIT) is an important test for examining unilateral vestibular hypofunction. The new video-head-impulse test (vHIT) is more sensitive and specific than the clinical bedside-head-impulse test. Alternatively, one can test for vestibular hypofunction with the caloric irrigation test. Various studies have shown that both tests may not always identify vestibular hypofunction; instead, the results of the tests might be contradictory. To further explore the question, of whether vHIT and caloric irrigation test the same part of the angular horizontal vestibulo-ocular reflex (VOR), we examined patients with unilateral vestibular neuritis at different points in time. The tonic vestibular imbalance (e.g., subjective-visual-vertical, ocular torsion and spontaneous nystagmus) and dynamic dysfunction of VOR (vHIT and bithermal caloric irrigation) were measured and quantified. While parameters of the tonic vestibular imbalance were well described by single exponential decay functions, dynamic parameters were less well defined. Therefore, to better compare the time course of pairs of two different parameters, we used a linear regression analysis. No linear correlation was found in the group and individually for the gain asymmetry and the ipsilesional gain of the vHIT with the unilateral weakness of the bithermal caloric irrigation tests. Linear correlation was found for most parameters of tonic vestibular imbalance. These findings are further evidence that vHIT and caloric irrigation test different parts of the angular VOR.     

Vestibular-evoked myogenic potentials in patients with dehiscence of the superior semicircular canal

Recently Minor and co-workers described patients with sound- and pressure-induced vertigo due to dehiscence of bone overlying the superior semicircular canal. Identifying patients with this "new" vestibular entity is important, not only because the symptoms can be very incapacitating, but also because they are surgically treatable. We present symptoms and findings for three such patients. On exposure to sounds, especially in the frequency range 0.5-1 kHz, they showed vertical/torsional eye movements analogous to a stimulation of the superior semicircular canal. They also showed abnormally large sound-induced vestibular-evoked myogenic potentials (VEMP), i.e. the short latency sternomastoid muscle response considered to be of saccular origin. The VEMP also had a low threshold, especially in the frequency range 0.5-1 kHz. However, in response to saccular stimulation by skull taps, i.e. when the middle ear route was bypassed, the VEMP were not enlarged. This suggests that the relation between the sound-induced and the skull tap-induced responses can differentiate a large but normal VEMP from an abnormally large response due to dehiscence of bone overlying the labyrinth, because only the latter would produce large sound-induced VEMP compared to those induced by skull taps.     

The extent of vestibular impairment is important in recovery of canal paresis of patients with vestibular neuritis

Objectives

We questioned whether the extent of vestibular impairment affected the recovery of vestibular function in acute vestibular neuritis (VN). The objective of this study was to identify how the extent of vestibular impairment influenced the recovery from canal paresis (CP) in patients with VN.

Clinical usefulness of the rotatory,caloric, and vestibular evoked myogenic potential test in unilateral peripheral vestibular pathologies

Abstract

Objective: The aim of this study was to investigate the diagnostic capacity of three different rotatory tests, and to investigate the clinical effectiveness of the caloric, rotatory, and vestibular evoked myogenic potential (VEMP) test. Design and study sample: Several rotatory tests—sinusoidal harmonic acceleration test (SHAT), pseudorandom rotation test (PRRT), velocity step test (VST)—and a caloric and a VEMP test, were given to 77 patients (mean age 52 years) with a unilateral peripheral vestibular pathology, and 80 control subjects (mean age 48 years). Results: For the rotatory test, the highest diagnostic capacity was obtained with the 0.01 Hz SHAT frequency, followed by 0.1 and 0.05 Hz. A higher diagnostic accuracy was reached for the caloric and VEMP test. The caloric test demonstrated high sensitivity and specificity values, but the 0.01 Hz SHAT rotation appeared more sensitive, and the VEMP more specific, than the caloric test. Conclusion: A selection of the 0.01, 0.05, and 0.1 Hz SHAT rotations is suggested as the most ideal rotatory test protocol, and a combination of rotatory, caloric, and VEMP testing will result in a more complete examination of our vestibular system.

Sumario

Objetivos: El objetivo de este estudio fue investigar la capacidad diagnóstica de tres diferentes pruebas rotatorias e investigar la efectividad clínica de las pruebas calóricas, rotatorias y de potenciales evocados vestibulares biogénicos (VEMP). Diseñ: Se aplicaron algunas pruebas rotatorias (prueba de aceleración sinusoidal armónica (SHAT), prueba de rotación pseudo-aleatoria (PRRT), prueba de velocidad de pasos (VST), prueba calórica y VEMP, a setenta y siete pacientes (edad promedio de 52 añs) con patología vestibular periférica unilateral y a 80 sujetos de un grupo control (edad media de 48 añs). Resultados: Para la prueba rotatoria, la más alta capacidad diagnóstica se obtuvo con la frecuencia SHAT 0.01, seguida por 0.1 y 0.05 Hz. La máxima precisión diagnóstica se alcanzó con las pruebas calórica y VEMP. La prueba calórica demostró altos valores de sensibilidad y especificidad, pero la de rotación SHAT en 0.01 pareció más sensitiva y el VEMP, más específico que la prueba calórica. Conclusiones: Se sugiere una selección de rotaciones SHAT de 0.01, 0.05 y 0.1 como protocolo ideal de pruebas rotatorias y una combinación de las pruebas rotatorias, calóricas y de VEMP, para lograr un examen más completo del sistema vestibular.     

Clinical experience with the vestibular evoked myogenic potential

The vestibular evoked myogenic potential (VEMP) is a promising test of the descending vestibulocollic system. Our aim was to determine whether the VEMP can be applied to an older patient population and can detect lesions in descending vestibulospinal pathways. We also compared VEMP clinical performance with that of the standard caloric test. VEMP test performance was retrospectively analyzed in relation to clinical diagnosis and other vestibular test performance in 62 patients (age, 30-85 years) referred for vestibular testing to Mayo Clinic, Jacksonville, Florida. The VEMP was evoked using a 250 Hz tone burst. Results suggest age-related changes in VEMP amplitude and latency in this patient population. VEMP tests were sensitive to lesions not detected by electronystagmography. VEMP and caloric sensitivity and specificity were essentially equal (d' = 1). Combining both tests improved sensitivity. However, VEMP false-positive rates hampered specificity. VEMP testing may be refined to improve false-positive rates and clinical utility.     

Vestibular evoked myogenic potential (VEMP) results in migraine and migrainous vertigo

Abstract

Background: The pathophysiology of vertigo is not fully known; thus, it is difficult to diagnose vestibular migraine (VM) in some migraine patients with vertigo symptoms.

Aims/objectives: We aimed to evaluate the diagnostic value of cervical vestibular evoked myogenic potential (cVEMP) in patients with VM.

Materials and Methods: Thirty-two patients diagnosed with migraine and 31 patients with VM were prospectively included in this study. The cVEMP responses were obtained, and P1-N1 latency, interpeak amplitude, amplitude asymmetry ratio were calculated. The patients' demographics, results of physical and audiometric examinations, and VEMP records as well as absence of responses were evaluated and compared between groups.

Results: The incidence of ears with absence VEMP responses was found to be numerically higher in the migraine group than in the VM group (p?=?.106). Additionally, there were no statistically significant differences detected between the groups in terms of the p13 or n23 latency, interpeak amplitude, and amplitude asymmetry ratio measured in both right and left ears (p?>?.05).

Conclusions: The increased rate of absent VEMPs was associated with the hypoperfusion of the sacculo-collic reflex pathway in migraine patients. In addition, it was concluded that VEMP reflex responses appear to be insufficient to differentiate between VM and migraine diagnoses.