Sudden hearing loss - or sudden sensorineural hearing loss - is defined as a loss greater than 30dB in three contiguous frequencies, occurring over a period of less than three days.
Sudden sensorineural hearing loss (SSNHL) may be noticed upon awakening in the morning or develop rapidly over hours or days. You may hear a ”?pop' in the ear prior to the hearing loss.
70% of Sudden sensorineural hearing loss patients also suffer from tinnitus. Vertigo is present in 50% of the Sudden sensorineural hearing loss cases.
Sudden onset sensorineural hearing loss is a medical emergency that continues to be poorly understood despite being recognized in the literature since 1944 (De Kleyn, 1944). A commonly used criterion to qualify for this diagnosis is a sensorineural hearing loss over three contiguous pure-tone frequencies of 30 dB or more that develops within 72 hours. The vast majority of cases are unilateral and the estimated annual incidence is 20 per 100 000 persons (Nosrati-Zarenoe et al, 2007). A cause for the hearing loss is only identified in up to 10% of cases but 50% of patients will improve spontaneously (Penido et al, 2009).
The most common treatment for sudden deafness, especially in cases where the cause is unknown, is corticosteroids. Steroids are used to treat many different disorders and usually work by reducing inflammation, decreasing swelling, and helping the body fight illness. Steroids are usually prescribed in pill form. In recent years, direct injection of steroids behind the eardrum into the middle ear (from here the steroids travel into the inner ear), called intratympanic corticosteroid therapy, has grown in popularity. In 2011, a clinical trial supported by the NIDCD showed that intratympanic steroids were no less effective than oral steroids , but were less comfortable overall for patients. They remain an option for people who can’t take oral steroids.