Comparison of two different intratympanic corticosteroid injection protocols as salvage treatments for idiopathic sudden sensorineural hearing loss.

ABSTRACT

PURPOSE: We aimed to investigate the effect of interval length and total count of intratympanic steroid (ITS) injections in salvage treatment of patients with idiopathic sudden sensorineural hearing loss (ISSNHL). METHODS: This retrospective case-control study included 64 patients with ISSNHL, who were treated with ITS injections as salvage therapy at a tertiary referral centre. From September 2019 to December 2020, 32 patients received up to four injections every 2-4 days (revised-protocol group). These patients were 11 matched to patients, who received up to three injections at 1-week intervals between January 2014 and August 2019 (initial-protocol group). Hearing outcomes of the two groups were compared. RESULTS: Both ITS salvage treatment protocols resulted in a statistically significant hearing improvement (p < 0.05). The initial-protocol declined hearing thresholds by 12 ± 11.7 dB (p < 0.001, d = 1, P = 99%). Mean hearing function was improved by 13.4 ± 19.1 dB in the revised-protocol group [p < 0.001, d = 0.7, P = 98%]. A clinically significant hearing improvement (> 10 dB) was seen in 18 patients (58.1%) in the initial-protocol group and in 14 patients (41.9%) in the revised-protocol group. A comparison of the hearing outcomes between protocol groups revealed no statistically significant differences (p > 0.05). CONCLUSION: These results indicate that a shorter injection interval does not lead to better hearing outcomes in ITS salvage treatment for ISSNHL. Moreover, fewer ITS injections may reduce costs, physical/mental stress of the patients and lower the risk of persistent tympanic perforations.