Sudden sensorineural hearing loss: early diagnosis improves outcome

Abstract

Sudden sensorineural hearing loss (SSNHL) is one of the most under recognised medical emergencies. Unilateral loss of hearing does not produce the same immediate concerns as unilateral loss of vision and the differential includes very common and benign conditions such as wax obstruction and otitis media with effusion. These two factors often conspire to delay the patient’s initial consultation and subsequent referral to the ear, nose, and throat (ENT) specialist. This is unfortunate as there is now evidence that early action significantly improves the chances of obtaining some recovery in hearing thresholds. There is no universal definition of SSNHL but based on the patient’s pure tone audiogram, it is often defined as an increase in pure tone threshold of greater than 30 decibels (dB) in at least three adjacent frequencies occurring within 72 hours. Its peak incidence is between 50 and 70 years of age although it can occur at any age. Figure 1 shows a typical audiogram of someone with a sudden unilateral sensorineural hearing loss. Figure 1. A typical pure tone audiogram of a patient with a sudden unilateral sensorineural hearing loss. For each frequency of sound the tester reduces the sound intensity of the tone to a level at which the patient can only just …