Serial cVEMP Testing is Sensitive to Disease Progression in Ménière Patients

Vestibular migraine or Meniere's disease: a diagnostic dilemma

Meniere's disease (MD) represents one of the vertigo disorders characterized by triad symptoms (recurrent vertigo, fluctuating hearing loss, tinnitus or ear fullness). The diagnosis of MD relies on the accurate and detailed taking of medical history, and the differentiation between MD and vestibular migraine (VM) is of critical importance from the perspective of the treatment efficacy. VM is a highly prevalent vertigo condition and its typical symptoms (headache, vestibular symptoms, cochlear symptoms) mimic those of MD. Furthermore, the misdiagnosis in MD and VM could lead to VM patients mistakenly receiving the traumatic treatment protocol designed for MD, and sustaining unnecessary damage to the inner ear. Fortunately, thanks to the advances in examination technologies, the barriers to their differentiation are being gradually removed. These advances enhance the diagnostic accuracy of vertigo diseases, especially VM and MD. This review focused on the differentiation of VM and MD, with an attempt to synthesize existing data on the relevant battery of differentiation diagnosis (covering core symptoms, auxiliary tests [audiometry, vestibular tests, endolymphatic hydrops tests]) and longitudinal follow-up. Since the two illnesses are overlapped in all aspects, no single test is sufficiently specific on its own, however, patterns containing all or at least some features boost specificity.

An Examination of Asymmetry in Adult Tympanometric Measures

BACKGROUND

 During audiologic evaluations, an examination of interaural asymmetry is commonly evaluated. To date, however, interaural differences for tympanometric indices have not been reported for adults. Without documented tympanometric right-left differences, one cannot determine if asymmetries are normal or are indicative of significant clinical asymmetries.

PURPOSE

 The purpose of this study was to investigate interaural asymmetries in peak compensated static acoustic admittance (Y_tm), equivalent ear canal volume (V_ea), tympanometric peak pressure (TPP), and tympanometric width (TW) in normal adults.

RESEARCH DESIGN

 Descriptive, correlational, and inferential measures designs were employed.

STUDY SAMPLE

 Participants were 188 otologically normal Caucasian young adults (i.e., 77 females and 111 males; M = 23.0 years, standard deviation [SD] = 2.7, range = 18-30 years).

DATA COLLECTION AND ANALYSES

 Y_tm, V_ea, TPP, and TW measures were obtained bilaterally from an admittance tympanogram using a 226 Hz probe tone. Separate two-factor mixed measures analysis of variance examined the effect of ear and sex for each tympanometric index. Correlation analyses examined the association between right and left ear indices. Interaural differences in tympanometric indices were examined with independent t-tests. Critical differences, for deciding if two tympanometric indices are different between ears, were computed from the standard deviations of the right-left ear difference for statistical confidence levels of 85, 90, 95, and 99%.

RESULTS

 The effect of ear was not statistically significant (p > 0.05) on any tympanometric index. Females had significantly lower Y_tm and smaller V_ea measures than males (p < 0.05). Correlations between all right and left tympanometric indices were positive and statistically significant (p < 0.05). There were no statistically significant differences in interaural differences for any of the tympanometric indices as a function of sex (p > 0.05). Critical differences, for confidence levels for 85% to 99% confidence ranged from ± 0.20-0.36 mmhos for Y_tm, ± 0.23-0.41 cm³ for V_ea, ± 11.1-19.8 daPa for TPP, and ± 27.2-48.7 daPa for TW.

CONCLUSION

 A clinician can use these critical differences to determine if tympanometric index interaural differences in ears of young normal Caucasian adults are statistically significant.

Predictive Value of Vestibular Evoked Myogenic Potentials in the Diagnosis of Menière's Disease and Vestibular Migraine

OBJECTIVE

To explore the usefulness of vestibular evoked myogenic potentials (VEMPs) in the diagnosis of Menière's disease (MD) and vestibular migraine (VM).

STUDY DESIGN

Retrospective cohort.

SETTING

Multidisciplinary neurotology clinic.

PATIENTS

Definite MD and definite VM patients between January, 2015 and May, 2017, as well as healthy volunteers.

INTERVENTIONS

Cervical and ocular VEMP (cVEMP and oVEMP) testing.

MAIN OUTCOME MEASURES

VEMP response, amplitude, and latency.

RESULTS

Twenty five definite MD, 34 definite VM, and 13 control subjects were analyzed. MD affected ears had significantly lower cVEMP (p = 0.007) and oVEMP (p < 0.001) amplitudes than control ears. VM ears had significantly lower oVEMP (p = 0.001), but not cVEMP (p = 0.198) amplitudes than control ears. MD affected ears, but not VM ears, had significantly more absent cVEMP (25.9% versus 0%, p = 0.005) and oVEMP responses (40.7% versus 0%, p < 0.001) than control ears. oVEMP latency was significantly shorter for both MD affected (p < 0.001) and VM ears (p < 0.001) than control ears. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated using a neurotology clinic MD prevalence of 7.9% in dizzy patients. A present cVEMP or oVEMP both have more than 93% chance of ruling MD out in the tested ear, while a cVEMP amplitude more than 54.9 μV or oVEMP amplitude more than 5.1 μV both have more than 94% of ruling out MD in the tested ear.

CONCLUSIONS

Despite some overlap in VEMP results between MD and VM, when the diagnosis is uncertain between the two disorders due to symptomatic overlap and nonspecific audiometric data, VEMPs can be helpful in guiding treatment toward one disease entity or the other until more evidence points to a definitive diagnosis.

Diagnosing vestibular hypofunction: an update

Unilateral or bilateral vestibular hypofunction presents most commonly with symptoms of dizziness or postural imbalance and affects a large population. However, it is often missed because no quantitative testing of vestibular function is performed, or misdiagnosed due to a lack of standardization of vestibular testing. Therefore, this article reviews the current status of the most frequently used vestibular tests for canal and otolith function. This information can also be used to reach a consensus about the systematic diagnosis of vestibular hypofunction.

A New Proposal for Severity Evaluation of Menière's Disease by Using the Evidence From a Comprehensive Battery of Auditory and Vestibular Tests

To date, no widely accepted criteria exist to quantify the severity of Menière's disease (MD) by using vestibular tests. This study aimed to compare association of hearing loss and vertigo severity with association of accurate assessments of vestibular function and the vertigo severity. The severity of vertigo was documented by a comprehensive medical history with number of vertigo attacks in the past 6 months and a Dizziness Handicap Inventory (DHI) questionnaire. The involvement of vestibular organs was verified by audio-vestibular tests in 80 definite MD patients. Correlations between DHI scores, number of vertigo attacks in the past 6 months, audio-vestibular function, and the number of involved vestibular end organs were evaluated. We show that there are no significant differences in either severity of vertigo or laboratory results across the degree of hearing loss. Furthermore, the number of involved vestibular end organs was significantly correlated with vestibulo-ocular reflex gain in anterior and posterior canal video head impulse test (vHIT), interaural asymmetry ratio in vestibular-evoked myogenic potentials (VEMPs), and number of vertigo attacks in the past 6 months and DHI score. The vestibulo-ocular reflex gain in the rotatory chair test (RCT) was significantly correlated with the DHI Physical scores and number of involved vestibular end organs at 0.08 Hz. These results indicate that hearing loss is a poor indicator of vertigo severity in MD whereas the number of involved vestibular end organs may serve as an objective measure for MD progress. A battery of vestibular tests targeting different sensor organs is a complementary method for evaluating inner ear deficits and may aid in "grading" the severity of MD.

Predicting Development of Bilateral Menière's Disease Based on cVEMP Threshold and Tuning

OBJECTIVE

To investigate if the cervical vestibular evoked myogenic potential (cVEMP) is predictive for developing bilateral Menière's disease (MD).

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary care center.

PATIENTS

Records of 71 patients previously diagnosed with unilateral MD at our institution who underwent cVEMP testing between 2002 and 2011 were screened.

INTERVENTION

Patients were contacted to answer a questionnaire to identify which patients had developed bilateral disease. Based on questionnaires and medical charts, 49 patients with a follow-up time of at least 5 years were included. The 49 originally asymptomatic ears are referred to as "study ears." Previously reported cVEMP criteria (original criteria) applied to study-ear cVEMPs separated them into Menière-like and normal-like groups.

MAIN OUTCOME MEASURE

The main purpose was to determine if previously obtained cVEMP thresholds and tuning ratios of unilateral MD patients could predict who develops bilateral disease.

RESULTS

From the 49 included patients, 12 developed bilateral disease (24.5%). The study ears characterized by original cVEMP criteria as Menière-like were significantly more likely to develop bilateral disease compared with the normal-like study ears. The original criteria predicted development of bilateral disease with a positive predictive value (PPV) and negative predictive value (NPV) of 58.3% and 86.5% respectively. ROC curves were used to revise cVEMP criteria for predicting the progression to bilateral disease. A revised criterion combining three cVEMP metrics, reached a PPV and NPV of 85.7% and 93.7%.

CONCLUSION

cVEMP threshold and tuning in unilateral MD patients are predictive of which patients will develop bilateral disease.

Vestibular evoked myogenic potentials in vestibular migraine and Menière's disease: cVEMPs make the difference

OBJECTIVE

Vestibular evoked myogenic potentials (VEMPs) have been suggested as biomarkers in the differential diagnosis of Menière's disease (MD) and vestibular migraine (VM). The aim of this study was to compare the degree of asymmetry for ocular (o) and cervical (c) VEMPs in large cohorts of patients with MD and VM and to follow up the responses.

STUDY DESIGN

Retrospective study in an interdisciplinary tertiary center for vertigo and balance disorders.

METHODS

cVEMPs to air-conducted sound and oVEMPs to bone-conducted vibration were recorded in 100 patients with VM and unilateral MD, respectively. Outcome parameters were asymmetry ratios (ARs) of oVEMP n10p15 and cVEMP p13n23 amplitudes, and of the respective latencies (mean ± SD).

RESULTS

The AR of cVEMP p13n23 amplitudes was significantly higher for MD (0.43 ± 0.34) than for VM (0.26 ± 0.24; adjusted p = 0.0002). MD-but not VM-patients displayed a higher AR for cVEMP than for oVEMP amplitudes (MD 0.43 ± 0.34 versus 0.23 ± 0.22, p < 0.0001; VM 0.26 ± 0.14 versus 0.19 ± 0.15, p = 0.11). Monitoring of VEMPs in single patients indicated stable or fluctuating amplitude ARs in VM, while ARs in MD appeared to increase or remain stable over time. No differences were observed for latency ARs between MD and VM.

CONCLUSIONS

These results are in line with (1) a more common saccular than utricular dysfunction in MD and (2) a more permanent loss of otolith function in MD versus VM. The different patterns of o- and cVEMP responses, in particular their longitudinal assessment, might add to the differential diagnosis between MD and VM.

Toward Optimizing VEMP: Calculating VEMP Inhibition Depth With a Generic Template

OBJECTIVES

Cervical vestibular evoked myogenic potentials (cVEMP) indirectly reveal the response of the saccule to acoustic stimuli through the inhibition of sternocleidomastoid muscle electromyographic response. VEMP inhibition depth (VEMPid) is a recently developed metric that estimates the percentage of saccular inhibition. VEMPid provides both normalization and better accuracy at low response levels than amplitude-normalized cVEMPs. Hopefully, VEMPid will aid in the clinical assessment of patients with vestibulopatholgy. To calculate VEMPid a template is needed. In the original method, a subject's own cVEMP was used as the template, but this method can be problematic in patients who do not have robust cVEMP responses. We hypothesize that a "generic" template, created by assembling cVEMPs from healthy subjects, can be used to compute VEMPid, which would facilitate the use of VEMPid in subjects with pathological conditions.

DESIGN

A generic template was created by averaging cVEMP responses from 6 normal subjects. To compare VEMPid calculations using a generic versus a subject-specific template, cVEMPs were obtained in 40 healthy subjects using 500, 750, and 1000 Hz tonebursts at sound levels ranging from 98 to 123 dB peSPL. VEMPids were calculated both with the generic template and with the subject's own template. The ability of both templates to determine whether a cVEMP was present or not was compared with receiver operating characteristic curves.

RESULTS

No significant differences were found between VEMPid calculations using a generic template versus using a subject-specific template for all frequencies and sound levels. Based on the receiver operating characteristic curves, the subject-specific and generic template did an equally good job at determining threshold. Within limits, the shape of the generic template did not affect these results.

CONCLUSIONS

A generic template can be used instead of a subject-specific template to calculate VEMPid. Compared with cVEMP normalized by electromyographic amplitudes, VEMPid is advantageous because it averages zero when there is no sound stimulus and it allows the accumulating VEMPid value to be shown during data acquisition as a guide to deciding when enough data has been collected.

Cervical Vestibular Evoked Myogenic Potentials in Menière's Disease: A Comparison of Response Metrics

OBJECTIVE

The cervical vestibular evoked myogenic potential (cVEMP) has been used to evaluate patients with Menière's disease (MD). Studied cVEMP metrics include: amplitude, threshold, frequency tuning, and interaural asymmetry ratio (IAR). However, few studies compared these metrics in the same set of MD patients, and methodological differences prevent such a comparison across studies. This study investigates the value of different cVEMP metrics in distinguishing one set of MD patients from age-matched controls.

STUDY DESIGN

Prospective study.

SETTING

Tertiary care center.

PATIENTS

Thirty patients with definite unilateral MD and 23 age-matched controls were prospectively included. All underwent cVEMP testing at 500, 750, 1000, and 2000 Hz on each side. Ears were separated into three groups: affected MD, unaffected MD, and control.

MAIN OUTCOME MEASURES

Sound level functions were obtained at each frequency, and normalized peak-to-peak amplitude (VEMPn), VEMP inhibition depth (VEMPid), threshold, frequency-tuning ratio, and IAR were calculated. For all metrics, the differentiation between MD and control ears was compared using receiver operating characteristic (ROC) curves.

RESULTS

500 Hz cVEMP threshold, VEMPn, and VEMPid were similarly good at distinguishing affected MD ears from healthy ears, with ROC area under the curves (AUCs) of more than 0.828 and optimal sensitivities and specificities of at least 80 and 70%. Combinations of these three metrics yielded slightly larger AUCs (>0.880). Tuning ratios and IAR were less effective in separating healthy from affected ears with AUCs ranging from 0.529 to 0.720.

CONCLUSION

The cVEMP metrics most useful in distinguishing MD patients from healthy controls are threshold, VEMPn, and VEMPid, using 500 Hz stimuli.