Factors Relating to the Vertigo Control and Hearing Changes Following Intratympanic Gentamicin for Intractable Ménière's Disease

Low Dose Intratympanic Gentamicin in Ménière’s Disease

Intratympanic gentamicin has become an accepted standard of care for Ménière's disease. But there still exists controversies regarding the dosing protocol as well as the drug concentration for optimum control of vertigo and hearing preservation. To determine if 20 mg of intratympanic gentamicin administered once a month for a maximum of 2 months can alleviate intractable vertigo caused by definite Ménière's disease with hearing preservation. Once diagnosed with definite Ménière's disease as per AAO-HNS criteria, the patient was given 0.5 ml of 40 mg/ml intratympanic gentamicin. Follow-up was done at 1-month and 6-month post-treatment. If at 1-month review patient continued to have vertigo one more dose of intratympanic gentamicin was administered. Thirty-two patients were included in the study. Seventeen patients (53.1%) received one dose and 15 patients (46.9%) received two doses of intratympanic injection. We achieved an effective vertigo control of 59.4% and complete vertigo control rate of 53.1%. Worsening of symptoms was noted in 1 patient. Hearing was preserved in all patients except for one. Among the patients who attained effective vertigo control, 72.2% had dead labyrinth at 6-month cold caloric status. A single injection of 20 mg intratympanic gentamicin can alleviate intractable vertigo caused by definite Ménière's disease with hearing preservation. Non-responders may be given a second dose after one month. Intratympanic gentamicin is a simple, cheap treatment that can be carried out in an out-patient setting.

Long-term Vertigo Control and Vestibular Function After Low-dose On-demand Transtympanic Gentamicin for Refractory Menière's Disease

OBJECTIVE

To describe the long-term clinical vertigo control along with measured lateral canal vestibular function in patients with unilateral refractory Menière's disease (MD) treated with gentamicin transtympanic injections (TTI).

STUDY DESIGN

Retrospective analytic study.

SETTING

Tertiary referral center.

PATIENTS

Thirty-eight patients treated by TTI for medically refractory unilateral MD, defined by the 1995 AAO-HNS criteria, between May 2006 and December 2012.

INTERVENTION(S)

One-year course of treatment with gentamicin TTI following a low dose on-demand protocol. TTI were repeated in new courses of treatment when MD recurrence occurred.

MAIN OUTCOME MEASURE(S)

AAO-HNS class of control, caloric tests (CalT), recurrence rate.

RESULTS

After an average clinical follow-up of 71 months, all patients entered a class of control A (78%) or B (22%), with an average of 2.3 TTI received. The mean maximal obtained deficit was 88.5%, and the mean long-term deficit was 85.5%. Ten (26%) patients had disease recurrence requiring a new course of treatment. A value of the first CalT in the 3 months following the first TTI strictly higher than 78% was significantly associated with disease control and the absence of symptom recurrence (p≤0.01). In the "recurrence" group, four patients had a significantly lower mean value of all CalT performed after the first TTI when compared with other patients (p≤0.001), indicating gentamicin resistance CONCLUSION:: Achieving a sustainable vestibular deficit on caloric testing is key for MD symptom control after gentamicin TTI. Gentamicin resistance must be diagnosed early to adapt therapeutic strategies.

Labyrinthectomy and Vestibular Neurectomy for Intractable Vertiginous Symptoms

Introduction Labyrinthectomy and vestibular neurectomy are considered the surgical procedures with the highest possibility of controlling medically untreatable incapacitating vertigo. Ironically, after 100 years of the introduction of both transmastoid labyrinthectomy and vestibular neurectomy, the choice of which procedure to use rests primarily on the evaluation of the hearing and of the surgical morbidity.

Objective To review surgical labyrinthectomy and vestibular neurectomy for the treatment of incapacitating vestibular disorders.

Data Sources PubMed, MD consult and Ovid-SP databases.

Data Synthesis In this review we describe and compare surgical labyrinthectomy and vestibular neurectomy. A contrast between surgical and chemical labyrinthectomy is also examined. Proper candidate selection, success in vertigo control and complication rates are discussed on the basis of a literature review.

Conclusions Vestibular nerve section and labyrinthectomy achieve high and comparable rates of vertigo control. Even though vestibular neurectomy is considered a hearing sparing surgery, since it is an intradural procedure, it carries a greater risk of complications than transmastoid labyrinthectomy. Furthermore, since many patients whose hearing is preserved with vestibular nerve section may ultimately lose that hearing, the long-term value of hearing preservation is not well established. Although the combination of both procedures, in the form of a translabyrinthine vestibular nerve section, is the most certain way to ablate vestibular function for patients with no useful hearing and disabling vertigo, some advocate for transmastoid labyrinthectomy alone, considering that avoiding opening the subarachnoid space minimizes the possible intracranial complications. Chemical labyrinthectomy may be considered a safer alternative, but the risks of hearing loss when hearing preservation is desired are also high.

Bedside vestibular examination in patients with unilateral definite Ménière's disease

CONCLUSION

Although vestibular clinical examinations are quite variable in Ménière's disease (MD), when used in a grouped fashion they attach valuable information to the understanding of MD.

OBJECTIVE

Evaluation of unilateral MD vestibular bedside examination.

METHODS

This was a retrospective study of patients with definite unilateral MD at a tertiary care facility. Assessment of spontaneous nystagmus (SN), head-shaking nystagmus (HSN), head impulse test (HIT) and vibration-induced nystagmus (VIN) was carried out. Clinical manifestations and auditory and vestibular function were studied.

RESULTS

The study included 97 patients: 47 presented SN, 75 a positive HSN (biphasic in 14) and in 73 a VIN was observed. After excluding patients with biphasic HSN, a homogeneous response was observed in 43.4%: no nystagmus in 15.7%; nystagmus of similar direction in 27.8% (paretic, 14.5%; irritative, 13.3%). There were no significant differences in duration of the disease, functional level and vertigo index, although a trend towards a shorter time since last crisis was observed in patients with an irritative nystagmus. In 36.1% nystagmus was revealed with a consistent direction in at least one of the tests and in 20.5% it was non-coherent, something more frequently observed closer to the crisis. Independently only in VIN an irritative response was associated with a higher functional level and a shorter time from last attack.

Single-shot, low-dose intratympanic gentamicin in Ménière disease: role of vestibular-evoked myogenic potentials and caloric test in the prediction of outcome

OBJECTIVE

The aim of this study was to assess the efficacy and safety of single and low-dose intratympanic gentamicin therapy in patients with Ménière disease and who were monitored both with caloric tests and vestibular-evoked myogenic potentials (VEMPs) to see if VEMPs have an additional role in predicting the efficacy of the drug.

STUDY DESIGN

This is a prospective cohort study.

SETTING

Tertiary referral center is the study setting.

PATIENTS

Twenty-five intractable Ménière disease patients were included as the study group.

INTERVENTION(S)

Low-dose (16 mg/mL), single-shot intratympanic gentamicin was applied. VEMP and caloric test were applied 2 weeks after the application.

MAIN OUTCOME MEASURE(S)

Safety and efficacy of protocol were evaluated at the sixth month postoperatively with tonal audiogram and visual analog scale, respectively.

RESULTS

Mean average pure-tone hearing threshold at 0.5, 1, 2, 4, and 8 kHz was 49.6 and 51.0 dB before and after the application, respectively (P > .05). Mean pretreatment and posttreatment visual analog scale scores of patients were 17.6 mm (10-30 mm) and 74.6 mm (41-100 mm), respectively (P < .01). Posttreatment VEMPs were absent in 17, deteriorated in 2, and not changed in 6 patients. VEMP was a significant predictor of posttreatment visual analog scale score, whereas caloric test was not (P < .01).

CONCLUSIONS

Low-dose, single-shot intratympanic gentamicin treatment proved to be effective and safe among intractable Ménière patients. VEMPs obtained at posttreatment second week were significant predictors of patients posttreatment sixth-month dizziness status and vertigo control.