Vestibulotoxicity as a consequence of systemically administered tobramycin in cystic fibrosis patients.

CONCLUSION: The reported prevalence of vestibulotoxicity (30.4%) in cystic fibrosis (CF) patients supports vestibulotoxicity screening in CF patients during or after tobramycin exposure. Prospective longitudinal investigation is required for a more specific evidence-based proposal. OBJECTIVE: To investigate the prevalence of tobramycin-induced vestibulotoxicity in CF patients, as it had not been investigated before. PATIENTS AND METHODS: In this observational cohort study, 23 CF patient volunteers from the Haga Teaching Hospital Adult CF centre who had been exposed to at least one treatment with systemically administered tobramycin were included. Subjective feelings of dizziness were measured using validated questionnaires and vestibular symptoms were assessed by physical examination. Electronystagmography (ENG) with caloric irrigation was used as the gold standard. RESULTS: Peripheral vestibular loss was found in seven patients (7/23 = 30.4%). Central vestibular loss was found in one patient. Analysis of the 19 completed questionnaires showed that 12 patients (12/19 = 63.2%) did not experience dizziness and 3 patients (3/19 = 15/8%) experienced specific vestibular symptoms. The results of the questionnaire could not predict the results of ENG with caloric irrigation. Physical examination showed no abnormalities in any patients. No age- or dose-related predictive factors were found.

Intratympanic gentamicin treatment after endolymphatic sac surgery.

CONCLUSIONS: Interval treatment with up to three intratympanic gentamicin injections once weekly effectively controlled vertigo while preserving hearing in patients with Ménière's disease and recurrent or resistant vertigo after saccotomy. OBJECTIVES: Recurrent or resistant incapacitating vertigo may occur after endolymphatic sac surgery (saccotomy) in patients with Ménière's disease. In these patients, revision saccotomy, vestibular nerve section or labyrinthectomy are the established treatment options. We advocate a once-weekly application of intratympanic gentamicin (12 mg) as an effective alternative in this group of patients. MATERIAL AND METHODS: Five patients (age range 39-65 years) with definite Ménière's disease according to the 1995 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria and incapacitating vertigo underwent gentamicin treatment after saccotomy. Control of vertigo and hearing preservation were the aims of treatment. The follow-up period ranged from 26 to 59 months. History and pure-tone audiometry were used to assess vertigo control and hearing, respectively. The frequency of vertigo in the 6-month period before gentamicin treatment ranged between 0.5 and four definitive episodes per month. Hearing stage (AAO-HNS criteria) before gentamicin treatment ranged between 2 and 4. Pre- and post-treatment pure-tone hearing thresholds at 0.5, 1, 2 and 3 kHz were compared by means of the Mann-Whitney U-test. RESULTS: Complete vertigo control (class A; AAO-HNS) and hearing preservation at 0.5, 1, 2 and 3 kHz were achieved.