Chemical labyrinthectomy for the worse ear of adult Nigerians with bilateral Meniere's disease: preliminary report of treatment outcomes.

The objective of this study was to assess the effectiveness of variable titration, low-dose intratympanic gentamycin (ITG) into the worse affected ear of patients with bilateral Meniere's disease (MD). It is a prospective analytic case series conducted in a tertiary care referral hospital in a developing economy and a tertiary care otologic private ENT clinic. Patients with MD who failed or are intolerant to medical treatment were recruited based on the criteria of definite MD and bilateral ear involvement. 0.75 cc of low-dose (40 mg/ml) buffered gentamycin was injected into the worse affected ear and patients followed up every 2 months, and the regime repeated only if subjective vertigo persists. The patient's age, sex, duration of MD symptom, ear first affected, ear selected for ITG, pure tone threshold at each visit, duration of caloric response (in seconds) for the injected ear, status of tinnitus in both ipsilateral (injected) and contralateral ears, total number of injections before last follow-up, and time since last follow-up are entered into the study protocol and analyzed. Nine patients with a mean age of 45 years and mean duration of symptoms of 59 months were treated. The mean total number of injections was 2.8 with a mean follow-up period of 34 months. Three cases showed drop in pure tone average threshold (2.5-7.5 dB) while an increase in threshold was noted in six cases (2.5-5 dB). All cases demonstrated decrease in duration of response to iced water caloric stimulation in ipsilateral ear, and 4/9 of contralateral ear. The variable titration method using low-dose intratympanic gentamycin directed at worse ear of adult Nigerians with bilateral Meniere's disease appears to be highly effective. More studies are needed.