[Vertigo and dizziness in child: a clinical analysis in 120 cases].

Objective: To investigate the disease composition, clinical features, diagnosis, and treatment characteristics of vertigo in children. Methods: A total of 120 children with vertigo diagnosed and treated in the Department of Otorhinolaryngology, Children's Hospital, Capital Institute of Pediatrics in Beijing from February 2018 to February 2022 were retrospectively analyzed to explore the clinical characteristics of common peripheral vertigo in children and to summarize the experience of diagnosis and treatment. Results: The etiological composition of 120 cases of vertigo in children are as follows: 63 (52.5%) cases of vestibular migraine of childhood (VMC), 19 (15.8%) of recurrent vertigo of childhood (RVC), 11 (9.2%) of probable vestibular migraine of childhood (PVMC), 10 (8.3%) of secretory otitis media (SOM), 6 (5.0%) of persistent postural-perceptual dizziness (PPPD), 4 (3.3%) of benign paroxysmal positional vertigo (BPPV), 2 (1.7%) of vestibular neuritis (VN), 2 (1.7%) of Meniere's disease (MD), 2 (1.7%) of inner ear malformation (IEM), and 1 (0.8%) of vestibular paroxysmal syndrome (VP).The major cause of vertigo in children of different ages was different. SOM was the most important cause in preschool children, followed by RVC and VMC; VMC was the most important cause in school-age children, followed by RVC; and MD and BPPV were exclusive found in adolescents. The incidence rate of PPPD was higher in adolescents than in preschool and school-age children. Children with vertigo had good prognosis in general. Conclusions: VMC, RVC and SOM are the most common causes in vertigo in children, and their proportion was different in different aged children. Transforming abstract feelings into specific information is the skill required for collecting medical history of children with vertigo. Considering the age and cooperation of children, appropriate hearing and vestibular examination techniques are recommended. We should pay more attention to the mental health of children with vertigo and their parents.

Potential Application of Hydrops MR Imaging: A Systematic Review.

BACKGROUND: Diagnostic dilemma between clinical Meniere's disease and radiological endolymphatic hydrops (EH) has emerged since the introduction of hydrops magnetic resonance imaging (MRI). The aim of this study is to explore the potential application of hydrops MRI on diagnosing the EH. METHODS: This review was developed from peer-reviewed articles published in those journals listed on journal of citation reports. The MEDLINE database of the US National Library of Medicine, Scopus, and Google Scholar were used to collect articles based on the guidelines (PRISMA 2020 statement) for reporting reviews. RESULTS: Initially, 470 articles were retrieved from 1983 to 2023, and 80 relevant articles were ultimately selected. The sensitivity (69%-92%) and specificity (78%-96%) values varied from each laboratory for detecting EH via hydrops MRI, probably due to candidate selection and the grading system employed. CONCLUSION: The application of hydrops MRI allows (1) differentiation between EH and sudden sensorineural hearing loss; (2) determination of the affected side of EH; and (3) confirmation of the diagnosis of EH concomitant with other disorders. Notably, not all differentials for EH can be visualized on MR images. One of the existing gaps to be filled is that updated hydrops MRI fails to identify distortion, that is, rupture, collapse, fistula, or fibrosis of the inner ear compartments, akin to what histopathological evidence can demonstrate. Hence, enhanced ultrahigh resolution of hydrops MRI is required for demonstrating fine structures of the inner ear compartments in the future.

[The research of the contralateral ear hearing thresholds and the hearing prognosis in unilateral Meniere's disease].

Objective:This study analyzed the pure tone audiometry results of the affected ear and the contralateral ear of unilateral Meniere's disease to investigate the correlation of the hearing threshold of the contralateral ear and the hearing prognosis of unilateral Meniere's disease. Methods:In this study, the follow-up data of 135 patients with unilateral Meniere's disease in Beijing Tongren Hospital were used to analyze the pure tone audiometry results of the affected and contralateral ears at the first visit and 1 year later. Results:①At the first visit, there was no statistically significant difference between the mean hearing thresholds of the affected ear in the normal hearing group and the high-frequency hearing loss group of the contralateral ear（P>0.05）. ②The range of improvement of hearing thresholds in the affected ear was greater in the contralateral ear normal hearing group than in the contralateral ear high-frequency hearing loss group. In the normal hearing group of the contralateral ear, the hearing thresholds of the affected ear at 0.25 kHz（P<0.01）, 0.50 kHz（P<0.01）, 1.00 kHz（P<0.01）, and 2.00 kHz（P<0.05） were significantly improved; and in the high-frequency hearing loss group of the contralateral ear, the hearing thresholds at 0.25 kHz（P<0.01） hearing thresholds improved significantly, and there was no significant difference between the rest of the frequencies before and after treatment（P>0.05）. A consistent pattern was observed in both higher and lower age groups. ③After 1 year of follow-up, the low and mid-frequency hearing of the affected ear improved. 0.25 kHz（P<0.01）, 0.50 kHz（P<0.01）, 1.00 kHz（P<0.01） hearing thresholds improved significantly; 8.00 kHz hearing thresholds decreased slightly（P<0.05）. Conclusion:After standardized treatment, the results of 1-year follow-up suggested that the low-frequency hearing of MD patients could be improved, but the high-frequency hearing was slightly decreased. The hearing prognosis of the affected ear with normal hearing threshold of the contralateral ear may be better.

Effects of Age on the Frequency Amplitude Ratio of Cervical and Ocular Vestibular Evoked Myogenic Potentials.

PURPOSE: An increase in the 1000/500 Hz frequency amplitude ratio (FAR) of the cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP, respectively) may serve as a potential biomarker for diagnosing Meniere's disease (MD). However, the aging process can also result in an increased FAR for VEMPs. In older patients, distinguishing whether changes in VEMP FAR are due to MD or aging processes becomes difficult. We aimed to investigate the effects of age on VEMP FARs and establish a FAR-normative range for different age groups. METHOD: cVEMP and oVEMP were recorded from a total of 106 participants grouped as young, middle-aged, and older adults using air-conducted tone bursts at 500, 750, and 1000 Hz at 125 dB pSPL. The FAR was calculated for the cVEMP and oVEMP for the following frequencies: FAR1 = 1000/500, FAR2 = 1000/750, and FAR3 = 750/500. RESULTS: A significant age-related effect was observed on the cVEMP FAR. Although the oVEMP FAR showed an increasing trend with age, it was not statistically significant. Age-based normative FAR values are provided. CONCLUSIONS: Drawing from the normative FAR from this study, there is evidence that the existing MD diagnostic criteria would misidentify a considerable number of older adults. Therefore, to reduce false positives, we recommend a more stringent cVEMP and oVEMP FAR criterion in older adults.

Machine learning models help differentiate between causes of recurrent spontaneous vertigo.

BACKGROUND: Vestibular migraine (VM) and Menière's disease (MD) are two common causes of recurrent spontaneous vertigo. Using history, video-nystagmography and audiovestibular tests, we developed machine learning models to separate these two disorders. METHODS: We recruited patients with VM or MD from a neurology outpatient facility. One hundred features from six "feature subsets": history, acute video-nystagmography and four laboratory tests (video head impulse test, vestibular-evoked myogenic potentials, caloric testing and audiogram) were used. We applied ten machine learning algorithms to develop classification models. Modelling was performed using three "tiers" of data availability to simulate three clinical settings. "Tier 1" used all available data to simulate the neuro-otology clinic, "Tier 2" used only history, audiogram and caloric test data, representing the general neurology clinic, and "Tier 3" used history alone as occurs in primary care. Model performance was evaluated using tenfold cross-validation. RESULTS: Data from 160 patients with VM and 114 with MD were used for model development. All models effectively separated the two disorders for all three tiers, with accuracies of 85.77-97.81%. The best performing algorithms (AdaBoost and Random Forest) yielded accuracies of 97.81% (95% CI 95.24-99.60), 94.53% (91.09-99.52%) and 92.34% (92.28-96.76%) for tiers 1, 2 and 3. The best feature subset combination was history, acute video-nystagmography, video head impulse test and caloric testing, and the best single feature subset was history. CONCLUSIONS: Machine learning models can accurately differentiate between VM and MD and are promising tools to assist diagnosis by medical practitioners with diverse levels of expertise and resources.

Assessing Cognitive Effort in Ménière's Disease: Pupillometry as a Novel Tool for Postural Control.

BACKGROUND: This study aimed to investigate the utility of pupillometry as a measure of cognitive effort in individuals with Ménière's disease experiencing chronic postural destabilization. By integrating pupillometry with static posturography, we sought to gain deeper insights into the cognitive demands and arousal levels associated with postural control in this specific patient population. METHODS: The study included 36 patients who met the diagnostic criteria for Ménière's disease and a control group comprising 36 healthy volunteers. We performed static posturography using a computerized static posturography platform to objectively assess postural imbalance. Additionally, pupillometry was recorded using infrared video-oculoscopy. Pupil dilation was measured before and after participants walked for 7 steps on-site with their vision obscured. RESULTS: Baseline tonic pupil size showed no significant difference between healthy controls and Ménière's patients. However, after walking stimulation, Ménière's patients exhibited highly significant abnormal walking-induced pupil dilation. This suggests increased arousal in response to the challenging task of walking with closed eyes, linked to static upright stance imbalance as correlated with posturography parameters. CONCLUSION: Pupillometry holds promise as an objective tool to assess cognitive effort and arousal during postural control in Ménière's disease. Implementing pupillometry in clinical practice could enhance the management of postural instability in these patients. Our findings contribute to the understanding of cognitive aspects in balance control and open new avenues for further investigations in vestibular dysfunction.

The correlation of hearing prognosis and caloric test results in Meniere's disease: a follow up study.

BACKGROUND: Hearing loss is important in the diagnosis and treatment of Meniere's disease (MD). However, little is known about the factors associated with hearing changes in MD. AIMS/OBJECTIVES: This study aimed to investigate the correlation between hearing prognosis and caloric test (CT) results in MD. MATERIAL AND METHODS: Ninety consecutive patients diagnosed with unilateral definite MD underwent pure tone audiometry (PTA) and CT at initial visits, and were re-tested PTA at the 6-month follow-up. RESULTS: Fifty-three of ninety MD patients (58.89%) had abnormal CT results. The change of PTA (cPTA = initial PTA-last PTA) was negatively correlated with canal paresis (CP) values (overall association p = 0.032 and non-linear association p = 0.413). Multivariate linear model showed that as the CP value changed from 0 to 1, the cPTA decreased by -13.31 dB (95% CI: -24.03, -2.6) (p = 0.016). Stratified analysis found that the association was present in MD patients of Stage 1 and 2 (p < 0.05) but not in patients of Stage 3 and 4 (p > 0.05). CONCLUSIONS AND SIGNIFICANCE: Elevated CP values may be linked to worse hearing outcomes in MD, especially in Stage 1 and 2 patients. Conducting a caloric test at the initial consultation may aid in assessing hearing regression in MD.

A 3-hour time interval may not be sufficient for delayed enhancement magnetic resonance imaging with intravenous gadoteridol injection based on 3d-real IR sequence of the inner ear in Meniere's disease patient.

BACKGROUND: Magnetic resonance imaging (MRI) can be applied to visualize endolymphatic hydrops (EH). AIMS/OBJECTIVES: To explore whether a 3-h time interval was feasible for clinical practice. MATERIALS AND METHODS: We prospectively enrolled 15 patients with unilateral Meniere's disease, each of whom underwent delayed enhancement MRI scan of the inner ear after intravenous gadoteridol injection at a 3-h interval. The ears of these patients were divided into two groups (group A: the affected ears; group B: the unaffected ears). Among the two groups, the signal intensity in perilymphatic area of the basal turn of cochlea, the results of visual evaluations in the vestibule, cochlea and semicircular canal and the detection results of EH were compared. RESULTS: Regarding the signal intensity, a difference was found between group A and group B (p = .016). Besides, no difference was found between the visual evaluations in the vestibule, cochlea and semicircular canal of the two groups. Regarding the detection results of EH, group A (6 vestibules were undiagnosable; 8 cochleae were undiagnosable); group B (9 vestibules were undiagnosable; 10 cochleae were undiagnosable). CONCLUSIONS AND SIGNIFICANCE: In the clinical application of gadoteridol for the inner ear, 3-h delayed MR imaging may not be sufficient.

Low-sodium diet with adequate water intake improved the clinical efficacy in Ménière's disease.

BACKGROUND: Ménière's disease (MD) is a common idiopathic inner ear disorder in otorhinolaryngology characterized by recurrent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus and ear fullness. OBJECTIVE: To study the effects of low-sodium diet with adequate water intake on the clinical efficacy in MD. METHODS: Fifty patients diagnosed with stage-3 unilateral MD were randomly divided into control group(n = 25) and experimental group(n = 25). The control group was given routine medication therapy, and the experimental group was restricted to an sodium intake of 1500 mg/d and a water intake of 35 ml/kg/d based in addition to the routine medication therapy. The two groups were assessed using pure tone audiometry, electrocochleography, Tinnitus Handicap Inventory (THI), and Dizziness Handicap Inventory (DHI). RESULTS: The pure tone audiometry and electrocochleography showed better improvements after treatment in the experimental group than the control group (p < 0.05). The THI improved values in the experimental group were significantly higher than the control group (p < 0.001). The DHI improved values in the experimental group were significantly higher than the control group (p = 0.004). CONCLUSIONS AND SIGNIFICANCE: Low-sodium diet with adequate water intake improved the hearing and alleviated vertigo and tinnitus in MD patients.

Cochlear Otosclerosis and Secondary Hydrops (Ménière's Syndrome).

ABSTRACT: This article discusses a case of cochlear otosclerosis leading to secondary hydrops and near-complete hearing loss. Histopathological examination revealed advanced multifocal otosclerosis in both temporal bones, with specific focus on cochlear invasion and significant bone resorption. The severity of the case ruled out surgical intervention due to the risk of further hearing loss. The article emphasizes the challenges in managing otosclerosis-related hydrops and highlights the potential use of advanced imaging techniques for diagnosis. The study underscores the complexity of otosclerosis-induced hearing loss, contributing to the understanding of this pathology and its impact on auditory function.

Probabilities of Isolated and Co-Occurring Vestibular Disorder Symptom Clusters Identified Using the Dizziness Symptom Profile.

OBJECTIVES: Dizziness is among the most common reasons people seek medical care. There are data indicating patients with dizziness, unsteadiness, or vertigo may have multiple underlying vestibular disorders simultaneously contributing to the overall symptoms. Greater awareness of the probability that a patient will present with symptoms of co-occurring vestibular disorders has the potential to improve assessment and management, which could reduce healthcare costs and improve patient quality of life. The purpose of the current investigation was to determine the probabilities that a patient presenting to a clinic for vestibular function testing has symptoms of an isolated vestibular disorder or co-occurring vestibular disorders. DESIGN: All patients who are seen for vestibular function testing in our center complete the dizziness symptom profile, a validated self-report measure, before evaluation with the clinician. For this retrospective study, patient scores on the dizziness symptom profile, patient age, and patient gender were extracted from the medical record. The dizziness symptom profile includes symptom clusters specific to six disorders that cause vestibular symptoms, specifically: benign paroxysmal positional vertigo, vestibular migraine, vestibular neuritis, superior canal dehiscence, Meniere disease, and persistent postural perceptual dizziness. For the present study, data were collected from 617 participants (mean age = 56 years, 376 women, and 241 men) presenting with complaints of vertigo, dizziness, or imbalance. Patients were evaluated in a tertiary care dizziness specialty clinic from October 2020 to October 2021. Self-report data were analyzed using a Bayesian framework to determine the probabilities of reporting symptom clusters specific to an isolated disorder and co-occurring vestibular disorders. RESULTS: There was a 42% probability of a participant reporting symptoms that were not consistent with any of the six vestibular disorders represented in the dizziness symptom profile. Participants were nearly as likely to report symptom clusters of co-occurring disorders (28%) as they were to report symptom clusters of an isolated disorder (30%). When in isolation, participants were most likely to report symptom clusters consistent with benign paroxysmal positional vertigo and vestibular migraine, with estimated probabilities of 12% and 10%, respectively. The combination of co-occurring disorders with the highest probability was benign paroxysmal positional vertigo + vestibular migraine (~5%). Probabilities decreased as number of symptom clusters on the dizziness symptom profile increased. The probability of endorsing vestibular migraine increased with the number of symptom clusters reported. CONCLUSIONS: Many patients reported symptoms of more than one vestibular disorder, suggesting their symptoms were not sufficiently captured by the symptom clusters used to summarize any single vestibular disorder covered by the dizziness symptom profile. Our results indicate that probability of symptom clusters indicated by the dizziness symptom profile is comparable to prior published work on the prevalence of vestibular disorders. These findings support use of this tool by clinicians to assist with identification of symptom clusters consistent with isolated and co-occurring vestibular disorders.

Cluster Analysis to Identify Clinical Subtypes of Ménière's Disease.

OBJECTIVE: To identify distinct clinical subtypes of Ménière's disease by analyzing data acquired from a UK registry of patients who have been diagnosed with Ménière's disease. STUDY DESIGN: Observational study. METHODS: Patients with Ménière's disease were identified at secondary/tertiary care clinics. Cluster analysis was performed by grouping participants sharing similar characteristics and risk factors into groups based on a defined measure of similarity. RESULTS: A total of 411 participants were recruited into this study. Two main clusters were identified: participants diagnosed with ear infections (OR = 0.30, p < 0.014, 95% CI: 0.11-0.78) were more likely to be allocated in Cluster 1 (C1). Participants reporting tinnitus in both ears (OR = 11.89, p < 0.001, 95% CI: 4.08-34.64), low pitched tinnitus (OR = 21.09, p < 0.001, 95% CI: 7.47-59.54), and those reporting stress as a trigger for vertigo attacks (OR = 14.94, p < 0.001, 95% CI: 4.54-49.10) were significantly more likely to be in Cluster 2 (C2). Also, participants diagnosed with Benign Paroxysmal Positional Vertigo (OR = 13.14, <0.001, 95% CI: 4.35-39.74), autoimmune disease (OR = 5.97, p < 0.007, 95% CI: 1.62-22.03), depression (OR = 4.72, p < 0.056, 95% CI: 0.96-23.24), migraines (OR = 3.13, p < 0.008, 95% CI: 1.34-7.26), drug allergy (OR = 3.25, p < 0.029, 95% CI: 1.13-9.34), and hay fever (OR = 3.12, p < 0.009, 95% CI: 1.33-7.34) were significantly more likely to be clustered in C2. CONCLUSIONS: This study supports the hypothesis that Ménière's disease is a heterogeneous condition with subgroups that may be identifiable by clinical features. Two main clusters were identified with differing putative etiological factors. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:3286-3292, 2024.

An Update on the Epidemiology and Clinicodemographic Features of Meniere's Disease.

OBJECTIVE: To characterize the estimated prevalence and clinicodemographic features of Ménière's disease (MD) using current diagnostic criteria. METHODS: A cross-sectional study was undertaken at our tertiary academic referral center. All patients seen in Otolaryngology clinic with ICD-10 diagnoses of MD, from January 1, 2013 to July 31, 2022 were identified. Chart review was undertaken to determine the estimated prevalence of MD meeting AAO-HNS diagnostic criteria. Clinicodemographic features were evaluated against a comparator group without MD seen in our health system. RESULTS: Of 806 ICD-10 diagnoses of MD, we identified 480 MD cases meeting diagnostic criteria (168 definite). Mean age at presentation for MD cases was 49 years. Forty-seven percent of cases were male. A significantly higher proportion of MD cases than comparators were white (76% vs. 66%, p < 0.001). Mean time since MD symptom onset was 6.7 years, with a mean attack duration of 4.6 h; 7.5% of MD cases reported a positive family history, and 7% had bilateral disease. The odds of reporting migraine were significantly greater among MD patients than comparators (OR 1.74 [1.26-2.42]); the odds of having autoimmune conditions were lower (OR 0.45 [0.28-0.74]); and the odds of reporting allergies were no different (OR 0.96 [0.74-1.25]) versus comparator patients after controlling for demographic characteristics. CONCLUSIONS: Among MD diagnoses, there is a low estimated prevalence of MD meeting diagnostic criteria, and an even lower prevalence of definite MD. Compared to a comparator group of patients seen for any disorder, patients with MD are more likely to be white, male, and have a history of migraine. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:3310-3315, 2024.

Significance of endolymphatic sac surgery with and/or without simultaneous cochlea implant surgery in respect of vertigo control and speech perception in patients with Menière's disease.

PURPOSE: The focus on treating patients with Menière's Disease (MD) lies on the reduction of vertigo attacks and the preservation of sensory function. Endolympathic hydrops is considered as an epiphenomenon in MD, which can potentially be altered by endolymphatic sac surgery (ESS). Purpose of the study was to investigate the influences on vertigo control through manipulation of the perilymphatic system with or without ESS. METHODS: Retrospective data analysis of 86 consecutive patients with MD according to current diagnostic criteria after endolymphatic sac surgery alone (ESSalone; n = 45), cochlear implantation (CI) alone (CIalone; n = 12), and ESS with CI (ESS + CI; n = 29), treated at a tertiary referral center. MAIN OUTCOME MEASURES: vertigo control, speech perception pre- and postoperatively. RESULTS: Gender, side, and preoperative treatment were similar in all groups. Age was younger in the ESSalone-group with 56.2 ± 13.0 years (CIalone = 64.2 ± 11.4 years; ESS + CI = 63.1 ± 9.7 years). Definitive MD was present in all the CIalone, in 79.3% of the ESS + CI and in 59.6% of the ESSalone-patients. Likewise, vertigo control rate was 100% in the CIalone, 89.7% in the ESS + CI and 66.0% in the ESSalone-group. CONCLUSIONS: Vertigo control was improved in all three groups, however, superior in groups treated with CI, potentially contributed by the manipulation of both the endo- and perilymphatic systems. A more systematic characterization of the patients with larger case numbers and documentation of follow up data would be needed to evaluate a clinical effect more properly.

Course of Duration and Trigger Factors of Vertigo Attacks in Patients with Benign Recurrent Vertigo, Menière's Disease, or Vestibular Migraine.

INTRODUCTION: Benign recurrent vertigo (BRV), Menière's disease (MD), and vestibular migraine (VM) show many similarities with regard to the course of vertigo attacks and clinical features. In this paper, we elaborate on the decreasing frequency of vertigo attacks observed in a previous study from our group by exploring changes in the duration and trigger factors of vertigo attacks in patients with BRV, MD, or VM. METHODS: For this 3-year prospective cohort study in our tertiary referral center we recruited patients with a confirmed diagnosis of BRV, MD, or VM by a neurologist and otorhinolaryngologist in our center in 2015-2016. A study-specific questionnaire was used to assess the usual duration of vertigo attacks and their potential triggers every 6 months. Main outcome measures were changes in duration and trigger factors of vertigo attacks in the subgroups of patients with persisting attacks, which were analyzed using repeated measures logistic regression models. RESULTS: 121 patients were included (BRV: n = 44; MD: n = 43; VM: n = 34) of whom 117 completed the 3-year follow-up period and 57 (48.7%) kept reporting vertigo attacks at one more follow-up measurements. None of the diagnosis groups showed statistically significant shortening of attack duration at the subsequent annual follow-up measurements compared to baseline. At baseline, stress and fatigue being reported as triggers for attacks differed significantly between the three groups (stress: BRV 40.9%, MD 62.8%, VM 76.5%, p = 0.005; fatigue: BRV 31.0%, MD 48.8%, VM 68.8%, p = 0.003). In the VM group, a consistent reduction of stress and fatigue as triggers was observed up until the 24- and the 30-month follow-up measurements, respectively, with odds ratios (ORs) ranging from 0.15 to 0.33 (all p < 0.05). In the MD group, a consistent reduction of head movements as trigger was observed from the 24-month measurement onward (ORs ranging from 0.07 to 0.11, all p < 0.05). CONCLUSION: Our study showed no reduction in vertigo attack duration over time in patients with BRV, MD, and VM who remain to have vertigo attacks. In VM and MD patients with persisting vertigo attacks stress, fatigue and head movements became less predominant triggers for vertigo attacks.

Item Level Psychometrics of the Dizziness Handicap Inventory in Vestibular Migraine and Meniere's Disease.

OBJECTIVES: Evaluate the measurement properties of the Dizziness Handicap Inventory (DHI) using item response theory in patients diagnosed with vestibular migraine (VM) and Meniere's disease (MD). DESIGN: One hundred twenty-five patients diagnosed with VM and 169 patients diagnosed with MD by a vestibular neurotologist according to the Bárány Society criteria in two tertiary multidisciplinary vestibular clinics and who completed the DHI at their initial visit, were included in the study. The DHI (total score and individual items) was analyzed using the Rasch Rating Scale model for patients in each subgroup, VM and MD, and as a whole group. The following categories were assessed: rating-scale structure, unidimensionality, item and person fit, item difficulty hierarchy, person-item match, and separation index, standard error of measurement, and minimal detectable change (MDC). RESULTS: Patients were predominantly female (80% of the VM subgroup and 68% of the MD subgroup) with a mean age of 49.9 ± 16.5 years and 54.1 ± 14.2 years, respectively. The mean total DHI score for the VM group was 51.9 ± 22.3 and for the MD group was 48.5 ± 26.6 ( p > 0.05). While neither all items nor the separate constructs met all criteria for unidimensionality (i.e., items measuring a single construct), post hoc analysis showed that the all-item analysis supported a single construct. All analyses met the criterion for showing a sound rating scale and acceptable Cronbach's alpha (≥0.69). The all-item analysis showed the most precision, separating the samples into three to four significant strata. The separate-construct analyses (physical, emotional, and functional) showed the least precision, separated the samples into less than three significant strata. Regarding MDC, the MDC remained consistent across the analyses of the different samples; approximately 18 points for the full analyses and approximately 10 points for the separate construct (physical, emotional, and functional). CONCLUSIONS: Our evaluation of the DHI using item response theory shows that the instrument is psychometrically sound and reliable. The all-item instrument fulfills criteria for essential unidimensionality but does seem to measure multiple latent constructs in patients with VM and MD, which has been reported in other balance and mobility instruments. The current subscales did not show acceptable psychometrics, which is in line with multiple recent studies favoring the use of the total score. The study also shows that the DHI is adaptable to episodic recurrent vestibulopathies. The total score shows better precision and separation of subjects in up to four strata compared to the separate construct that separate subjects into less than three strata. The measurement error smallest detectable change was found in our analysis to be 18 points, which means any change in the DHI of less than 18 points is not likely to be clinically significant. The minimal clinically important difference remains indeterminate.

Impact of endolymphatic hydrops on the function of the horizontal canal during caloric stimulation in Ménière's disease.

PURPOSE: When a dizzy patient with episodic vertigo has an abnormal caloric and a normal video head impulse test (vHIT), this caloric-vHIT dissociation provides vital information for a diagnosis of Ménière's disease (MD). Endolymphatic hydrops (EH), a histological marker of MD, is hypothesized to be involved in the caloric-vHIT dissociation in MD through hydropic duct distension of the horizontal semicircular canal (SC). This study was designed to determine the impact of EH on the function of horizontal SC during caloric stimulation. METHODS: Caloric test and vHIT were used to evaluate the function of horizontal SC every six months, annual magnetic resonance imaging (MRI) was used to evaluate the degree of EH size in the vestibule, and monthly vertigo and hearing evaluation was done for 12 months. EH shrinkage was defined as the size change of vestibular EH from significant to none. RESULTS: Among 133 MD patients evaluated for eligibility, 67 patients with caloric-vHIT dissociation entered the study. Fifteen participants had EH shrinkage (G-I), while 52 participants had no remarkable EH change (G-II). Average values (IQR) of the maximum slow phase velocity in G-I and G-II were 29.6 (13.0-34.0) and 25.9 (17.3-31.3), respectively, at baseline, 26.1 (9.0-38.0) and 23.6 (18.0-28.3) at 12 months. Two-factor repeated-measures ANOVA showed no significant differences between the groups (P = 0.486). The values of vestibulo-ocular reflex gain of the horizontal SC in G-I and G-II remained above 0.8 during the study period. CONCLUSIONS: EH detected by MRI shows limited correlation with caloric stimulation results.