Intratympanic Gentamicin for Intractable Ménière's Disease – A Review and Analysis of Audiovestibular Impact

Abstract

Introduction Intratympanic gentamicin regulates the symptoms in most patients with incapacitating Ménière's disease. The treatment protocols have changed over the years from medical labyrinthectomy to preservation of vestibular function. Objectives This study aims to review the audiovestibular response related to the effect of the drug in controlling vertigo. Data Synthesis Articles were identified by means of a search in the PubMed database using the key words Meniere and intratympanic or transtympanic gentamicin . Total 144 articles were reviewed after excluding those that were technical reports, those based on experimental animal studies, those that focused on outcomes other than vertigo (tinnitus or aural fullness), those with delivery methods other than tympanic membrane injection, and those with bilateral cases. If there was more than one article by the same author(s) or institution, only the most recent one matching the aforementioned criteria and those that were not overlapping were included. Conclusion Titration methods or multiple injections on a daily basis can be preferred if the patients have profound or non-serviceable hearing, since these methods have significant incidence of hearing loss. Treatment protocols with a frequency of injection not shorter than once a week, or those with injections on a monthly basis as “needed” provide the same level of vertigo control with better preservation of hearing. Caloric testing is not an ideal tool to analyze the correlation between vertigo control and the effect of gentamicin as compared with gain asymmetry of the vestibulo-ocular reflex. Vestibular-evoked myogenic potentials and the head thrust test are more reliable than other vestibular tests for the follow-up of patients undergoing gentamicin treatment.

A comparison of endolymphatic shunt surgery and intratympanic gentamicin for meniere's disease

“…However, both hearing and vertigo outcomes after ITG can vary depending on the dose, titration, number, and frequency of injections, which has contributed to the large variability in outcomes of previous ITG studies. 14,26,27 In our study, 52.0% of patients showed hearing deterioration after ITG, which is higher than previous findings and could be the result of variability in the numbers of injections patients received along with other previously mentioned factors. 14,22,[25][26][27] Of note, in our study, eight out of 27 patients (29.6%) who underwent ITG developed chronic imbalance and unsteadiness after the treatment.…”

“…9 Two randomized controlled trials have shown a beneficial effect of ITG for MD compared with placebo, and subsequent studies have further validated the effectiveness of ITG. [10][11][12][13][14] Despite its efficacy and less invasive nature (when compared with surgical procedures), ITG can be hazardous to hearing and can have significant long-term vestibular sequelae. While vestibular hair cells are more sensitive to gentamicin than cochlear hair cells, ITG can still lead to cochlear hair cell and spiral ganglion neuron injury.…”

“…While vestibular hair cells are more sensitive to gentamicin than cochlear hair cells, ITG can still lead to cochlear hair cell and spiral ganglion neuron injury. [14][15][16] The first study directly comparing outcomes between ELS and ITG for intractable MD reported that ITG had better posttreatment functional outcomes as well as better overall quality of life scores but no statistically significant difference in vertigo control. 17 This provides further support for the comparability of both treatments with regards to vertigo outcomes.…”

Clinical Practice Guideline: Ménière’s Disease

“…Studies show that IT gentamicin injections are well tolerated, improve vertigo symptoms, and have a low incidence of severe hearing loss. 17,19,[303][304][305][306][307][308] Caution must be given to patients who have bilateral MD, as chemical ablation carries the risk for significant bilateral vestibular hypofunction and rare hearing loss. Moreover, despite its effectiveness, the vestibular status of the other (noninvolved) ear should be assessed before recommending treatment with gentamicin to avoid potential bilateral hypofunction.…”

Current Understanding and Clinical Management of Meniere's Disease: A Systematic Review

“…[93][94][95] Finally, in case of failure of conservative therapies, intratympanic gentamicin could be proposed to induce a partial chemical labyrinthectomy. 86,[96][97][98][99][100][101][102][103] Several reviews have evaluated the effectiveness of intratympanic therapies, supporting their use in MD. 104,105 -Surgery: This must be considered with caution, since MD may become bilateral after surgery.…”