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.

Functional outcomes and caloric response changes after endolymphatic sac decompression.

OBJECTIVE: To evaluate caloric response changes after endolymphatic sac decompression (ESD), together with hearing outcomes and the functional benefit of the operation. METHODS: A retrospective chart review of subjects who underwent endolymphatic sac decompression at a tertiary referral centre was performed. Data on audiological results, caloric testing, and functional level scale of the patients were analysed. RESULTS: Twenty-eight patients who met our criteria were eligible for enrolment in the study. The average follow-up after surgery was 25 months (range, 13-41). Postoperative pure-tone threshold averages and reduced vestibular response values (RVR) were not significantly altered by ESD; whereas, functional level scores improved significantly. CONCLUSION: Endolymphatic sac decompression is a surgical procedure that preserves hearing and vestibular function, and improves the daily functional level of patients with Ménière's disease. ESD can be preferred both in bilateral and unilateral disease because it does not alter vestibular function and preserves hearing.

Preliminary Evidence for the Effects of Gentamicin on Vertical Semicircular Canals.

INTRODUCTION: Gentamicin is a vestibulotoxic antibiotic often used in patients with Ménière's disease for its vestibular ablative effects. Gentamicin's effect on the horizontal semicircular canal does not always correlate with the degree of vertigo control achieved by patients; its effect on the vertical semicircular canals remains unknown. We sought to examine the effect of intratympanic gentamicin on vertical semicircular canal function in patients with Ménière's disease using video head impulse testing. METHODS: A retrospective case series was carried out at a tertiary academic center. Patients with Ménière's disease who received ≥1 intratympanic gentamicin injection from 2019-2022 and had video head impulse testing performed were included. Outcomes of interest were vertical semicircular canal function following intratympanic gentamicin, correlations between vertical semicircular canal function and horizontal semicircular canal function, and residual symptoms following injection. RESULTS: Ten patients met inclusion criteria. Twenty percent had abnormal V-SCC function prior to any injection and 40% following the first injection. There was an association between abnormal vertical and horizontal semicircular canal function following the first intratympanic gentamicin injection, though the relationship did not reach statistical significance (p = 0.058). While patients with abnormal vertical semicircular canal function following the first injection were less likely to report ongoing vertigo attacks, the relationship was not statistically significant (p = 0.260). CONCLUSIONS: Intratympanic gentamicin leads to changes in vertical semicircular canal function in at least a proportion of patients with Ménière's disease. Further study is required to better assess correlations between vertical semicircular canal function and symptom control following intratympanic gentamicin.

Ocular Movement Examination in Peripheral Vestibular Disorders as a Tool to Improve Diagnosis: A Literature Review.

Background and Objectives: This study reviews the current literature on ocular movements, specifically focusing on nystagmus associated with peripheral vestibular disorders, to enhance diagnostic accuracy. The evaluation of ocular movements, particularly nystagmus, provides essential insights into the function and dysfunction of the vestibular system, helping clinicians distinguish between peripheral and central causes of vertigo and imbalance. Materials and Methods: A comprehensive search of PubMed was conducted using key terms such as "ocular movements", "nystagmus", "vestibular nystagmus", and "peripheral vestibular disorders". Results: The search yielded 2739 titles, and after a rigorous selection process, 52 articles were reviewed in full. Discussion: The review highlights different classifications and types of nystagmus, including physiological and pathological forms, and their diagnostic relevance in vestibular disorders such as benign paroxysmal positional vertigo (BPPV), vestibular neuritis, and Meniere's disease. Diagnostic techniques like video/electro-oculography are emphasized for their role in assessing vestibular function and identifying abnormalities. The study underscores the importance of detailed ocular examination in the diagnosis of peripheral vestibular disorders and proposes an algorithm to aid this process. Conclusions: While not a systematic review, this study highlights the importance of detailed ocular examination in diagnosing peripheral vestibular disorders and presents an algorithm to facilitate this process. It also emphasizes the need for continued research and advancements in vestibular medicine to further understand ocular movements and their clinical significance, ultimately contributing to improved patient outcomes.

Evaluating vertebrobasilar insufficiency and Meniere's disease: Insights from cervical vestibular evoked myogenic potential and video head impulse test.

Background and purpose:

This prospective study aimed to investigate diffe-rences in video head impulse test (vHIT) and cervical vestibular evoked myogenic poten-tial (cVEMP) findings between patients with vertebrobasilar insufficiency (VBI) and Meniere’s disease (MD) who experience episodic vertigo attacks.

A total of 27 patients with VBI and 37 patients with MD were enrolled into the study in a tertiary referral center. Inclusion criteria consisted of patients with a minimum of two previous vertigo attacks, unaccompanied by any neurological symptoms during an attack. All patients underwent horizontal canal h-vHIT and c-VEMP assessments following pure sound audiometric examinations. First, vHIT and cVEMP results for low and high flow sides in VBI patients were analyzed. Subsequently, data from the low-flow side in VBI patients and the affected side in MD patients were compared.

The mean vHIT values for low and high-flow volume sides in VBI patients were 0.68 and 0.88, respectively. In MD patients, mean vHIT values for affected and healthy sides were measured as 0.77 and 0.87, respectively. Abnormal results were observed in 66.7% of VBI patients and 51.4% of MD patients, with no statistically significant difference between the findings (p> 0.05). Upon examining the affected side, c-VEMP responses were absent in 41% of MD patients and 48% of VBI patients, with no statistically significant difference between the groups (p> 0.05).

vHIT and cVEMP assessments can be utilized as supplementary tools to radiologic investigations for the clinical diagnosis and follow-up of VBI. However, no significant differences were observed between vHIT and cVEMP findings in patients with MD and VBI.

Meniere's disease: Medical management, rationale for vestibular preservation and suggested protocol in medical failure.

Meniere's disease is a peripheral audiovestibular disorder characterized by vertigo, hearing loss, tinnitus, and aural fullness. Management of these symptoms includes medical and surgical treatment. Many patients with Meniere's disease can be managed using nonablative therapy, such as intratympanic steroids and endolymphatic shunt surgery, prior to ablative techniques such as intratympanic gentamicin. Recognition of concurrent migraine symptoms may aid in medical therapy and also underscore the importance of preserving vestibular function where possible. The goal of this review is to explain the importance of nonablative therapy options and discuss treatment protocols after medical failure.

Intratympanic steroid versus gentamicin for treatment of refractory Meniere's disease: A meta-analysis.

PURPOSE: Intratympanic steroid injections (ITSI) have become a promising treatment for refractory Meniere's disease due to less cochleovestibular damage. However, whether ITSI would be a good alternative to intratympanic gentamicin injections (ITGI) for refractory Meniere's disease still remains controversial. Here we intended to compare the therapeutic effect of ITSI and ITGI in patients with Meniere's disease refractory to conservative treatments, in terms of vertigo control and hearing outcomes, via a meta-analysis. METHODS: Using MEDLINE, PubMed, and EMBASE databases, we calculated pooled odds ratio (OR) estimates of vertigo control rate (i.e., class A according to AAO-HNS guideline) and standardized mean differences (SMD) of spell count, pure tone audiometry (PTA) threshold and speech discrimination score (SDS) with a 95% confidence interval (CI). The trim-and-fill method and sensitivity analysis were used as post-hoc analyses to verify the integrity of the quantitative analysis results. Furthermore, subgroup analyses were performed according to steroid type (methylprednisolone versus dexamethasone) and follow-up period (>1-year versus <1-year). RESULTS: Five studies involving 332 patients with refractory unilateral Meniere's disease were included. In the pooled analysis, those treated with ITGI showed higher ORs than those treated with ITSI in terms of vertigo control rate (OR: 2.39, 95% CI: 0.84-6.79, P = 0.102) and spell counts (SMD: 0.24, 95% CI: -0.12-0.59, P = 0.195), but it did not reach statistical significance. However, a substantial amount of heterogeneity (I2 = 71.0%, Q = 13.79, P = 0.008) and publication bias was found, suggesting a significant small-study effect. Additionally, ITSI elicited better hearing outcomes of the mean PTA threshold (SMD: 3.08, 95% CI: -1.18-7.35) and mean SDS (SMD: 11.15, 95% CI: -23.21-0.90) compared with ITGI, although no statistical significance. In subgroup analysis, the difference in vertigo control rate between ITGI and ITSI was not significant, regardless of the follow-up period and steroid type. Further, methylprednisolone appeared to be superior to dexamethasone for vertigo control. No significant complications from either treatment were reported in the literature. CONCLUSION: The results of this study further refine the recently proposed efficacy of ITSI for the treatment of refractory Meniere's disease, demonstrating the comparable value of ITGI on vertigo control as well as better hearing preservation. Collectively, ITSI could be a safe and the effective treatment for refractory Meniere's disease. However, the current evidence on efficacy of ITSI for refractory Meniere's disease needs to be further clarified, given the substantial heterogeneity and potential biases.

Differences in responsiveness of intratympanic steroid injection for intractable vertigo in Meniere's disease.

OBJECTIVES: The efficacy of intratympanic steroid (ITS) injection for intractable Meniere's disease has been reported; however, its differences in responsiveness are not fully understood. This study investigated the clinical characteristics of patients who responded to ITS injection treatment. METHODS: This retrospective study included 32 patients with Meniere's disease who were unable to control frequent vertigo attacks despite conservative treatment for at least 3 months. They received an intratympanic injection of dexamethasone (3.3 mg/mL) in the affected side at least three times. We measured hearing threshold, subjective symptom scores, cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP), and performed glycerol and bithermal caloric tests. RESULTS: Satisfactory control of vertigo for 1 year after the first round of injection was found in 18 patients (56.3%; the response group). However, the injections failed to control vertigo in the other 14 patients (43.8%; the non-response group), and they were then treated with middle ear micropressure therapy. The response group showed improvement in low-frequency hearing, whereas hearing acuity did not change in the non-response group. Significantly reduced amplitude of cVEMP on the affected side was found in 62.5% of patients in the response group; however, no patients in the non-response group showed reduced amplitude of cVEMP. CONCLUSIONS: ITS injection significantly improved the subjective symptoms for intractable Meniere's disease; however, the long-term effects were heterogeneous. Our results suggest that reduced amplitude in cVEMP is associated with the effectiveness of ITS injection treatment.

Quantification of endolymphatic hydrops and its correlation with Meniere's disease clinical features.

OBJECTIVE: We aimed to quantitatively evaluate the degree of endolymphatic hydrops and its correlation with the clinical features of Meniere's disease. METHODS: We retrospectively collected data from patients with Meniere's disease who underwent gadolinium-enhanced magnetic resonance imaging (MRI) at our department from January 2018 to December 2019. Mimics software was used to perform three-dimensional modelling of the labyrinth, and volume information was obtained to calculate the endolymphatic hydrops index (EHI). A correlation analysis was conducted with data from pure tone audiometry, electrocochleography (EchoG), vestibular myogenic-evoked potential (VEMP) testing, caloric testing and video head impulse testing (vHIT). A two-dimensional method was also employed to calculate the hydrops ratio (HR) of cochlea and vestibule. The test-retest reliability of EHI/HR from different operators was evaluated. RESULTS: A total of 23 affected ears were examined, and the EHI was significantly correlated with Meniere's disease stage, low-frequency hearing threshold, EchoG summating potential/action potential ratio (-SP/AP) and VEMP binaural asymmetry ratio, but no significant correlation was observed between EHI and the caloric test or vHIT. The Intraclass correlation coefficient (ICC) of EHI data calculated by two otologists was 0.946 (p < .001). And the ICC of cochlea and vestibule HR were 0.844 and 0.832 (p < .001). CONCLUSION: Mimics software can be used to quantitatively evaluate the degree of endolymphatic hydrops and have shown higher test-retest reliability than traditional two-dimensional evaluation method. Endolymphatic hydrops correlates with clinical data, such as Meniere's disease stage, low-frequency hearing threshold, EchoG and VEMP asymmetry ratio.

Current Understanding and Clinical Management of Meniere's Disease: A Systematic Review.

Meniere's disease (MD) is a set of uncommon disorders with core phenotype of tinnitus, episodic vertigo, and sensorineural hearing loss. MD shows a genetic predisposition and a family history is found in 10% cases, with an autosomal dominant inheritance pattern. It is a multifactorial condition whose onset and development are triggered by the combined effect of genetic and environmental factors. Histopathological studies have associated MD with the accumulation of endolymph in the cochlea and the vestibular organs. However, endolymphatic hydrops does not fully explain the persistence of tinnitus, hearing loss progression, or the frequency of vertigo attacks.There are several comorbidities associated with MD, such as migraine, anxiety, autoimmune, and autoinflammatory disorders, adding more complexity to the phenotype. This "extended phenotype" can make the diagnosis and clinical management more complex, but it could also lead to a better characterization, understanding, and treatment of MD patients.We have conducted a systematic review on MD to update current knowledge, focusing on its mechanisms, diagnosis, comorbidities, and practical management.

Bone Mineral Density in Patients Suffering from Ménière's Disease.

INTRODUCTION: Previous studies have reported an association between reduced bone mineral density and the occurrence of benign paroxysmal positional vertigo, balance impairment, and saccular dysfunction. Furthermore, the results of recent animal studies have raised the possibility that vestibular dysfunction could affect bone remodeling and bone mass. The goal of the study was to compare bone mineral density of patients suffering from definite Ménière's disease to that of a matched control group. METHODS: We conducted a case-control cross-sectional study in a tertiary referral center. The study group included 23 patients suffering from definite Ménière's disease, and the control group was comprised of 23 patients matched in their race, gender, and age parameters in whom no vestibular pathology could be found. Dual energy X-ray absorptiometry of the femoral head was used for the assessment of bone mineral density. The T and Z scores of the femoral heads' bone mineral density were compared. RESULTS: The average T scores were -1.53 ± 1.08 in the study and -0.39 ± 0.72 (p = 0.016) in the control groups, and the Z scores were -0.4 ± 0.63 and 0.33 ± 0.31 (p = 0.018), respectively. Seventeen patients (74%) of the study group and 9 (39%) of the control group had T scores less than -1.0, indicating osteopenia/osteoporosis (p = 0.036). CONCLUSIONS: The results showed a significant association between Ménière's disease and reduced bone mineral density of the femoral head. Bone mineral density studies of the weight-bearing bones are warranted in Ménière's disease for the early diagnosis and treatment of osteopenia/osteoporosis on the one hand and possible benefit of this treatment for the evolution of Ménière's disease on the other hand.

The role of endogenous Antisecretory Factor (AF) in the treatment of Ménière's Disease: A two-year follow-up study. Preliminary results.

PURPOSE: To evaluate the effects of increased endogenous Antisecretory Factor (AF) synthesis using specially processed cereals (SPC) in a sample of patients with defined unilateral Meniere's disease (MD), compared to the results of a treatment protocol of intravenous glycerol and dexamethasone. MATERIALS AND METHODS: Twenty-six patients with unilateral MD were divided in 2 groups and treated with SPC and with intravenous glycerol and dexamethasone for 24 months. Audio-vestibular evaluation was performed before (T0) and every six months. The number of vertigo spells were evaluated before and after therapy and the Efficacy Index (EI) was calculated. Questionnaires for hearing loss, tinnitus and quality of life were administered. RESULTS: EI decreased in the SPC group after 18 (T18) (p = .0017) and 24 (T24) months of therapy (p = .0111). There was a significant reduction for tinnitus score in the SPC group at T24 (p = .0131). No significant differences were found between the two groups at T0 (p = .4723), while a significant difference was found at T24 (p = .0027). Quality of life showed a significant improvement in daily activities in the SPC group (p = .0033) compared to the infusion therapy group. No statistically significant changes in PTA thresholds were found in both groups between T0 and T24. CONCLUSION: The preliminary results of our study show a significant reduction of vertigo spells and a positive effect on tinnitus severity and on quality of life in patients with unilateral MD treated with SPC and when compared to patients treated with intravenous glycerol and dexamethasone. No effects on hearing thresholds were noted in both groups.

Menière's disease patients improve specific posturographic parameters following diagnostic intratympanic injection.

PURPOSE: Evaluation of specific computerized posturographic parameters in patients with Menière's disease (MD) following the intratympanic injection of gadolinium, a contrast agent, used in radiological diagnosing. MATERIALS AND METHODS: We have observed 12 adult patients with unilateral Menière's Disease subjected to inner ear magnetic resonance imaging (MRI) examination after intratympanic gadolinium injection (ITG). The diagnoses have been performed according to the guidelines of the American Academy of otolaryngology. Before and after 24 h the ITG, all patients were subjected to the clinical evaluation and computerized posturography (CP), in 4 conditions depending on open/closed eyes and with/without foam cushion under feet. RESULTS: After ITG, in the affected ear the MRI confirmed the endolymphatic hydrops revealing a thin or even disappeared perilymphatic space. The statokinesigram showed improvement of stability only with closed eyes on a foam cushion. The CP performed 24 h after the contrast intratympanic injection showed a significant reduction of Path Length and Confidence Ellipse Area, due to an improvement of vestibular function on static balance. This improvement could be directly dependent to intratympanic pressure modification mediated by volume of contrast liquid, by "columella effect". CONCLUSIONS: This study demonstrates the absence of vestibular damage in patients undergoing intratympanic gadolinium infiltration and confirms the relationship between intratympanic pressure and vestibular stability modifications providing positive evidences for an applicative use of CP as a functional assessment to better address diagnosis and follow-up in MD patients treated with intratympanic injections.

Bidirectional analysis of the association between Ménière's disease and depression: Two longitudinal follow-up studies using a national sample cohort.

OBJECTIVE: This study aimed to delineate the causal relationship between Ménière's disease and depression. DESIGN: Two longitudinal follow-up studies. MAIN OUTCOME MEASURES: The 2002-2013 Korean National Health Insurance Service-Health Screening Cohort was used. In study I, Ménière's disease patients were 1:4 matched with the control I group for age group, sex, income group and region of residence, and the occurrence of depression was observed. In study II, the depression patients were 1:4 matched with the control II group for the same variables, and the occurrence of Ménière's disease was observed. The stratified Cox proportional hazard model was used. Subgroup analyses were performed according to age and sex. RESULTS: In study I, 6.9% (420/6044) of the Ménière's disease patients and 3.7% (885/24 176) of the control I participants experienced depression. The adjusted hazard ratio (HR) of Ménière's disease for depression was 1.94 (95% confidence intervals [CI] = 1.73-2.18, P < .001). In study II, 1.6% (490/31 649) of the depression patients and 1.0% (1240/126 596) of the control II participants were diagnosed with Ménière's disease. The adjusted HR of depression for Ménière's disease was 1.58 (95% CI = 1.43-1.76, P < .001). All age and sex subgroups demonstrated higher HRs of Ménière's disease for depression (study I) and depression for Ménière's disease (study II). CONCLUSION: Ménière's disease patients showed an increased likelihood of depression. Conversely, depression patients showed an elevated likelihood of Ménière's disease.

Wide-Band Tympanometry Results during an Acute Episode of Ménière's Disease.

BACKGROUND: Wide-band tympanometry (WBT) was introduced as a beneficial diagnostic test for Ménière's disease (MD) almost 15 years ago. However, an acute episode of MD has not been evaluated by using WBT yet. OBJECTIVE: To investigate WBT findings in patients with MD during acute attacks. METHOD: Thirty definite MD patients with unilateral acute low-tone sensorineural hearing loss and aural fullness, and thirty age- and sex-matched control subjects were enrolled prospectively in a tertiary referral center. Ears were divided into three groups as follows: (1) affected ears of MD patients, (2) contralateral ears of MD patients, (3) control ears. Individuals underwent WBT. The resonance frequency (RF), mean absorbance value, mean low- and high-frequency absorbance values (LF-A and HF-A), and double peak width at 2 kHz of conductance tympanometry (2-kHz PW) were assessed. RESULTS: Seventy percent in group 1, 66.7% in group 2, and 78.3% in group 3 demonstrated double peaks at 2 kHz. The mean 2-kHz PW values were 157.52 ± 79.19, 177.40 ± 79.14, and 139.64 ± 87.501 daPa for groups 1, 2, and 3, respectively. There were no significant differences between groups with respect to 2-kHz PW, RF, absorbance, LF-A, and HF-A. CONCLUSION: This was the first study that evaluated the effects of acute Ménière attacks on WBT findings. An acute Ménière attack was found to have no significant effect on the 2-kHz PW and other variables measured using WBT.

Rat Model of Ménière's Attack: Intratympanic Injection of Potassium Chloride Produces Direction-Changing Spontaneous Nystagmus and Hearing Fluctuations.

The major symptoms of Ménière's disease are episodic vertigo, fluctuating hearing loss, and tinnitus. Direction-changing spontaneous nystagmus is a characteristic vestibular finding in Ménière's disease. In the acute stage, spontaneous nystagmus beating to the affected side (irritative nystagmus) is often observed, while paralytic nystagmus beating to the healthy side is found in the chronic stage. This direction-changing nystagmus can be reproduced in guinea pigs by increasing the potassium ion concentration in the perilymph. The objectives of the present study were to examine the effects of increasing the potassium ion concentration of the rat perilymph on hearing and nystagmus. Under isoflurane anesthesia, 22 rats received intratympanic injection of different concentrations of potassium chloride (KCl) solution or distilled water: groups 1, 2, 3, and 4 received saturated (3.4 M) KCl solution, 2 M KCl, 1 M KCl, and distilled water, respectively. The nystagmus direction and number per 15 s were monitored for 150 min. In the other 8 rats, hearing was monitored 30 min and 20 h after intratympanic injection of 2 M KCl (group 5) or distilled water (group 6) using the auditory brainstem responses. Rats in groups 1 and 2 showed spontaneous irritative nystagmus beating to the affected ear followed by paralytic nystagmus beating to the contralateral side. In group 3, irritative nystagmus occurred but paralytic nystagmus was rarely observed. Rats in group 4 showed no nystagmus. Rats in group 5 showed significant hearing impairment 30 min after KCl injection that recovered 20 h later. Control animals in group 6 showed no significant changes in hearing. The reversible hearing impairment with direction-changing spontaneous nystagmus induced by potassium injection into the tympanic cavity in rats was quite similar to that observed in acute Ménière's attacks. This rat model could be used for basic research investigating the pathophysiological mechanisms underlying Ménière's attacks.

Effects of Glycerol Test on Resonance Frequency in Patients with Ménière's Disease.

OBJECTIVE: To evaluate resonance frequency (RF) values via dehydration effects in the inner ear caused by the glycerol test, which is used as a diagnostic method for Ménière's disease (MD). METHODS: Twenty adult patients with unilateral MD were included in the study. Before, and then at 1, 2, and 3 h after administration of glycerol (1 g/kg), pure-tone hearing levels (125-8,000 kHz) and multifrequency tympanometry tests were performed. As a control, the RF values of the ears of 25 healthy subjects (i.e., 50 ears) were compared to the affected and unaffected ears in the 20 MD patients. RESULTS: There was a significant difference between the RF values of affected and healthy ears before glycerol administration (p = 0.047). The RF values before and after glycerol administration into affected ears were compared. The average RF values decreased significantly from 748.0 ± 402.1 to 808.0 ± 410.1 Hz at 1 h after glycerol intake, and this value increased during the subsequent hours. There were no statistically significant differences between the pure-tone levels before and 1 h after glycerol administration, but a significant decrease was observed at 3 h. CONCLUSION: We suggest that MD has different inner-ear dynamics and normal RF values when compared to healthy ears. Furthermore, decreased inner ear pressure causes reduction of the mass effect and a stiffening of the annular ligament. We conclude that pre- and post-RF tests should be added to the test battery for diagnosis of MD.

High-Frequency Horizontal Semicircular Canal Function in Certain Menière's Disease.

OBJECTIVES: To characterize video head impulse testing (vHIT) in definitive Menière's disease and to investigate the relationship between vHIT results and other audiovestibular function tests. DESIGN: Fifty-four patients with certain Menière's disease, that is, patients with clinically definite Menière's disease and endolymphatic hydrops visualized by locally enhanced inner ear MR imaging, were recruited for this study. All patients underwent vHIT. The vestibular-ocular reflex gain at 60 ms and refixation saccades were the outcome parameters measured. Saccades were characterized by determining the saccade frequency, their mean latency, and their mean velocity. RESULTS: Seven of 54 patients had bilateral normal vHITs. Clearly pathologically vHITs with decreased gain and refixation saccades were observed in further seven patients. The majority of patients exhibited vHITs with refixation saccades but normal gain. Saccades mostly occurred bilaterally. There was no correlation between vHIT gain or saccades and caloric irrigation, cervical vestibular evoked myogenic potential or audiometry for Menière's ears. Furthermore, vHIT gain or saccades correlated neither with age nor with the duration of the disease. CONCLUSIONS: Pathological low vHIT gain values are rarely observed in patients with certain Menière's disease, while refixation saccades occur very frequently. In the majority of patients, saccades occur bilaterally. In Menière's disease, in contrast to vestibular neuritis, there is no compensatory decrease of saccade latency over time.

Correlation between auditory-vestibular functions and estrogen levels in postmenopausal patients with Meniere's disease.

BACKGROUND: To investigate auditory and vestibular functions, estrogen levels, and its clinical correlation in postmenopausal females with Meniere's disease (MD). METHODS: We retrospectively analyzed the serum estradiol (E2) levels and the auditory and vestibular functions measured by auditory brainstem response (ABR) to high click rate, pure-tone audiometry (PTA), and caloric test on postmenopausal women who suffered from MD or not at the Specialist Clinic of Vertigo, Shandong Provincial Hospital, during September 2010 to October 2014. RESULTS: A total of 76 postmenopausal patients with MD and 50 healthy postmenopausal controls were included. The patients with MD had lower estrogen levels (22.50 ± 16.66 pg/mL vs 30.69 ± 18.59 pg/mL, P = 0.011), longer I-V interpeak latency of ABR (left 0.22 ± 0.16 mseconds vs 0.18 ± 0.10 mseconds, P = 0.118; right 0.24 ± 0.13 mseconds vs 0.17 ± 0.09 mseconds, P = 0.001), and higher unilateral weakness (UW) value (P < 0.001) in comparison with the controls. The mean pure-tone thresholds of at the speech frequency (500 Hz, 1 kHz, 2 kHz, and 3 kHz) were significantly elevated in patients with MD than those in the controls (left P < 0.001, right P < 0.01). The estradiol level of patients with MD was correlated with ABR latency (left r = -0.229, P < 0.05; right r = -0.220, P < 0.05) and UW value (r = -0.328, P < 0.05), but not with mean pure-tone threshold. CONCLUSIONS: Estrogen levels correlated with auditory and vestibular function in postmenopausal patients with MD. Low estrogen may be involved in the microcirculatory disturbance of the inner ear, affecting the occurrence and development of MD.

Sir Hugh Cairns: a pioneering collaborator.

In April 1988, Peter Schurr delivered the twelfth Sir Hugh Cairns Memorial Lecture to the Society of British Neurological Surgeons. In his lecture, The Cairns Tradition, Schurr extolled the personal virtues of Cairns. He encouraged his colleagues to draw inspiration from Cairns' renowned determination, organisation, drive for perfection, compassion, and commitment to the training of those around him. Indeed, Cairns' own personality has come to define the specialty which he established in Britain. Today's neurosurgeons are, whether knowingly or not, formed in his image. But there is a side to Hugh Cairns that has been lost in the telling of his remarkable story, and yet it played a central role in his greatest achievements. This is the side of himself which he turned towards others. Throughout his career, Cairns received an inordinate number of personal accolades. His tutelage under Cushing during a formative trip to America and the impact of his role in caring for T. E. Lawrence are well known to many. But, more than thirty years after Peter Schurr's memorial lecture, and following the eightieth anniversary of the department of neurosurgery founded by Cairns in Oxford, it is his work as a pioneering collaborator which defines his legacy today, and which calls us to learn yet another lesson from his remarkable life. In this legacy article, we review the origins of Cairns' collaborative spirit and uncover the achievements he shared with Charles Hallpike, Howard Florey, Derek Denny-Brown, William Ritchie Russell, Ludwig Guttman, and Peter Medawar, among many others.