Audiovestibular testing in patients with Meniere’s disease. Otolaryngol Clin North Am. 2010;43:995-1009. [PMID: 20713239 DOI: 10.1016/j.otc.2010.05.008]

Characterization of Vestibular Phenotypes in Patients with Genetic Hearing Loss

Background: The vestibular phenotypes of patients with genetic hearing loss are poorly understood. Methods: we performed genetic testing including exome sequencing and vestibular function tests to investigate vestibular phenotypes and functions in patients with genetic hearing loss. Results: Among 627 patients, 143 (22.8%) had vestibular symptoms. Genetic variations were confirmed in 45 (31.5%) of the 143 patients. Nineteen deafness genes were linked with vestibular symptoms; the most frequent genes in autosomal dominant and recessive individuals were COCH and SLC26A4, respectively. Vestibular symptoms were mostly of the vertigo type, recurrent, and persisted for hours in the genetically confirmed and unconfirmed groups. Decreased vestibular function in the caloric test, video head impulse test, cervical vestibular-evoked myogenic potential, and ocular vestibular-evoked myogenic potential was observed in 42.0%, 16.3%, 57.8%, and 85.0% of the patients, respectively. The caloric test revealed a significantly higher incidence of abnormal results in autosomal recessive individuals than in autosomal dominant individuals (p = 0.011). The genes, including SLC26A4, COCH, KCNQ4, MYH9, NLRP3, EYA4, MYO7A, MYO15A, and MYH9, were heterogeneously associated with abnormalities in the vestibular function test. Conclusions: In conclusion, diverse vestibular symptoms are commonly concomitant with genetic hearing loss and are easily overlooked.

Effect of Glycerol Administration on ECochG and VEMP Findings in Individual with Meniere's Disease

The present study aimed to find the effect of glycerol administration on Electrocochleography (ECochG), cervical and ocular Vestibular Evoked Myogenic Potential (c-VEMP, o-VEMP) findings in individual with Meniere's disease. Sixteen participants (32 ears) diagnosed with Meniere's disease underwent ECochG, c-VEMP and o-VEMP for both pre and 1 h post-glycerol administration. Paired t-test indicated that the SP/AP ratio of ECochG measures was significantly improved with post-glycerol administration. There was no significant difference in the mean amplitude of o-VEMP and c-VEMP between pre and post-glycerol administration. However, while individual differences were compared, 75% of the participants reported either improvement in c-VEMP amplitude or newly emerging c-VEMP& o-VEMP. Based on the recommendation by Adams et al. (Otolaryngol Clin North Am 43(5):995-1009, 2010), the improvement on these tests results with post glycerol administration were considered as a significant indicator for the presence of Meniere's disease.With post glycerol administration, the present study found that 84%of participants were found to have an improvement in the amplitude for ECochG measures. There was an improvement in the amplitude measures of o-VEMP and c-VEMP, which were observed in 75% and 68%of participants respectively with post-glycerol administration. Improvement in the amplitude of test measures with post-glycerol administration were observed to be more for cochlear potentials of ECochG followed by vestibular potentials of c-VEMP and o-VEMP. Thus, improvement of ECochG amplitude with post-glycerol administration might serve as an additional indicator for the presence of Meniere's disease.

Comparison of Glycerol Test, ECochG and VEMP Findings in Patients with Meniere’s Disease

Present study aimed to find if multiple audio-vestibular tests can be used to improve in diagnosing Meniere's disease. The study compares the results of four test procedures of glycerol test, Electrocochleography (ECochG), cervical Vestibular Evoked Myogenic Potential (c-VEMP) and ocular Vestibular Evoked Myogenic Potential (o-VEMP) individually and also together to see whether the diagnosis of Meniere's disease can be improved. Experimental group consist of 16 participants (32 ears) diagnosed with Meniere's disease as per American Academy of Otolaryngology (AAO) -Head and Neck Foundation (2020) guidelines. Control group consist of 16 participants with compliant of only vertigo participated in the study. Participants in both group underwent glycerol test, Electrocochleography (ECochG), cervical Vestibular Evoked Myogenic Potential (c-VEMP) and ocular Vestibular Evoked Myogenic Potential (o-VEMP). Glycerol test showed a 38% positive rate for the presence of Meniere's disease. ECochG indicated the presence of endolymphatic hydrops in 62% of the participants. Abnormal finding in c-VEMP and o-VEMP was seen in 31% and 56% of the participants respectively. The combination of two tests such as ECochG and o-VEMP has increased the positive rate upto 87%. Adding one more test of c-VEMP or combining all four audiovestibular tests had a positive rate of 94% only. The present study indicated ECochG is a more sensitive tool in the diagnosis of Meniere disease followed by o-VEMP. Thus, the present study indicated that combination ECochG and o-VEMP could be used to find the presence of Meniere's disease successfully.

Similarities and Differences Between Vestibular and Cochlear Systems - A Review of Clinical and Physiological Evidence

The evoked response to repeated brief stimuli, such as clicks or short tone bursts, is used for clinical evaluation of the function of both the auditory and vestibular systems. One auditory response is a neural potential - the Auditory Brainstem Response (ABR) - recorded by surface electrodes on the head. The clinical analogue for testing the otolithic response to abrupt sounds and vibration is the myogenic potential recorded from tensed muscles - the vestibular evoked myogenic potential (VEMP). VEMPs have provided clinicians with a long sought-after tool - a simple, clinically realistic indicator of the function of each of the 4 otolithic sensory regions. We review the basic neural evidence for VEMPs and discuss the similarities and differences between otolithic and cochlear receptors and afferents. VEMPs are probably initiated by sound or vibration selectively activating afferent neurons with irregular resting discharge originating from the unique type I receptors at a specialized region of the otolithic maculae (the striola). We review how changes in VEMP responses indicate the functional state of peripheral vestibular function and the likely transduction mechanisms allowing otolithic receptors and afferents to trigger such very short latency responses. In section "ELECTROPHYSIOLOGY" we show how cochlear and vestibular receptors and afferents have many similar electrophysiological characteristics [e.g., both generate microphonics, summating potentials, and compound action potentials (the vestibular evoked potential, VsEP)]. Recent electrophysiological evidence shows that the hydrodynamic changes in the labyrinth caused by increased fluid volume (endolymphatic hydrops), change the responses of utricular receptors and afferents in a way which mimics the changes in vestibular function attributed to endolymphatic hydrops in human patients. In section "MECHANICS OF OTOLITHS IN VEMPS TESTING" we show how the major VEMP results (latency and frequency response) follow from modeling the physical characteristics of the macula (dimensions, stiffness etc.). In particular, the structure and mechanical operation of the utricular macula explains the very fast response of the type I receptors and irregular afferents which is the very basis of VEMPs and these structural changes of the macula in Menière's Disease (MD) predict the upward shift of VEMP tuning in these patients.

Methods for Testing the Subjective Visual Vertical during the Chronic Phase of Menière's Disease

The subjective visual vertical (SVV) evaluates the function of the utricle, which, in patients with Menière’s disease (MD), can be affected by endolymphatic hydrops. This study aimed to determine the SVV in MD patients during the chronic phase of illness compared to healthy participants. The second aim was to compare the SVV measurement tools: the analog bucket test, digital bucket test, and C-SVV© goggles. The SVV scores differed significantly between MD patients and the control group for the analog bucket test (p < 0.001) and the C-SVV^® goggles (p = 0.028), but no significance was shown when using the digital bucket test (p = 0.062). When comparing the analog bucket test and the C-SVV^® goggles applying the calculated threshold (1.125° in analog bucket test, 2.5° in C-SVV^® goggles), the bucket test showed higher accuracy (bucket test 73.84%, C-SVV^® goggles 69.23%). When examining the influence of betahistine on SVV scores, there were no statistically significant differences in both the analog bucket test and C-SVV© goggles. We conclude that SVV test can be used as an additional tool to evaluate utricle function during the chronic phase of MD and that the analog bucket test produces the most reliable results. The intake of betahistine does not influence the perception of SVV.

Clinical Practice Guideline: Ménière's Disease

OBJECTIVE

Ménière's disease (MD) is a clinical condition defined by spontaneous vertigo attacks (each lasting 20 minutes to 12 hours) with documented low- to midfrequency sensorineural hearing loss in the affected ear before, during, or after one of the episodes of vertigo. It also presents with fluctuating aural symptoms (hearing loss, tinnitus, or ear fullness) in the affected ear. The underlying etiology of MD is not completely clear, yet it has been associated with inner ear fluid (endolymph) volume increases, culminating in episodic ear symptoms (vertigo, fluctuating hearing loss, tinnitus, and aural fullness). Physical examination findings are often unremarkable, and audiometric testing may or may not show low- to midfrequency sensorineural hearing loss. Conventional imaging, if performed, is also typically normal. The goals of MD treatment are to prevent or reduce vertigo severity and frequency; relieve or prevent hearing loss, tinnitus, and aural fullness; and improve quality of life. Treatment approaches to MD are many and typically include modifications of lifestyle factors (eg, diet) and medical, surgical, or a combination of therapies.

PURPOSE

The primary purpose of this clinical practice guideline is to improve the quality of the diagnostic workup and treatment outcomes of MD. To achieve this purpose, the goals of this guideline are to use the best available published scientific and/or clinical evidence to enhance diagnostic accuracy and appropriate therapeutic interventions (medical and surgical) while reducing unindicated diagnostic testing and/or imaging.

Contrast-Enhanced MRI Combined With the Glycerol Test Reveals the Heterogeneous Dynamics of Endolymphatic Hydrops in Patients With Menière's Disease

BACKGROUND

The sensitivity of endolymphatic hydrops (EH) to the glycerol test varies in patients with Menière's disease (MD).

PURPOSE

To explore the features of EH and its glycerol-induced dynamics in MD.

STUDY TYPE

Case-control study.

POPULATION

Twenty patients with MD (24 affected ears) were included.

FIELD STRENGTH/SEQUENCE

3.0T 3D-FLAIR (fluid-attenuated inversion recovery) MRI and late gadolinium enhancement.

ASSESSMENT

Intratympanic gadolinium-enhanced MRI was performed in the MD-affected ears before and after the glycerol test. The borders of the endolymphatic and total lymphatic space were contoured on the axial MRI slices to evaluate the volume of hydrops in both the cochlear and vestibular regions.

STATISTICAL TESTS

Paired and unpaired t-tests, the Mann-Whitney U-test, linear discriminant analysis, Pearson's correlation, and linear regression.

RESULTS

After glycerol ingestion, vestibular EH decreased in all patients, whereas cochlear EH significantly decreased only in patients with positive glycerol test results (all P < 0.01). At baseline, cochlear EH in the positive result group was greater than in the negative result group (P = 0.007). Unexpectedly, in the positive result group a drastic glycerol-induced dehydrating effect was observed in patients whose pretest cochlear EH ratio was >16% (P = 0.011). Moreover, the dehydrating role of glycerol was positively correlated with the baseline cochlear hydrops level (r = 0.7691, P < 0.001).

DATA CONCLUSION

MRI provides evidence that glycerol administration improves the hearing threshold via dehydrating the EH. In the cochlear region, the baseline level of cochlear EH is a closely related factor for the validity of the glycerol test, whereas EH is consistently dehydrated in the vestibular component.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 3 J. Magn. Reson. Imaging 2020;52:1066-1073.

Electrocochleography Results in Patients With Bilateral Vestibular Paresis and Sound- or Pressure-Induced Horizontal Nystagmus

OBJECTIVE

To describe the electrocochleography (ECochG) findings in patients with bilateral vestibular paresis and sound- and/or pressure-induced horizontal nystagmus.

DESIGN

Retrospective case series.

SETTING

Tertiary care center.

PATIENTS

Three adult patients with bilateral vestibular paresis and sound- and/or pressure-induced horizontal nystagmus were evaluated from 2012 to 2016.

MAIN OUTCOME MEASURE

All patients underwent ECochG, vestibular evoked myogenic potential (VEMP) testing, bithermal caloric testing, rotary chair testing, audiometric testing, and temporal bone computed tomography (CT). For ECochG, the summating potential (SP) to action potential (AP) ratio was determined.

RESULTS

All patients had normal temporal bone CT, reduced caloric responses bilaterally, decreased gain on rotary chair, and abnormal ECochG. For two subjects, the SP/AP was elevated bilaterally. One subject had unilateral SP/AP elevation. Cervical VEMPs were present in all subjects, but at reduced thresholds in two subjects.

CONCLUSION

SP/AP elevation was found in all three patients with the syndrome of bilateral vestibular paresis and/or sound- or pressure-induced horizontal nystagmus. As the etiology of this syndrome remains unclear, understanding the basis for abnormal ECochG may shed insight into the pathophysiology of this condition.

Evaluation of vestibular evoked myogenic potentials (VEMP) and electrocochleography for the diagnosis of Ménière's disease

INTRODUCTION

Ménière's disease (MD) is an inner ear disorder characterized by episodic vertigo, tinnitus, ear fullness, and fluctuating hearing. Its diagnosis can be especially difficult in cases where vestibular symptoms are present in isolation (vestibular MD). The definitive diagnosis is made histologically and can only be performed post-mortem, after analysis of the temporal bone. Endolymphatic hydrops is a histopathological finding of the disease and occurs more often in the cochlea and saccule, followed by the utricle and semicircular canals. Vestibular evoked myogenic potentials (VEMP) emerged as the method of assessment of vestibular function in 1994. Until then, there was no unique way of assessing saccular function and the inferior vestibular nerve. Given that the saccule is responsible for most cases of severe hydrops, VEMP appears as a new tool to assist in the diagnosis of MD.

OBJECTIVE

To evaluate the sensitivity and specificity of VEMP and electrocochleography (EcochG) in the diagnosis of definite MD compared with clinical diagnosis.

METHODS

The study includes 12 patients (24 ears) diagnosed with definite MD defined according to the clinical criteria proposed by the American Academy of Otolaryngology - Head and Neck Surgery (AAO-HNS) in 1995, as well as 12 healthy volunteers allocated to the control group (24 ears). A clinical diagnosis by the AAO-HNS criteria was considered as the gold standard. All patients underwent an otoneurological examination, including pure tone and speech audiometry, VEMP, and extratympanic EcochG. The sensitivity and specificity to detect the presence or absence of disease were calculated, as well as their 95% confidence intervals. The reliability of VEMP and EcochG in both ears was assessed using the kappa index.

RESULTS

In both tests and in both ears, the ability to diagnose healthy cases was high, with specificity ranging from 84.6% to 100%. Moreover, the ability of the tests to diagnose the disease varied from low to moderate sensitivity, with values ranging from 37.5% to 63.6%. The agreement of both tests in the right ear, measured by the kappa coefficient, was equal to 0.54 (95% CI: 0.20-0.89), indicating a moderate agreement. In the left ear, that agreement was equal to 0.07 (95% CI: -0.33 to 0.46), indicating a weak correlation between the tests. The sensitivity of the VEMP for the right ear was 63.6% and for the left ear, 62.5%. The sensitivity of EcochG for the right ear was 63.6% and 37.5% for the left ear.

CONCLUSION

The specificity of both tests was high, and the sensitivity of VEMP was higher than that of EcochG.

Characteristics of the Cochlear Symptoms and Functions in Meniere's Disease

BACKGROUND

Meniere's disease is a unique, progressive disease of the inner ear. The complex manifestation presents diagnostic challenges. The cochlear symptoms often present before vertigo and tend to be ignored. This study aimed to analyze the characteristics of cochlear symptoms and functions associated with Meniere's disease to investigate the regularity of the development of this disorder.

METHODS

One-hundred fifteen patients who were diagnosed with definite unilateral Meniere's disease at the Hearing and Vestibular Clinic of the Department of Otorhinolaryngology of Beijing Tongren Hospital from August 2013 to November 2015 were recruited in this retrospective study. Initial symptoms, duration from initial symptoms to the diagnosis, hearing thresholds, audiogram patterns, and caloric test results were collected and analyzed for each patient. Data were analyzed using SPSS 13.0 statistical software by Spearman's correlation, Kruskal-Wallis H test, Chi-square test, and Fisher's exact test.

RESULTS

The average hearing threshold of these patients was 45.24 ± 18.40 dB HL. A majority of the patients (55.65%) were in Stage 3. The initial presentation of the disorder in 58 cases (50.43%) comprised only cochlear symptoms without vertigo. A weak, positive correlation was found between the degree of hearing loss and duration of the disease from initial symptoms to the diagnosis (rs = 0.288, P = 0.002). Upward-sloping, inverted "V," downward-sloping, and flat pattern were the main audiometric patterns observed with a distinctive distribution between stages (P < 0.001). Based on the configurations of audiograms, the audiometric patterns had a weak correlation to the duration (rs = 0.269, P = 0.004), and there was a tendency of duration to rising from upward-sloping, inverted "V", downward-sloping to flat pattern. (H = 10.024, P = 0.018). Frequencies of tinnitus in 56 patients (64.4%) were at the lowest points of the audiograms, i.e., the frequencies of the poorest hearing threshold. The patients at an advanced stage (Stage 3 [56] and Stage 4 [73]) exhibited a significantly higher abnormality of canal paresis than those at the earlier stages (Stage 1 [23] and Stage 2 [42]) (χ2 = 5.973, P = 0.015).

CONCLUSIONS

Patients with definite Meniere's disease always have a moderate to severe sensorineural hearing loss before diagnosis. Cochlear symptoms are the most common initial presentation. With the progression of the duration, the hearing impairment becomes more severe and the distribution of the audiometric pattern is distinctive between stages.

Is dehydration test using isosorbide useful in Meniere's disease?

CONCLUSION

The dehydration test using isosorbide is well tolerated when used to detect endolymphatic hydrops and may also be used to improve the sensitivity of ECoG performed on patients with MD, especially in poor hearing at low-frequency.

OBJECTIVE

This prospective study was to explore the diagnostic utility of a dehydration test, administering oral isosorbide, which has been used to treat Meniere's disease (MD).

METHOD

Electrocochleography (ECoG) and the dehydration test with isosorbide were performed on 32 patients diagnosed with definite diagnosed MD. Isosorbide (120 mL) was orally administered after baseline audiometric testing, and the testing was repeated 3 h later. The dehydration test was considered positive when improvements in hearing thresholds of 10 dB or more were evident at two or more frequencies, or the speech discrimination score increased by 12% or more. An abnormal ECoG finding was defined as an SP/AP (summating potential/action potential) ratio ≥0.4.

RESULTS

The dehydration test using isosorbide was positive in 10 of 32 patients (31.3%). The test was not associated with development of any serious side-effect. Abnormal ECoG findings were noted in 14 of 32 patients (43.8%). When endolymphatic hydrops was defined as an abnormal ECoG or a positive dehydration test, the condition was detected in 21 of 32 patients (65.6%). The positive result in dehydration test was significantly higher in patients with above moderate hearing loss at low-frequency.

It is 2015: What are the best diagnostic and treatment options for Ménière’s disease?

Ménière’s disease (MD) is a common cause of recurrent vertigo. Its pathophysiology is still unclear and controversial. The most common histological finding in postmortem temporal bone studies of patients is endolymphatic hydrops (EH). However, not all cases of hydrops are associated with MD and it may represent the end point of various etiologies. The diagnostic criteria for MD have undergone changes during the past few decades. A recent collaboration among specialty societies in United States, Europe and Japan has given rise to a new set of guidelines for the diagnosis and classification of MD. The aim is to develop international consensus criteria for MD that would help improve the quality of data collected from patients. The diagnosis of MD can be difficult in some cases as there is no gold standard for testing. Previous use of audiometric data and electrocochleography are poorly sensitive as screening tools. Recently magnetic resonance imaging as a diagnostic tool for identifying EH has gained popularity in Asia and Europe. Vestibular evoked myogenic potentials are also used but lack specificity. Finally, the treatment for MD has improved with the introduction of intratympanic treatments with steroids and gentamicin as well as less invasive treatment with the Meniett device.

The Prevalence of High-Riding Jugular Bulb in Patients with Suspected Endolymphatic Hydrops

Background To determine the prevalence of a high-riding jugular bulb (HRJB) in the endolymphatic hydrops population. Methods This was a retrospective chart and radiology review of patients seen at a tertiary care medical center. Patients were identified using the International Classification of Diseases, 9th edition, code 386.xx (Meniere disease-unspecified), and were required to have undergone an imaging study that included views of the jugular bulb that were available for review. A radiologist then evaluated all of the imaging studies for evidence of HRJB or inner ear dehiscence with a jugular bulb abnormality. Results The prevalence of a HRJB in all endolymphatic hydrops patients was 9.0% (7 of 78), and it was 4.5% (7 of 156) in all ears. The prevalence of HRJB ipsilateral to an ear with endolymphatic hydrops was 4.6% (4 of 88 ears); it was 4.4% (3 of 68 ears) in ears without endolymphatic hydrops. The incidence of inner ear dehiscence with a HRJB was 1.3% (1 of 78). Electrocochleography results were not correlated with jugular bulb volume. Discussion The results of this study indicate that a small subset of patients treated for endolymphatic hydrops patients have a HRJB. Overall, these results suggest that HRJB does not play a major role in endolymphatic hydrops, although it may play a role in a few isolated patients.

Reappraisal of the glycerol test in patients with suspected Menière's disease

BACKGROUND

Recent advances in magnetic resonance imaging make it possible to visualize the presumed pathophysiologic correlate of Menière's disease: endolymphatic hydrops. As traditional diagnostic tests can provide only indirect evidence, they are hardly competitive in this respect and need to be rethought. This is done here for the glycerol test.

METHODS

The data of a previous retrospective analysis of the glycerol test in patients with suspected Menière's disease are reinterpreted using a simple model. The mean threshold reduction (MTR) in the frequency range from 125 to 1500 Hz (calculated from audiograms obtained immediately before and four hours after the glycerol intake) is used as the test statistic. The proposed model explains the frequency distribution of the observed MTR by the convolution of a Gaussian probability density function (representing measurement errors) with a template representing the frequency distribution of the true MTR. The latter is defined in terms of two adjustable parameters. After fitting the model to the data, the performance of the test is evaluated using receiver operating characteristic (ROC) analysis.

RESULTS

The cumulative frequency distribution of the observed MTR can be explained almost perfectly by the model. According to the ROC analysis performed, the capability of the currently used audiometric procedure to detect a glycerol-induced threshold reduction corresponds to a diagnostic test of rather high accuracy (area under the ROC curve greater than 0.9). Simulations show that methodological improvements could further enhance the performance.

CONCLUSIONS

Owing to their ability to reveal functional aspects without an obvious morphological correlate, traditional test for Menière's disease could be decisive for defining the stage of the disease. A distinctive feature of the glycerol test is that it is capable of determining, with high accuracy, whether the pathophysiologic condition of the inner ear is partially reversible. Prospectively, this could help to estimate the chances of specific therapies.

Motion sensitivity and caloric responsiveness in vestibular migraine and Meniere's disease

OBJECTIVES/HYPOTHESIS

We examined whether scores on a motion sensitivity questionnaire (MSQ) could distinguish between vestibular migraine (VM) and Meniere's disease (MD). As a secondary goal, we examined whether scores on the MSQ correlated with results from caloric testing.

STUDY DESIGN

This study administered a telephone questionnaire to subjects who met clinical criteria for vestibular migraine, Meniere's disease, and controls.

METHODS

A MSQ was administered to 20 subjects meeting American Academy of Otolaryngology (AAO) criteria for MD, 30 subjects meeting Neuhauser criteria for both probable vestibular migraine (pVM) and definite vestibular migraine (dVM), and 22 controls.

RESULTS

The average score on the MSQ was 5.9 for VM, 4.25 for MD, and 0.4 for controls. Both the VM and MD scored significantly higher than the controls (P = 0.0001), but results were not statistically different from each other (P = 0.17). However, the average score for subjects with dVM was 7.1, which was significantly higher than subjects with pVM whose average score was 4.2 (P = 0.045) and higher than subjects with MD (P = 0.048). When each question of the MSQ was analyzed, motion sensitivity to riding in a car was found to be significantly different between VM (average score 1.1) and MD (average score 0.5), with P value of 0.048. Scores of MSQ did not correlate with the total eye speed (TES) on caloric testing.

CONCLUSIONS

Subjects with VM and MD had elevated levels of motion sensitivity compared to controls. Subjects with VM had more motion sensitivity to riding in a car than those with MD, but their TES was not different.

LEVEL OF EVIDENCE

3b.

Predictive modeling for diagnostic tests with high specificity, but low sensitivity: a study of the glycerol test in patients with suspected Menière's disease

A high specificity does not ensure that the expected benefit of a diagnostic test outweighs its cost. Problems arise, in particular, when the investigation is expensive, the prevalence of a positive test result is relatively small for the candidate patients, and the sensitivity of the test is low so that the information provided by a negative result is virtually negligible. The consequence may be that a potentially useful test does not gain broader acceptance. Here we show how predictive modeling can help to identify patients for whom the ratio of expected benefit and cost reaches an acceptable level so that testing these patients is reasonable even though testing all patients might be considered wasteful. Our application example is based on a retrospective study of the glycerol test, which is used to corroborate a suspected diagnosis of Menière’s disease. Using the pretest hearing thresholds at up to 10 frequencies, predictions were made by K-nearest neighbor classification or logistic regression. Both methods estimate, based on results from previous patients, the posterior probability that performing the considered test in a new patient will have a positive outcome. The quality of the prediction was evaluated using leave-one-out cross-validation, making various assumptions about the costs and benefits of testing. With reference to all 356 cases, the probability of a positive test result was almost 0.4. For subpopulations selected by K-nearest neighbor classification, which was clearly superior to logistic regression, this probability could be increased up to about 0.6. Thus, the odds of a positive test result were more than doubled.

Bedside vestibular examination in patients with unilateral definite Ménière's disease

CONCLUSION

Although vestibular clinical examinations are quite variable in Ménière's disease (MD), when used in a grouped fashion they attach valuable information to the understanding of MD.

OBJECTIVE

Evaluation of unilateral MD vestibular bedside examination.

METHODS

This was a retrospective study of patients with definite unilateral MD at a tertiary care facility. Assessment of spontaneous nystagmus (SN), head-shaking nystagmus (HSN), head impulse test (HIT) and vibration-induced nystagmus (VIN) was carried out. Clinical manifestations and auditory and vestibular function were studied.

RESULTS

The study included 97 patients: 47 presented SN, 75 a positive HSN (biphasic in 14) and in 73 a VIN was observed. After excluding patients with biphasic HSN, a homogeneous response was observed in 43.4%: no nystagmus in 15.7%; nystagmus of similar direction in 27.8% (paretic, 14.5%; irritative, 13.3%). There were no significant differences in duration of the disease, functional level and vertigo index, although a trend towards a shorter time since last crisis was observed in patients with an irritative nystagmus. In 36.1% nystagmus was revealed with a consistent direction in at least one of the tests and in 20.5% it was non-coherent, something more frequently observed closer to the crisis. Independently only in VIN an irritative response was associated with a higher functional level and a shorter time from last attack.