Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSNHL) is defined as a sensorineural hearing loss of at least 30 dB in 3 consecutive speech frequencies that occurred within the previous 3 days. In most cases the cause is not identified, although various infective, vascular, and miscellaneous causes have been proposed. It has a reported incidence of 5 to 20 per 100,000 patients per year. Many treatments are used, including corticosteroids, antiviral drugs, hemodilution agents, minerals, vitamins, herbal preparations, batroxobin, carbogen, and oxygen-based treatments. Intra-tympanic dexamethasone injection into the middle ear may be useful to SSNHL patients with profound hearing loss that is intractable to medical treatment or who also have diabetes mellitus. In SSNHL, early treatment with combined modalities that include steroid injection is generally recognized as the current best practice. The spontaneous recovery rates have been reported to be between 32-70%, and although various treatment protocols have been tried, only about half of patients completely recover, usually within 2 weeks. There is much to learn about pathogenesis of sudden sensorineural hearing loss, and more clinical trials are needed to establish evidence-based management.