Sudden sensorineural hearing loss is a relatively rare event in general practice but is regarded as needing urgent ENT assessment. The difficulty is that most patients with sudden hearing loss in general practice are much more likely to have a conductive rather than a sensorineural loss. It is important to distinguish between the two.
Sudden sensorineural hearing loss is frequently NOT a complete hearing loss. There is no strict definition, but it is often defined as a hearing loss of at least 30 dB in three sequential frequencies in the standard pure-tone audiogram, which has occurred in less than three days. It is a mistake to focus on risk factors and complete dramatic loss, as this might well result in patients with milder symptoms being missed.
A history is useful. If the hearing loss occurred at the time of putting a cotton bud or olive oil in the ear then a conductive loss seems much more likely. If there is a giddiness (not one typical of Ménière’s disease which often lasts 20 minutes to a few hours) that also started at the same time as the hearing loss, then a sensorineural loss should be seriously considered.
Ideally one would always examine the patient. However just seeing wax in a patient’s ear canal does not tell you if the hearing loss they are experiencing is necessarily conductive.
Tuning fork tests are vital here, assuming the hearing loss is in just one ear. I would normally do Rinne’s test, however Weber’s test is the useful one in these cases. For Weber’s test the base of the tuning fork is in the middle of the patient’s head. In conductive deafness the fork sounds louder to the patient in the affected ear. In sensorineural deafness the fork is louder in the good ear
In a Covid19 world you can ask your patient to hum. The hum should be louder in the deaf ear if the problem is conductive and louder in the good ear if the problem is sensorineural.
If you believe the problem is a sudden sensorineural loss I would recommend a telephone discussion that day with your local on-call ENT surgeons.
It is often at least the day after the hearing loss started that the patient contacts the GP. Therefore you need to assess the patient rapidly and discuss with the ENT department rapidly as it is thought that the greatest benefit in restoring hearing is with early treatment.
Normally the ENT department would wish to rapidly assess the patient. They would want audiometry including bone conduction and make a decision if the patient should commence steroids and have an MRI scan.
Around 30-70% of patients can get some spontaneous recovery but it is thought that this may be increased by the use of steroids.
Dr Ian Sweetenham is a GPwSI in ENT and a GP partner in Cambridgeshire