Efficacy analysis of intratympanic injection of dexamethasone at different concentrations for the treatment of unilateral idiopathic sudden sensorineural hearing loss.

Objective: Our study tried to evaluate and compare the therapeutic efficacy of intratympanic injection of dexamethasone (DEX) at different concentrations for the treatment of idiopathic sudden sensorineural hearing loss (ISSNHL).

Methods: A prospective randomized controlled study was conducted on 203 patients with unilateral ISSNHL. Patients were divided into four groups: the control group (n = 47, systemic treatment only), the high-concentration group (n = 51, intratympanic injection of DEX 20 mg/ml), the medium-concentration group (n = 55, 10 mg/ml), and the low-concentration group (n = 50, 5 mg/ml). Pure tone audiometry (PTA) thresholds were measured before treatment and on the 10th day post-treatment, with a follow-up period of 2 months. Hearing gains and efficacy rates were compared among the groups.

Results: Significant differences were observed in PTA thresholds before and after treatment in all four groups (P < 0.05), indicating that both systemic therapy and intratympanic injection were effective. The overall efficacy rate and hearing gain were higher in the intratympanic injection groups compared to the control group, but the differences were not statistically significant. Specifically, the control group achieved an efficacy rate of 57.4 % with a hearing gain of 11.25 ± 10.00 dB HL. The intratympanic injection groups showed an overall efficacy rate of 67.3 % and a hearing gain of 12.50 ± 10.94 dB HL, with subgroup results as follows: low-concentration group (62.0 %, 12.50 ± 11.56 dB HL), medium-concentration group (69.1 %, 11.25 ± 13.75 dB HL), and high-concentration group (70.6 %, 12.50 ± 8.75 dB HL). Among patients with severe or profound hearing loss, the high-concentration group exhibited significantly greater hearing gains compared to the control group, while no significant differences were observed in efficacy rates.

Conclusion: Combined intratympanic injection of DEX with systemic treatment for SSNHL provides higher hearing gains and efficacy rates compared to systemic treatment alone, though the differences were not statistically significant. In patients with severe or profound hearing loss, intratympanic injection of high-concentration DEX resulted in significantly greater hearing improvement, suggesting a potential therapeutic advantage in this subgroup.