Long-term outcome of Ménière's disease: endolymphatic mastoid shunt versus natural history

Vestibular and audiometric results after endolymphatic mastoid shunt surgery in patients with Menière's disease

PURPOSE

Treatment of Menière's Disease (MD) comprises an array of both non-destructive and destructive treatment options. In patients who are therapy-refractory to non-destructive medical treatment, endolymphatic mastoid shunt surgery (EMSS) is both recommended and debated controversially. The aim of this study was to investigate safety in terms of hearing, vestibular function, complication rate, and efficacy with regards to vertigo control of EMSS in patients with MD according to the current diagnostic criteria of 2015.

METHODS

Retrospective analysis of 47 consecutive patients with definite or probable MD with description of demographic parameters, pre- and postoperative MD treatment, pre- and postoperative audiometric (pure tone audiometry) and vestibular (caloric testing) results. The parameters were compared between patients with and without postoperative vertigo control.

RESULTS

31/47 patients (66.0%) had improved vertigo control postoperatively. Postoperative hearing and vestibular preservation were predominantly stable. No significant differences between patients with improved vertigo control and patients with no change or worse vertigo episodes were found. In the treatment refractory group, 4 patients required a revision EMSS and 6 a destructive MD treatment (5 gentamicin intratympanically, 1 labyrinthectomy). No peri- or postsurgical complications were reported.

CONCLUSIONS

EMSS was found to be beneficial in two thirds of the patients with definite or probable Morbus Menière and a safe procedure regarding hearing and vestibular preservation with no postoperative complications. Therefore, EMSS should be considered before inducing destructive treatment options, such as intratympanic gentamicin application or labyrinthectomy.

Therapeutic strategies in the treatment of Menière's disease: the Italian experience

PURPOSE

Ménière's disease (MD) is an inner ear disorder of unknown etiology, whose pathological substrate is the endolymphatic hydrops. Different treatments have been proposed; however, evidence of their effectiveness is lacking. The aim of this study was to evaluate by a questionnaire which medical and surgical treatments are used in Italy for the treatment of MD and to compare them with those proposed in other countries.

METHODS

An electronic questionnaire of 40 questions was formulated and sent to Italian otolaryngologist (ENT) divided into two groups: Group 1 ("generalists" 60.8%) and Group 2 ("neurotologist- NO" 39.2%).

RESULTS

One hundred and twenty five ENT replied. Treatment of the acute phase, apart from symptomatics, was based on diuretics that are prescribed by 83.5% of respondents, steroids, prescribed by 66.7%, and vasodilators, prescribed by 22%. In the intercritical phase, 87.2% of respondents recommended low-salt diet, 78.4% of respondents prescribed betahistine, and 52.8% diuretics. Statistical analysis did not show correlation neither with the declared specialization nor with the number of patients treated. In case of failure of medical treatment, IT gentamicin was suggested by 48.8% of the respondents and IT steroids by 40.8%. Statistical analysis showed that generalists prefer IT steroids and NO IT gentamicin (p 0.019). In case of failure of both medical treatment and IT treatment, vestibular neurectomy was indicated by 58.4% of the respondents, 6.4% indicated endolymphatic sac surgery, and 2.4% surgical labyrinthectomy.

CONCLUSION

In Italy, the treatment of MD stand on a gradual approach that starts from the dietary-behavioral changes and a pharmacological therapy based on betahistine. In refractory cases, IT treatment initially with steroids and, therefore, with gentamicin allows the control in vertigo in the majority of cases. In case of failure of IT treatment, VNS is the surgery of choice.

Current evidence for endolymphatic sac surgery in the treatment of Meniere's disease: a systematic review

This paper aims to identify emerging evidence for endolymphatic sac surgery (ESS) in the treatment of Meniere's disease since the landmark study by Thomsen et al, published in 1998 (conducted from 1981 to 1989). Using the MEDLINE database (PubMed), a systematic review of the literature published from January 1990 to June 2014 was performed. We included all English-language, peer-reviewed randomised controlled trials (RCTs) and controlled studies. Single-arm cohort studies were included if the sample size was ≥ 90 with a response rate > 60%. Altogether, 11 studies fulfilled our inclusion criteria; one was an RCT, two were controlled trials and eight were single-arm cohort studies. There currently exists a low level of evidence for the use of ESS in the treatment of Meniere's disease. Further studies, in particular RCTs and/or controlled studies, are required to fully evaluate this modality. However, there are difficulties in designing a valid placebo and achieving adequate blinding of observers and investigators.

Intratympanic dexamethasone versus high dosage of betahistine in the treatment of intractable unilateral Meniere disease

PURPOSE

The objective of our randomized, double-blind study was to compare the effectiveness of intratympanic (IT) dexamethasone versus high-dosage of betahistine in the treatment of patients with intractable unilateral Meniere disease (MD).

MATERIALS AND METHODS

Sixty six patients with definite unilateral MD were randomly divided in two groups: Group A received a combination of IT dexamethasone (DX) and identical-appearing placebo pills while Group B received a combination of high-dosage betahistine and IT saline. Intratympanic injections were repeated for three times with an interlude of 3days. High-dosage of betahistine entailed 144mg/day. Mean outcome measures consisted of vertigo control, pure tone average (PTA), speech discrimination score, Functional Level Score, Dizziness Handicap Inventory and Tinnitus Handicap Inventory.

RESULTS

Fifty nine patients completed the study and were available at 12months for analysis. In Group A complete vertigo control (class A) was attained in 14 patients (46.6%) and substantial control (class B) in 7 patients (20%). In Group B, 12 patients (41%) achieved complete vertigo control (class A), 5 patients (17%) substantial control (class B). There is no statistical difference in vertigo control between the two treatment groups. In Group A hearing was unchanged in 14 patients and improved in 4 patients, while in Group B hearing was unchanged in 16 patients and improved in 2 patients.

CONCLUSIONS

Our preliminary results demonstrate that high-dosage of betahistine achieved similar outcomes as IT dexamethasone in the control of vertigo and hearing preservation.

Endolymphatic sac surgery for Ménière's disease: a systematic review and meta-analysis

OBJECTIVE

To analyze current endolymphatic surgery techniques and quantify their efficacy in controlling vertigo and maintaining hearing in the short and long term.

DATA SOURCES

A comprehensive literature search using the PubMed-NCBI database from 1970 to 2013.

STUDY SELECTION

Articles on sac decompression and mastoid shunt (with and without silastic) were included. Included studies had to report data using the 1985 or 1995 American Academy of Otolaryngology-Head and Neck Foundation (AAO-HNS) guidelines, describe surgical technique in detail, include a minimum of 10 patients, and have minimum 12 months of follow-up.

DATA EXTRACTION

Endpoints were vertigo control and hearing preservation using AAO-HNS guidelines. Analysis included short-term (>12 mo) and long-term (>24 mo) follow-up.

DATA SYNTHESIS

Data analysis was performed using MedCalc 12.7.0. Each article was weighted according to the number of patients treated. Analysis of pooled proportion was performed, and Freeman-Tukey transformation was used to correct for probable variance. A t test (of proportions) was performed to compare differences between groups.

CONCLUSION

Endolymphatic sac surgery (sac decompression or mastoid shunt) is effective at controlling vertigo in the short term (>1 yr of follow-up) and long term (>24 mo) in at least 75% of patients with Ménière's disease who have failed medical therapy. Sac decompression and mastoid shunting techniques provide similar vertigo control rates. Mastoid shunting, with and without silastic, also provides similar vertigo control rates. Non-use of silastic, however, seems to maintain stable or improved hearing in more patients compared to silastic sheet placement. The data suggest that, once the sac is opened, placing silastic does not add benefit and may be deleterious.

Intratympanic treatment of intractable unilateral Meniere disease: gentamicin or dexamethasone? A randomized controlled trial

OBJECTIVE

To determine the efficacy and safety of low-dose intratympanic gentamicin (ITG) compared with intratympanic dexamethasone (ITD) in patients with intractable unilateral Ménière disease (MD).

STUDY DESIGN

Open prospective randomized controlled study.

SETTING

Tertiary referral center.

SUBJECTS AND METHODS

Sixty patients affected by definite unilateral MD were enrolled between January 1, 2007, and June 30, 2008. Thirty-two patients were treated with a buffered gentamicin solution injected in the middle ear (maximum of 2 injections); 28 patients were treated with ITD (4 mg/mL, 3 injections at intervals of 1 every 3 days). Mean outcome measurements consisted of control of vertigo attacks, pure tone average (PTA), speech discrimination score, functional disability score, and statistical analysis using repeated measures analysis of variance.

RESULTS

In the ITG group at 2-year follow-up, complete control of vertigo (class A) was achieved in 26 patients (81%) and substantial control of vertigo (class B) in 4 patients (12.5%). In the ITD group, class A was achieved in 12 (43%), and class B in 5 (18%) patients. In the gentamicin group, 4 patients showed a reduction in PTA of ≥10 dB. In the ITD group, PTA was unchanged or slightly improved in 16 patients (belonging to class A-B) and worse in 12.

CONCLUSIONS

Low-dose ITG achieved better outcome than ITD in the control of vertigo attacks in patients suffering from unilateral MD, with a very low incidence of hearing deterioration. ITD offers poorer vertigo control rate, and hearing preservation is achieved only in cases with no vertigo recurrences.

Contemporary perspectives on the pathophysiology of Meniere's disease: implications for treatment

PURPOSE OF REVIEW

Meniere's disease is characterized by episodic vertigo, fluctuating hearing loss, aural fullness and tinnitus. Endolymphatic hydrops, found on post-mortem examination, is the histologic hallmark. Recent research suggests that endolymphatic hydrops results from cytochemical perturbations of unknown etiology that lead to disturbance of the normal endolymphatic fluid homeostasis. This consequent hydropic state or the associated cytochemical perturbations appears to create a neurotoxic environment that ultimately leads to spiral ganglion cell death likely via the apoptotic mechanism. This review highlights some of the recent advances in the understanding of the pathophysiology of endolymphatic hydrops and progressive cochleovestibular deterioration, with emphasis placed on its potential therapeutic implications.

RECENT FINDINGS

Recent evidence supports that endolymphatic hydrops is possibly an epiphenomenon, and is preceded by perturbation of the normal ionic transport regulatory mechanisms. Furthermore, chronic cochleovestibular deterioration appears to be the result of an excitotoxic response to chronic hydrops. A recently described animal model, the Phex mouse, carrying a mutation in the Phex Hyp-Duk gene, provides a novel insight to genetically regulated postnatal endolymphatic hydrops and a useful tool to expand our understanding.

SUMMARY

Despite encouraging recent advances, there are considerable challenges that remain in the development of targeted therapeutic interventions that may offer new avenues of neuroprotection in known cases of Meniere's disease. These advances will hopefully provide pharmacotherapeutic interventions aimed at preventing progressive cochleovestibular dysfunction.

Influence of Meniett® treatment on hearing

CONCLUSIONS

Meniett® treatment was not shown to avoid deterioration of hearing threshold in patients with Meniere's disease (MD), even when achieving a fairly good therapeutic outcome on vertigo control.

OBJECTIVES

To describe the effect of Meniett® treatment on hearing threshold in patients with MD.

METHODS

From a cohort of 55 patients with diagnosis of definitive MD, who underwent Meniett® treatment over the last decade, 27 were selected for the present study as having at least 2 years from the end of treatment. They all received the treatment for 1 month and underwent hearing evaluation as pure tone average (PTA) from 500 to 4000 Hertz at the time of diagnosis, immediately before the treatment, immediately after the treatment, and at the end of the follow-up. Vertigo control was assessed by applying the 1995 AAO-HNS criteria as well as by administration of the Dizziness Handicap Inventory (DHI) questionnaire. Statistical analysis was carried out using paired t test, Wilcoxon signed-rank tests, and multiple linear regressions.

RESULTS

PTA values increased on average by 7.1 dB (95% CI = 2.7-11.5; p = 0.003) during the time period from the beginning of the treatment to the end of the follow-up. Q scores decreased on average by 20.6 (95% CI = 8.8-32.4; p < 0.001) during the pre- and post-Meniett® time-span. These two outcomes appeared not to influence each other.

Long-Term Results of Endolymphatic Mastoid Shunt Surgery in Patients with Intractable Ménière's Disease

OBJECTIVE: To evaluate changes in vertigo and hearing from patients with Ménière's disease managed by endolymphatic mastoid shunt (EMS).

STUDY DESIGN: Case series with chart review.

SETTING: Tertiary referral center.

SUBJECTS AND METHODS: Data from 16 patients were analyzed using 1995 AAO–HNS criteria.

RESULTS: Among 16 patients, six had class A vertigo control two years after treatment, five had class B, one class C, three class D, and one class F. At four years after surgery, seven patients had class A, four class B, three class C, and two class F. The mean functional level before surgery was 4.8 and improved to 2.9 and 2.6 at two years and four years after surgery, respectively. The bone conduction pure-tone averages (four frequencies) were 43.3 before surgery and improved to 33.5 dB HL and 35.5 dB HL at three and six months after surgery, respectively. At two years of follow-up, the hearing level was 38.6 dB HL and was not different from the preoperative hearing level. Two years after surgery, the hearing level gradually decreased and was 42.0 dB HL at five years of follow-up.

CONCLUSION: EMS appears to be beneficial in the short term for the symptomatic patients.

Contemporary Role of Endolymphatic Mastoid Shunt Surgery in the Era of Transtympanic Perfusion Strategies

Objectives:

Although there exist undisputed methods to permanently silence the aberrant end organ, controversy surrounds the durable efficacy of non-ablative interventions. This study provides a contemporary review of our institution's clinical experience in performing endolymphatic mastoid shunt surgery (EMSS) in patients with medically refractory endolymphatic hydrops, or Meniere's disease.

Methods:

Between 1984 and 2002, 1,612 patients were referred to our institution with a diagnosis of Meniere's disease. Of these referrals, 1,172 patients met the criteria for Meniere's disease. Although 553 patients responded to medical management, 486 patients underwent EMSS and 133 patients had refractory disease that required chemical or surgical obliterative interventions. The retrospective study utilizes data collected on 226 patients who were followed for a minimum of 5 years.

Results:

Overall, 78% patients responded favorably to EMSS, according to the functional level scale and class categories delineated by the American Academy of Otolaryngology-Head and Neck Surgery 1995 guidelines for control of vertigo. According to the Arenberg anatomic classification for endolymphatic sac location, EMSS achieved adequate control of vertigo in 86% of type I cases, 90% of type II cases, and 82% of type III cases.

Conclusions:

Endolymphatic mastoid shunt surgery is a relatively safe, effective procedure for the long-term control of vertigo in patients with medically refractory Meniere's disease.

Long-Term follow-up after Gentamicin Application via the Silverstein MicroWick in the Treatment of Ménière's Disease

We conducted a retrospective study to evaluate the long-term effectiveness of gentamicin applied directly to the round window membrane via the Silverstein MicroWick system in patients with definite or probable Ménière's disease. The study population was made up of 69 patients who had received 3 drops of gentamicin 10 mg/ml three times daily; the duration of treatment was guided by objective data obtained from weekly electronystagmography and audiometry. Relief of vertigo was assessed by chart review and telephone interviews. After a minimum follow-up of 24 months, we found that vertiginous symptoms remained controlled in 53 patients (76.8%) after one or more courses of drug therapy. A single course of treatment was successful in 41 patients (59.4%). We conclude that long-term control of vertigo can be achieved in patients with Ménierè's disease by direct application of gentamicin to the round window membrane via the Silverstein MicroWick. This minimally invasive self-treatment technique was well tolerated and free of long-term complications.

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.

Randomized double-blinded, placebo-controlled clinical trial of famciclovir for reduction of Ménière's disease symptoms

OBJECTIVE

To conduct a clinical trial of famciclovir for symptom control in Meniere's disease.

STUDY DESIGN AND SETTING

Randomized, double-blinded placebo-controlled clinical trial in a tertiary referral center, with 12 subjects in the active treatment arm and 11 subjects in the placebo arm.

RESULTS

There were no serious adverse events. Twenty-five percent of the famciclovir group and 18% of the placebo group showed a reduction in number of vertigo spells, the primary efficacy endpoint. This difference was not statistically significant. All subjects improved in dizziness and health-related quality of life. There was a trend for the famciclovir arm to have less fluctuation in hearing relative to the placebo arm.

CONCLUSION

No dramatic effects of famciclovir were found on vertigo or dizziness. Some promising effects on reduction of the fluctuation in hearing were observed.

SIGNIFICANCE

Famciclovir may suppress the fluctuation of hearing in Meniere's disease, but had a minimal effect on vertigo or dizziness symptoms in this study. The probable multifactorial etiology in Meniere's disease requires that further studies be conducted to determine the effects of antiviral medications.

EBM RATING

A.

Increased antisecretory factor reduces vertigo in patients with Ménière's disease: a pilot study

It has been hypothesized that the symptoms of vertigo in patients with Ménière's disease somehow are related to impaired production and/or transport of endolymph. Antisecretory factor (AF) is a protein known to affect transport processes in the intestine and it has been shown that intake of specially processed cereals (SPC) can increase endogenous AF synthesis. In a prospective open pilot study, 24 patients with severe Ménière's disease (functional level scale 5-6 according to the criteria of AAO-HNS) received SPC for 14-30 days. AF levels in plasma increased by 83% in 20 of the 24 patients studied. The attacks of rotatory vertigo were reduced, to final AAO-HNS functional level scale 1-3, in 12 patients and in three of these hearing was normalized. Twelve patients had no or minor effects of the treatment. The correlation between AF activity after treatment and the final AAO-HNS functional level scale was -0.65, P<0.001. Studies in rats using immunohistochemistry methods showed that AF was localized to the cochlea and the vestibule of the inner ear. The present results suggest that AF might be a new regulator of the endolymph.

Intratympanic corticosteroids for Meniere's disease and vertigo

Hearing loss can be caused by acoustic trauma, aging, ototoxic medications, and various other causes. At the cellular level hearing loss seems to be mediated by reactive oxygen species and ultimately through the activation of apoptotic mechanisms. This article explains the cellular and molecular mechanisms of hearing loss and presents medications that could be used in the intratympanic treatment of hearing loss.

Hearing outcome after concurrent endolymphatic shunt and vestibular nerve section

OBJECTIVE

To determine if endolymphatic shunt surgery concurrent with vestibular nerve section improves hearing outcome compared with vestibular nerve section alone.

STUDY DESIGN

Retrospective observational study with cross-sectional survey.

SETTING

Tertiary otologic private practice.

PATIENTS

Thirty-five patients who underwent vestibular nerve section and endolymphatic shunt surgery and 17 patients who had vestibular nerve section alone between 1985 and 2000.

METHODS

Chart review and correspondence for audiogram results and survey.

MAIN OUTCOME MEASURES

Hearing at last follow-up. Hearing Handicap Inventory, Dizziness Handicap Inventory, Tinnitus Handicap Inventory, and SF-36.

RESULTS

Eight patients in the vestibular nerve section and 15 in the vestibular nerve section and endolymphatic shunt surgery group had an audiogram at more than 16 months after surgery available for review. In the vestibular nerve section group, three patients had same hearing whereas five were worse. In the vestibular nerve section and endolymphatic shunt surgery group, 2 patients showed improvement, 2 were the same, and 11 were worse. There was no significant difference in the change from preoperative pure tone average or Word Discrimination Score to postoperative levels between the surgical groups. Eighteen patients had serviceable hearing preoperatively. Five of 8 in the vestibular nerve section and 4 of 10 in the vestibular nerve section and endolymphatic shunt surgery groups maintained serviceable hearing postoperatively. Of the 52 patients, 33 responded to the survey (63%). There were no significant differences between the groups for Dizziness Handicap Inventory, Hearing Handicap Inventory, Tinnitus Handicap Inventory, or SF-36, suggesting that patient-oriented outcomes are the same in both groups.

CONCLUSIONS

Concurrent endolymphatic shunt surgery and vestibular nerve section does not improve hearing or tinnitus outcome over vestibular nerve section alone.

Intratympanic steroid injections for intractable Ménière's disease

OBJECTIVE

To examine whether intratympanic injection of dexamethasone is effective in controlling vertigo in patients with Ménière's disease who have persistent vertigo despite standard medical treatment, including a low-salt/no-caffeine diet and diuretics.

STUDY DESIGN

A prospective study.

METHODS

From August 1999 to November 2000, 21 patients with intractable Ménière's disease underwent intratympanic injections of 4 mg/mL dexamethasone over a period of 4 weeks as an office procedure. American Academy of Otolaryngology-Head and Neck Surgery guidelines for the definition and reporting of results in Ménière's disease were used.

RESULTS

Complete relief of vertigo was maintained in 11 of the 21 patients (52%) at 3 months and in 9 of 21 patients (43%) at 6 months. Repeat injections in 5 patients who had initial control of vertigo, but later failed, yielded control in 3 (60%) patients. The complication rate was low: one patient had a 35-decibel pure tone average decrease in hearing during treatment and one patient had a persistent tympanic membrane perforation.

CONCLUSIONS

Intratympanic injections of dexamethasone are a reasonable initial surgical treatment for persistent vertigo in Ménière's disease. The principal benefits are avoidance of systemic administration of steroids, lower cost than endolymphatic sac surgery, and ease of administration as an office procedure. The disadvantages are the need for repeated office visits for injections and the decreasing effectiveness over time.

Intratympanic therapy for Ménière's disease. High-concentration gentamicin with round-window protection

Many therapeutic options exist for the management of patients with Ménière's disease. In the last few years, the use of intratympanic gentamicin has been investigated as an alternative treatment to vestibular nerve section or labyrinthectomy. In humans, the concentration of gentamicin used for intratympanic treatment of vertigo ranges from 10 mg/mL to 40 mg/mL, and the number of doses from 2 to 14, with a total administered amount between 6 and 2.400 mg. Here lower doses of gentamicin were used, usually had the lowest incidence of hearing loss, but more injections were needed to ablate vestibular function. The purpose of this study was to evaluate the acute and chronic ototoxic effects of intratympanic high-concentration gentamicin after having obliterated the round-window niche with connective tissue in 11 subjects' ears with Ménière's disease. Intratympanic gentamicin was administered according to a predetermined and fixed schedule consisting of two doses of 0.5 mL gentamicin solution, injected once a week with a drug concentration of 80 mg/mL. The total dose of gentamicin was < or = 80 mg. The charts of the patients were surveyed in accordance with the 1995 AAO-HNS guidelines. Three patients had recurrence of vertigo between 3 and 6 months after the second injection and went on to one additional dose of gentamicin. At 2 years follow-up, 10 patients (91%) had complete and 1 (9%) substantial control of vertigo; 3 subjects (27%) had hearing decreased. Tinnitus disappeared or decreased in 3 patients (27%); eight subjects (73%) reported their aural pressure abolished or decreased. The present study demonstrates that in patients with Ménière's disease, 0.5 mL gentamicin solution, with a concentration of 80 mg/mL (total dose < or = 80 mg), injected intratympanically once a week after having obliterated the round-window niche, permits complete or substantial control of vertigo in two-thirds of cases after two doses and in all subjects after three doses. This vertigo control rate is compared to that observed after vestibular nerve section. Hearing results are not different from those with natural control, with endolymphatic sac surgery, and with vestibular nerve section.