Sudden Sensorineural Hearing Loss

Rapid unexplained sensorineural hearing loss developing within about three days

Overview

Sudden sensorineural hearing loss is a rapid loss of hearing, usually in one ear, that develops over hours to a few days. Common clinical definitions require a drop of at least 30 dB across three contiguous frequencies within 72 hours. In most cases no cause is found, and proposed mechanisms include viral infection, disruption of the blood supply to the cochlea, and immune mediated inner ear damage; a minority of cases are linked to identifiable causes such as vestibular schwannoma. It is often accompanied by tinnitus, ear fullness, and sometimes vertigo. Because it can be mistaken for earwax or congestion, clinical guidelines treat it as a condition needing prompt assessment, including a hearing test to confirm a sensorineural pattern. Corticosteroids, given by mouth or by injection through the eardrum, are the most commonly used treatment, although the strength of evidence is debated. A substantial proportion of people recover some or all hearing, with outcomes influenced by severity and the presence of vertigo.