Intratympanic injection in Meniere’s disease; symptomatic and audiovestibular; comparative, prospective randomized 1-year control study
Authors: ElBeltagy Yasser Fawzi , Shafik Amr Gouda , Mahmoud Ahmed Maher , Hazaa Nagwa Mohammed 
Published: September 2023

EnAbstract
Objective
The aim of this work is to compare the effectiveness of intratympanic therapy of gentamicin versus steroids in the treatment of Meniere’s disease in terms of symptomatic control and audiovestibular changes.

Patients and methods
Thirty patients with intractable unilateral Meniere’s disease were included in our study. They were divided into two groups. The first group was administered intratympanic (IT) gentamicin and the second group was administered IT dexamethasone. We followed our patients with respect to three main symptoms including vertigo, which was determined by the number and duration of attacks, and the class according to AA-HNS 1995 guidelines. We also assessed tinnitus and aural fullness in addition to the Dizziness Handicap Inventory. These parameters were followed up after 6 months and 1 year. Audiological assessment included pure tone audiometry, the speech reception threshold, and the speech discrimination score. Vestibular assessment included the caloric test, rotatory chair stimulation, and vestibular evoked myogenic potential. These parameters were checked at 1 week, 6 months, and 1 year after injection.

Results
Our results showed complete control of vertigo in 76.9% of patients in group I and 30.8% in group II, which was found to be statistically significant. Both groups showed 80–86% satisfactory control of vertigo by 6 months of follow-up, which increased to 100% by 1 year. We found an improvement in tinnitus in 30.8% of the patients in group I and in 38.4% of the patients in group II; the difference between the two groups was nonsignificant. In terms of aural fullness, both groups showed a significant improvement in aural fullness (76.9% in group I and 61.5% in group II). Patients in group I had a 15.4% rate of significant hearing loss and those in group II had 7.7%. Also, we found a significant difference in the rate of hearing loss between both the groups in the high frequencies as gentamicin produced more deterioration in the hearing threshold than dexamethasone. However, the dexamethasone group showed a significant improvement in hearing at low frequencies much more than the gentamicin group. In terms of vestibular testing, we found that gentamicin significantly affected the phase parameter in the rotatory chair test and it also increased the canal paresis in caloric testing. Both effects were absent in the dexamethasone group. We did not find any significant correlation between control of vertigo and any of the vestibular tests.

Conclusion
IT therapy, whether gentamicin or dexamethasone, is an effective way to treat intractable Meniere’s disease, with very little side effects. When considering complete control of vertigo, IT gentamicin produces better results than dexamethasone. IT dexamethasone leads to greater improvement in tinnitus than gentamicin, but not significantly. Both drugs significantly improve aural fullness. IT gentamicin produces more hearing loss than dexamethasone at high frequencies. No benefit can be gained from vestibular testing in the follow-up of therapy.