Primary Observation of Early Transtympanic Steroid Injection in Patients with Delayed Treatment of Noise-Induced Hearing Loss

Abstract

Approximately 5% of the population worldwide suffer from varieties of noise-induced hearing loss (NIHL). Prevention and early identification remain the best methods of approaching NIHL. Over the years, numerous methods of improving the outcome in patients presenting with NIHL have been evaluated; however, these are far from sufficient. The present trial aimed to evaluate the effectiveness of early transtympanic steroid injection in patients with delayed treatment of NIHL. Because systemic steroid treatment is the most common treatment of choice in the management of NIHL, it was considered unethical to replace the first-line systemic steroid treatment with transtympanic treatment. Therefore, the present study evaluated the combination of conventional steroid treatment with a transtympanic steroid injection. A total of 53 patients diagnosed with delayed treatment of NIHL were randomized into a transtympanic group (TR group, n = 27) and a control group (n = 26). The TR group received the conventional steroid treatment plus four courses of additional transtympanic injections of methylprednisolone 3 days after NIHL onset, and the control group received the conventional steroid treatment. Transtympanic injection was performed through laser-assisted myringotomy (a 0.5- to 1-mm perforation was made in the tympanic membrane) under an operation microscope. A total of 51.9% of the patients in the TR group had a ≥15-dB HL improvement in pure-tone average, compared with 23.1% of the patients in the control group, at the 8-week follow-up audiogram. A total of 66.7% of the patients in the TR group had an improvement of ≥15% in the speech discrimination score, compared with 30.8% of patients in the control group, 8 weeks after the treatment. The differences between the two groups were statistically significant. The outcome of this trial indicates that delayed treatment of NIHL may be preferable if transtympanic therapy can be applied earlier. The large variability in the individual results indicates that additional carefully controlled studies with larger sample sizes are needed to understand the effect of early transtympanic therapy in patients with delayed treatment of NIHL.