Application of intratympanic steroid injection as salvage therapy for idiopathic sudden sensorineural hearing loss

Objectives: Although several studies have reported the benefits of intratympanic steroid injection (ISI) in the treatment of idiopathic sudden sensorineural hearing loss (SSHL), its effectiveness remains controversial. The purpose of this study was to evaluate the efficacy of ISI as a salvage therapy for SSHL and identify factors associated with treatment outcomes. Methods: We retrospectively reviewed the medical records of 119 patients who received systemic steroids for the treatment of SSHL at our hospital between 2014 and 2023. Of the 76 patients who were not complete recovery after systemic administration, 56 were treated using ISI as a salvage therapy. Results: Among the 76 patients who were not complete recovery after systemic administration, a short period between onset and systemic steroid administration (<4 days) showed favorable treatment effects (p = 0.020). We focused on the 56 patients treated using salvage ISI therapy to evaluate the prognostic factors affecting the efficacy of ISI therapy. The mean hearing loss values were 84.1 dB at the initial visit, 70.7 dB on completion of systemic steroid administration, and 61.8 dB at the final evaluation after ISI. In the univariate analysis, patients who received ISI <23 days after SSHL onset, those who had a hearing loss of >= 60 dB at the initial visit, and those who presented with vertigo at the initial presentation had better hearing recovery with ISI than those who did not (p <0.01, p = 0.021, and p = 0.052, respectively). Multivariate analysis revealed that a period of <23 days from onset to salvage therapy was independently associated with favorable ISI effects (p = 0.032). Conclusions: In patients with SSHL, the introduction of salvage ISI therapy <23 days after onset contributes to good hearing recovery. In addition, salvage ISI therapy might be an optional treatment for patients whose hearing loss is >= 60 dB at the initial visit or who present with vertigo at the initial examination.