Material and Methods
The study was conducted at Otolaryngology Department of AORN“S.G.Moscati” between January 2005 and May 2015.We selected 72 consecutive patients(28 males and 44 females, mean age 49.5 years, range:21-78 years) with disabling unilateral Ménière’s disease treated with ITG. Patients included in the study were not responsive to conservative therapies(lifestyle change, diuretics, salt-restricted diet, steroid or betahistine). Inclusion criteria for this study were: definite diagnosis of MD based on criteria of the 1995 Equilibrium Committee2, lack of response to medical therapy for six months with invalidating vertigo attacks, unilateral MD, satisfactory hearing in the contralateral ear, no previous treatment with surgical conservative procedures or intratympanic steroid injections, absence of hypersensitivity to aminoglycosides. All patients included in the study met the inclusion criteria. After a detailed explanation of the procedure, a written consent was obtained. To exclude other inner ear diseases, all patients were submitted to magnetic resonance with contrast. Before intratympanic treatment all patients underwent a neuro-otological examination, including evaluation of spontaneous, positional and positioning nystagmus, head shaking test, subjective visual vertical test, Romberg and stepping test. A caloric test was used to evaluate the vestibular semicircular canal excitability. Otomicroscopic examination was performed to evaluate tympanic membrane. All patients underwent to tympanometry and pure tone audiometry. Pure tone average(PTA) was calculated on air conduction thresholds at 500, 1000, 2000 and 3000dB. Before treatment all patients filled out a questionnaire about number of vertigo, so to calculate a monthly rate of vertigo.We use gentamicin sulfate at a concentration of 40mg/ml, the intratympanic injection was performed with a 25G spinal needle in our ambulatory. Without local anesthesia, 0,2-0,3 mL of gentamicin was injected into the affected ear through posterior-inferior quadrant of tympanic membrane. Patient was instructed to maintain a supine position with the head 30 degree tilted toward the healthy side avoiding to swallow for at least 30 min. The same procedure was carried out the following two days. After treatment audiometric revaluation was performed at 3 and 7 days after the third injection. In absence of vertigo patients were revaluated after 1-3-6-12 months and then every year. The follow up ranged from 2 to12 years(mean follow-up 7 years). The aim of the study was to evaluate hearing threshold changes and vertigo control after ITG treatment.The t student test was used to compare outcomes. For quantitative variables, descriptive statistics were computed as mean and Standard Deviation(SD) or median and Interquartile Range(IQR 25th to 75thpercentiles), if they were not normally distributed, and as absolute frequency and percentage for qualitative variables. The reporting guideline followed in this study was STROBE statement.