Intratympanic therapy for Ménière's disease: effect of administration of low concentration of gentamicin.

We present results at 2 years follow-up of a group of 15 patients with Ménière's disease treated with a low concentration of intratympanic gentamicin (IG group), compared with a group of 15 patients who refused any surgical treatment (NH group). IG was administered according to a predetermined and fixed schedule consisting of 2 doses of 0.5 ml gentamicin solution, pH 7.8, injected once a week, with a drug concentration of 20 mg/ml; the total dose of gentamicin was < or = 20 mg. Additional doses of IG were administered only in patients who had recurrence of vertigo. The results were evaluated following the American Academy of Otolaryngology Head and Neck Surgery 1995 criteria for reporting Ménière's disease treatment results by means of interviews, audiologic and vestibular evaluations, and a questionnaire based on a six-point functional level scale. Seven of the 15 IG patients had recurrence of vertigo after the second injection and received a third dose of IG. Four patients had recurrence of vertigo after the third infiltration; three subjects received a fourth dose and one refused additional injection. At 2 years follow-up, 93% of the IG patients had complete (class A) or substantial (class B) control of vertigo. Only 47% of the NH patients had no vertigo or were substantially improved. Hearing deteriorated in 7% of the IG group and in 40% of the NH group. Tinnitus disappeared or improved in 20% of the IG patients and in 27% of the NH patients; 40% of the IG patients and 27% of the NH patients reported that their aural pressure was abolished. The present study demonstrates that, in patients with Ménière's disease, 0.5 ml doses of gentamicin solution, with a concentration of 20 mg/ml, injected intratympanically once a week minimize the risk of hearing loss in the treated ear, permitting complete control of vertigo in more than half of cases after 2 doses and in almost all subjects (93%) after 4 doses.