Recurrences in Sudden Sensorineural Hearing Loss: A Long-Term Observational Study

Purpose: Long-term outcomes of sudden sensorineural hearing loss (SSNHL) are poorly studied. The recurrence rate is heterogeneous, and the prognosis of relapses is uncertain. The aim of this retrospective study was to evaluate the recurrence rate of SSNHL and to analyze the correlation with clinical and audiometric characteristics.Method: Seventy-three patients with idiopatic SSNHL were evaluated. Clinical and audiometric features were recorded. Seventy patients (95.8%) had at least a 2-year follow-up, whereas 50 (68.4%) had a 5-year follow-up.Results: Two- and 5-year recurrence rates were 5.60% and 10.34%, respectively. Mean time lapse between 1st episode and recurrence was 29.33 +/- 26.60 months. About 70% of patients had a partial recovery at recurrence. The same ear was affected in 42.8% of patients, the contralateral ear was affected in 42.8% of patients, and recurrence was bilateral in 14.4% of cases. Recurrence correlated only with the presence of tinnitus during follow-up. However, the small number of participants with recurrence represented a limiting factor of our study.Conclusions: Recurrences of SSNHL are rare events that can involve ipsilateral or contralateral ear. Further studies are necessary to identify predictors of recurrence.