Systemic Corticosteroids versus Intratympanic Corticosteroids as Primary Treatments for Idiopathic Sudden Sensorineural Hearing Loss: A Systematic Review and Meta-Analysis

Objectives: Idiopathic sudden sensorineural hearing loss (ISSNHL) is a rapidly progressive disease that may cause permanent hearing loss. Standard primary treatments include oral corticosteroids (OCs) or intratympanic corticosteroids (ITCs). This study aimed to evaluate the effectiveness and safety of OCs versus ITCs as primary treatments for ISSNHL. Design: This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched Medline, Google Scholar, Web of Science, Embase, and Scopus, identifying 11 RCTs comprising 833 patients. Results: Both OCs and ITCs significantly improved hearing, with average pure tone audiometry (PTA) gains ranging from 12 to 40 dB. No significant between-intervention difference was observed in post-treatment PTA. Generally, combination therapy yielded the greatest improvements (>40 dB and >60% recovery). OCs caused systemic adverse effects, whereas ITCs produced mostly mild local effects. Conclusions: Both treatment routes effectively improved hearing in patients with ISSNHL, with neither demonstrating clear superiority in overall efficacy. However, combination therapy may be associated with better hearing outcomes.