Efficacy of high dose systemic versus combined (systemic and intratympanic) corticosteroid therapy in idiopathic sudden sensorineural hearing loss: A prospective randomized trial and risk factor analysis

The pathophysiology and the proper treatment of idiopathic sudden sensorineural hearing loss (ISSNHL) are an ongoing subject of debate. Locally or systemic administered corticosteroids are the most accepted drugs of treatment in reference to ISSNHL (idiopathic sudden sensorineural hearing loss), however, no strong evidence nor guidelines regarding their effectiveness yet exists.In our prospective, randomized, controlled trial 78 participants were enrolled. Patients were randomly assigned based on the day of admission to two groups according to treatment: group SS (n = 43) received intravenous systemic methylprednisolone alone, and group CT (n = 35) received intratympanic dexamethasone + systemic methylprednisolone. The primary outcome was to compare the hearing outcomes between the treatment groups based on different, widely accepted categories (Siegel, Kanzaki, modified Siegel and PTA4 gain). In consideration of the secondary outcome, we examined the effect of the various risk factors on the hearing improvement.No differences were detected regarding hearing improvement between the two groups, based on any criteria [Siegel's criteria (p = 0.604); Kanzaki's criteria (p = 0.720); modified Siegel's criteria (p = 0.524) and PTA 4 gain (p = 0.569)]. However, several clinical factors such as vertigo (p = 0.039), or cardiovascular comorbidity (p = 0.02) and the severity of initial hearing loss (p = 0.033) were found to bear a significant impact upon the hearing outcome.To the best of our knowledge, this is the first randomized controlled trial comparing high dose systemic and combination corticosteroid therapy in ISSNHL patients. Our findings suggest coexisting cardiovascular comorbidity, vertigo and severity of the initial hearing loss may bear a significantly higher impact upon hearing improvement, than the additional intratympanic steroid administration.The presented trial was registered in the European Union Drug Regulating Authorities Clinical Trials Database (name: Combinated systemic and intratympanic steroid therapy in idiopathic sudden sensorineural hearing loss, No.: 2017-000658-20) and with the ethical approval of The National Institute of Pharmacy and Nutrition (OGY ' EI) (protocol No.: 7621, on 2017.02.16.)