Effects of exposing the opened endolymphatic sac to large doses of steroids to treat intractable Meniere's disease

Endolymphatic Sac Drainage Surgery and Plasma Stress Hormone Vasopressin Levels in Meniere's Disease

Meniere's disease is a common inner ear disorder accompanied by vertigo attacks and fluctuating hearing loss that some believe is due to a stressful lifestyle. To elucidate the scientific relationship in neuro-endocrinology between Meniere's disease and stress, we examined the surgical results of endolymphatic sac drainage surgery and changes in stress-induced plasma arginine-vasopressin levels. We enrolled 100 intractable Meniere's patients and examined surgical results and plasma vasopressin levels. Fifty-four chronic otitis media patients who underwent tympano-mastoidectomy formed a control group. We assessed surgical results during a 2-year follow-up period, including vertigo and hearing loss. We examined plasma vasopressin levels just before surgery and 1 week, 1 year, and 2 years after surgery. In patients with intractable Meniere's disease, plasma vasopressin levels were significantly reduced 1 week after surgery compared to the decrease observed in chronic otitis media patients after tympano-mastoidectomy. In intractable Meniere's disease, long-lasting low plasma vasopressin levels after surgery were associated with significantly good surgical results. In recurrent Meniere's disease, a gradual plasma vasopressin level elevation was observed after surgery, followed by recurrent vertigo attacks and sensorineural hearing loss. It is suggested that long-lasting high levels of plasma vasopressin could have adverse effects on inner ear water metabolism and the subsequent Meniere's disease symptoms. Effective treatments for Meniere's disease might be best based on the maintenance of low plasma vasopressin levels.

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.

Surgical results and psychological status in patients with intractable Ménière's disease

OBJECTIVES

Mental disorder is often one of the causes to make treatments for Ménière's disease more difficult. The aim in the present study is to examine ratios of the neurosis and depression in patients with intractable Ménière's disease and also relationships between the ratios and surgical results after endolymphatic sac drainage with large doses of steroids.

METHODS

Between 1998 and 2009, we enrolled 263 intractable Ménière's patients and divided into two groups, 207 in surgical group and 56 in non-surgical group. We used the Cornell Medical Index (CMI) and the Self-rating Depression Scale (SDS) at the diagnosis in our hospital to evaluate their psychological condition before treatments. CMI domains III and IV were defined as neurosis and SDS scores more than 40 as depression as a matter of convenience. Two years as well as seven years after surgery, patients with vertigo zero/month and hearing change>-10dB were evaluated in success group and the others in non-success group.

RESULTS

Neurosis and depression were diagnosed in approximately 40% and 60%, respectively, of intractable Ménière's disease. Our results showed that surgical treatment significantly improved vertigo suppression and hearing gain in patients with no psychological symptoms compared with those exhibiting psychological symptoms both in surgical and non-surgical groups. Furthermore, surgical results in cases with mental disorder were superior to non-surgical results in cases without mental distress.

CONCLUSIONS

All taken together, psychological supports could be necessary for improving results both in the surgical and non-surgical treatments for patients with intractable Ménière's disease. Some cases with intractable Ménière's disease should really require additional surgical treatments even after psychological therapies.

Surgical Management of Special Cases of Intractable Meniere's Disease: Unilateral Cases with Intact Canals and Bilateral Cases

If a clinician seeks to allow patients with vertigo to return to work as soon as possible, it is very important to determine the appearance of vestibular symptoms during convalescence just after treatment, as well as the long-term results. Apprehensive patients with vertigo may undergo severe psychological torment if treatment requires long-term rest in bed before they can return to daily life. In this paper, we observed postoperative vestibular symptoms (subjective sensation and objective nystagmus) in 50 patients with intractable Meniere's disease, including cases from our previous preliminary report, during the period of convalescence just after endolymphatic sac drainage and steroid instillation surgery (EDSS). All symptoms were eliminated within 8 days after EDSS. There was no significant difference in the duration of any vestibular symptoms between bilateral (n = 8) and unilateral cases (n = 42). This result indicates that EDSS could be as safe a treatment for bilateral Meniere's disease as for unilateral disease. In unilateral cases with intact semicircular canal function (n = 17), postoperative evoked vestibular sensation, positional, and positioning (Dix-Hallpike) nystagmus disappeared significantly earlier than in those with canal paresis (n = 25). This result indicates that EDSS could keep the vestibular peripheral function of patients with unilateral Meniere's disease with intact canals quite stable after surgery. Therefore, EDSS could be recommended as an initial, less-invasive surgical treatment for intractable Meniere's disease, especially in unilateral cases with intact canals and in bilateral cases.

Effects of posterior tympanotomy with steroids at round window on hearing recovery after revision surgery for intractable Meniere's disease

CONCLUSIONS

At the second postoperative year, there were no significant differences between results for vertigo and hearing after endolymphatic sac drainage with steroid instillation surgery (EDSS) and EDSS with posterior tympanotomy with steroids at the round window (EDRW). In particular, as regards hearing recovery to the preoperative level, the periods after EDRW were shorter than those after the second EDSS.

OBJECTIVES

Patients sometimes faces recurrent problems years after EDSS due to endolymphatic sac closure and/or disease progression. In the present study, we examined the effects of EDRW on vertigo and hearing after revision surgery for intractable relapsed Meniere's disease.

METHODS

Sixteen patients with Meniere's disease had revision surgery due to intractable recurrence of disease, and were followed up regularly at least for 2 years. As revision surgery, EDSS was performed repeated in eight cases and EDRW was performed in the other eight. There were no significant differences between the patients' backgrounds in the two groups.

RESULTS

Periods of hearing recovery to the preoperative level were 11.5 ± 4.4 months after the first EDSS, although it took 16.4 ± 2.6 months longer after revision surgery with the second EDSS (p = 0.038 < 0.05: first EDSS vs second EDSS) and was 10.0 ± 3.3 months shorter after revision surgery with EDRW (p = 0.010 < 0.05: second EDSS vs EDRW).

Expression and translocation of aquaporin-2 in the endolymphatic sac in patients with Meniere's disease

Meniere's disease, characterised by episodic vertigo, fluctuating hearing loss and tinnitus, can occur under conditions of stress. Its pathology was first revealed to be inner ear hydrops through temporal bone studies in 1938. Although its pathogenesis has been proposed to be a disorder of water transport in the inner ear, subsequently, it remains unsolved, until now. A recent study revealed that both plasma stress hormone, vasopressin (pAVP) and its receptor, V2 (V2R) expression in the inner ear endolymphatic sac were significantly higher in Meniere's patients. In the present study, to link V2R-related molecules and inner ear hydrops, we examined V2R-linked water channel molecule, aquaporin-2 (AQP2) expression and translocation in human endolymphatic sac. AQP2 mRNA expression in the endolymphatic sac was significantly higher in Meniere's patients by using real-time polymerase chain reaction, as further confirmed by western blotting. AQP2-like immunoreactivity (-LIR) was translocated from luminal to basolateral side with endosomal trapping in the endolymphatic sac at the time of AVP exposure in human endolymphatic sac tissue culture. The similar AQP2-LIR translocation was also demonstrated by forskolin and blocked by vasopressin/V2R specific antagonist, OPC31260 and protein kinase A (PKA) specific antagonists, H-89 and KT-5720. We concluded that in the pathogenesis of inner ear hydrops resulting in Meniere's attacks, pAVP elevation as a result of stress and subsequent V2R-cAMP-PKA-AQP2 activation and endosomal trapping of AQP2 in the endolymphatic sac, might be important as a basis of this disease. Further experimental and clinical studies are needed to better clarify the neuroscientific relationship between stress and Meniere's disease.

Plasma vasopressin and V2 receptor in the endolymphatic sac in patients with delayed endolymphatic hydrops

OBJECTIVE

There are some kinds of sicknesses provoked by inadequate adaptation to physical and/or psychogenic stress in daily life. Delayed endolymphatic hydrops (DEH) is an inner ear disease like Ménière's disease (MD) characterized by episodic vertigo in the setting of preexisting unilateral deafness that especially occurs in civilized people with a stressful lifestyle. Its otopathologic finding was demonstrated to be inner ear endolymphatic hydrops through a temporal bone study in 1976, as in the case with MD in 1938. To elucidate the relationship between stress and the inner ear, we examined the plasma antidiuretic stress hormone vasopressin (pAVP) and its type 2 receptor (V2R) expression in the endolymphatic sac in patients with DEH.

STUDY DESIGN

A prospective molecular biological study.

METHODS

Between 1998 and 2007, we enrolled 20 patients with ipsilateral DEH to examine their pAVP during remission from vertigo attacks. Plasma vasopressin was also examined in 87 patients with unilateral MD and 30 control patients with chronic otitis media. Using the real-time polymerase chain reaction method with tissue samples obtained during surgery, we examined V2R mRNA expression in the endolymphatic sac in 6 patients with ipsilateral DEH, 9 patients with unilateral MD, and 6 control patients with acoustic neuroma.

RESULTS

Plasma vasopressin (1.5 times versus controls; unpaired t test, p = 0.140) and V2R mRNA expression in the endolymphatic sac (35.8 times versus controls; unpaired t test, p = 0.002) were higher in patients with DEH compared with those with acoustic neuroma. There were no significant differences in pAVP or V2R expression in the endolymphatic sac between DEH and MD. Patients with DEH showed a significantly negative correlation between pAVP and V2R (Pearson test, r = -0.92, p = 0.009) as in those with MD (Pearson test, r = -0.68, p = 0.043).

CONCLUSION

Civilized people are frequently exposed to stress in their daily life, and pAVP can easily become elevated at any time. Therefore, a negative feedback system between pAVP and V2R in the endolymphatic sac may function for inner ear fluid homeostasis against stress-induced increases in pAVP. For the pathogenesis of endolymphatic hydrops resulting in vertigo attacks in patients with DEH as well as MD, pAVP may represent a matter of consequence, but V2R overexpression in the endolymphatic sac could be much more essential as a basis for these diseases.

Bilateral progressive hearing loss and vestibular dysfunction with inner ear antibodies

Autoimmune inner ear disease (AIED) is a clinical syndrome of uncertain etiology. We present the neuro-otological findings of 2 cases of bilateral hearing loss, dizziness and the antibody profiles of the inner ears. Case 1 had bilateral progressive hearing loss, vestibular dysfunction and abnormal eye movement as the disease progressed. She had inner ear antibodies against 42 and 58kDa protein antigency on Western blot immune assay, and responded to glycocorticosteroid but not to immunosuppressant treatment. Intratympanic steroid injection temporally eliminated her symptoms. However, she developed idiopathic Cushing's syndrome and underwent labyrinthectomy. Case 2 became deaf as a teenager and experienced dizziness 10 years after becoming deaf. He reacted strongly to 68kDa protein and was a good responder to immunosuppressant with steroid. As we still lack a definitive diagnostic test for AIED, careful observation of the clinical course is critical for differential diagnosis regarding the bilateral progressive hearing loss.

Meniere's attacks occur in the inner ear with excessive vasopressin type-2 receptors

Meniere's disease is peculiar to humans and is characterised by episodic vertigo, fluctuating hearing loss and tinnitus, and attacks of the affliction occurring under conditions of stress. Its pathology was first revealed to be inner ear hydrops through temporal bone studies in 1938. Although subsequently proposed as a disorder of water metabolism in the inner ear, its pathogenesis remains unsolved. The present study aimed to assess the link between the inner ear pathology in Meniere's disease and vasopressin, an anti-diuretic stress hormone with a potential role in inner ear fluid homeostasis. Blood samples were obtained from Meniere's disease patients in the morning, before any surgical treatment, to examine plasma vasopressin (pAVP) levels, and then from inner ear tissue during surgical treatment, to examine vasopressin type-2 receptor (V2R) in the endolymphatic sac. pAVP and the relative V2R mRNA expression in the endolymphatic sac were examined using a real-time polymerase chain reaction. Relative cAMP activity in the endolymphatic sac was also examined using tissue culture and cAMP assay. Both pAVP (1.6-fold versus controls; P = 0.048) and inner ear V2R mRNA expression (41.5-fold versus controls; P = 0.022) were significantly higher in Meniere's patients. cAMP activity was basally up-regulated (2.1-fold versus controls) and cAMP sensitivity to vasopressin application was largely elevated (4.9-fold versus controls) in Meniere's patients. We conclude that, in the pathogenesis of inner ear hydrops, resulting in Meniere's attacks, elevation of pAVP levels (probably as a result of stress) may present as a matter of consequence, but susceptibility of the V2R-overexpressed and cAMP-hypersensitized inner ear to pAVP elevation might be essential as the basis of this disease. Further experimental and clinical studies are needed to better clarify the relationship between Meniere's disease and stress.

Effects of endolymphatic sac drainage with steroids for intractable Meniere's disease: a long-term follow-up and randomized controlled study

OBJECTIVE

Meniere's disease is a common inner ear disease with an incidence of 15 to 50 per 100,000 population. Since Meniere's disease is thought to be triggered by an immune insult to the inner ear, we examined intraendolymphatic sac application of steroids as a new therapeutic strategy for intractable Meniere's disease.

STUDY DESIGN

Prospective randomized controlled study.

METHODS

Between 1996 and 2005, we enrolled and assigned 197 intractable Meniere's patients to three groups in a randomized controlled trial: Group I (G-I)- patients who underwent endolymphatic sac drainage and steroid-instillation; Group II (G-II)-those who underwent endolymphatic sac drainage without steroid-instillation; and Group III (G-III)-those who declined endolymphatic sac drainage. Definitive spells and hearing in all three groups were determined for 2 to 7 years after treatment.

RESULTS

According to the 1995 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria, 2-year results demonstrated that vertigo was completely controlled in 88.0% of patients in G-I (n = 100), 85.1% of patients in G-II (n = 47), and 8.0% in G-III (n = 50). Statistically, G-I = G-II>G-III. Hearing was improved in 49.0% of patients in G-I, 31.9% in G-II, and 6.0% in G-III (G-I>G-II>G-III). Results after 7 years showed that vertigo was completely controlled in 78.8% of patients in G-I, 79.2% in G-II, and 25.0% in G-III (G-I = G-II>G-III). Hearing improved in 36.5% of patients in G-I, 8.3% in G-II, and 0.0% in G-III (G-I>G-II = G-III).

CONCLUSIONS

From non-surgical observation in G-III for at least 7 years after treatment, steroids instilled into endolymphatic sac in G-I patients significantly improved hearing in intractable Meniere's patients, more so than endolymphatic sac drainage without steroids in G-II patients.

Self-curing controlled release systems for steroids. Application of prednisolone-based polymeric systems to ear diseases

An injectable delivery system for prednisolone has been prepared based on a self-curing formulation comprised of poly(methyl methacrylate) particles and hydroxyethyl methacrylate as monomer. The polymerisation reaction was initiated by the redox system 4,4'-bis (dimethylaminobenzydrol)/benzoyl peroxide (BZN/BPO) and followed at 25 degrees C by measuring the time-temperature profile. A maximum temperature of 53 degrees C and a setting time of 15 min were obtained, calculated according to standard specifications. The swelling of the cured system was studied in phosphate-buffered saline (PBS) at 37 degrees C giving a hydration degree at equilibrium of 20%. The swelling kinetics fitted a fickian behaviour at the initial stages of the experiments, with a diffusion coefficient of 0.72 x 10(-7) cm2/s. The release of the drug was sustained from the beginning without an initial drug burst. The study of the wettability showed a rather hydrophilic character of the surface of the loaded system, and the biocompatibility evaluated through MTT assay revealed the absence of cytotoxicity due to the release of toxic substances.

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.

Surgical Treatment of Peripheral Vertigo and Vertiginous Diseases

Although our understanding of the mechanisms of vertigo and pathophysiology of vertiginous disorders has increased, diagnosis and treatment of various vertiginous diseases is challenging. The objective for the treatment of a vertiginous disease is to eliminate the underlying pathology either with maneuvers or drugs. In vertiginous diseases, surgery is performed either to eliminate the underlying pathologic event or to create stability in the incoming vestibular signals. It is not always possible to treat the underlying disease. Therefore, surgery is usually performed for the relief of vertigo. There are various surgical approaches used to treat a variety of vertiginous diseases. Selection of the approach depends on the type of vertiginous disease. This review mainly focuses on the current status and outcome of the surgeries used in the treatment of a variety of vertiginous diseases.

Up-regulation of cochlear aquaporin-3 mRNA expression after intra-endolymphatic sac application of dexamethasone

The final aim of the present study is to see if the endolymphatic sac is really available as a drug delivery system to have effect on the inner ear organs. In the present study, we examined effects of a single insertion of dexamethasone into the rat unilateral endolymphatic sac on mRNA expression of the inner ear aquaporin (AQP) family, transmembrane water transporters and putative endolymphatic fluid modulators, by means of real-time quantitative PCR. Only AQP-3 mRNA expression in the ipsilateral cochlea was significantly up-regulated in comparison with controls and the up-regulation was demonstrated both in dose-dependent and time-dependent manners. These findings suggest that the intra-endolymphatic sac steroids could make regulatory effects on the inner ear AQP-3 expression via vestibular aqueduct and modulate the homeostasis of endolymphatic fluids, encouraging the possibility that the endolymphatic sac could be a therapeutic window for the inner ear disease.

Effects of intratympanic injection of steroids on changes in rat inner ear aquaporin expression

Although steroid treatment is generally administered for patients with inner ear disorders, including Meniere's disease, the mechanism via which steroids exert their effects remains to be clarified. The aquaporins (AQPs) are a family of small transmembrane water transporters, and it has recently been revealed that they play a role in regulating homeostasis in the inner ear fluids. In order to elucidate the action points of steroids in the inner ear, we firstly identified AQPI, 2, 3, 4, 5 and 6 mRNAs in the rat cochlea and AQP1, 3, 4, 5 and 6 in the rat endolymphatic sac by means of reverse transcription-polymerase chain reaction. Subsequently, we found that intratympanic injections of steroids upregulated AQPI mRNA of the rat cochlea in a dose-dependent manner. These results suggest that steroids may affect water homeostasis in the rat inner ear mainly via AQP1.