Sudden deafness (sudden sensorineural hearing loss)

Sudden deafness (sudden sensorineural hearing loss)

Sudden deafness or sudden sensorineural hearing loss (SSNHL) is a distressful condition and should be managed as a medical emergency. Patients who experience this must not wait to see the doctor or blame it on some other condition such as a cold or earwax. The reason for this is that only one third of patients will have a complete recovery if treated early enough.

SSNHL is loss of hearing of at least 30 decibels (measurement of loudness), in at least 3 consecutive frequencies (pitch) within 3 days. It can be noticed suddenly or develop over hours to days. Usually only one ear is affected.

The incidence of SSNHL is approximately 30 per 100 000 per year. This represents 1% of all sensorineural hearing loss cases. It occurs equally in male and female patients. It is most commonly diagnosed in patients between 50 and 60 years of age.

Intracannaliculur acoustic neuroma with sudden deafness shown by yellow arrow
An acoustic neuroma may present with sudden deafness.

Sudden deafness may be accompanied by tinnitus (noise in the ear) and dizziness. Dizziness and vertigo carry a poor prognosis for recovery. Other poor prognostic factors for recovery are increasing age, time of onset and the specific configuration of the hearing loss with testing.

Sudden deafness caused by an intracannaliculur acoustic neuroma indicated by yellow arrow
An acoustic neuroma may present with sudden deafness
Only 15% of patients have an identifiable cause. Virus infections and blood circulation problems can cause SSNHL. There are also less common conditions that can cause it. Magnetic resonance imaging (MRI) should be ordered to exclude an acoustic neuroma, which in 15% of patients can present with SSNHL. Other tests depend on the suspected cause.

Treatment usually includes steroids. In cases of unknown cause ant- virals are often added. The effect of vasodilators and hyperbaric oxygen is still controversial. 85% of patients treated will recover some hearing. If no hearing has returned by two weeks it is unlikely that it will.

In conclusion it should be emphasized that sudden hearing loss should be considered as a medical emergency that should be confirmed and managed as soon as possible.