Immunoperoxidase study of the endolymphatic sac in Menière's disease

Role of prior intratympanic gentamicin and corticosteroids therapy on speech understanding in patients with Menière's disease after cochlear implantation

AIM

Intratympanic injection of corticosteroids (ITC) and gentamicin therapy (ITG) are widely used treatments for vertigo in Meniere's disease (MD). Even though studies show good results after cochlea implantation (CI) in MD patients when compared to non-MD groups, there is no indication on the effect of ITC and ITG prior to CI on hearing after CI. This study compares the post-operative hearing of CI patients with and without MD and patients who have received ITG or ITC prior to CI.

METHODS

In a retrospective case control study, adult patients with MD who received CI from 2002 till 2021 were compared to a matched control group of CI patients without MD. Patients with prior ITC/ITG were extracted from MD group. Pre-operative audiological results were measured and trends across post-operative monosyllabic word recognition score at 65 decibels (WRS65CI) at switch-on, 3-6 months, 1 year and last yearly value were analyzed across all groups.

RESULTS

28 MD ears were compared with 33 control ears. From MD ears 9 had received ITG and 6 ITC prior to CI. WRS65CI increased significantly with time within MD and control groups, but no difference in WRS65CI was found between these 2 groups. ITG ears showed fluctuating WRS65CI after CI with no change across time, while ITC ears showed significant increase in trend of WRS65CI values across time.

CONCLUSION

MD and non-MD patients showed comparable hearing results after CI. Prior ITC might positively influence hearing preservation after CI in MD patients whereas ITG group showed fluctuating hearing.

Cyclophosphamide inhibits the progression of Meniere's disease by reducing the generation of circulating immune complex

Endolymphatic hydrops is a characteristic pathological manifestation of Meniere's disease (MD) that has been previously associated with autoimmunity. Interest in the circulating immune complex (CIC) has increased due to its reported role in the occurrence of MD. The present study aimed to investigate the potential value of serum CIC concentration in the diagnosis of MD and the therapeutic potential of cyclophosphamide (CTX) for the treatment of MD. In the present study, guinea pigs were immunized with isologous crude inner ear antigens to establish an autoimmune MD model. Pure tone audiometry, Vestibular-evoked myogenic potential test, electrocochleography test and auditory brainstem response was applied in this study for assessing the severity of MD in guinea pigs. ELISA was applied to measure CIC, tumor necrosis factor α (TNF-α) and heat shock protein 70 (HSP70) expression levels in the serum samples of different groups of patients. Western blotting was applied to detect the protein expression of HSP70 in inner ear tissues in guinea pigs. Hematoxylin and eosin staining was applied to visualize the spiral ganglions in spiral ganglions models. CIC expression in the inner ear was detected by immunohistochemistry. In vivo experiments were performed to confirm the therapeutic effects of CTX in MD. Serum concentrations of CIC, TNF-α and HSP70 were found to be significantly higher in patients with MD, which were also associated with increases in hearing classification and the severity of endolymphatic hydrops. Using a guinea pig MD model, ELISA results revealed significantly increased serum CIC, TNF-α and HSP70 concentrations compared with those in the control group. ABR results showed that the thresholds in the CTX group were notably decreased compared with that in the dexamethasone group, whereas CIC concentrations in the serum were reduced following dexamethasone and CTX treatments compared with those after saline treatment. In the inner ear tissues, the CIC concentration in CTX group was lower than that in the dexamethasone group. Similarly, reductions in HSP70 and TNF-α concentrations was also observed in a similar manner. Immunohistochemistry staining found notably lower CIC deposition in the inner ear tissues following CTX treatment than that in dexamethasone group. Taken together, higher CIC expression can be used as a biomarker for MD diagnosis. The efficacy of CTX in MD was found to be higher compared with that in dexamethasone, which may be associated with the effective inhibition of CIC, HSP70 and TNF-α generation.

Intratympanic Treatment in Menière's Disease, Efficacy of Aminoglycosides Versus Corticosteroids in Comparison Studies: A Systematic Review

OBJECTIVE

To compare the functional outcomes and complications of intratympanic gentamicin (ITG) versus intratympanic corticosteroids (ITC) in Menière's disease.

DATA SOURCES

An electronic search was conducted in the Cochrane Library, PubMed, and Embase databases on February 3, 2019. Articles written in English, Dutch, German, French, or Turkish language were included.

STUDY SELECTION

Study inclusion criteria were: 1) patients diagnosed with definite Menière's disease according to the criteria of the American Academy of Otolaryngology-Head and Neck Surgery, 2) treated with ITG or ITC in a comparison study, and 3) reported subjective and objective outcomes concerning Menière's disease.

DATA EXTRACTION

The quality of eligible studies was assessed according to an adjusted version of the Cochrane Risk of Bias tool. The extracted data were study characteristics (study design, publication year, and number of relevant patients), patient's characteristics (sex and age), disease characteristics (uni or bilateral and duration of Menière's disease), treatment protocol, and different therapeutic outcomes (vertigo, tinnitus, aural fullness, and hearing loss).

DATA SYNTHESIS

A total of eight articles were included for data extraction and analysis. For subjective outcomes, ITG was slightly favored compared to intratympanic corticosteroids. This was significant only in three studies (p < 0.05). For objective outcomes and complications, no significant differences were seen.

CONCLUSIONS

The result of this systematic review shows some benefit of ITG over ITC for subjective outcomes and no difference regarding objective outcomes or complication rate. However, this superiority of ITG is rather weak. Both interventions can be effectively and safely used in controlling Menière's disease in acute situations.

Autoinflammatory characteristics and short-term effects of delivering high-dose steroids to the surface of the intact endolymphatic sac and incus in refractory Ménière's disease

Objective

To investigate immune-related genetic background in intractable Meniere’s disease (MD) and the immediate results of a novel therapy by delivering steroids to the surface of the intact endolymphatic sac (ES) and incus in a sustainable manner.

Case report and methods

Candidate genes involved in immune regulation were sequenced using a next-generation sequencing method in a patient with intractable MD. Mutations were confirmed using the Sanger sequencing method. The ES was exposed, and gelatin sponge particles were immersed in high-dose methylprednisolone solution and placed onto the surface of ES. “L”-shaped gelatin sponge strips were immersed in dexamethasone solution and served as a guiding device for the steroids by touching the incus and gelatin sponge particles on the surface of the ES. Gelatin sponge particles immersed in dexamethasone solution were placed around the gelatin sponge strips and sealed using fibrin glue.

Results

Autoinflammation in the refractory MD case was indicated by genotype, including novel heterozygous mutations of PRF1, UNC13D, SLC29A3, ITCH, and JAK3, as well as phenotype. The vertigo was fully relieved immediately after operation. Tinnitus and aural fullness were resolved 3 weeks after operation, whereas hearing improved in 2 mon postoperation. No recurrence was noted during the 5-monfollow-up, and the final MRI supported the novel therapeutic hypothesis.

Conclusion

Autoinflammation was involved in a refractory MD. This novel therapy, which involves the delivery of steroids to the surface of the intact ES and incus, is effective in relieving vertigo and tinnitus and improves hearing function of refractory MD.

Intratympanic therapy in Meniere's syndrome or disease: up to date evidence for clinical practice

BACKGROUND

Meniere's syndrome or disease (MS/D) is typically characterised by episodic vertigo, aural fullness, tinnitus and fluctuating hearing loss. There are multiple options available for treatment with variation in consensus on the best intervention.

OBJECTIVE

To evaluate the evidence on the efficacy of intratympanic therapies [steroids, gentamicin, antivirals and other therapies] on the frequency and severity of vertigo and other symptoms of MS/D.

SEARCH STRATEGY

A literature search was performed on AMED, EMBASE, HMIC, MEDLINE, PsycINFO, BNI, CINAHL, HEALTH BUSINESS ELITE, CENTRAL and Cochrane Ear, Nose and Throat disorders group trials register using various MeSH. The search was restricted to English and human subjects, and the last date of search was December 2014.

SELECTION CRITERIA

Randomised controlled trials of intratympanic therapies [steroids, gentamicin antivirals and latanoprost] versus a placebo or another treatment.

RESULTS

We analysed 8 RCT's comparing intratympanic steroids, gentamicin, ganciclovir (antiviral) and latanoprost versus another form of intratympanic treatment or placebo.

CONCLUSIONS

On the basis of 6 RCT's (n = 242), there is evidence to support the effectiveness of intratympanic steroids and gentamicin to control symptoms of vertigo in MS/D albeit with a risk of hearing loss with gentamicin. However, there was no consensus found on doses or treatment protocols. There was no evidence to support the use of other forms of intratympanic therapy (antivirals and latanoprost) in MS/D.

Immune system of the inner ear as a novel therapeutic target for sensorineural hearing loss

Sensorineural hearing loss (SNHL) is a common clinical condition resulting from dysfunction in one or more parts in the auditory pathway between the inner ear and auditory cortex. Despite the prevalence of SNHL, little is known about its etiopathology, although several mechanisms have been postulated including ischemia, viral infection or reactivation, and microtrauma. Immune-mediated inner ear disease has been introduced and accepted as one SNHL pathophysiology; it responds to immunosuppressive therapy and is one of the few reversible forms of bilateral SNHL. The concept of immune-mediated inner ear disease is straightforward and comprehensible, but criteria for clinical diagnosis and the precise mechanism of hearing loss have not been determined. Moreover, the therapeutic mechanisms of corticosteroids are unclear, leading to several misconceptions by both clinicians and investigators concerning corticosteroid therapy. This review addresses our current understanding of the immune system in the inner ear and its involvement in the pathophysiology in SNHL. Treatment of SNHL, including immune-mediated inner ear disorder, will be discussed with a focus on the immune mechanism and immunocompetent cells as therapeutic targets. Finally, possible interventions modulating the immune system in the inner ear to repair the tissue organization and improve hearing in patients with SNHL will be discussed. Tissue macrophages in the inner ear appear to be a potential target for modulating the immune response in the inner ear in the pathophysiology of SNHL.

Oral steroid treatment for hearing improvement in Ménière's disease and endolymphatic hydrops

OBJECTIVE

To determine the effect of oral steroid treatment on hearing in unilateral Ménière's disease and endolymphatic hydrops patients.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

All patients presenting during the 2010 calendar year with confirmed unilateral Ménière's disease or endolymphatic hydrops. Those with a first visit and second visit audiogram (n = 58) were included in the analysis of oral steroid treatment effect.

INTERVENTION

Steroid treatment for hearing loss.

MAIN OUTCOME MEASURE

Change in hearing, as defined by change in affected ear threshold values or speech discrimination score from pretreatment visit to posttreatment visit.

RESULTS

Hearing (threshold, speech discrimination score) in patients' affected ear did not significantly change from first visit to second visit after treatment with steroids relative to patients who did not receive steroid treatment.

CONCLUSION

The results of this and other studies would indicate that a Ménière's disease or endolymphatic hydrops patient is unlikely to experience an improvement in hearing from a short course of oral steroid. Clinically observed temporary improvement did not sustain over several months. Further work to elucidate the mechanisms underlying hearing loss in hydrops, perhaps focusing on the dendrite damage noted in animal models of hydrops, is warranted.

The Effect of Intratympanic Methylprednisolone and Gentamicin Injection on Ménière’s Disease

Objectives

To compare the efficacy of intratympanic injections of methylprednisolone (ITMP) and intratympanic injections of gentamicin (ITG) to control the symptoms of Ménière’s disease and to evaluate their effect on hearing level.

Study Design

A historical cohort study.

Setting

Tertiary referral center.

Subjects and Methods

Eighty-nine patients affected by Ménière’s disease were included in this study, of whom 47 were treated with ITG and 42 were treated with ITMP. Two periods of follow-up were considered: 0 to 6 months and 6 to 12 months after the intratympanic injections (ITI). Mean outcome measurements consisted of control of vertigo attacks, tinnitus, and aural fullness; pure-tone average (PTA); and speech discrimination score (SDS).

Results

The 2 groups had the same number of vertigo spells per month before ITI ( P = .883). Six to 12 months after ITI, 82.9% of the ITG group and 48.1% of the ITMP group achieved complete control of vertigo ( P = .004). There was better control of tinnitus and aural fullness with ITG than with ITMP ( P ≤ .002). The 2 groups had a statistically significant difference in hearing level before ITI ( P ≤ .001). This difference was no longer present 6 to 12 months after ITI ( P > .05).

Conclusion

Intratympanic injections of gentamicin are more efficient than ITMP in controlling the symptoms of Ménière’s disease. The 2 groups ended up without a difference in hearing level after ITI. According to these findings, administrating ITMP to control Ménière’s disease seems to be less beneficial than ITG.

Experimental hyperactivity of the endolymphatic sac

Injury to the endolymphatic sac may play an important role in the pathogenesis of Ménière's disease, an inner ear disorder characterized by hearing loss, tinnitus and attacks of vertigo. Isoimmunization of 16 inbred Lewis rats with a crude endolymphatic sac extract and complete Freund's adjuvant induced hyperactivity of the endolymphatic sac. One group of rats was immunized by a single dose whereas a second group was immunized twice. Control animals were injected with Freund's adjuvant in saline only. Serum was collected from all rats by the end of the study and harvested autoantibodies were tested by immunohistochemistry. The endolymphatic sacs were investigated by transmission electron microscopy. Endolymphatic sac stimulation was observed in all immunized rats. Based on detailed ultrastructural observations, the degree of reactivity seemed proportional to the number of injections and the extent of immunization. Moreover, the ribosome-rich cells seemed hyperactive with an extravagant content of intracellular components: numerous rough endoplasmic reticulum and free ribosomes, morphological signs of extensive endo- and exocytosis, vesicles of material with a density similar to the homogeneous substance of which many were observed to fuse with primary lysozymes. Basolateral foldings were numerous and in the subepithelial capillaries formation of multiple and apposing fenestrations were observed. No endolymphatic sac stimulation was observed in the control animals. Specific ribosome-rich cell alterations identical to those present in the endolymphatic sac of Ménière's disease were observed 21 days after the first immunization. The observations suggest that either an autoantigen or a trophic factor, capable of inducing a hyperactivity of the ribosome-rich cells and an imbalance of the homogeneous substance metabolism, exists in the endolymphatic sac of the rat.

Intratympanic steroids for Ménière's disease or syndrome

BACKGROUND

Ménière's disease is a disorder characterised by hearing loss, tinnitus and disabling vertigo. The use of intratympanic steroids to reduce the severity of these symptoms has been gaining popularity.

OBJECTIVES

To assess the effectiveness of intratympanic steroids on the frequency and severity of attacks of vertigo, on chronic symptoms such as tinnitus, imbalance and hearing loss, and on the progression of these symptoms in patients with definite Ménière's disease or syndrome, as defined by the AAO-HNS Committee.

SEARCH STRATEGY

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 13 January 2011.

SELECTION CRITERIA

Randomised controlled trials of intratympanic dexamethasone versus placebo in patients with Ménière's disease.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial risk of bias and extracted data. We contacted study authors for further information where possible.

MAIN RESULTS

A single trial containing 22 patients, with a low risk of bias was included. This trial found that after 24 months, compared with placebo, the use of intratympanic dexamethasone demonstrated a statistically significant improvement in vertigo as defined by a respective improvement in functional level (90% versus 42%), class (82% versus 57%), change in Dizziness Handicap Inventory scores (60.4 versus 41.3) and mean vertigo subjective improvement (90% versus 57%). The treatment regime described by the authors involved daily injections of dexamethasone solution 4 mg/ml for five consecutive days. These results were clinically significant. No complications were reported.

AUTHORS' CONCLUSIONS

The results of a single trial provide limited evidence to support the effectiveness of intratympanic steroids in patients with Ménière's disease. This trial demonstrated a statistically and clinically significant improvement of the frequency and severity of vertigo measured 24 months after the treatment was administered. It is important to note that there were a few aspects of the study which we were unable to clarify with the study authors.

Distribution of bone marrow-derived cells in the vestibular end organs and the endolymphatic sac

CONCLUSION

Bone marrow-derived cells (BMDCs) are constitutively present in the vestibular end organs and in the endolymphatic sac, and may play a role in the maintenance of inner ear homeostasis.

OBJECTIVES

The aim was to examine the distribution and characteristics of BMDCs in the vestibular end organs and in the endolymphatic sac.

METHODS

Bone marrow-chimeric mice were generated by bone marrow transplantation from mice genetically labeled with enhanced green fluorescent protein to C57 Bl/6 mice to visualize BMDCs. Three months after bone marrow transplantation, inner ear specimens were processed for histochemical analyses.

RESULTS

BMDCs were widely distributed in the vestibular end organs and the endolymphatic sac, whereas there were differences in the phenotype and the distribution between the vestibular end organs and the endolymphatic sac. A subpopulation of BMDCs in the vestibular end organs expressed antigen-presenting protein MHC class II. Moreover, the density of BMDCs in the vestibular end organs increased in response to local mechanical stress.

Meniere's disease: update of etiopathogenetic theories and proposal of a possible model of explanation

Meniere's Disease (MD) is an affection consisting of an association of sensorineural hearing loss, tinnitus and vertigo initially presenting by crises. A review of the most considered possible causative factors and pathophysiologic interpretations allows us to underline the uncertainties which still exist about the genesis of this illness. We propose a mechanistic model based on the effect of a haemodynamic imbalance leading to transient ischaemia which could have an effect on the pH of the inner ear as well as on the work of the inner ear proton pumps. It is hypothesized that under ischaemic conditions and consequent metabolic acidity a preserved proton pump activity can generate an overload of anions in the endolymphatic partition, which is a closed system, thus resulting in an enhancement of osmolarity and consequently in the formation of a hydrops resulting in the development of fluctuating hearing loss, tinnitus and vertigo which characterize Meniere's Disease.

Expression of histamine receptors (H(1), H(2), and H(3)) in the rabbit endolymphatic sac: an immunohistochemical study

OBJECTIVE

The endolymphatic sac (ES) is part of the membranous labyrinth of the inner ear. Its central role in immunologic activity within the inner ear has been confirmed by numerous studies. The aim of this study was to investigate the expression of histamine receptors (H(1), H(2), H(3)) in the rabbit ES.

METHODS

A total of 10 healthy male New Zealand white rabbits weighing 2 to 3 kg were used in the experiments. For immunohistochemical studies, immunostaining was performed according to the avidin-biotin-peroxidase complex technique.

RESULTS

Serial sections of the ES of rabbits revealed the presence of H(1), H(2), and H(3) receptor immunoreactivity. Immunoreactive cells for all H(1), H(2), and H(3) were found in the epithelial and subepithelial layers of the duct and the proximal ES. In conclusion, this study showed the immunohistochemical localization of H(1), H(2), and H(3) receptors in the ES of rabbits. These receptors may be important in the homeostasis of the inner ear. In addition, they may be target receptors in the medical treatment of inner ear disorders such as endolymphatic hydrops.

Personal factors involved in onset or progression of Ménière's disease and low-tone sensorineural hearing loss

PURPOSE

To identify personal causative factors for Ménière's disease.

PROCEDURES

Patterns of hearing loss progression were studied in patients with Ménière's disease and low-tone sensorineural hearing loss, and the involvement of stress and the relation of stressors to the onset or progression of the disease were analyzed.

RESULTS

Low-tone loss recurred in 40% of patients even after hearing was restored, and low-tone loss progressed to high-tone loss after frequent repetitions of recovery and recurrence. High-tone loss tended to proceed to all-tone loss. Eighty percent of patients reported that stress was involved or deeply involved in the onset or progression of the disease. Common causative stressors were business-related pressure, insufficient sleep, and troubles at the workplace or at home.

CONCLUSIONS

The present findings indicate that recovery and recurrence may be influenced by the strength and duration of stress that is produced when patients do not feel rewarded for engrossment in their work or for self-inhibiting behaviors.

Dexamethasone inner ear perfusion by intratympanic injection in unilateral Ménière's disease: a two-year prospective, placebo-controlled, double-blind, randomized trial

OBJECTIVE

To investigate the efficacy of dexamethasone inner ear perfusion by intratympanic injection in hearing loss, tinnitus, aural fullness, and vertigo in the treatment of unilateral Ménière's disease and compare it with the control group.

STUDY DESIGN AND SETTING

A prospective, randomized, double-blind study with 2-year follow-up comparing changes secondary to dexamethasone inner ear perfusion versus placebo consisting of saline solution.

PATIENTS

Twenty-two patients having definite Ménière's disease as outlined by the 1995 American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium. All the patients were older than 18 years of age and were not receiving any other form of treatment with steroids for their Ménière's disease.

METHOD

Five consecutive daily intratympanic injections of dexamethasone or placebo to the involved ear.

RESULTS

In the dexamethasone group at 2-year follow-up, complete control of vertigo (class A) was achieved in 9 of 11 patients (82%) and substantial control of vertigo (class B) in the remaining 2 patients (18%.) In the control group only 7 of 11 patients (64%) finished the 2-year follow-up because in the other 4 patients (36%) we had to give another treatment for the continuing vertigo and thus they were classified as failure (class F.) From the 7 patients who have finished the follow-up of 2 years in the control group, 4 patients (57%) achieved class A, 2 patients (29%) achieved class C, and 1 patient (14%) class F.

CONCLUSIONS

Dexamethasone (4 mg/mL) inner ear perfusion in a group of patients with unilateral Ménière's disease (Shea's stage III) showed 82% of complete control of vertigo over placebo (57%). There was also a subjective improvement in tinnitus (48%), hearing loss (35%), and aural fullness (48%) in the dexamethasone group compared with 20%, 10%, and 20% respectively in the control group.

Intratympanic treatment of hearing loss with novel and traditional agents

As knowledge of the cellular and molecular pathophysiology behind otopathologies expands, the possibility exists of preventing sensorineural hearing loss and perhaps reversing the loss. Cellular and molecular mechanisms seem to be similar in hearing loss secondary to aging, drug ototoxicity, noise, or other mechanisms. A final common pathway may hinge upon apoptosis. It is likely that anti-apoptotic factors will increasingly be realized as an important intervention strategy for sensorineural hearing loss. Furthermore, it is also possible that mounting a staged attack at the various regions in the pathway leading to cellular damage using a combination of several protective substances such as steroids, antioxidants, neurotrophic factors, anti-apoptotic compounds, and mitochondrial enhancers may prevent hearing loss and even reverse it in some situations. This article has presented some of the molecular and cellular mechanisms for hearing loss and potential ways of treating them. In theory, the delivery of these medications to the inner ear transtympanically would decrease systemic side effects and be more target specific. Because most of the studies conducted to date have been animal studies, randomized, double-blind, placebo-controlled clinical trials would be necessary before the use of these therapies becomes common practice.

Medical management of Meniere's disease

Medical therapy of Meniere's disease is geared not only toward the differential diagnosis that has led to Meniere's disease and the supportive therapy for the physical manifestations of the disease but also for the psychologic sequelae of the disease such as mild-to-moderate situational depression and even chronic depression. Overall, with adequate medical therapy, allergy workup, and immunotherapy for patients with known diagnoses of allergies, the author's clinic has been able to help more than 85% of its patients who present with symptoms of Meniere's disease. For intractable cases where autoimmune phenomena can be suspected with a strong degree of suspicion, the author's clinic has also treated patients with immunosuppressive medications such as azathioprine and/or methotrexate in a low dose.

Menière's disease: pathophysiology and treatment

Menière's disease is defined by the association of 4 symptoms: vertigo attacks, fluctuating hearing loss, tinnitus and an auricular plenitude sensation. The pathophysiology is commonly explained by a distension of membranous labyrinth by the endolymph, equally called endolymphatic hydrops. Recent studies also tend to relate the disease to immune mechanisms. The treatment is medical in the majority of patients but there is no international consensus on the management of the different stages of Menière's disease. Regarding the lack of clinical studies clearly demonstrating the effectiveness of a certain therapy or another. the recommendations are usually based on the empirical experience of practitioners and on the observation of a marked amelioration at 2 years of treatment in the majority of patients. The treatment of the acute phase of Menière's disease is basically symptomatic. Vestibular suppressant drugs have a well-established record in controlling acute attacks of vertigo. Most have variable anticholinergic, anti-emetic and vestibular sedative effects. If necessary, the administration of benzodiazepines will help to alleviate anxiety. Long term management of Menière's disease includes a low salt diet, the use of diuretics in the post-crisis phase, and the very common use in Europe of histaminergic agents. Corticosteroids are used in bilateral forms of Menière's disease, particularly if an autoimmune basis is suspected. All authors insist on the interest and the importance of regular follow-up, especially with regard to the psychological status and responsiveness to treatment of the patient. Surgical indications are rare and the least invasive procedures are used first. The choice of the procedure should take into consideration the need to preserve the auditory function of the patient.

Pathophysiological mechanisms in immune inner ear disease

Immune inner ear disease is a somewhat controversial entity which describes cochleovestibular dysfunction that is related to immune-mediated mechanisms. The diagnosis of this disease is based on clinical presentation and response to various treatment protocols. Unfortunately, the presentation is variable and the treatment empirical, and this has caused much confusion in the diagnosis and management of the condition. To elucidate the variable nature of the disease, it is important to understand that more than one mechanism of immune injury may be involved. This paper attempts to classify clinical and experimental cases of immune inner ear disease with regard to the Gell and Coombs classification scheme of immune-mediated injury. By understanding the different pathophysiological mechanisms involved, the clinician should be better able to diagnose and manage this difficult problem in a directed fashion. The ramifications of the proposed classification system on the diagnosis, treatment and future research of immune inner ear disease are discussed.

Low-dose Oral Methotrexate Management of Patients with Bilateral Ménière's Disease

In this retrospective clinical trial, we evaluated the effectiveness of low-dose oral methotrexate in the management of bilateral Ménière's disease of immune-mediated origin. At our tertiary-care referral center, we evaluated ten men and eight women who had longstanding bilateral Ménière's disease that had been unresponsive to traditional conservative medical management. Sixteen of these patients had steroid-responsive bilateral Ménière's disease. Two patients had contraindications to steroids, but their clinical and laboratory evaluations were consistent with an immune-mediated process.

Patients were treated with 7.5 to 20 mg/week of oral methotrexate. The mean duration of treatment was 16.7 months (range: 8 to 35), with a mean followup of 2 years (range: 9 mo to 5 yr). Changes in clinical symptoms (vertigo, hearing loss, tinnitus, and aural fullness), audiometric changes, and side effects of therapy were evaluated.

Vertigo resolved in 14 patients (78%), was substantially alleviated in three patients (17%), and remained unchanged in one patient (6%). Hearing improved in five patients (28%) and stabilized in seven patients (39%). Tinnitus and aural fullness resolved or was relieved in 11 of 17 (65%) and 13 of 14 (93%) patients, respectively. Side effects were minimal and reversible.

We conclude that low-dose oral methotrexate is effective and safe for treating bilateral Ménierè's disease of immune-mediated origin. In this study, methotrexate alleviated vertiginous symptoms and improved or stabilized hearing in most patients. Low-dose methotrexate can be considered for patients with immune-mediated bilateral Meniérè's disease when long-term treatment is required or when a steroid or cyclophosphamide is contraindicated.

Demonstration of autoantibodies to the endolymphatic sac in Meniere's disease

Recent evidence suggests that immune mechanisms may underlie some cases of Meniere's disease. This study was conducted to determine whether an autoimmune mechanism is involved. Sera from 30 patients with Meniere's disease were reacted with human endolymphatic sacs and examined by indirect immunohistochemistry and fluorescence microscopy. Three of the samples (10%) showed positive staining, indicating immunoglobulin G (IgG) binding against the sac. No positive staining occurred when sera from healthy individuals or phosphate-buffered saline was used as a control. Clinical data showed an association between immunoreactivity and extent of disease (worse hearing over a shorter disease course and bilateral involvement). This study suggests that, in some cases of Meniere's disease, autoantibodies directed against human endolymphatic sac are present in the sera, supporting the theory that a specific autoimmune reaction takes place in a minority of patients with Meniere's disease.