Audiometric Outcomes of Topical IGF1 Treatment for Sudden Deafness Refractory to Systemic Steroids

Abstract

To examine the effects of topically applied recombinant human insulin-like growth factor 1 (IGF1) via gelatin hydrogels on alterations in pure-tone audiometry (PTA) in patients with sudden sensorineural hearing loss (SSHL) refractory to systemic steroids. Retrospective chart review. A single university hospital. Twenty-five patients with SSHL refractory to systemic steroids who received topical IGF1 treatment. Single topical application of IGF1 to the round window niche using gelatin hydrogels. The primary outcome was alterations in PTA thresholds at frequencies of 0.25, 0.5, 1, 2, and 4 kHz after topical IGF1 application. Secondary outcomes included differences in final improvements in PTA thresholds among frequencies tested and cumulative numbers of patients showing 10- or 20-dB recovery in PTA during the observation period. Topical IGF1 application via gelatin hydrogels significantly altered PTA thresholds at each frequency tested and at the average frequency. The numbers of patients with a 10-dB recovery in PTA increased until 4 weeks after treatment and then stabilized, whereas those patients showing 20-dB recovery gradually increased during the observation period. Topical IGF1 application via gelatin hydrogels contributes to the recovery of PTA levels in patients with SSHL refractory to systemic steroids. Major recovery of PTA levels occurs within 4 weeks after treatment.