Estimated number and prevalence of patients with delayed endolymphatic hydrops in Japan: a nationwide survey.

BACKGROUND: Delayed endolymphatic hydrops (DEH) is a rare disease, and the actual number of patients in Japan remains unknown. OBJECTIVE: To investigate the number and prevalence of patients with DEH in Japan. METHODS: In total, 781 departments of otolaryngology in Japan were selected for survey by stratified random sampling according to the total number of hospital beds. We sent questionnaires to the target departments and collected data regarding the number of patients with DEH who visited those departments in 2019. RESULTS: The overall response rate was 68.0% (531 departments). The estimate number of patients with DEH in Japan was 962, and the prevalence was calculated to be 0.8 per 100,000 population. CONCLUSION: Patients with DEH were extremely rare in Japan. SIGNIFICANCE: This may be the first nationwide epidemiological study on the number and prevalence of patients with DEH in Japan or in the world.

A 14-year nationwide epidemiological analysis of delayed endolymphatic hydrops in Japan.

BACKGROUND: Delayed endolymphatic hydrops (DEH) is an inner ear disease that causes recurrent vertigo in the ipsilateral ear or fluctuating hearing in the contralateral ear due to endolymphatic hydrops secondary to preceding deafness. There are few reports of large, multicentre studies investigating the clinical-epidemiological characteristics of DEH. OBJECTIVE: This study aimed to clarify the characteristics of DEH in Japan. METHODS: Clinical data on 662 patients with DEH were analysed by nationwide, multicentre surveys conducted by the Peripheral Vestibular Disorders Research Group of Japan. RESULTS: The proportion of ipsilateral DEH (IDEH) was slightly higher than that of contralateral DEH (CDEH) at 55.4%. The time delay between onset of precedent deafness and onset of DEH was significantly longer for CDEH than for IDEH. The most common cause of precedent deafness was a disease of unknown cause with onset in early childhood (33.1%). Epidemiological characteristics were not significantly different between CDEH with and without vertigo. CONCLUSION: DEH appearing to be caused by viral labyrinthitis has a high rate of onset within 40 years of precedent deafness. Clinical and epidemiological characteristics of IDEH, CDEH with vertigo, and CDEH without vertigo were very similar. SIGNIFICANCE: The clinical-epidemiological characteristics of DEH in Japan were clarified.

Prevalence of Endolymphatic Hydrops in Cochlear Implant Candidates with Idiopathic Profound Sensorineural Hearing Loss.

OBJECTIVE: To determine the prevalence of endolymphatic hydrops (EH) in cochlear implant (CI) candidates with idiopathic profound sensorineural hearing loss (SNHL) and its influence on the preservation of audiovestibular function after cochlear implantation. STUDY DESIGN: Prospective case series. SETTING: Tertiary referral center. PATIENTS: CI candidates with idiopathic progressive SNHL, but without classic EH-associated symptoms. INTERVENTIONS: Delayed intravenous gadolinium-enhanced inner ear fluid-attenuated inversion recovery magnetic resonance imaging as well as pure-tone audiograms, video head impulse tests, and vestibular evoked myogenic potentials before and 4 weeks after cochlear implantation. MAIN OUTCOME MEASURES: Prevalence of EH before cochlear implantation, audiovestibular function before and after surgery in hydropic and nonhydropic ears. RESULTS: Thirty-two ears in 16 CI candidates were included. Nine ears (28%) with EH were detected. Although preoperative hearing thresholds, utricular function, and semicircular canal function were not different between the two groups, saccular function was reduced in hydropic ears. Ten subjects received a unilateral CI. Of these, 3 (30%) showed EH on the implanted side. There was no difference regarding postoperative hearing loss between the two groups, but the results point toward a higher vulnerability of hydropic ears with respect to loss of otolith function after cochlear implantation. CONCLUSIONS: This is the first study showing that EH can be assumed in about one third of CI candidates with idiopathic profound SNHL, but no classic EH-associated symptoms. Preliminary results suggest that EH has no influence on the preservation of cochlear function but could be a risk factor for loss of otolith function after cochlear implantation.

The Role of Endolymphatic Hydrops in Patients with Pantonal Idiopathic Sudden Sensorineural Hearing Loss: A Cause or Secondary Reaction.

The purpose of this study was to investigate the presence of endolymphatic hydrops (EH) in both affected and unaffected ears of patients with pantonal unilateral idiopathic sudden sensorineural hearing loss (ISSNHL) using three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI) and further evaluate the significance of EH in this disorder. Twenty-seven ISSHL patients were enrolled in this study. 3D-FLAIR MRI was performed 24 h after intratympanic injection of gadolinium-diethylenetriaminepentaacetic acid (Gd-DPTA). The incidences of EH in the affected ears and contralateral unaffected ears were compared and the correlations of EH with vertigo or prognosis were analyzed using the Chi-square test. The results showed that the incidence of EH was 68.0% (17/25) in the affected ears and 34.8% (8/23) in the unaffected ears. There was a statistically significant difference between affected ears and unaffected ears in regard to the incidence of EH (P<0.05). There were no significant correlations of EH with vertigo (P=1.000) or with prognosis (P=0.359) in the affected ears. In conclusion, there is EH in the inner ear of patients with pantonal ISSNHL; EH is not related to vertigo, a concomitant symptom of ISSNHL, and the prognosis of this condition. The presence of EH may be a secondary reaction following the impairment of the inner ears with pantonal ISSNHL.

Systematic review of magnetic resonance imaging for diagnosis of Meniere disease.

The diagnostic criteria for Meniere Disease (MD) are clinical and include two categories: definite MD and probable MD, based on clinical examination and without the necessity of advanced vestibular or audiological testing. The condition is a heterogeneous disorder and it is associated with endolymphatic hydrops (EH), an accumulation of endolymph in the inner ear that causes damage to the ganglion cells. Patients with suspected EH can be examined by Magnetic Resonance Imaging (MRI), offering new insights into these inner ear disorders. Results of imaging studies using the hydrops protocols show conflicting results in MD patients. These discrepancies can be dependent either on the MRI sequence parameters or on the method of hydrops grading or the inclusion criteria to select patients. The visualization of EH can be classified based on a semi-quantitative ratio between endolymph and perilymph liquids, or on the distinction between the saccule and the utricle structures. In addition, MRI can also be used to evaluate whether cochleovestibular nerves can present with imaging signs of axonal loss.In this systematic review, we have selected case-controlled studies to better characterize the potential added value in the diagnosis and management of patients with MD. Using different techniques, studies have identified the saccule as the most specifically involved structure in MD, and saccular hydrops seems to be associated with low to medium-tone sensorineural hearing loss degree. However, early symptoms still appear too subtle for identification using MRI and the reproducibility of the hydrops protocols with various MRI scan manufacturers is debatable, thus limiting expansion of these techniques into clinical practice for the diagnosis of MD at this time.Further research is needed. The future inclusion of semicircular canal hydrops location in the imaging signs and the application of MRI in patients with atypical presentations hold promise.

Idiopathic benign paroxysmal positional vertigo with persistent vertigo/dizziness sensation is associated with latent canal paresis, endolymphatic hydrops, and osteoporosis.

OBJECTIVE: The aim of the present study was to examine the association of neuro-otological examination, blood test, and scoring questionnaire data with treatment-resistant intractability in idiopathic benign paroxysmal positional vertigo (BPPV) patients. METHODS: We experienced 1520 successive vertigo/dizziness patients at the Vertigo/Dizziness Center in Nara Medical University during May 2014 to April 2018. Six hundred and eleven patients were diagnosed as BPPV (611/1520; 40.2%) according to the diagnostic guideline of the International Classification of Vestibular Disorder in 2015. Among BPPV patients, there were 201 intractable patients (201/611; 32.9%), 66 of whom were idiopathic and enrolled to be hospitalized and receive neuro-otological examinations, including the caloric test (C-test), vestibular evoked cervical myogenic potentials (cVEMP), subjective visual vertical (SVV), glycerol test (G-test), electrocochleogram (ECoG), inner ear magnetic resonance imaging (ieMRI), blood tests including anti-diuretic hormone (ADH) and bone alkaline phosphatase (BAP), and self-rating questionnaires of depression score (SDS). Sixty-six patients were diagnosed as horizontal type cupula (hBPPVcu; n=30), horizontal type canal (hBPPVca; n=10), posterior type (n=20), and probable and/or atypical BPPV (n=6). Data are presented as ratios (+) of the number of idiopathic BPPV patients with examination and questionnaire data outside of the normal range. RESULTS: The ratio (+) data were as follows: C-test=21.2% (14/66), cVEMP=24.2% (16/66), SVV=48.5% (32/66), G-test=18.2% (12/66), ECoG=18.2% (12/66), ieMRI=12.1% (8/66), ADH=9.1% (6/66), BAP=13.6% (9/66), and SDS=37.9% (25/66). Multivariate regression analysis revealed that the periods of persistent vertigo/dizziness were significantly longer in BPPV patients with hBPPVcu, C-test (+), endolymphatic hydrops (+), and BAP (+) compared with those with negative findings. CONCLUSION: Although patients with idiopathic BPPV are usually treatable and curable within 1 month, the presence of hBPPVcu, canal paresis, endolymphatic hydrops, and elevated BAP may make the disease intractable, and thus require additional treatments.

Endolymphatic hydrops in idiopathic intracranial hypertension: prevalence and clinical outcome after lumbar puncture. Preliminary data.

Idiopathic intracranial hypertension is characterized by raised intracranial pressure (ICP) without any underlying pathology, presenting with (IIH) or without papilledema (IIHWOP). Headache, often on daily basis, is the most frequent symptom. Among audiovestibular symptoms, tinnitus and dizziness are commonly reported, while vertigo and hearing impairment are infrequent reports. Endolymphatic hydrops (ELH) is the typical histopathologic feature of Ménière disease, a condition featured by episodes of vertigo, dizziness, fluctuating hearing loss, tinnitus, and aural fullness. Evidences suggest that ICP is transmitted to inner ear. The aim of this study is to investigate the prevalence of ELH symptoms in IIH/IIHWOP and the relationship between the raised ICP and ELH. The prevalence of chronic headache and of ELH symptoms was investigated in a consecutive series of IIH/IIHWOP patients, and a standard audiometry with hearing threshold measurement (pure-tone average-PTA) was performed. Differences in chronic headache and ELH symptoms prevalence and changes of PTA threshold were calculated after ICP normalization by lumbar puncture (LP). Thirty-one patients (17 with IIH and 14 with IIHWOP) were included. Before LP, chronic headache was present in 93.5%. The percentages of patients reporting tinnitus, dizziness, vertigo, and aural fullness were 67.7, 77.4, 22.6, and 61.3%, respectively. Headache frequency as well as ELH symptoms and PTA significantly improved after LP. The improvement of PTA and of ELH symptoms observed after LP in this series of IIH/IIHWOP patients indicates that a raised ICP, a condition known to be involved in the progression and refractoriness of migraine pain, has also a role in ELH. We propose that intracranial hypertension may represent the shared pathogenetic step explaining the large epidemiological comorbidity between migraine and vestibular symptoms, at present conceptualized as "vestibular migraine."

How Often Does Stapedectomy for Otosclerosis Result in Endolymphatic Hydrops?

OBJECTIVES: 1) To evaluate the long-term (≥10 year) clinical incidence of endolymphatic hydrops (EH) after stapedectomy for otosclerosis, using low-frequency sensorineural hearing loss (LFSNHL) as a marker for EH. 2) To determine the histologic incidence of EH in human temporal bone specimens (TBS) with a history of stapedectomy for otosclerosis. 3) To determine the histologic incidence of EH in a control group of human TBS. STUDY DESIGN: Retrospective review and temporal bone study. SETTING: Tertiary medical center and temporal bone pathology laboratory. PATIENTS: Patients with otosclerosis, human TBS with otosclerosis, and human TBS with presbycusis as the control group. INTERVENTION: Pure-tone audiometry, temporal bone pathology. MAIN OUTCOME MEASURES: 1) LFSNHL, defined as >10 decibel elevation of bone conduction thresholds at 250 and 500 Hz, after correcting for age-related hearing loss (per ISO 7029). 2) Histologic assessment of EH. RESULTS: In patients with otosclerosis, 8 of 110 (7.3%) operated patients versus 3 of 123 (2.4%) nonoperated patients developed LFSNHL (p = 0.08). No patients with LFSNHL had other symptoms of EH. In TBS with otosclerosis, 11 of 93 (11.8%) operated TBS versus 3 of 156 (1.9%) nonoperated TBS had evidence of EH (p <0.001). In the control group of TBS with presbycusis, 9 of 253 (3.5%) had EH. CONCLUSION: The long-term incidence of LFSNHL, a marker for EH, in patients with otosclerosis was not significantly higher in those who underwent stapedectomy. The histologic incidence of EH, however, was significantly higher in TBS that had undergone stapedectomy compared with nonoperated TBS or a control group of TBS.

Endolymphatic hydrops in patients with vestibular migraine and auditory symptoms.

Vertigo patients exhibiting features of vestibular migraine (VM) and Menière's disease (MD) present a difficult diagnostic challenge to the clinician, and the two entities are likely to overlap. The aim of the present study was to investigate the occurrence of endolymphatic hydrops in patients with VM and auditory symptoms. This was an observatory diagnostic study. At an academic interdisciplinary dizziness centre, nineteen consecutive patients with definite or probable VM and auditory symptoms were examined by locally enhanced inner ear MR imaging. MR images were evaluated for the presence of endolymphatic hydrops. Of the 19 included patients, four patients (21 %) demonstrated evidence of cochlear and vestibular endolymphatic hydrops on locally enhanced inner ear MR imaging (three with "definite VM", one with "probable VM"). Locally enhanced inner ear MR imaging may be useful in the diagnostic evaluation of patients with VM and auditory symptoms, as some of these patients have signs of endolymphatic hydrops. Whether these patients suffer from MD only and are misdiagnosed as VM or suffer from both, VM and MD or whether endolymphatic hydrops is a consequence of inner ear damage due to VM are clinically relevant questions that can be evaluated by application of this technique.

Clinical characteristics of delayed endolymphatic hydrops in Japan: A nationwide survey by the Peripheral Vestibular Disorder Research Committee of Japan.

CONCLUSION: Similarly to almost all delayed endolymphatic hydrops (DEH) cases with both precedent sudden deafness and mumps deafness, two-thirds of DEH cases with precedent deafness of unknown cause with onset in early childhood developed DEH symptoms within 40 years after the precedent deafness. In spite of the diagnosis of precedent deafness, viral labyrinthitis may build up the late endolymphatic hydrops in most DEH cases up to four decades. OBJECTIVE: To clarify the characteristics of DEH in Japan. METHODS: Clinical information on 198 DEH cases was collected by nationwide, multicenter surveys conducted by the Peripheral Vestibular Disorders Research Committee of Japan. RESULTS: The incidence of the ipsilateral type of DEH was 47.5%, which was almost equal to that of the contralateral type. In both types of DEH, the most common diagnosis of precedent deafness was deafness of unknown cause with onset in early childhood: 43.9% in both types of DEH. Sudden deafness and mumps deafness were the subsequent diagnoses of precedent deafness. The distribution of time delay of the onset between precedent deafness of unknown cause with onset in early childhood and DEH was different from that between precedent sudden and mumps deafness and DEH.

Our experience with the medical treatment of endolymphatic hydrops.

Ménière's syndrome is an idiopathic disorder of the cochlea and labyrinth. It is caused by endolymphatic hydrops and is a relatively frequent, lifelong disorder affecting patients' quality of life and work performance. This article presents our clinical experience with the medical treatment of this disease. Patients were treated with a blend of drugs according to their condition (stage of illness and presence of associated diseases).

Meniere's disease: prevalence of contralateral ear involvement.

OBJECTIVE: Determine the prevalence and time interval for conversion from unilateral to bilateral involvement in Meniere's disease and cochlear hydrops. STUDY DESIGN AND SETTING: Retrospective chart review in a tertiary otologic referral center. PATIENTS: 232 patients diagnosed with Meniere's Disease (n=186) or cochlear hydrops (n=46) between 1959 and 2001, who visited the clinic over a five-year period between 1997-2001 and have at least 2 audiograms more than 12 months apart. MAIN OUTCOME MEASURES: Prevalence of cochlear hydrops relative to Meniere's Disease, rate of progression from unilateral to bilateral involvement; interval between unilateral onset of symptoms and bilateral involvement; and rate of progression from cochlear hydrops to Meniere's disease. RESULTS: Initial diagnosis was Meniere's disease in 71% and cochlear hydrops in 29% of all 950 hydropic patients presenting between 1997 and 2001. In the study sample, Meniere's disease was bilateral at presentation in 11%; an additional 12% (14% of unilaterals) became bilateral during the follow-up period. At presentation, 6.5% of cochlear hydrops patients were bilateral, with another 26% becoming bilateral. Conversion from cochlear hydrops to Meniere's disease occurred in 33% and some of these are included among the bilateral. The average time interval for conversion from unilateral to bilateral Meniere's was 7.6 years (SD=7.0 years). CONCLUSION: Most otologists are aware of the potential for contralateral ear involvement and conversion from cochlear hydrops to Meniere's disease after diagnosis. These changes are significant, require long-term follow-up for detection, and may necessitate further treatment. Patients should be counseled regarding this potential when interventions are considered, especially with respect to ablative treatments.

Pathophysiology of Meniere's syndrome: are symptoms caused by endolymphatic hydrops?

BACKGROUND: The association of Meniere's syndrome with endolymphatic hydrops has led to the formation of a central hypothesis: many possible etiologic factors lead to hydrops, and hydrops in turn generates the symptoms. However, this hypothesis of hydrops as being the final common pathway has not been proven conclusively. SPECIFIC AIM: To examine human temporal bones with respect to the role of hydrops in causing symptoms in Meniere's syndrome. If the central hypothesis were true, every case of Meniere's syndrome should have hydrops and every case of hydrops should show the typical symptoms. METHODS: Review of archival temporal bone cases with a clinical diagnosis of Meniere's syndrome (28 cases) or a histopathologic diagnosis of hydrops (79 cases). RESULTS: All 28 cases with classical symptoms of Meniere's syndrome showed hydrops in at least one ear. However, the reverse was not true. There were 9 cases with idiopathic hydrops and 10 cases with secondary hydrops, but the patients did not exhibit the classic symptoms of Meniere's syndrome. A review of the literature revealed cases with asymptomatic hydrops (similar to the current study), as well as cases where symptoms of Meniere's syndrome existed during life but no hydrops was observed on histology. We also review recent experimental data where obstruction of the endolymphatic duct in guinea pigs resulted in cytochemical abnormalities within fibrocytes of the spiral ligament before development of hydrops. This result is consistent with the hypothesis that hydrops resulted from disordered fluid homeostasis caused by disruption of regulatory elements within the spiral ligament. CONCLUSION: Endolymphatic hydrops should be considered as a histologic marker for Meniere's syndrome rather than being directly responsible for its symptoms.

Ménière's disease and delayed endolymphatic hydrops in children.

In order to study the characteristics of pediatric patients (< or = 15 years at onset) with endolymphatic hydrops disorders, we selected 5 patients with Ménière's disease (MD) and 3 patients with delayed endolymphatic hydrops (DEH) from 7418 patients who had visited the Neurotological Clinic of the Toyama Medical and Pharmaceutical University Hospital between 1979 and 1999. Clinical features were characterized as follows: (i) pediatric MD patients were rare, comprising approximately 1.5% of all the 337 MD patients in the sample; (ii) a fluctuating hearing loss, strong positive response in glycerol test, high SP/AP amplitude ratio in electrocochleography and moderate positive response in furosemide vestibulo-ocular reflex test were recorded; (iii) in 2 of the 5 pediatric MD patients, vertiginous attacks had persisted for a long period and they had undergone surgical procedures (sac operation and vestibular neurectomy); and (iv) the ipsilateral type of DEH was observed in 2/3 children, and contralateral DEH in 1/3.

Endolymphatic hydrops associated with otosclerosis.

Endolymphatic hydrops (EH) associated with otosclerosis has been noted for many years. However, the causal relationship of these two entities remains controversial. Having reviewed the records of patients with otosclerosis describing fluctuant hearing loss and vertiginous symptoms, the authors found the EH may coexist with otosclerosis preoperatively; they may be two separate diseases that exist coincidentally; or EH may be caused by the otosclerotic process. Secondly, EH may occur with a fistula after surgery. Occurring after stapedectomy, EH may be caused by fistulization of the bony labyrinth, which is effectively treated by surgery to seal the fistula, which may cause EH to subside and hearing to improve. Thirdly, delayed EH may occur months or years after stapedectomy, possibly as a result of otosclerotic foci or surgical insult to the labyrinth. Dexamethasone, diuretics, and a room air rebreather can be used in the treatment of delayed EH. Hearing may be maintained or may deteriorate, but there usually is no dizziness. The clinical manifestations of EH associated with otosclerosis include a conductive or mixed type of hearing loss; the presence of fullness, tinnitus, fluctuation of hearing, episodic vertigo, an elevated negative summating potential (SP), and an increased summating potential:action potential (SP:AP) ratio shown by ECoG. This report presents five cases of EH associated with otosclerosis.