scholarly journals Toward Optimizing Vestibular Evoked Myogenic Potentials: Normalization Reduces the Need for Strong Neck Muscle Contraction

2017 ◽  
Vol 22 (4-5) ◽  
pp. 282-291 ◽  
Author(s):  
Kimberley S. Noij ◽  
Barbara S. Herrmann ◽  
Steven D. Rauch ◽  
John J. Guinan Jr.
Keyword(s):  
Muscle Contraction ◽  
Acoustic Stimulus ◽  
Acoustic Stimulation ◽  
Sound Level ◽  
Vestibular Evoked Myogenic Potentials ◽  
Emg Activity ◽  
Neck Muscle ◽  
Vestibular Evoked Myogenic Potential ◽  
Contraction Amplitude ◽  
Myogenic Potential

Background: The cervical vestibular evoked myogenic potential (cVEMP) represents an inhibitory reflex of the saccule measured in the ipsilateral sternocleidomastoid muscle (SCM) in response to acoustic or vibrational stimulation. Since the cVEMP is a modulation of SCM electromyographic (EMG) activity, cVEMP amplitude is proportional to muscle EMG amplitude. We sought to evaluate muscle contraction influences on cVEMP peak-to-peak amplitudes (VEMPpp), normalized cVEMP amplitudes (VEMPn), and inhibition depth (VEMPid). Methods: cVEMPs at 500 Hz were measured in 25 healthy subjects for 3 SCM EMG contraction ranges: 45-65, 65-105, and 105-500 μV root mean square (r.m.s.). For each range, we measured cVEMP sound level functions (93-123 dB peSPL) and sound off, meaning that muscle contraction was measured without acoustic stimulation. The effect of muscle contraction amplitude on VEMPpp, VEMPn, and VEMPid and the ability to distinguish cVEMP presence/absence were evaluated. Results: VEMPpp amplitudes were significantly greater at higher muscle contractions. In contrast, VEMPn and VEMPid showed no significant effect of muscle contraction. Cohen's d indicated that for all 3 cVEMP metrics contraction amplitude variations produced little change in the ability to distinguish cVEMP presence/absence. VEMPid more clearly indicated saccular output because when no acoustic stimulus was presented the saccular inhibition estimated by VEMPid was zero, unlike those by VEMPpp and VEMPn. Conclusion: Muscle contraction amplitude strongly affects VEMPpp amplitude, but contractions 45-300 μV r.m.s. produce stable VEMPn and VEMPid values. Clinically, there may be no need for subjects to exert high contraction effort. This is especially beneficial in patients for whom maintaining high SCM contraction amplitudes is challenging.

scholarly journals Vestibular evoked myogenic potential

2014 ◽  
Vol 67 (suppl. 1) ◽  
pp. 38-45
Author(s):  
Slobodanka Lemajic-Komazec ◽  
Zoran Komazec ◽  
Ljiljana Vlaski ◽  
Slobodan Savovic ◽  
Maja Buljcik-Cupic ◽  
...  
Keyword(s):  
Tone Burst ◽  
Acoustic Stimulation ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Evoked Myogenic Potential ◽  
Average Value ◽  
Myogenic Potential ◽  
The Difference ◽  
Interaural Differences ◽  
The Right ◽  
A Prospective Study

Introduction. Vestibular evoked myogenic potentials are neurophysiological method for examining of saccular function, the bottom of the vestibular nerve that in nervates the sacculus and central vestibular pathways. Those are inhibitory potentials of the sternocleido mastoid musclein response to ipsilateral acoustic stimulation of the sacculus. Parameters of vestibular evoked myogenic potential testing include threshold, latencies of p1 and n1 wave and interamplitude p13-n23, interaural difference of p13 and n23 latency and interaural amplitude difference ratio. The aim of this study was to compire parameters standardization of vestibular evoked myogenic potentials responses, latency p13 and n23 of waves, the amplitude of responses and interaural differences in the amplitude andto determinewhether there is a difference in values between the sexes. Material and methods. This research was meant to be a prospective study which included 30 normal audiovestibular volunteers of both sexes. The group consisted of 53.3% women and 46.7% men. The saccular function testing by vestibular evoked myogenic potentials was performed monoaurally using air-conductive 500 Hz tone burst auditory stimulation. Results. The average value of the p13 wave latency in healthy subjects of this study was 15.18 ms (?1.24) while the mean latency of n23 waves in the same subjects was 25.00 ms (?2.23). The average value of the amplitude of the p13-n23 waves was 80.28 (34. ?04) microvolts. Conclusion. The difference in the values of the basic parameters of vestibular evoked myogenic potential responses between men and women does not exist. No differences between the right and the left ear in the values of latency and amplitude were observed.

Does the method of sternocleidomastoid muscle activation affect the vestibular evoked myogenic potential response?

2007 ◽  
Vol 16 (4-5) ◽  
pp. 187-191 ◽  
Author(s):  
Brandon Isaacson ◽  
Emily Murphy ◽  
Helen Cohen
Keyword(s):  
Muscle Activation ◽  
Body Position ◽  
Sternocleidomastoid Muscle ◽  
Vestibular Evoked Myogenic Potentials ◽  
Emg Activity ◽  
Potential Response ◽  
Vestibular Evoked Myogenic Potential ◽  
Amplitude Response ◽  
Myogenic Potential ◽  
Significant Difference

The objective of this study was to assess the effects of different methods of sternocleidomastoid muscle (SCM) activation on vestibular evoked myogenic potentials (VEMP). Forty normal volunteers were tested using three different methods of SCM activation: sitting with the head turned away from the test ear (SIT), supine with the head held straight up (SHU), and supine with the head held up and turned away from the test ear (SHT). Dependent measures were latency, and amplitude. Head and body position significantly affected the amplitude of the VEMP, but had no significant effect on latency. Testing subjects in the supine position with the head up and turned toward the non-test ear yielded the most robust amplitude response and sternocleidomastoid EMG activity. When amplitude measures where corrected according to tonic electromyographic (EMG) activity no significant difference was noted between the three different test positions. The increased amplitude in the supine with head turned position can be directly attributed to increased tonic SCM EMG activity.

Quantifying the effects of electrode placement and montage on measures of cVEMP amplitude and muscle contraction

2020 ◽  
pp. 1-13
Author(s):  
Sendhil Govender ◽  
Sally M. Rosengren
Keyword(s):  
Muscle Contraction ◽  
Normal Subjects ◽  
Electrode Placement ◽  
Electrode Position ◽  
Test Results ◽  
Vestibular Evoked Myogenic Potential ◽  
Active Electrode ◽  
Myogenic Potential ◽  
Position Errors ◽  
Test Outcomes

BACKGROUND: The cervical vestibular evoked myogenic potential (cVEMP) can be affected by the recording parameters used to quantify the response. OBJECTIVE: We investigated the effects of electrode placement and montage on the variability and symmetry of sternocleidomastoid (SCM) contraction strength and cVEMP amplitude. METHODS: We used inter-side asymmetries in electrode placement to mimic small clinical errors in twenty normal subjects. cVEMPs were recorded at three active electrode sites and referred to the distal SCM tendon (referential montages: upper, conventional and lower). Additional bipolar montages were constructed offline to measure SCM contraction strength using closely-spaced electrode pairs (bipolar montages: superior, lower and outer). RESULTS: The conventional montage generally produced the largest cVEMP amplitudes (P <  0.001). SCM contraction strength was larger for referential montages than bipolar ones (P <  0.001). Inter-side electrode position errors produced large variations in cVEMP and SCM contraction strength asymmetries in some subjects, producing erroneous abnormal test results. CONCLUSION: Recording locations affect cVEMP amplitude and SCM contraction strength. In most cases, small changes in electrode position had only minor effects but, in a minority of subjects, the different montages produced large changes in cVEMP and contraction amplitudes and asymmetry, potentially affecting test outcomes.

scholarly journals Toward Optimizing cVEMP: 2,000-Hz Tone Bursts Improve the Detection of Superior Canal Dehiscence

2018 ◽  
Vol 23 (6) ◽  
pp. 335-344 ◽  
Author(s):  
Kimberley S. Noij ◽  
Barbara S. Herrmann ◽  
John J. Guinan Jr. ◽  
Steven D. Rauch
Keyword(s):  
Roc Analysis ◽  
Matched Control ◽  
Tone Burst ◽  
Sound Level ◽  
Vestibular Evoked Myogenic Potential ◽  
Superior Semicircular Canal Dehiscence ◽  
Myogenic Potential ◽  
Superior Canal Dehiscence ◽  
Inferior Vestibular Nerve ◽  
Canal Dehiscence

Background: The cervical vestibular evoked myogenic potential (cVEMP) test measures saccular and inferior vestibular nerve function. The cVEMP can be elicited with different frequency stimuli and interpreted using a variety of metrics. Patients with superior semicircular canal dehiscence (SCD) syndrome generally have lower cVEMP thresholds and larger amplitudes, although there is overlap with healthy subjects. The aim of this study was to evaluate which metric and frequency best differentiate healthy ears from SCD ears using cVEMP. Methods: Twenty-one patients with SCD and 23 age-matched controls were prospectively included and underwent cVEMP testing at 500, 750, 1,000 and 2,000 Hz. Sound level functions were obtained at all frequencies to acquire threshold and to calculate normalized peak-to-peak amplitude (VEMPn) and VEMP inhibition depth (VEMPid). Third window indicator (TWI) metrics were calculated by subtracting the 250-Hz air-bone gap from the ipsilateral cVEMP threshold at each frequency. Ears of SCD patients were divided into three groups based on CT imaging: dehiscent, thin or unaffected. The ears of healthy age-matched control subjects constituted a fourth group. Results: Comparing metrics at all frequencies revealed that 2,000-Hz stimuli were most effective in differentiating SCD from normal ears. ROC analysis indicated that for both 2,000-Hz cVEMP threshold and for 2,000-Hz TWI, 100% specificity could be achieved with a sensitivity of 92.0%. With 2,000-Hz VEMPn and VEMPid at the highest sound level, 100% specificity could be achieved with a sensitivity of 96.0%. Conclusion: The best diagnostic accuracy of cVEMP in SCD patients can be achieved with 2,000-Hz tone burst stimuli, regardless of which metric is used.

Comparison of vestibular evoked myogenic potentials elicited by click and short duration tone burst stimuli

2010 ◽  
Vol 125 (4) ◽  
pp. 343-347 ◽  
Author(s):  
K Kumar ◽  
S Kumar Sinha ◽  
A Kumar Bharti ◽  
A Barman
Keyword(s):  
Short Duration ◽  
Clinical Assessment ◽  
Low Frequency ◽  
Tone Burst ◽  
Normal Hearing ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Evoked Myogenic Potential ◽  
Acoustic Stimuli ◽  
Myogenic Potential ◽  
Electrical Impulses

AbstractIntroduction:Vestibular evoked myogenic potentials are short latency electrical impulses that are produced in response to higher level acoustic stimuli. They are used clinically to diagnose sacculocollic pathway dysfunction.Aim:This study aimed to compare the vestibular evoked myogenic potential responses elicited by click stimuli and short duration tone burst stimuli, in normal hearing individuals.Method:Seventeen subjects participated. In all subjects, we assessed vestibular evoked myogenic potentials elicited by click and short duration tone burst stimuli.Results and conclusion:The latency of the vestibular evoked myogenic potential responses (i.e. the p13 and n23 peaks) was longer for tone burst stimuli compared with click stimuli. The amplitude of the p13–n23 waveform was greater for tone burst stimuli than click stimuli. Thus, the click stimulus may be preferable for clinical assessment and identification of abnormalities as this stimulus has less variability, while a low frequency tone burst stimulus may be preferable when assessing the presence or absence of vestibular evoked myogenic potential responses.

Vestibular evoked myogenic potentials: review

2010 ◽  
Vol 124 (10) ◽  
pp. 1043-1050 ◽  
Author(s):  
R Mudduwa ◽  
N Kara ◽  
D Whelan ◽  
Anirvan Banerjee
Keyword(s):  
Vestibular Function ◽  
Extensive Study ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Evoked Myogenic Potential ◽  
Clinical Role ◽  
Myogenic Potential ◽  
Future Developments ◽  
Early Results ◽  
Clinical Conditions ◽  
Based Medicine

AbstractBackground:Disorders of balance often pose a diagnostic conundrum for clinicians, and a multitude of investigations have emerged over the years. Vestibular evoked myogenic potential testing is a diagnostic tool which can be used to assess vestibular function. Over recent years, extensive study has begun to establish a broader clinical role for vestibular evoked myogenic potential testing.Objectives:To provide an overview of vestibular evoked myogenic potential testing, and to present the evidence for its clinical application.Review type:Structured literature search according to evidence-based medicine guidelines, performed between November 2008 and April 2009. No restrictions were applied to the dates searched.Conclusion:The benefits of vestibular evoked myogenic potential testing have already been established as regards the diagnosis and monitoring of several clinical conditions. Researchers continue to delve deeper into potential new clinical applications, with early results suggesting promising future developments.

Ocular and cervical vestibular evoked myogenic potentials in response to bone-conducted vibration in patients with probable inferior vestibular neuritis

2012 ◽  
Vol 126 (7) ◽  
pp. 683-691 ◽  
Author(s):  
L Manzari ◽  
A M Burgess ◽  
I S Curthoys
Keyword(s):  
Sense Organ ◽  
Vestibular Neuritis ◽  
Vestibular Evoked Myogenic Potentials ◽  
Detectable Effect ◽  
Vestibular Evoked Myogenic Potential ◽  
Previous Evidence ◽  
Surface Electrodes ◽  
Myogenic Potential ◽  
Function Testing ◽  
Utricular Function

AbstractBackground and aims:Previous evidence shows that the n10 component of the ocular vestibular evoked myogenic potential indicates utricular function, while the p13 component of the cervical vestibular evoked myogenic potential indicates saccular function. This study aimed to assess the possibility of differential utricular and saccular function testing in the clinic, and whether loss of saccular function affects utricular response.Methods:Following vibration conduction from the mid-forehead at the hairline, the ocular n10 component was recorded by surface electromyograph electrodes beneath both eyes, while the cervical p13–n23 component was recorded by surface electrodes over the tensed sternocleidomastoid muscles.Results:Fifty-nine patients were diagnosed with probable inferior vestibular neuritis, as their cervical p13–n23 component was asymmetrical (i.e. reduced or absent on the ipsilesional side), while their ocular n10 component was symmetrical (i.e. normal beneath the contralesional eye).Conclusion:The sense organ responsible for the cervical and the ocular vestibular evoked myogenic potentials cannot be the same, as one response was normal while the other was not. Reduced or absent saccular function has no detectable effect on the ocular n10 component. On vibration stimulation, the ocular n10 component indicates utricular function and the cervical p13–n23 component indicates saccular function.

Vestibular-Evoked Myogenic Potential Testing in Vestibular Localization and Diagnosis

2020 ◽  
Vol 40 (01) ◽  
pp. 018-032 ◽  
Author(s):  
Rachael L. Taylor ◽  
Miriam S. Welgampola ◽  
Benjamin Nham ◽  
Sally M. Rosengren
Keyword(s):  
Vestibular System ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Disorders ◽  
Complementary Information ◽  
Vestibular Evoked Myogenic Potential ◽  
Myogenic Potential ◽  
Superior Canal Dehiscence ◽  
Otolith Function ◽  
Utricular Function ◽  
Canal Dehiscence

AbstractVestibular-evoked myogenic potentials (VEMPs) are short-latency, otolith-dependent reflexes recorded from the neck and eye muscles. They are widely used in neuro-otology clinics as tests of otolith function. Cervical VEMPs are recorded from the neck muscles and reflect predominantly saccular function, while ocular VEMPs are reflexes of the extraocular muscles and reflect utricular function. They have an important role in the diagnosis of superior canal dehiscence syndrome and provide complementary information about otolith function that is useful in the diagnosis of other vestibular disorders. Like other evoked potentials, they can provide important localizing information about lesions that may occur along the VEMP pathway. This review will describe the VEMP abnormalities seen in common disorders of the vestibular system and its pathways.

Tone-induced cervical and ocular vestibular-evoked myogenic potentials: comparing abnormalities in traumatic and non-traumatic vestibular disease

2018 ◽  
Vol 132 (10) ◽  
pp. 906-910 ◽  
Author(s):  
N S Longridge ◽  
A I Mallinson
Keyword(s):  
Companion Paper ◽  
High Rate ◽  
Vestibular Evoked Myogenic Potentials ◽  
Tertiary Referral ◽  
Vestibular Evoked Myogenic Potential ◽  
Vestibular Disease ◽  
Myogenic Potential ◽  
Number Of Patients ◽  
History Of ◽  
Vestibular Assessment

AbstractBackgroundOtolithic function is poorly understood, but vestibular-evoked myogenic potential testing has allowed the documentation of pathology in patients who complain of imbalance.MethodsSeventy-four patients with traumatic and non-traumatic vestibular disease were sequentially assessed at a tertiary referral neuro-otology unit in a teaching hospital. A detailed history of all patients was taken and standard vestibular assessment was conducted using the technique described in the companion paper. The results of both groups of patients were analysed and the rate of abnormalities was assessed.ResultsThere was a high rate of abnormalities, including bilateral pathology, in a significant number of patients. Many patients in both groups inexplicably failed to recover.ConclusionVestibular-evoked myogenic potentials are helpful in documenting pathology, including bilateral pathology, which is outlined in the literature as being exceedingly difficult to compensate for.

The Effect of Muscle Contraction Level on the Cervical Vestibular Evoked Myogenic Potential (cVEMP): Usefulness of Amplitude Normalization

2013 ◽  
Vol 24 (02) ◽  
pp. 077-088 ◽  
Author(s):  
Jamie M. Bogle ◽  
David A. Zapala ◽  
Robin Criter ◽  
Robert Burkard
Keyword(s):  
Muscle Contraction ◽  
Repeated Measures ◽  
A Posteriori ◽  
Regression Analyses ◽  
Signal Averaging ◽  
Vestibular Evoked Myogenic Potential ◽  
Myogenic Potential ◽  
Normalization Methods ◽  
The Relationship ◽  
Amplitude Normalization

Background: The cervical vestibular evoked myogenic potential (cVEMP) is a reflexive change in sternocleidomastoid (SCM) muscle contraction activity thought to be mediated by a saccular vestibulo-collic reflex. CVEMP amplitude varies with the state of the afferent (vestibular) limb of the vestibulo-collic reflex pathway, as well as with the level of SCM muscle contraction. It follows that in order for cVEMP amplitude to reflect the status of the afferent portion of the reflex pathway, muscle contraction level must be controlled. Historically, this has been accomplished by volitionally controlling muscle contraction level either with the aid of a biofeedback method, or by an a posteriori method that normalizes cVEMP amplitude by the level of muscle contraction. A posteriori normalization methods make the implicit assumption that mathematical normalization precisely removes the influence of the efferent limb of the vestibulo-collic pathway. With the cVEMP, however, we are violating basic assumptions of signal averaging: specifically, the background noise and the response are not independent. The influence of this signal-averaging violation on our ability to normalize cVEMP amplitude using a posteriori methods is not well understood. Purpose: The aims of this investigation were to describe the effect of muscle contraction, as measured by a prestimulus electromyogenic estimate, on cVEMP amplitude and interaural amplitude asymmetry ratio, and to evaluate the benefit of using a commonly advocated a posteriori normalization method on cVEMP amplitude and asymmetry ratio variability. Research Design: Prospective, repeated-measures design using a convenience sample. Study Sample: Ten healthy adult participants between 25 and 61 yr of age. Intervention: cVEMP responses to 500 Hz tone bursts (120 dB pSPL) for three conditions describing maximum, moderate, and minimal muscle contraction. Data Collection and Analysis: Mean (standard deviation) cVEMP amplitude and asymmetry ratios were calculated for each muscle-contraction condition. Repeated measures analysis of variance and t-tests compared the variability in cVEMP amplitude between sides and conditions. Linear regression analyses compared asymmetry ratios. Polynomial regression analyses described the corrected and uncorrected cVEMP amplitude growth functions. Results: While cVEMP amplitude increased with increased muscle contraction, the relationship was not linear or even proportionate. In the majority of cases, once muscle contraction reached a certain “threshold” level, cVEMP amplitude increased rapidly and then saturated. Normalizing cVEMP amplitudes did not remove the relationship between cVEMP amplitude and muscle contraction level. As muscle contraction increased, the normalized amplitude increased, and then decreased, corresponding with the observed amplitude saturation. Abnormal asymmetry ratios (based on values reported in the literature) were noted for four instances of uncorrected amplitude asymmetry at less than maximum muscle contraction levels. Amplitude normalization did not substantially change the number of observed asymmetry ratios. Conclusions: Because cVEMP amplitude did not typically grow proportionally with muscle contraction level, amplitude normalization did not lead to stable cVEMP amplitudes or asymmetry ratios across varying muscle contraction levels. Until we better understand the relationships between muscle contraction level, surface electromyography (EMG) estimates of muscle contraction level, and cVEMP amplitude, the application of normalization methods to correct cVEMP amplitude appears unjustified.

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