What is an acoustic neuroma?
An acoustic neuroma is a rare, slow-growing tumour that develops on the eighth cranial nerve – the nerve of hearing and balance. It's benign, which means it is not malignant or cancerous.
An acoustic neuroma grows extremely slowly over several years. Eventually, it presses on the balance, hearing and facial nerves and can therefore affect hearing and balance. More rarely, it can cause symptoms in the face. If it becomes very large it can press against the brain, though with modern diagnostic techniques this doesn’t happen very often.
An acoustic neuroma is not a life-threatening condition except in very unusual cases where the tumour grows so large that it presses on the brain. As it's benign – that is, non-cancerous – it doesn't spread around the body. If it's completely removed, it's unlikely to grow back again.
Often, there's no obvious cause for an acoustic neuroma and they tend to effect people aged 30-60 years of age.
What are the signs of an acoustic neuroma?
An acoustic neuroma may not cause any obvious symptoms at first.
Any symptoms tend to develop gradually and often include:
A large acoustic neuroma can also sometimes cause:
- persistent headaches
- temporary blurred or double vision
- numbness, pain or weakness on one side of the face
- problems with limb co-ordination (ataxia) on one side of the body
- a hoarse voice or difficulty swallowing.
If you experience any of the symptoms, it’s important to speak to your GP and get a referral to the hospital for an assessment. Some other conditions such as Ménière’s disease have similar symptoms - the specialist will check for an acoustic neuroma to ensure that you're treated appropriately.
If it's suspected that you have an acoustic neuroma, you should:
- Have your hearing assessed to establish your levels of hearing, whether it is a sensorineural or conductive hearing loss and whether both ears are affected. You may have a series of tests to establish whether it is your hearing nerves that are the cause.
- a magnetic resonance imaging (MRI), which uses strong magnetic fields and radio waves to produce a detailed picture of the inside of your head
- a computerised tomography (CT) scan, which uses a series of X-rays to create a detailed image of the inside of your head.
How is an acoustic neuroma treated?
If you're diagnosed with an acoustic neuroma, your treatment will depend on a number of things, including:
- your general health
- the size and the position of the tumour
- results of other tests.
Because acoustic neuromas grow very slowly, there's no need to rush into a decision regarding treatment. It is best to consider all the options carefully and discuss them in detail with the surgeon or radiotherapist. All treatments are carried out in specialist centres and most people have to travel for their treatment.
These treatments include:
There are some side effects to some of the treatments. For example, surgery and radiosurgery can sometimes cause facial numbness or paralysis.
It’s important to speak to your specialist about the best option for you and what the benefits and risks are.
For more information, see our factsheet Acoustic neuroma.