Prognostic impact of salvage treatment on hearing recovery in patients with sudden sensorineural hearing loss refractory to systemic corticosteroids: A retrospective observational study

To determine the prognostic factors for hearing recovery in patients with sudden sensorineural hearing loss (SSHL) refractory to systemic corticosteroids following salvage treatment.This is a retrospective observational study at nine tertiary referral hospitals. A total of 120 patients with sudden deafness refractory to systemic corticosteroids were enrolled. The patients were randomly assigned to receive topical application of recombinant human IGF-1 or intratympanic injection of dexamethasone as salvage treatment. Multiple regression analysis was performed to identify determinants of hearing recovery using pure tone audiometry results at 8 weeks after treatment. Clinical predictors that were evaluated included age, sex, pretreatment hearing level, presence of vertiginous symptoms, days to study entry from symptom onset and salvage treatment assignment (IGF-1 vs. dexamethasone).The linear regression model identified age (P=0.001), pretreatment hearing level (P0.001), days to study entry from symptom onset (P=0.011) and treatment assignment (P=0.033) at 8 weeks after treatment as significant variables influencing the recovery of pure tone audiometry average thresholds. Younger age (60 years), early initiation of salvage treatment and treatment with topical IGF-1 therapy had significant effects on hearing recovery.The results indicate that early initiation and choice of treatment modalities for salvage treatment may be important for the prognosis of patients with refractory SSHL. The positive effect of topical IGF-1 therapy on hearing recovery indicates its utility as salvage treatment.