Acoustic Neuroma - A guide to Hearing Loss

This is the name given to a benign (non-cancerous) brain tumour which grows in the auditory or ‘vestibulocochlear’ nerve which is responsible for hearing and balance.

This nerve is adjacent to the facial nerve which transmits signals from the brain to the facial muscles. This is a slow growing type of tumour which is usually contained within the auditory nerve. And because it grows so slowly, and remains quite small it may not cause any problems.

An acoustic neuroma is not considered a life threatening condition. In a few rare cases the tumour may grow to the extent that it presses on the brain but this type of tumour is usually treated before it gets to that stage.

So how does this affect hearing?

The main problem is that as it grows it then compresses the auditory nerve. This results in facial paralysis, tingling of the skin in that area and impaired hearing. This manifests itself as problems with balance, a build up of pressure within the ear and tinnitus.

These symptoms may be unnoticeable at first as the tumour gradually develops over time. You may not realise that anything is wrong at first but only when you notice problems with your facial muscles, balance and hearing. For example, a tendency to stumble when walking and a buzzing noise in your ears.

This tumour mainly affects middle aged people, and more women than men.

What causes acoustic neuroma?

No-one is quite sure as to the cause of acoustic neuroma although there appears to be a link with neurofibromatosis. Research is continuing into this area.

Treatment for acoustic neuroma

If you notice any of the above mentioned symptoms then your first port of call is your GP. He or she will examine you and ask about your family history before referring you to a specialist for further investigation.

The specialist will carry out a series of tests

These tests will include an assessment of the size and shape of the tumour and its impact on your nervous system; a hearing test and checking your sense of balance. He/she will also send you for an MRI or CT scan.

Your treatment will be carried out by a specialist, multi-disciplinary team who are best placed to decide what is right for you. Surgery is the usual option although radiotherapy can work equally as well. Surgery involves partial or a complete removal of the tumour although this very much depends upon where it is located and how easy it is to access it. In some cases this is the only treatment you require.

If the tumour is very small then your team may decide against treating it until it is larger and likely to cause problems. They will advise you to undergo regular scans in order to check the growth and progress of the tumour. Unfortunately, hearing loss is very common with this type of tumour. If it has reached a large enough size where it is compressing the auditory nerve then this damage will result in impaired hearing. Once this has happened then it is unlikely that your hearing will return to normal.

A hearing aid is your best bet in this situation. Your GP will be able to advise you further about this.

If you have more than one tumour which has affected both ears then surgery may be postponed because of the risk of complete hearing loss. The growth of your tumours will be monitored and if/when surgery is performed it will be carried out on one ear to start with. This will be the ear with the worst hearing loss.

If this goes smoothly then the other ear will be operated on.

But if something goes wrong and hearing is completely lost in that ear then surgery may be delayed on the other tumour, or an alternative method such as radiotherapy, will be used.

There is the risk of damage occurring to the facial nerve during surgery which can result in a drooping (palsy) of this nerve. This can cause problems with certain facial movements such as blinking, smiling or chewing but physiotherapy can help. But in some cases the damage is irreversible.