Live Imaging of the Dehydration Effect of Isosorbide on the Normal and Hydropic Guinea Pig Cochleae Using Optical Coherence Tomography.

OBJECTIVE: To investigate the isosorbide-induced dehydration effect on the endolymphatic space by intratympanic administration of isosorbide. BACKGROUND: Isosorbide, an osmotic diuretic, is used orally as a typical conservative therapy for Menière's disease (MD) in Japan. The dehydration effect occurs 6 hours after isosorbide ingestion. Intratympanic administration of isosorbide resolves endolymphatic hydrops faster than oral ingestion. In addition, the dehydration effect has never been shown directly. Therefore, we investigated the dehydration effect of intratympanic administration of isosorbide on endolymphatic hydrops using optical coherence tomography. METHODS: We used eight Hartley guinea pigs, divided into normal and hydrops groups. In the hydrops group, the animals underwent endolymphatic sac obliteration to create endolymphatic hydrops. We obtained midmodiolar section images of the cochleae using optical coherence tomography. Then, 50 to 70% isosorbide was sequentially administered intratympanically for 5 minutes, and the apical turn of the cochlea was observed. The relative midmodiolar cross-sectional area of the scala media was calculated for quantitative assessment of the endolymphatic space. RESULTS: In the normal group, 50% isosorbide had a slight but significant dehydration effect on the scala media; at 55 to 70%, Reissner's membrane became flat. In the hydrops group, 50% isosorbide slightly reduced endolymphatic hydrops; 65% flattened Reissner's membrane, and 70% slightly concaved it toward the basilar membrane. CONCLUSION: The results suggest that we could select the concentration of isosorbide according to the stage or severity of MD and relief from acute attack. Intratympanic administration of isosorbide may be a promising treatment for patients with MD.

15-year follow-up for steroid-responsive, fluctuating hearing loss in the ear with endolymphatic hydrops confirmed by magnetic resonance imaging.

Autoimmune mechanisms may play crucial roles in the etiology of endolymphatic hydrops (ELH), which was previously regarded as a postmortem finding in the temporal bone. Recently, ELH has been visualized using 3-T MR imaging in living patients. A 47-year-old woman with deafness in the left ear since adolescence developed right-sided steroid-responsive sensorineural hearing loss in the low frequencies. During over 15 years of follow-up at our otolaryngology clinic, acute deteriorations of hearing in the only hearing ear repeatedly recovered with administration of intravenous and oral steroids. Hearing in the only hearing ear at 62 years old was preserved and comparable to that at 47 years old. At 61 years old, cochlear ELH was documented bilaterally on MR imaging, appearing more severe in the deafened ear than in the hearing ear. This case provides new evidence of the potential steroid-responsiveness of hearing loss due to contralateral-type delayed ELH distinctly visualized on MR imaging.

Evaluation of changes in endolymphatic hydrops volume after medical treatments for Meniere's disease using 3D magnetic resonance imaging.

OBJECTIVE: To elucidate the relationship between vertigo and EH volume after medical treatment, we investigated changes in endolymphatic hydrops (EH) volume using inner ear magnetic resonance imaging (ieMRI) in relation to clinical results for vertigo and hearing after administration of the anti-vertiginous medications betahistine, adenosine triphosphate (ATP), isosorbide (ISO), and saireito (SAI) for Meniere's disease (MD). METHODS: We retrospectively enrolled 202 consecutive patients diagnosed with unilateral MD from 2015 to 2021 and assigned them to four groups: Group I (G-I), symptomatic oral medication with betahistine only (CONT); Group II (G-II), inner ear vasoactive oral medication (ATP); Group III (G-III), osmotic diuretic oral medication (ISO); and Group IV (G-IV), kampo oral medication (SAI). In total, 172 patients completed the planned one-year-follow-up, which included the assessment of vertigo frequency, hearing improvement, and changes in EH using ieMRI (G-I, n=40; G-II, n=42; G-III, n=44; G-IV, n=46). We constructed 3D MRI images semi-automatically and fused the 3D images of the total fluid space (TFS) of the inner ear and endolymphatic space (ELS). After fusing the images, we calculated the volume ratios of the TFS and ELS (ELS ratios). RESULTS: One year after treatment, vertigo was controlled with zero episodes per month in 57.5% (23/40) of patients in G-I, 78.6% (33/42) in G-II, 81.8% (36/44) in G-III, and 82.6% (38/46) in G-IV (statistical significance: G-I 10 dB in 5.0% (2/40) of patients in G-I, 16.7% (7/42) in G-II, 18.2% (8/44) in G-III, and 21.7% (10/46) in G-IV (statistical significance: G-I=G-II=G-III=G-IV). ELS ratios were significantly reduced after treatment only in the vestibule for G-II, G-III, and G-IV when compared with G-I. Especially among patients with complete control of vertigo after treatment, ELS ratios were significantly reduced after treatment in the vestibule and total inner ear for G-II; in the cochlea, vestibule, and total inner ear for G-III; and in the cochlea, vestibule, and total inner ear for G-IV compared with G-I. However, there were no significant findings in the relationship between hearing results and changes in ELS ratios. CONCLUSION: These results indicate that daily administration of anti-vertiginous medications including ATP, ISO, and SAI could be an effective treatment option for patients with MD at an early stage before it becomes intractable. Treatments to reduce EH might offer better control of vertigo rather than improve hearing.

Betahistine prevents development of endolymphatic hydrops in a mouse model of insulin resistance and diabetes.

BACKGROUND: Diabetes is associated with inner ear dysfunction. Furthermore, C57BL/6J mice fed high fat diet (HFD), a model for insulin resistance and diabetes, develop endolymphatic hydrops (EH). AIM: Evaluate if betahistine, spironolactone (aldosterone antagonist) and empagliflozin (sodium -glucose cotransporter2 inhibitor) can prevent EH induced by HFD and explore potential mechanisms. METHODS: C57BL/6J mice fed HFD were treated with respective drug. The size of the endolymphatic fluid compartment was measured using contrast enhanced MRI. Secondarily, mice treated with cilostamide, a phosphodiesterase3 inhibitor, to induce EH and HEI-OC1 auditory cells were used to study potential cellular mechanisms of betahistine. RESULTS: HFD-induced EH was prevented by betahistine but not by spironolactone and empagliflozin. Betahistine induced phosphorylation of protein kinaseA substrates but did not prevent cilostamide-induced EH. CONCLUSIONS: Betahistine prevents the development of EH in mice fed HFD, most likely not involving pathways downstream of phosphodiesterase3, an enzyme with implications for dysfunction in diabetes. The finding that spironolactone did not prevent HFD-induced EH suggests different mechanisms for EH induction/treatment since spironolactone prevents EH induced by vasopressin, as previously observed. SIGNIFICANCE: This further demonstrates that independent mechanisms can cause hydropic inner ear diseases which suggests different therapeutic approaches and emphazises the need for personalized medicine.

Spironolactone Ameliorates Cochlear Implant Induced Endolymphatic Hydrops.

BACKGROUND: Endolymphatic hydrops (EH) has been observed in both animal and human cochleae following cochlear implant (CI) surgery. We tested whether EH could be eliminated by administration of mineralocorticoid steroid antagonist spironolactone and explored the electrophysiological consequences of this. METHODS: Sixty-four adult guinea pigs underwent cochlear implantation with a dummy electrode. Animals then survived either 2, 7, or 28 days. Auditory function was monitored by recording electrocochleography from the round window membrane preimplantation, and on the last day of the experiment. Spironolactone or control solution was added to animals' feed for 7 days (if they survived that long) beginning immediately prior to surgery. The presence of EH was determined using thin-sheet laser imaging microscopy. RESULTS: Treatment with spironolactone resulted in significant reduction in EH in the second cochlear turn 7 days postimplantation. In all animals, the compound action potential (CAP) threshold was elevated 2 days postimplantation, but for most frequencies had recovered substantially by 28 days. There was no treatment effect on CAP thresholds. SP/AP ratios were elevated at day 2. The amplitude growth of the CAP did not differ between test and control groups at any time after implantation. CONCLUSIONS: EH can be suppressed by antagonism of mineralocorticoid receptors in the week after cochlear implantation. Reduction in EH did not lead to any change in hearing, and there was no indication of synaptopathy signalled by reduced CAP amplitude at high sound intensities. We found no electrophysiological evidence that EH early after implantation impacts negatively upon preservation of residual hearing.

Long-term efficacy of triple semicircular canal plugging in the treatment of patients with ipsilateral delayed endolymphatic hydrops.

This study aims to explore the long-term efficacy of triple semicircular canal plugging (TSCP) in the treatment of intractable ipsilateral delayed endolymphatic hydrops (DEH), so as to provide an alternative therapy for this disease. Forty-eight patients diagnosed with ipsilateral DEH referred to vertigo clinic of our hospital between Dec. 2010 and Dec. 2017, were included in this study for retrospective analysis. All patients were followed up for 2 years. Vertigo control and auditory functions were measured and analyzed. Pure tone audiometry, caloric test, and vestibular evoked myogenic potential (VEMP) were performed in two-year follow-up. Forty-five patients who accepted intratympanic gentamicin (26.7 mg/mL) twice given one week apart were selected as a control group. The total control rate of vertigo in TSCP group was 97.9% (47/48) in the two-year follow-up, with complete control rate of 83.3% (40/48) and substantial control rate of 14.6% (7/48). The rate of hearing loss was 22.9% (11/48). The total control rate of vertigo in intratympanic gentamicin group was 80.0% (36/45), with complete control rate of 57.8% (26/45) and substantial control rate of 22.2% (10/45), and the rate of hearing loss was 20.0% (9/45). The vertigo control rate of TSCP was significantly higher than that of intratympanic gentamicin (χ2 = 6.01, p < 0.05). There was no significant difference of hearing loss rate between two groups. (χ2 = 0.12, p > 0.05). TSCP, which can reduce vertiginous symptoms in patients with intractable ipsilateral DEH, represents an effective therapy for this disorder.

Letter to Editor concerning the "Therapeutic strategies in the treatment of Meniere's disease: the Italian Experience".

In this letter, we discuss possible alternatives and future perspectives in the therapy of Meniere's disease. Special attention should be paid to the role of dietary restrictions for glucose in patients with Meniere's disease, as there is a strong evidence about the presence of insulin receptors in the saccule, the main structure affected by pathological changes due to endolymphatic hydrops; to the possible use of endogenous antisecretory factor administered in specially processed cereals; and to the effects of low-dose intratympanic gentamicin, especially in patients with intractable Meniere's disease.

Gentamicin delivery to the inner ear: Does endolymphatic hydrops matter?

INTRODUCTION: Middle ear application of gentamicin is a common medical treatment for uncontrolled Ménière's disease. The objective of the study was to evaluate the impact of endolymphatic hydrops on inner ear delivery. METHODS: Perilymph gentamicin concentrations and correlation with endolymphatic hydrops in an animal model were assessed. A group of 24 guinea pigs was submitted to surgical obstruction of the endolymphatic sac and duct of the right ear. Gentamicin was applied either to the right ear's round window niche or through a transtympanic injection. Perilymph specimens were collected at different times. Histologic morphometry was used to evaluate both turn-specific and overall hydrops degree. RESULTS: In animals with endolymphatic hydrops, lower concentrations of gentamicin were observed after 20 or 120 minutes of exposure and in both types of administration, when compared to controls. This difference reached statistical significance in the round window niche application group (Mann-Whitney, p = 0,007). A negative correlation between perilymphatic gentamicin concentration and hydrops degree could be observed in both groups, after 120 minutes of exposure (Spearman correlation, round window niche p<0,001; TT p = 0,005). CONCLUSIONS: The study indicates that the endolymphatic hydrops degree has a negative interference on the delivery of gentamicin into the inner ear following middle ear application.

Delayed endolymphatic hydrops. Special emphasis on nystagmus associated with episodes and contribution of chemical labyrinthectomy.

OBJECTIVES: The main objective was to describe spontaneous nystagmus characteristics during an episode of delayed endolymphatic hydrops (DEH), including an initial vertical upbeating nystagmus in one patient. The secondary objective was to highlight the contribution of chemical labyrinthectomy. METHODS: Episodic vertigo after a prolonged period of time of sensorineural hearing loss (profound or total) in one ear characterized ipsilateral DEH and was associated with the development of hearing loss in the opposite ear in contralateral DEH. RESULTS: Ten patients met the criteria for DEH: 7 ipsilateral and 3 contralateral. Three (all ipsilateral DEH) were examined during a vertigo episode. Two patients had a typical horizontal-torsional nystagmus beating contralaterally to the hearing loss. One patient showed atypic initial vertical upbeating nystagmus with a slight torsional component, which secondarily became horizontal-torsional beating contralaterally to the hearing loss. Four patients had disabling vertigo with unilateral total deafness (ipsilateral DEH), successfully treated by 1-3 transtympanic gentamycin (Gentalline®) injections. CONCLUSION: Nystagmus direction during vertigo episodes varies, and may initially present as vertical upbeating nystagmus, which, to our knowledge, has not been previously reported in DEH or Menière's disease. This nystagmus might reflect an inhibition of the superior semicircular canal (on the hearing-impaired side), suggesting incipient hydrops in this canal. Chemical labyrinthectomy is a simple and effective procedure in unilateral DEH, especially as the patient often suffers from total deafness.

Intratympanic Injections of Dexamethasone in Delayed Endolymphatic Hydrops: A Prospective Clinical Study.

OBJECTIVE: This study was designed to evaluate the effectiveness of intratympanic dexamethazone (ITD) for the treatment of ipsilateral delayed endolymphatic hydrops (DEH). METHODS: Forty-one patients were diagnosed with ipsilateral DEH. Only 37 patients completed this study. Patients were randomly divided into 2 groups. Group A (n = 16) received oral medication, and group B (n = 21) received ITD once weekly for 4 consecutive weeks. RESULTS: In group A, 6 patients showed improvement in their vertigo. Four patients (25%) showed complete vertigo control, and 2 patients (12.5%) showed substantial vertigo control. In group B, 21 patients showed improvement in their vertigo, 11 patients (52%) showed complete vertigo control, and 10 patients (47%) showed substantial vertigo control. Only 1 case did not show any improvement in their vertigo. CONCLUSION: ITD is proven to be a valuable and promising alternative modality for the management of ipsilateral DEH.

Intratympanic steroids injection is effective for the treatment of drop attacks with Ménière's disease and delayed endolymphatic hydrops: A retrospective study.

Drop attack (DA) associated with Ménière's disease (MD) and delayed endolymphatic hydrops (DEH) is not common and may cause life-threatening clinical problems. The intratympanic dexamethasone (ITD) is one of primary treatments for MD or DEH. Our study investigated the effect of ITD on the DA associated with endolymphatic hydrops (EH).We retrospectively reviewed 10 patients with MD- and DEH-associated DA between January 2009 and December 2013 in Outpatient Department of Otolaryngology, Union Hospital, Wuhan, China. Among them, 7 patients (5 cases with MD, 2 cases of DEH) received ITD (4 times, on weekly basis). Further repeated ITD courses or intratympanic gentamicin (ITG) were given if the vertigo was not satisfactorily controlled. The number of DA and status of vertigo control after intratympanic injection were evaluated. After a follow-up study lasting from 19 to 35 months, DA in 5 cases (71.4%) disappeared after initial ITD course. In 2 cases, DA was altogether controlled after an additional intratympanic injection (repeated ITD or/and ITG).This study showed that ITD promises to be a first-line conservative treatment for MD- or DEH-related DA since the steroid possesses no inner-ear toxicity. Furthermore, for MD- or DEH-related DA refractory to ITD, ITG can be an effective alternative.

Dehydration effects of a V2 antagonist on endolymphatic hydrops in guinea pigs.

We investigated the influence of vasopressin type 2 receptor antagonist (OPC-41061; Tolvaptan) on experimentally induced endolymphatic hydrops (EH) in guinea pigs. In the first series, the endolymphatic sac (ES) of the left ear of all animals was electrocauterized. Four weeks after surgery, the animals were allocated to four groups: three systemic applications groups (saline, OPC 10 and 100 mg/kg) and a local round window (RW) OPC 1 mg/body application group. We examined the histopathology of the temporal bones and assessed volumetric changes of the endolymphatic space in the cochlea and saccule. In the second series, we investigated the effects of systemic and topical applications of OPC on plasma vasopressin (p-VP) concentrations and plasma osmolality (p-OSM). In the first series, we found that EH was reduced in the OPC 10 mg/kg systemic and OPC RW application groups. In contrast, EH increased in the OPC 100 mg/kg systemic application group. In the second series, neither p-VP levels nor p-OSM were significantly different among the non-OPC, OPC 10 mg/kg systemic, and OPC RW application groups. However, in the OPC 100 mg/kg systemic application group, the p-VP level was significantly higher than that in other groups, and p-OSM was higher than that in the non-OPC group. The systemic application of a low dose of OPC and topical application of OPC resulted in reduced EH in the face of minimal systemic effects (p-VP and p-OSM). These findings suggest that OPC-41061 may be one useful treatment option for EH.

Endolymphatic Hydrops Reversal following Acetazolamide Therapy: Demonstration with Delayed Intravenous Contrast-Enhanced 3D-FLAIR MRI.

Endolymphatic hydrops, the primary pathologic alteration in Menière disease, can be visualized by using delayed intravenous contrast-enhanced 3D-FLAIR MR imaging. It is not known whether MR imaging-demonstrable changes of hydrops fluctuate with disease activity or are fixed. We describe the results of baseline and posttreatment MR imaging studies in a group of subjects with Menière disease with hydrops who were treated with acetazolamide. Seven subjects with untreated Menière disease with MR imaging evidence of hydrops had repeat MR imaging during acetazolamide treatment. Symptoms and imaging findings were assessed at each time point. Five subjects showed symptom improvement, of whom 3 had improvement or resolution of hydrops. One subject had recurrent symptoms with recurrent hydrops after discontinuing therapy. Two had unchanged hydrops despite symptom improvement. Subjects with unchanged symptoms had unchanged hydrops. Hydrops reversal may be seen with acetazolamide treatment in Menière disease. MR imaging may provide an additional biomarker of disease.

Intratympanic injection in delayed endolymphatic hydrops.

CONCLUSIONS: The present study showed that intratympanic dexamethasone injection (ITD) is a promising approach for the treatment of contralateral and ipsilateral delayed endolymphatic hydrops (DEH). Moreover, intratympanic gentamicin injection (ITG), as a chemical labyrinthectomy, is a simple alternative for controlling vertigo in patients with ipsilateral DEH. OBJECTIVE: This study examined the effect of ITD or ITG on DEH. METHODS: Fourteen patients with DEH completed the clinical and audio-vestibular evaluation. Among them, 10 cases (ipsilateral type: nine cases, contralateral type: one case) were treated with intratympanic injection. Four patients with ipsilateral DEH underwent ITG, five patients with ipsilateral type and one patient with contralateral type received ITD. All 10 cases were followed up for 8-48 months. RESULTS: Complete and substantial vertigo control was achieved in four of nine ipsilateral DEH patients treated with ITG. In the other five ipsilateral cases who received ITD, two accomplished complete vertigo control and two had substantial control. In one case, the vertigo was not effectively controlled. One case of contralateral DEH underwent ITD and this case had complete vertigo control. The vertigo intensity, vertigo frequency, vertigo duration and the functional level scale after intratympanic injection was decreased significantly.

Transitory effect on endolymphatic hydrops of the intratympanic steroids for Ménière's disease.

OBJECTIVES/HYPOTHESIS: This study aimed to evaluate the changes in electrocochleography (EcohG) measurements after intratympanic (IT) dexamethasone therapy and to correlate them with the long-term effects on the control of vertigo. STUDY DESIGN: Prospective outcomes research. METHODS: This study included 62 patients with unilateral Ménière's Disease (MD) refractory to medical therapy for at least 1 year. Each patient was treated with a fixed protocol of three consecutive weekly injections of a commercial 4 mg/mL dexamethasone preparation. The 1995 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria for reporting treatment outcomes for MD were used. Electrocochleography (EcohG) measurements were performed 1 month before and 1 and 12 months after IT steroid therapy. Caloric test and vestibular evoked myogenic potential (VEMPs) were performed before the IT treatment. The summating potential/action potential (SP/AP) ratio was measured before and after the IT treatment. A Kaplan-Meier analysis was used to evaluate the control of vertigo over a 2-year period. RESULTS: Complete vertigo control (class A) was achieved in 26 patients (41.9%) at the 12-month follow-up and in 12 patients (19.3%) at the 24-month follow-up. A significant reduction (P < 0.01) in the SP/AP ratio after the IT steroid treatment was observed in the first-month determination, but no significant differences were found when the initial and 12-month determination were compared. CONCLUSIONS: IT dexamethasone provides an alternative treatment for patients with Ménière's Disease. A transitory reduction of the endolymphatic hydrops is detected by the EcohG 1 month after treatment. The hydrops levels returned to their initial values in the 1-year EcohG follow-up. LEVEL OF EVIDENCE: 2b.

Management of intractable Ménière's disease after intratympanic injection of gentamicin.

OBJECTIVES/HYPOTHESIS: 1) To evaluate the efficacy of, and problems with, intratympanic gentamicin injection (ITG) in medically intractable definite Ménière's disease (MD) and secondary endolymphatic hydrops (EH); and 2) to review the vestibular status and treatment options of intractable vertigo even after ITG. STUDY DESIGN: Retrospective case review and survey. METHODS: 780 patients with definite MD and secondary EH were enrolled. Long-term outcomes and problems of applied treatment options including ITG and exploratory tympanotomy and gentamicin application (ETG) were analyzed. RESULTS: Of the 780 patients, 95 patients received ITG. Class A and B control of vertigo was achieved in 85 (89.5%) patients; two patients were class C and eight patients were class F (ETG: 6; labyrinthectomy: 1; vestibular neurectomy: 1). Among seven patients who received ETG including 1 patient who skipped ITG due to chronic otitis media, five patients improved to class A, showing a 71.4% success rate; and labyrinthectomies were performed subsequently in the two remaining patients. Vertigo was controlled (class A) in all the patients who received labyrinthectomies (n = 4) or vestibular neurectomy (n = 1). Eight patients (8.4%) experienced more than 10 dB worsening, and two patients (2.1%) progressed to bilateral Ménière's disease. CONCLUSION: ITG failed to control vertigo in 10.5% of cases. ETG may be a reasonable option to facilitate the delivery of gentamicin into the inner ear by direct application of gentamicin over the round window and the oval window. Labyrinthectomy and vestibular neurectomy still have roles in the era of ITG.

Type 1 allergy-induced endolymphatic hydrops and the suppressive effect of H1-receptor antagonist (olopatadine hydrochloride).

OBJECTIVE: To investigate whether endolymphatic hydrops (EH) is experimentally induced by type 1 (or immediate) hypersensitivity allergic reaction and to investigate the inhibitory action of a histamine H(1)-receptor antagonist (olopatadine hydrochloride [OLO-Hy]) on allergic EH induced by systemic immune challenge with 2,4-dinitrophenylated-Ascaris (DNP-As). METHODS: The experimental animals were actively sensitized with DNP-As twice at a 4-week interval and were provoked by an injection of DNP-BSA including DNP-As 1 week after the second sensitization. The OLO-Hy (+) group received oral administration of OLO-Hy (30 mg/kg) 1 hour before the provocation, whereas the OLO-Hy (-) group received distilled water. The temporal bones in all animals were light microscopically examined to assess the degree of EH quantitatively and the expression of degranulated mast cells in the endolymphatic sac. RESULTS: Endolymphatic hydrops was observed 1, 6, 12, and 24 hours after the last sensitization in the OLO-Hy (-) group but was not observed in the OLO-Hy (+) group. Quantitative analysis of the increase ratios (IRs) of the cross-sectional area of the scala media revealed that the IRs of the OLO-Hy (-) group were significantly greater compared with those of the control group (p < 0.001). There was also a significant difference in the IRs between the OLO-Hy (-) and OLO-Hy (+) groups (p < 0.001). CONCLUSION: The systemic sensitization with DNP-As produced allergy-induced experimental EH by type 1 hypersensitivity allergic reaction, and the development of this EH was prevented by histamine H(1)-receptor antagonists.

[Effects of intratympanic injection of dexamethasone on endolymphatic hydrops and changes in guinea pigs inner ear CFTR expression].

OBJECTIVE: To observe the effect of tympanic injection of dexamethasone in the guinea pig endolymphatic hydrops and the change CFTR expression, to explore the effect of glucocorticoid treatment endolymphatic and its possible mechanism. METHOD: Thirty guinea pigs were divided into three groups: hormone group, water group, control group. The animals(hormone group, water group) in study were injected DDAVP 4 µg/kg in the first 7 d, and will increase to 6 µg/kg in the second 3 d. The control group was given normal saline, continuous 10 d. After twelfth days, the hormone group transtympanic injection of dexamethasone (5 mg/ml, 0.5 ml), and water group, control group transtympanic given normal saline (0.5 ml), continuous injection 5 d. Using immuno- histochemistry and Western blot to detect the cystic fibrosis transmembrane conductance regulator cochlear factor (CFTR) expression. RESULT: The water group ABR thresholds was significantly higher than that before the experiment (P < 0.01), and the water group was significantly higher than the rest of the groups (P < 0.01); Hormone group compared with the control group increased threshold value (P < 0.05). The control group had no endolym- phatic hydrops, the water group showed varying degrees of endolymphatic hydrops, cochlear duct and vestibular plus cochlear duct area ratio compared with the control group, hormone group was significantly higher (P < 0.01). hormone group area ratio was higher than the control group (P < 0.05). CFTR was primarily expressed in the stria vascularis, Corti's, spiral ligament, basilar membrane, cochlear ganglion,etc . The expression of CFTR in the water group was increased than that in the control group, and the hormone group (P < 0.01); the expression of hormone group increased compared with the control group (P < 0.05). CONCLUSION: Tympanic injection of dexa- methasone can alleviate the desmopressin acetatein guinea pigs caused by membranous labyrinth, and the improve- ment of the hearing; Tympanic injection of dexamethasone can make the endolymphatic hydrops cochlea of guinea pigs decreased CFTR expression, indicating that the expression and possible mechanisms of CFTR intratympanic steroids reduce endolymphatic hydrops changes.

Effect of standard-dose Betahistine on endolymphatic hydrops: an MRI pilot study.

This study aimed to assess whether standard-dose Betahistine (48 mg daily) exerts an effect upon the degree of endolymphatic hydrops in patients with Menière's disease using a retrospective case series in the setting of a tertiary neurotology referral centre. In six patients with definite unilateral Menière's disease, the degree of cochlear and vestibular endolymphatic hydrops was assessed before and after treatment with a standard dose of Betahistine (48 mg daily), using high-resolution 3 T MR imaging after intratympanic contrast medium application. The treatment duration was 3-7 months (mean 5 months), and the patients were followed-up for 6-29 months (mean 11 months). In the study cohort, the standard dose of Betahistine did not have an MR morphologically measurable beneficial effect on the degree of endolymphatic hydrops. The results indicated no effect of standard-dose Betahistine on endolymphatic hydrops found on high-resolution MR imaging. Possible explanations are: (1) insufficient dosage or duration of treatment with betahistine, (2) insufficient resolution of the MR imaging technique, and (3) insufficient length of follow-up. Further studies addressing these issues are warranted.

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.