Intratympanic gentamicin for intractable Meniere's disease

OBJECTIVE: The study aimed to analyze the results of the intratympanic injection of gentamicin as a treatment option for patients with unilateral Meniere's disease who were refractory to medical treatment. STUDY DESIGN: Prospective study in the setting of a tertiary care medical center. METHODS: Seventy-one patients with unilateral Meniere's disease according to 1995 American Academy of Otolaryngology-Head and Neck Surgery 1995 guidelines who had been unresponsive to medical therapy for at least 1 year were studied. Intratympanic injections of a prepared concentration of 27 mg/mL gentamicin were performed at weekly intervals until the development of symptoms and signs indicative of vestibular hypofunction in the treated ear. As the main outcome measure, the 1995 American Academy of Otolaryngology-Head and Neck Surgery criteria for reporting treatment outcome in Meniere's disease were used. The results of treatment were expressed in terms of control of vertigo, disability status (functional level and degree of overall impairment evaluated by the Dizziness Handicap Inventory and the University of California Los Angeles Dizziness Questionnaire), hearing level, and quantitative measurement of vestibular function. RESULTS: Vertigo was controlled in 83.1% of the 71 patients. Recurrence of vertigo spells after initially complete control was noted in 17 patients. In 13 of these patients, this was cured by another course of intratympanic injections of gentamicin. Functional level and measures of self-reported handicap were significantly and promptly lowered after treatment in the patients who attained control of vertigo. Hearing level as pure-tone average was unchanged 2 years after treatment, but hearing loss as a result of gentamicin injections occurred in 23 patients at the end of treatment and in 9 and 11 patients at 3 months and 2 years after the treatment, respectively. Vestibular function was kept normal or reduced in 49.3% of the patients, whereas in the rest of the patients vestibular areflexia was observed. Control of vertigo did not depend on the amount of vestibular damage. CONCLUSIONS: Ending weekly intratympanic injections when clinical signs of vestibular deafferentation appear can control vertigo in the majority of patients, and it is a useful alternative, together with other surgical options, for the treatment of patients with Meniere's disease who do not respond to medical treatment.     

小剂量庆大霉素鼓室内注射治疗难治性梅尼埃病眩晕的临床研究

目的：分析小剂量庆大霉素鼓室内注射治疗难治性梅尼埃病眩晕的疗效。方法：19例单侧难治性梅尼埃病患者显微镜下鼓室内注射庆大霉素,根据床旁试验（自发性眼震、摇头实验、甩头试验）,听力变化或患者主观症状来决定3周后是否需要再次注射。结果：19例患者中17例眩晕能得到控制,眩晕控制率89％,其中5例患者经1次注射后眩晕就得到控制;8例患者2次注射后眩晕达到控制,其中1例患者因不能忍受耳内肿胀感,要求进一步治疗,行内淋巴囊减压后,症状缓减;有4例患者经3次注射后眩晕得到控制;另外2例患者注射2次后眩晕无改善,要求终止治疗。2例患者注射后听力好转,14例患者注射后听力无变化,3例患者（15％）注射后听力进一步下降。结论：运用小剂量鼓室内庆大霉素注射治疗难治性梅尼埃病眩晕,1次注射后观察3周决定再次注射的必要性,结果显示这一治疗方案既能有效控制眩晕的发作,又能降低听力损伤的风险。     

Intratympanic gentamicin titration therapy for intractable Meniere's disease.

OBJECTIVE: This study aimed to assess the efficacy and morbidity of intratympanic gentamicin titration therapy on patients with intractable unilateral Meniere's disease. STUDY DESIGN: The study design was a retrospective chart review and patient interviews. SETTING: The study was conducted at a tertiary referral ambulatory dizziness clinic at the London Health Sciences Centre, University Campus, from July 1992 to June 1997. INTERVENTION: Eighty-three patients received weekly intratympanic gentamicin injections in their diseased ear. Treatments were terminated after four injections or sooner if patients met clinical or audiologic criteria. Sixty-eight patients were available for detailed follow-up. MAIN OUTCOME MEASURES: Vertigo frequency, hearing status, personal disability ratings, tinnitus level, and caloric responses before and after gentamicin therapy were measured. RESULTS: Eighty-four percent of patients showed complete, and an additional 6% showed substantial, vertigo control. At 24 months, 17% of patients demonstrated a clinically significant (10-dB) reduction in hearing, but 26% showed a significant hearing improvement. Overall, the group showed no combined statistically significant changes in any of the hearing parameters. No patients had an "extreme" drop in hearing (>30 dB). CONCLUSIONS: Intratympanic gentamicin titration therapy provides excellent vertigo control with a low incidence of hearing loss.     

Long-term hearing outcome in patients receiving intratympanic gentamicin for Ménière's disease

OBJECTIVE: To determine the long-term hearing outcome in patients with intractable vertigo caused by unilateral Ménière's disease who were treated with intratympanic injection of gentamicin. STUDY DESIGN: The study was a longitudinal analysis of hearing and control of vertigo in patients with unilateral Ménière's disease who received intratympanic gentamicin. METHODS: Pure-tone thresholds and speech discrimination scores on audiometry were analyzed, along with the control of vertigo. Criteria described in 1995 by the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) were used. Patients treated with intratympanic gentamicin had "definite" Ménière's disease and had intractable vertigo despite optimal medical therapy, no symptoms suggestive of Ménière's disease in the contralateral ear, and serviceable hearing in the contralateral ear. The study analyzed the outcomes of 34 patients for whom follow-up data were available for periods greater than 24 months after intratympanic gentamicin. RESULTS: Complete control of vertigo (AAOHNS Class A) was obtained in 90% of the patients. Profound sensorineural hearing loss occurred as a result of gentamicin injection in 1 of the 34 patients (3%). When data from all patients were grouped together, hearing was improved in 5 (15%), unchanged in 23 (68%), and worse in 6 (17%) patients. This distribution of hearing outcome is similar to that in patients whose symptoms of Ménière's disease were managed with medical measures. Recurrent vertigo developed in 10 patients (29%) at an interval of 4 to 15 months after initially complete control. Treatment with additional intratympanic injection(s) of gentamicin did not result in a change in hearing. CONCLUSION: The risk of hearing loss in patients treated with infrequent intratympanic injection(s) of gentamicin is low.     

Use of intratympanic gentamycin for the treatment of Meniere's disease

The ablation treatment of Meniere's disease by intratympanic streptomycin applications was first reported by Schuknecht in 1957. Streptomycin and gentamycin are the most frequent aminoglycosides used for the Meniere's disease treatment. Gentamycin is responsible for the damage of vestibular dark cells causing the impairment of endolymph production. This method gives the possibility for the control of the vertigo with a potential hearing preservation. Fifteen patients with unilateral Meniere's disease who had not responded to conventional therapy, were treated by intratympanic gentamycin injections. The hearing status and the caloric test were staged before and after treatment according to the AAO-HNS guidelines. Overall results after minimum 1 year follow-up in this group were as shown below: complete vertigo control--5 patients, substantial vertigo control--8 patients, complete relief of tinnitus--10, relief of aural fullness--12 patients, hearing loss--none. According to presented results, intratympanic injections of gentamycin is the useful alternative to the surgery. This method should be consider in every patient with the unilateral Meniere's disease, who had not responded to the conventional treatment.     

Intratympanic gentamicin therapy for vertigo in nonserviceable ears

PURPOSE: Intratympanic ototoxic agents have become a widely accepted means of managing vertigo in patients with Meniere's disease while preserving residual hearing. We investigated expanding the indications for intratympanic gentamicin to include control of vertigo in patients without serviceable hearing in the involved ear caused by a variety of end-organ pathologies. MATERIALS AND METHODS: We present a retrospective series of 6 patients suffering from vertigo caused by end-organ disease, in an ear without serviceable hearing. Two patients suffered from delayed endolymphatic hydrops, 3 from Meniere's disease, and 1 from poststapedectomy vertigo. These patients chose unilateral vestibular ablation with serial intratympanic gentamicin injection rather than labyrinthectomy for a variety of reasons. Conventional electronystagmography (ENG) testing and audiometry were completed on all patients. The ENG testing included bithermal calorics and rotational testing. All patients had a magnetic resonance image with gadolinium to exclude retrocochlear or central pathology. Rotational testing was repeated before each injection and at the conclusion of therapy to assess changes in the peripheral vestibular response. The patients' subjective response to therapy was followed. RESULTS: Follow-up has been 10 to 69 months with successful control of vertigo in all patients. CONCLUSIONS: Intratympanic gentamicin therapy offers a minimally invasive, ambulatory, low morbidity, cost-effective means of managing vertigo in patients with nonserviceable hearing.     

Intratympanic gentamicin: a 1-day protocol treatment for unilateral Meniere's disease

PURPOSE: The objective of this study was to assess the usefulness of low-dose intratympanic gentamicin administration in patients with Meniere's disease (MD). MATERIALS AND METHODS: We carried out a retrospective review of the charts of 55 patients with definite MD in accordance with the AAO-HNS (American Academy of Otolaryngology-Head and Neck Surgery) Diagnostic Scale who were treated at Gruppo Otologico (Piacenza, Rome, Italy). The treatment protocol consisted of 3 intratympanic injections of gentamicin at a 12-hour interval between each administration. RESULTS: Results were resumed in accordance with AAO-HNS criteria and showed complete control of vertigo spells in 60% (class A), good control in 16% (class B), moderate control in 4% (class C), poor control in 16% (class D), and no control in 4% (class E) of the patients. Audiological assessment showed unchanged thresholds in 61%, improvement in 22%, and worsening in 17% of the cases. CONCLUSION: Administration of gentamicin is a good alternative to medical and surgical procedures in the treatment of intractable MD. One-day treatment allows for adequate control of vertigo attacks without compromising hearing and quality of life and with reduced costs.     

Vestibular function at the end of intratympanic gentamicin treatment of patients with Ménière's disease

The aim of this study is to analyze the effects of intratympanic gentamicin injections on vestibular function in 33 patients with unilateral Meniere's Disease (according to AAO-HNS guidelines 1995) that had been unresponsive to medical therapy for at least one year. In such patients, the results of bedside examination of vestibular function vestibular examination is compared to those from laboratory tests. Intratympanic gentamicin injections (27 mg/ml) were performed at weekly intervals until symptoms or signs of vestibular hypofunction developed in the treated ear. Vestibular function was evaluated in two different rotatory chair tests. The parameters that were specifically considered were the time constant of the vestibulo-ocular reflex (VOR) after impulse rotation with a peak chair velocity of 100 degrees s(-1), and the phase and gain of the VOR after the sinusoidal harmonic acceleration (SHA) test with a peak chair velocity of 50 degrees s(-1). After treatment, both the time constant of the VOR after rotation towards the treated side and the gain in the SHA test were significantly reduced. These reductions were in accordance with the number of additional signs observed upon bedside examination at the end of the treatment. The changes observed in the VOR correlate well with the results of bedside examination of vestibular function, which in turn reflects the damage induced by intratympanic gentamicin injection.     

Intratympanic gentamicin treatment after endolymphatic sac surgery

CONCLUSIONS: Interval treatment with up to three intratympanic gentamicin injections once weekly effectively controlled vertigo while preserving hearing in patients with Ménière's disease and recurrent or resistant vertigo after saccotomy. OBJECTIVES: Recurrent or resistant incapacitating vertigo may occur after endolymphatic sac surgery (saccotomy) in patients with Ménière's disease. In these patients, revision saccotomy, vestibular nerve section or labyrinthectomy are the established treatment options. We advocate a once-weekly application of intratympanic gentamicin (12 mg) as an effective alternative in this group of patients. MATERIAL AND METHODS: Five patients (age range 39-65 years) with definite Ménière's disease according to the 1995 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria and incapacitating vertigo underwent gentamicin treatment after saccotomy. Control of vertigo and hearing preservation were the aims of treatment. The follow-up period ranged from 26 to 59 months. History and pure-tone audiometry were used to assess vertigo control and hearing, respectively. The frequency of vertigo in the 6-month period before gentamicin treatment ranged between 0.5 and four definitive episodes per month. Hearing stage (AAO-HNS criteria) before gentamicin treatment ranged between 2 and 4. Pre- and post-treatment pure-tone hearing thresholds at 0.5, 1, 2 and 3 kHz were compared by means of the Mann-Whitney U-test. RESULTS: Complete vertigo control (class A; AAO-HNS) and hearing preservation at 0.5, 1, 2 and 3 kHz were achieved.     

Effects of a single intratympanic gentamicin injection on Meniere's disease

CONCLUSION: Both single and multiple injections of ITGM were effective in vertigo control and functional improvement. However, the risk of sensorineural hearing loss was much lower for a single injection than for multiple injections. OBJECTIVES: While intratympanic gentamicin injection (ITGM) has been established as treatment option for intractable Meniere's disease, several injection protocols have been introduced. The risk of sensorineural hearing loss (SNHL) has been reported to be variable for each protocol. Among the protocols, the single injection protocol is an easy to administer, well-tolerated and cost effective technique, as compared with others. We compared the clinical efficacy of ITGM with regard to the vertigo control rate and the incidence of SNHL between two different protocols: the use of single and multiple injections. MATERIALS AND METHODS: A retrospective review was conducted for 30 subjects who were treated with ITGM with intractable unilateral Meniere's disease from May 1997 through February 2005. The patients were divided into two groups according to the protocol utilized: the multiple injection group (n =10) and the single injection group (n =20). Treatment efficacy was evaluated by using the AAO-HNS Committee on Hearing and Equilibrium guidelines (1995). RESULTS: Effective vertigo control (Class A and B) were accomplished in 90% of patients in the multiple injection group and in 90% of patients in the single injection group. Functional status was also markedly improved in both groups. However, a significant hearing loss occurred more frequently in the multiple injection group (71%) than in the single injection group (5%). The rate of caloric loss was not different for the two groups (88% for the multiple injection group vs. 85% for the single injection group).     

Factors relating to the vertigo control and hearing changes following intratympanic gentamicin for intractable Ménière's disease.

OBJECTIVE: To look for factors relating to the vertigo control and hearing changes after intratympanic injections of gentamicin (GM). STUDY DESIGN: Prospective. SETTING: Tertiary referral medical center. PATIENTS: Twenty-eight patients with intractable Ménière's disease. INTERVENTIONS: Three intratympanic injections of GM (once per day for three consecutive days). MAIN OUTCOME MEASURES: Although five patients needed further GM injections or vestibular neurectomy because of poor control (Group I), 23 patients had their vertigo controlled for more than two years without further treatment (Group II). The number of vertigo spells per month, pure-tone audiometry, electrocochleography, caloric response, post-head shake nystagmus, and plasma vasopressin as a stress marker were examined. RESULTS: Before GM injections, there was no difference in the number of vertigo spells per month between Groups I and II. However, the hearing thresholds were higher in Group I. Hearing improvement, increase in percentage of canal paresis and induction of post-head shake nystagmus were observed after GM injections only in Group II. Even in the 11 patients who showed an improvement in hearing of more than 10 dB (hearing improvement group), percentage of canal paresis was increased after GM. More, premedication plasma vasopressin levels were lower in the hearing improvement group as compared with the hearing loss/no changes group. Four of eight patients became negative for dominant negative summating potential in electrocochleography after GM injections in the hearing improvement group. CONCLUSION: Our data indicate that the frequency of vertigo is not a key factor in the vertigo control after GM injections, that induction of vestibular damage in the injected ear is essential for the control of vertigo and this effect is mostly pronounced in patients with milder hearing loss, and that hearing improvement is not only a consequence of good vertigo control but also affected by the stress level before treatment.     

Intratympanic gentamicin for unilateral Meniere's disease: results of therapy

Patients with Meniere's disease that remains refractory to conservative treatment have traditionally been subjected to ablative surgery. The purpose of this prospective study was to evaluate the use of intratympanic gentamicin in eliminating incapacitating vertigo, while preserving hearing. Over the past 8 years, 83 patients have received between 1 and 6 intratympanic injections of gentamicin in an out-patient setting, with duration of therapy titrated to individual symptom response and effect on hearing. Using established AAO-HNS guidelines, we present data on 50 patients who have a minimum of 2 years follow-up. Control or significant improvement of definitive Meniere's attacks was achieved in 92% of patients and hearing preserved or improved in 76%. Only one patient experienced profound sensorineural hearing loss. We feel this treatment option should be considered and offered to patients in whom medical treatment has failed.     

Low-dose intratympanic gentamicin administration for unilateral Meniere's disease using a method based on clinical symptomatology: Preliminary results

PurposeThere are many therapeutic options for Meniere's disease (MD); intratympanic (IT) gentamicin has been proposed for intractable cases although controversy about dosage and method exists. The purpose of this study was to assess the efficacy and safety of low-dose IT gentamicin on vertigo attacks in MD using a clinical symptomatology-based method in which administration was repeated only if vertigo attacks recurred, with a 2-week interval between injections.Materials and methodsForty-eight patients with unilateral intractable MD were included in the study. All patients received one to five IT injections with 0.5 ml of 10 mg of gentamicin (80 mg/2 ml) with an interval of 2 weeks between injections. Vertigo attacks were evaluated before and after therapy and categorized into classes A–F according to the 2015 Equilibrium Committee criteria. Audiovestibular assessment with pure tone audiometry, vestibular bed-side examination and video head impulse test was performed.ResultsBefore treatment patients had an average of 4.4 vertigo attacks/month; after treatment the average number decreased to 0.52. The majority of patients (77%) reached Class A vertigo control with 5 or less gentamicin injections. VOR gain was unaffected in the healthy side and significantly reduced in the affected side. No hearing deterioration was found in all treated patients.ConclusionsLow-dose IT gentamicin administration based on clinical symptomatology can produce a satisfactory control of vertigo attacks after treatment; such protocol had an effect mainly on the vestibular function as demonstrated by the significant reduction in VOR gain in the affected side avoiding a cochlear damage.     

Intratympanic gentamicin for the treatment of Meniere's disease and other forms of peripheral vertigo

Titration therapy with intratympanic gentamicin offers class A or B control of vertigo in 87% (range, 75%-100%) of patients with unilateral Ménière's disease. The risk of additional hearing loss is about 21% (range,0-37%). Vertigo may recur, however, in nearly one third of patients over time. These recurrences can also be treated by intratympanic gentamicin with a similar risk of hearing loss. The salient effect of intratympanic gentamicin is probably the reduction of vestibular function through damage to hair cells, but a complete ablation of function does not seem to be necessary for vertigo control.     

Intratympanic gentamicin in monolateral Meniere’s disease: our experience

The aim of this study was to verify the efficacy of a modified Odkvist titration protocol of intratympanic gentamicin application in the control of vertigo attacks and the effects on the auditory and vestibular function in a group of 71 patients affected by monolateral MD resistant to medical therapy. All the patients underwent an intratympanic administration of a 1-ml solution containing 26.6 mg of gentamicin sulfate. The treatment protocol provided one to three injections for a total amount of gentamicin varying from 26.6 to 80 mg. Five days after the first gentamicin administration, cochlear and vestibular function tests were performed. The worsening of the PTA greater than 15 dB, the appearance of clinical signs of vestibulotoxicity such as imbalance or persistent spontaneous nystagmus beating away from the injected ear or of a curative vertigo were the criteria taken into consideration to stop the treatment. In the absence of any sign, a second and third injection were performed. The presence of an unchanged frequency of the attacks at least 3 months after the previous cycle was the parameter considered to perform a second or third cycle. Seventeen (24%) patients were submitted to a second cycle of therapy and two (3%) to a third cycle. After a mean follow-up period of 20.3 months (range: 3 to 48) all 71 patients experienced good control of the vertigo attacks: grade A in 46 cases and grade B in 25 cases according to the AAO-HNS CoHE criteria. The pure tone average (PTA) hearing threshold (500–3,000 Hz) worsened in 19 patients, improved in 5 and was unchanged in 47. On the basis of the experience acquired during the treatment, we progressively decreased the number of injections from 3/cycle to a 1–2/cycle of therapy. Moreover, in the later phase of the study re-injections were administered 1 or 2 weeks after the previous application and avoided in the presence of signs of depression of the vestibular and/or cochlear function. A residual caloric excitability was found in 30% of the cases. Vertigo control doesnt seem to be linked to the achievement of vestibular inexcitability. The marker of successful gentamicin treatment at short-term is the appearance of signs of curative vertigo and/or vestibular imbalance, and at long-term the disappearance of vertigo attacks.     

Triple semicircular canal occlusion for the treatment of Ménière's disease

CONCLUSION: Triple semicircular canal occlusion (TSCO) controls vertigo, is easy to perform, and could be used as an alternative procedure for the treatment of Meniere's disease in selected patients who complain mainly of intractable vertigo. OBJECTIVE: To seek an effective alternative surgical procedure for treating Ménière's disease in selected patients with intolerant rotational vertigo. PATIENTS AND METHODS: Three patients with Ménière's disease who underwent unsuccessful endolymphatic sac decompression or mastoid shunt, then underwent TSCO. Vertigo control and vestibular and auditory function were measured. RESULTS: The early vestibular symptoms caused by surgery resolved quickly and no hearing deterioration occurred after surgery. At the end of the follow-up period, based on the AAO-HNS criteria, two cases had complete control of vertigo (class A) and the other had substantial control of vertigo attacks (class B). Hearing was similar to the preoperative level at the end of the follow-up period.     

Distortion product otoacoustic emissions after intratympanic gentamicin therapy for unilateral Ménière's disease

The treatment of patients with Ménière's disease that do not respond to conventional therapy becomes complicated, particularly when taking into account the issue of hearing damage as well as the control of vertigo. Treatment often involves the intratympanic administration of gentamicin, for which different protocols are used. Hence, it is important that we better understand how this treatment influences hearing, beyond mere audiometric assessments. The aim of this prospective study was to evaluate the effect of intratympanic gentamicin treatment for Ménière's disease on cochlear function, as assessed by otoacoustic emissions. The 41 patients included in the study had been diagnosed with unilateral Ménière's disease as defined by the American Academy of Otolaryngology-Head and Neck Surgery guidelines (1995), and had been refractory to medical treatment for at least 1 year. Intratympanic injections of gentamicin at a concentration of 27 mg/ml were performed at weekly intervals until indications of vestibular hypofunction appeared in the treated ear. Before beginning the treatment and 3 months after ending it, pure tone and speech audiometry tests were performed and the results are expressed in terms of the pure tone average (0.5, 1, 2, and 3 kHz) and the speech discrimination score, respectively. At the same time, a distortion product otoacoustic emission (DPOAE) study was performed and the results are expressed in terms of its presence or absence, and as the amplitude and threshold of the emission. When analyzed 3 months after the treatment had terminated, hearing loss was seen in 13 patients (31.7%). However, no significant change in the threshold and/or amplitude of otoacoustic emissions was observed in any of the patients. Neither were changes in the audiometric stage, number of injections required or the existence of DPOAE before treatment detected. Hence, the treatment method used here for patients with intractable unilateral Ménière's disease can be considered as having a low risk on auditory function, as assessed both audiometrically and with otoacoustic emissions, and can be considered as subablative for hearing function.     

Intratympanic Gentamicin for Treatment of Intractable Meniere's Disease: A Preliminary Report

Topical administration of aminoglycoside antibiotics in the middle ear can achieve “chemical labyrinthectomy” in patients with intractable Meniere's disease. Herein we report our results of intratympanic gentamicin therapy in 21 patients using two different dosing protocols, twice weekly and twice daily(b.i.d.). Both hearing and vertigo outcome were evaluated. Complete control of episodic vertigo was achieved initially in 20 of 21 patients (95.2%). However, 6 of 20 responders (30%) developed relapsing symptoms within 12 months. Retreatment was successful in 75% of these patients. Overall, hearing was preserved or improved in 62% of cases, worse in 24%, and not yet tested in 14%. When the cumulative dose of gentamicin was ≤4 injections in the first week, only 1 of 14 (7.1%) lost hearing. Intratympanic gentamicin offers better risk/benefit outcome than other invasive therapies for intractable Meniere's disease.     

Intratympanic gentamicin for intractable Meniere's disease: 5-year follow-up

OBJECTIVE: To determine the efficacy and morbidity of intratympanic gentamicin titration therapy on patients with incapacitating unilateral Meniere's disease. METHOD: The study consisted of a retrospective chart review and patient interviews. Sixty-eight patients had been followed for a minimum of 24 months and were reported on in an earlier study. Forty-six of these individuals were available for detailed follow-up at 5 years post-gentamicin therapy. MAIN OUTCOME MEASURES: Vertigo frequency, hearing status, personal disability ratings, and tinnitus level before and after gentamicin therapy were measured. RESULTS: Seventy-four percent of patients showed complete vertigo control and an additional 7% showed substantial vertigo control. There was also significant improvement in personal ratings of social and economic functioning. Overall, the group showed no combined statistically significant changes in any of the hearing parameters. CONCLUSION: Intratympanic gentamicin titration therapy provides excellent vertigo control, with a similarly significant improvement in both personal and occupational functioning.     

Delayed onset of ototoxic effects of gentamicin in treatment of Menière's disease. Rationale for extremely low dose therapy

Five patients with Menière's disease and disabling vertigo were treated with two intratympanic instillations of gentamicin given at an interval of about 12 h. Although no further gentamicin treatment was given despite the absence of any discernible effects on the vestibular endorgan at that time, all patients developed vertigo and nystagmus beating toward the untreated ear within 3 to 5 days after the last instillation. Neither at the 3 month follow-up nor 1 year later did the treated ear show any reaction to bithermal caloric stimulation despite the fact that the hearing levels were almost the same as before treatment. All 5 patients obtained complete relief from attacks of vertigo, but had persisting tinnitus. As gentamicin has been shown to be slowly eliminated from the inner ear, and may thus exert persistent ototoxic effect, it is suggested that gentamicin treatment should not be continued until symptoms of ototoxic effects on the inner ear can be discerned. Extremely low-dose treatment may produce sufficient loss of vestibular function to provide relief from vertigo, and with less risk of affecting the hearing level.