Evaluation of cochlear ototoxicity with otoacoustic emissions and pure-tone audiogram following treatment for multidrug-resistant tuberculosis in our tertiary care center

Abstract

Background and Objectives: Hearing is a vital function and can be impaired by drugs causing ototoxicity which is inevitable in situations such as multidrug-resistant tuberculosis (MDR-TB). A longitudinal study was conducted to evaluate cochleotoxicity by otoacoustic emissions (OAEs) and pure-tone audiogram (PTA) in patients following treatment for MDR-TB. Materials and Methods: Sixty-five patients were included in the study after excluding cases as per criteria. Baseline pure-tone audiometry and OAEs were done. If asymptomatic, the patient followed up with PTA and distortion product OAE after 3 months and 6 months of treatment with a selected regimen for MDR-TB. Results: Compared to the pretreatment prevalence of 67% hearing loss, 81% of patients had hearing loss at 3 months and 97% at 6 months. OAEs were abnormal in 32% before treatment, which increased to 86% at 3 months and 97% at 6 months' follow-up. Conclusion: OAEs were able to pick up early the cochlear damage before it became apparent in PTA and well ahead of becoming symptomatic in patient. OAEs should be included in the pre- and post-treatment assessment of hearing with a high-frequency PTA for follow-up in MDR-TB patients or any patient on treatment which may cause ototoxicity.