Clinical Evaluation and Early Diagnosis of Streptomycin Ototoxicity

초록

Objectives: Despite its strong anti-tuberculous effect, streptomycin (SM) is used only restrictively because of its risk of ototoxicity. The authors tried to assess the rates and clinical features of SM-induced ototoxicity. The authors also tried to find out how the early detection of ototoxicity based on symptoms and laboratory tests works for preservation of cochlear and vestibular function. Methods: From 1996 to 2008, 418 patients who had got SM because of tuberculosis in various parts of the body were enrolled in the study. All the patients underwent electronystagmography, caloric test, slow harmonic acceleration test, pure tone audiometry including 8 kHz and 12 kHz and oto-acoustic emission before the initial injection as a baseline evaluation. The patients were reevaluated immediately if any cochlear or vestibular symptoms arose during the course of injection. The authors reviewed incidence, duration, total doses injection, risk factors as well as vestibulocochlear function retrospectively. Results: Thirty patients (7.1%) complained of vestibular symptoms. Among them, only 17 patients (4.1%) showed objective laboratory findings of vestibulopathy. No patients have dropped total bilateral vestibulopathy in followup caloric test. No patients could be restored caloric response, but symptom was improved after cessation of injection. Twelvepatients (2.8%) suffered from hearing symptoms such as tinnitus and subjective hearing impairment. Vestibular symptoms occurred earlier (within 38 days) than cochlear symptoms (137 days) (P<0.05), even no cases of audiometrically proven threshold shift among them. Nobody had newly developed dizziness or hearing loss after the completion of injection. Conclusions: Our 12 year experience of SM injection for treatment of tuberculosis showed 4.1% incidence of vestibular toxicity within 38 days, and no cochlear toxicity. Early detection of SM ototoxicity could minimize the risk, preserve the function,