Idiopathic sudden sensorineural hearing loss: prognostic factors and outcomes of salvage treatment with intratympanic dexamethasone

Introduction and objectives: Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL) is commonly defined as greater than 30 dB of hearing loss in at least 3 audiometric frequencies occurring over 3 days or less, of unknown cause. Since the effect of steroid therapy in this syndrome is currently under discussion, we will evaluate the efficacy of intratympanic corticosteroid (ITC) as rescue treatment. As a secondary objective, we will study the influence of certain factors considered risk or prognostic. Patients and methods: The results of two population groups with similar age and hearing loss are compared. The first of 99 patients received exclusively systemic treatment with corticosteroids. In the second group of 70, with ISSNHL refractory to general treatment, we instilled intratympanic corticosteroids. We compared the differences in mean hearing threshold at diagnosis and at 3 months, as well as the general degree of recovery. Results: Intratympanic application of 3 doses of dexamethasone (8mg/ml) in refractory ISSNHL did not produce, in our population, a significant change with respect to systemic treatment. We also analyzed the influence of selected prognostic factors. Discussion: We do not know the efficacy of corticosteroid treatment in idiopathic sudden deafness. The type of lesion and patient characteristics could be decisive in the final prognosis and therapeutic outcome. Conclusions: Rescue treatment with ITC has not provided significant hearing improvement in the population studied. The factors with the worst prognosis are the presence of vestibular symptoms, profound hearing loss, high-frequency hearing loss in audiometry, the beginning of treatment after 2 weeks and fundamentally, the lack of improvement of at least 10 dB on the 4th day of treatment.