Vestibular Evoked Myogenic Potentials Recording Research Articles

Vertigo in brainstem and cerebellar strokes

The aim of this study is to review the recent findings on the prevalence, clinical features, and diagnosis of vertigo from brainstem and cerebellar strokes. Patients with isolated vertigo are at higher risk for stroke than the general population. Strokes involving the brainstem and cerebellum may manifest as acute vestibular syndrome, and acute isolated audiovestibular loss may herald impending infarction in the territory of the anterior inferior cerebellar artery. Appropriate bedside evaluation is superior to MRI for detecting central vestibular syndromes. Recording of vestibular-evoked myogenic potentials is useful for evaluation of the central otolithic pathways in brainstem and cerebellar strokes. Accurate identification of isolated vascular vertigo is very important since misdiagnosis of acute stroke may result in significant morbidity and mortality, whereas overdiagnosis of vascular vertigo would lead to unnecessary costly work-ups and medication.

Comparison of tone burst versus logon stimulation for vestibular evoked myogenic potentials

The following study has been carried out to compare the effectiveness of logon and tone burst acoustic stimulation to elicit vestibular evoked myogenic potential (VEMP) responses. The methods and the subjects include 31 healthy adult volunteers (62 ears) who were enrolled in this study. Two different acoustic stimuli, logon (L-VEMP) and tone burst (T-VEMP), were used to elicit VEMP responses in each subject. Bilateral recordings with simultaneous binaural acoustic stimulations were used during VEMP recordings. During the recording period, the subjects were in supine position with their head elevated. The results observed were that the response rate of p1n1 wave was 91.9% for L-VEMP and 88.7% for T-VEMP. The response rate of n2p2 wave was 80.6% for L-VEMP, and 75.8% for T-VEMP. There were no significant differences between the two groups with respect to the latencies of p1, n1, n2 and p2, p1n1 and n2p2 interval, and p1n1 and n2p2 amplitude. The conclusion was that there was no difference between logon and tone burst stimulation with respect to VEMP response rates and VEMP parameters. Therefore, they are not superior to each other.

Effect of Anesthetic Drugs on Vestibular Evoked Myogenic Potential Recording

The human saccule has preserved the ancestral ability to respond to high-intensity acoustic stimulations, generating a contraction reflex of the cervical tract muscles. Recording the muscular bioelectric potentials following saccular stimulation allows the evidence of the vestibular-evoked myogenic potentials (VEMPs). The aim of this study was to record VEMPs in alert and anesthetized guinea pigs to evaluate the possible different impacts of some anesthetic drugs on VEMP recording. Sixteen guinea pigs, divided into four groups, were employed for the study. Each group underwent general anesthesia induced using different pharmacological regimens; auditory and vestibular functions were examined with Auditory Brain Response (ABR) and VEMP methods. The analysis of the results showed that the VEMPs recording performance was strictly related to the alert status of the guinea pigs: VEMPs were not recordable during anesthesia while reappeared at awakening, with the same temporal and morphological characteristics of pre-anesthesia. ABR was instead normally present during anesthesia without showing any differences with all the various anesthetic drugs employed. These results prompted us to conclude that anesthetic drugs cause the disappearance of saccular reflex in guinea pigs, not minding the specific type of drugs employed. This evidence, in agreement with the data available in literature for humans, induces and encourages future studies about sacculocollic reflex and its possible application in clinical practice.

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 evoked myogenic potentials in patients with BPPV

SummaryBackgroundThe probable cause of Benign Paroxysmal Positional Vertigo (BPPV) is a degeneration of the oto lithic organs (utricle and saccule). The aim of the study is to find possible alterations in Vestibular Evoked Myogenic Potentials (VEMP) recordings in BPPV patients, because the saccule is part of the VEMP pathway.Material/Methods27 BPPV patients (24 unilateral and 3 bilateral) aged 20 to 70 years and 30 healthy age matched controls. BPPV was diagnosed by the upbeating geotropic nystagmus found in the supine position with the head overextended towards one side. The subjects were investigated with pure tone audiometry, bi-thermal caloric test with electronystagmographic (ENG) recording, and VEMP recording.ResultsP1 latency and N1 latency did not present any statistical difference between control ears and affected ears of the BPPV population. The percentage of abnormal VEMP in the BPPV population was statistically higher than in the control ears (p<0.005). No significant relationship could be shown between the occurrence of Canal Paresis and abnormal VEMP. No relationship was found between the side (right or left ear) where BPPV appeared clinically and the side where abnormal VEMP was registered.ConclusionsBPPV is a clinical entity associated with increased occurrence of abnormal VEMP recordings, possibly due to degeneration of the saccular macula, which is part of the neural VEMP pathway.

Age-Related Changes in Vestibular Evoked Myogenic Potentials Using a Modified Blood Pressure Manometer Feedback Method

To collect age-specific vestibular evoked myogenic potential (VEMP) data and to characterize age-related differences in VEMP parameters using a modified blood pressure manometer (BPM) method of sternocleidomastoid (SCM) muscle monitoring. VEMPs were recorded on healthy adults ranging in age from 23 to 84 years with no history of dizziness, neuromuscular pathologies, or cervical complaints. Participants were assigned to 3 groups using a nonprobability static group assignment based on their age. VEMP P1 and N1 latency, threshold, peak-to-peak amplitude, and interamplitude difference (IAD) ratios were obtained at 130 dB SPL. Statistical differences were detected in peak-to-peak mean amplitude and threshold measures among groups. Post hoc analysis revealed that differences shown were between the young group and both older groups. No significant differences were noted in P1 and N1 latencies or IAD ratios. This study confirmed a significant decline in VEMP amplitude and increase in VEMP thresholds in healthy older persons. Normative age-related data may be necessary to properly interpret VEMP recordings in a clinical setting when evaluating aging populations. The BPM method utilized for controlling SCM muscle may be a valuable alternative to control SCM muscle contraction when electromyography equipment is not available.

Vestibular evoked myogenic potential in noise-induced hearing loss

Noise affects one's hearing as well as balance mechanism. The hearing mechanism of the noise-exposed individuals has been extensively studied. However, in view of the poor research focus on the sacculo-collic reflexes, especially in this study area, the present study was undertaken to examine the vestibular evoked myogenic potentials (VEMP) in subjects with noise-induced hearing loss (NIHL). A total of 30 subjects (55 ears) with NIHL participated in the present study within the age range of 30-40 years. VEMP recordings were done at 99 dBnHL using IHS instrument. The results indicated that as the average pure tone hearing threshold increased, the VEMP latencies were prolonged and peak to peak amplitude was reduced in NIHL subjects. Out of the 55 ears, VEMP was absent in 16 (29.0%) ears. The latency was prolonged and the peak to peak amplitude was reduced in 19 (34.6%) ears. VEMP results were normal in 20 (36.4%) ears. Therefore, VEMP was abnormal or absent in 67% of NIHL subjects in the present study. Hence it can be concluded that the possibility of vestibular dysfunction, specially the saccular pathway, is high in individuals with NIHL. VEMP, a non-invasive and user friendly procedure, can be employed in these individuals to assess sacculo-collic reflex.

Modeling the vestibular evoked myogenic potential

Measuring the vestibular evoked myogenic potential (VEMP) promises to become a routine method for assessing vestibular function, although the technique is not yet standardized. To overcome the problem that the VEMP amplitude depends not only on the inhibition triggered by the acoustic stimulation of the vestibular end organs in the inner ear, but also on the tone of the muscle from which the potential is recorded, the VEMP is often normalized by dividing through a measure of the electromyogram (EMG) activity. The underlying idea is that VEMP amplitude and EMG activity are proportional. But this would imply that the muscle tone is irrelevant for a successful VEMP recording, contradicting experimental evidence. Here, an analytical model is presented that allows to resolve the contradiction. The EMG is modeled as the sum of motor unit action potentials (MUAPs). A brief inhibition can be characterized by its equivalent rectangular duration (ERD), irrespective of the actual time course of the inhibition. The VEMP resembles a polarity-inverted MUAP under such circumstances. Its amplitude is proportional to both the ERD and the MUAP rate. The EMG activity, by contrast, is proportional to the square root of the MUAP rate. Thus, the normalized VEMP still depends on the muscle tone. To avoid confounding effects of the muscle tone, the standard deviation of the EMG could be considered. But the inhibition effect on the standard deviation is small so that the measuring time would have to be much longer than usual today.

Vestibular Evoked Myogenic Potentials in Normal Mice and Phex Mice With Spontaneous Endolymphatic Hydrops

Vestibular evoked myogenic potentials (VEMPs) have been recorded from the neck musculature and the cervical spinal cord in humans and a limited number of laboratory animals in response to loud sound. However, the mouse VEMP has yet to be described. Evaluation of the sacculocollic pathway via VEMPs in mice can set the stage for future evaluations of mutant mice that now play an important role in research regarding human auditory and vestibular dysfunction. Sound-evoked potentials were recorded from the neck extensor muscles and the cervical spinal cord in normal adult mice and in circling Phex(Hyp-Duk/y) mice with known vestibular abnormalities, including endolymphatic hydrops (ELH). Biphasic potentials were recorded from all normal animals. The mean threshold of the VEMP response in normal adult mice was 60 dB normal hearing level with a mean peak latency of 6.25 +/- 0.46 and 7.95 +/- 0.42 milliseconds for p1 and n1 peaks, respectively. At the maximum sound intensity used (100 dB normal hearing level), 4 of 5 Phex mice did not exhibit VEMP responses, and 1 showed an elevated threshold, but normal response, with regard to peak latency and amplitude. The histologic findings in all of these Phex mice were consistent with distended membranous labyrinth, displaced Reissner membrane, ganglion cell loss, and ELH. This is the first report of VEMP recordings in mice and the first report of abnormal VEMPs in a mouse model with ELH. The characteristics of these potentials such as higher response threshold in comparison to auditory brainstem response, myogenic nature of the response, and latency correlation with the cervical recording (accessory nerve nucleus) were similar to those of VEMPs in humans, guinea pigs, cats, and rats, suggesting that the mouse may be used as an animal model in the study of VEMPs. The simplicity and reliability of these recordings make the VEMP a uniquely informative test for assessing vestibular function, and these results suggest that they may be informative in mice with various mutations. However, further investigation is necessary.

Comparison of head rotation versus head elevation methods for vestibular evoked myogenic potentials by using logon stimulus

To compare vestibular evoked myogenic potentials (VEMP) between two different methods, head rotation (HR) with unilateral recording and head elevation (HE) with bilateral simultaneous recording. Twenty-eight healthy children (56 ears) were involved in the study. The subjects were tested in two different positions: head rotation (HR) method and head elevation (HE) method. Right- and left-side recordings were made separately in HR method and simultaneously in HE method. Logon type stimulus with 120dB Hl intensity was used to trigger VEMPs in both methods. The response rate was 80.4% for HR method and 89.3% for HE method (p>0.05). There was no significant difference between the two groups with respect to P1 latency, N1 latency, and P1-N1 interval. The mean P1-N1 amplitude of HE method was higher than HR method (p<0.05). There were very strong positive correlations between two methods regarding N1 latency and P1-N1 interval (r: 0.849 and 0.841, respectively). Bilateral simultaneous VEMP recording in head elevation position by using logon stimulus is a practical way to evaluate vestibulocollic reflex in children and it gives superior results than unilateral recording with head rotation position.

Vestibular Evoked Myogenic Potentials in Preterm Infants

The goal of this study was to determine whether there was an association between perinatal risk factors of prematurity and vestibular evoked myogenic potentials (VEMPs). A prospective case-control trial was designed. Fifty preterm newborns (100 ears) with a gestational age <37 weeks were included. The control group consisted of 20 healthy term infants (40 ears). VEMP recordings were performed, and mean latencies of p13 were calculated in all study subjects. Multivariable logistic regression was used to investigate the influence of perinatal variables on abnormal VEMP responses. VEMPs were elicited in all term infants (40 ears). In preterm infants, the responses were normal in 71 ears, delayed in 24 and absent in 5. There was a significant difference between abnormal VEMP rates for preterm and term infants (p < 0.001). Asphyxia (OR = 13.985, p = 0.048) and time of VEMP test (OR = 0.865, p = 0.038) were related to abnormal VEMP responses. There was no association between delayed VEMPs and gestational age, birth weight, hemoglobin and bilirubin levels, phototherapy, intracranial hemorrhage, convulsions, sepsis, ototoxic drugs, transfusion, mechanical ventilation, retinopathy of prematurity, bronchopulmonary dysplasia and respiratory distress syndrome. These results suggest a delay in the maturation of VEMPs in premature infants. Asphyxia was the most important risk factor for abnormal VEMP responses in preterm infants.

Vestibular evoked myogenic potentials in Behcet’s disease

The aim of this study was to investigate vestibular evoked myogenic potentials (VEMPs) and their clinical significance in Behcet's disease. Twenty-six patients with Behcet's disease and 25 healthy volunteers were evaluated for pure tone audiometry, caloric response, and VEMPs. Sensorineural hearing loss was found in 53.8% of patients with Behcet's disease, which was significantly higher than controls. Four patients had canal paresis, but no controls; this difference was not significant. Although VEMP recordings were elicited in all study subjects, mean p13 and n23 latencies were prolonged in Behcet's patients compared with controls. Seven patients had delayed VEMP responses. There were no correlations regarding p13 values and age, duration or activity of disease, vertigo, or sensorineural hearing loss. The results of this preliminary study suggest an association between delayed VEMP responses and Behcet's disease. Further research with large samples is needed to confirm that VEMP testing is useful to diagnose and follow vestibular dysfunction in Behcet's disease.

Vestibular Evoked Myogenic Potentials: Clinical Implications of a Normative Investigation

Vestibular Evoked Myogenic Potential (VEMP) assessment may assist in the diagnosis of balance disorders. Currently, however, there are limited guidelines available for clinicians to maximise its application. This study aimed to develop procedures for ensuring reliable VEMP recordings in the clinical setting and to provide comprehensive normative data. VEMP responses from 30 normal adults were collected using the Biologic Navigator. The factors of stimulus type, frequency and intensity were considered. Only stimulus type had a significant effect on VEMP recordings, with responses from click stimuli having lower thresholds, shorter latencies and higher test-retest correlations than the tone burst stimuli. However, as the maximum click intensity of the system was 90 dB nHL, the click stimulus only elicited responses from 73.3% of ears. The results of this investigation, along with a review of the existing literature, have led to the creation of a clinical protocol for VEMP testing.

Clinical application of vestibular evoked myogenic potentials in healthy newborns

Auditory and vestibular functions have critical importance in infancy because they may affect motor and mental development. We aimed to determine the normal values of the vestibular evoked myogenic potential (VEMP) parameters to provide a reference for further research regarding the early diagnosis of vestibular dysfunction in newborns. Twenty-four term newborns (12 girls, 12 boys), with birth weights greater than 2500 g and Apgar scores higher than 7 at 1 min, were studied. Tympanometry, auditory-evoked brainstem responses, transient-evoked otoacoustic emissions, and VEMP recordings were assessed in all subjects during fourth week after birth. All newborns passed the audiologic evaluation, and biphasic waveforms of the VEMP were obtained in all 48 tested ears. Mean latencies of p13, n23, and p13-n23 intervals were 13.7+/-1.1, 20.5+/-1.6, and 7.1+/-2.1 ms, respectively. The mean amplitude value was 22.6+/-18.4 microV. There were no significant differences in latency values or amplitudes with regard to sex or side of ear tested in newborns. VEMP may easily be used for early evaluation of vestibular dysfunction in newborns. Because results may differ owing to test techniques and age, every laboratory should have its own normal values.

Assessment of vestibular function of infants and children with congenital and acquired deafness using the ice-water caloric test, rotational chair test and vestibular-evoked myogenic potential recording

Conclusions. The vestibular function can be assessed by ice-water caloric test, rotational chair test and VEMP recording in severely hearing impaired infants and young children, and 85% of these patients showed abnormal responses in these tests. Objectives. To evaluate the vestibular function of infants and young children with congenital and acquired deafness, we examined the semicircular canal and otolith function in their early childhood. Materials and methods. Our subjects were 20 children (11 boys, 9 girls; age range 31–97 months, mean age 54.2 months) with severe hearing impairment. Their vestibular functions were assessed by the ice-water caloric test, rotational chair test and vestibular-evoked myogenic potential (VEMP) recording. Results. Among these 20 severely hearing impaired children, only 3 (15%) showed normal responses in the caloric test, rotational chair test and VEMP recording bilaterally. Seven (35%) showed responses asymmetrically in the caloric test despite normal responses in the rotational chair test and VEMP recording bilaterally. Five (25%) showed hyporeflexia or areflexia in the caloric test bilaterally, but showed normal responses in the rotational chair test and normal reproducible or decreased VEMPs. Five (25%) showed no responses at all in the caloric test, rotational chair test and VEMP recording.

Does acute dysfunction of the saccular afferents affect the subjective visual horizontal in patients with vestibular neurolabyrinthitis?

Conclusions. The results of a series of studies including the present study suggest that acute dysfunction of the utricular afferents accompanied by acute dysfunction of the saccular afferents might require more time for the compensation of the otolith-ocular system than acute utricular dysfunction that was not accompanied by acute saccular dysfunction. Perhaps the inputs from the saccule also have some contribution to the subjective visual horizontal (SVH). Objective. To clarify if acute dysfunction of the saccular afferents affects the SVH. Patients and methods. Twenty-six patients with vestibular neurolabyrinthitis (20 men and 6 women, 23–67 years of age) were enrolled in this study. They had undergone measurement of SVH at the early stage (within 1 month after the attack) and 3 months after the attack. For the measurement of SVH, we used a device that has a red bar of light-emitting diodes with a head fixing frame. They also underwent vestibular evoked myogenic potentials (VEMPs) testing. For the recording of VEMPs, 95 dBnHL clicks were presented. Results. Patients with vestibular neurolabyrinthitis showed deviation of SVH toward the affected side-down at the early stage after the attack, irrespective of VEMP results. However, 3 months after the attack SVH was significantly more deviated toward the affected side-down in patients who showed absent VEMPs than those with VEMPs present (p<0.01 Mann–Whitney U test).

The Influence of Unilateral Versus Bilateral Clicks on the Vestibular-Evoked Myogenic Potentials

Because a continuous muscular effort is required during recording of vestibular-evoked myogenic potentials, we assume vestibular-evoked myogenic potentials elicited by simultaneous bilateral clicks can be used as a more convenient mode compared with respective unilateral clicks. To investigate whether bilateral clicks provide the same information as unilateral clicks, we examined whether the responses are different between them in normal subjects and whether bilateral clicks have the same diagnostic value as vestibular-evoked myogenic potentials elicited by unilateral clicks in detecting retrolabyrinthine lesions. Prospective study. Academic tertiary referral center. Fourteen healthy volunteers and four patients with unilateral cerebellopontine angle tumors were enrolled in this study. Recordings of vestibular-evoked myogenic potential responses. The latency of each peak (p13, n23), the peak-to-peak interval, and amplitude (p13-n23). Both unilateral and bilateral click stimulation of 28 ears (100%) produced vestibular-evoked myogenic potentials in normal subjects. The mean latencies of p13 and n23, peak-to-peak interval, and amplitude of vestibular-evoked myogenic potentials elicited with unilateral clicks were 11.62 +/- 0.99 ms, 19.74 +/- 1.30 ms, 8.12 +/- 1.66 ms, and 110.79 +/- 61.37 microV, respectively, whereas those elicited with bilateral clicks were 11.16 +/- 0.51 ms, 19.22 +/- 1.61 ms, 8.06 +/- 1.66 ms, and 111.77 +/- 40.98 microV, respectively. There was a significant difference (p < 0.05) in the latencies, but not for the interval and amplitude (p > 0.05). Four patients with unilateral cerebellopontine angle tumors and prolonged latencies of unilateral clicks vestibular-evoked myogenic potentials also showed latency prolongation in bilateral clicks vestibular-evoked myogenic potentials. Although the use of bilateral acoustic stimulation shortens the vestibular-evoked myogenic potential latencies in normal subjects, it does not affect the bilateral clicks vestibular-evoked myogenic potential ability to detect retrolabyrinthine lesions. Bilateral clicks vestibular-evoked myogenic potentials are a more convenient mode with which to help diagnose both labyrinthine and retrolabyrinthine lesions than unilateral clicks vestibular-evoked myogenic potentials.

VEMP recording by binaural simultaneous stimulation in subjects with vestibulo-cochlear disorders

To reduce the testing time of vestibular evoked myogenic potentials (VEMP) and the physical efforts of subjects, we studied if VEMP recording by binaural simultaneous stimulation in patients with vestibulo-cochlear disorders can be applicable as a screening test. Twenty-eight patients with vestibulo-cochlear disorders (12 men and 16 women, 22 to 77 years of age) were enrolled in this study. Patients were presented with binaural or monaural click (95 dBnHL) stimulation to record VEMPs. Their VEMP responses to binaural simultaneous stimulation were compared with those of monaural individual stimulation. Twenty-six of the 28 patients (93%) showed the same results in binaural simultaneous stimulation as in monaural individual stimulation. Amplitudes of p13-n23 to binaural simultaneous stimulation showed significant correlation to those of monaural individual stimulation ( r =0.774, P <0.0001 t -test). Peak latencies of p13 and n23 of binaural simultaneous stimulation also showed significant correlation to those of monaural individual stimulation (p13: r =0.684, P <0.0001 t -test, n23: r =0.657, P <0.0001 t -test). The binaural simultaneous stimulation method for VEMP recording is applicable for patients with vestibulo-cochlear disorders as a screening test in the clinic.

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.

The application of vestibular evoked myogenic potentials (VEMP) in otoneurosurgery

Objectives: It is the aim of the present paper to use VEMP recordings in the perioperative assessment of patients who have to undergo various otoneurosurgical or otosurgical procedures Methods: VEMP recordings were done routinely by bone-conduction stimulation at the mastoid and EMG recording at the sternocleidomastoid muscle (SCM) of each side before and after the surgery. The intraoperative stimulation was done at the vestibular nerve by a monopolar electrode (VIKING IV) with different impulses. The patients (56) underwent cochlear implantations(CI) (28), acoustic tumor removals (AN) (via different approaches)(19), microvascular decompressions (MVD)9). They had previously various degree of vertigo (DHI). The follow-up was 2 years. Results: VEMP recordings could only successfully be performed intraoperatively when they could be preoperatively elicited. A preservation of VEMP was related to a decrease in vertigo after the operation (AN/MVD). A postoperative loss of VEMP was accompanied by long-term instability, enhanced in the dark and on fast movements and in elderly (AN/CI). Conclusions: VEMP can be reliably recorded in this way. They can also be recorded in deaf patients and originate from the otolith organs (saccule). They provide additional helpful information for the surgeon in otoneurosurgery about the function of the inferior branch of the vestibular nerve (AN/MVD) and about the otolithic part of the labyrinth (CI). Loss of VEMP require long-standing vestibular rehabilitation, particularly in the elderly.