Acoustic neuroma (vestibular schwannoma)
An acoustic neuroma is a type of brain tumour. It’s sometimes called a vestibular schwannoma.
This information is about acoustic neuroma, its symptoms, diagnosis, and treatments. It should be read with our general information about brain tumours which has more detailed information on tests, treatments and side effects.
We hope this information answers your questions. If you have any further questions, you can ask your doctor or nurse at the hospital where you are having treatment.
An acoustic neuroma is a benign (non-cancerous) tumour that usually grows slowly. A benign tumour can cause problems as it grows by pressing on surrounding tissue. But, unlike a malignant tumour, it can’t spread from where it started to other parts of the brain.
Acoustic neuroma develops from the lining of the main nerve that connects the inner ear to your brain. This is called the acoustic or hearing nerve. It controls your hearing and balance. Alongside it runs the facial nerve. Although acoustic neuromas are a type of brain tumour, they don’t spread into (invade) the brain. But if a tumour grows large enough it can interfere with important functions of the brain.
Acoustic neuromas start in schwann cells, which cover the nerve, so they are sometimes called a vestibular schwannoma. They are most likely to be found in people in their 40s to 60s.
Causes of acoustic neuromas
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The cause is unknown. In a small number of people, acoustic neuroma is associated with an inherited (genetic) condition called neurofibromatosis type 2 (NF2). In this situation, there are usually tumours affecting both sides of the brain (bilateral tumours).
Low-dose radiation for benign head and neck conditions as a child may increase the risk of developing acoustic neuroma.
Symptoms of acoustic neuromas
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Acoustic neuromas are usually slow-growing tumours and symptoms often develop gradually over several years. The most common symptoms are loss of hearing in the affected ear, a buzzing or ringing noise (tinnitus), feeling dizzy and problems with balance. If the tumour presses on the facial nerve, it can cause numbness or tingling of half of the face. Larger tumours may lead to increased pressure in the brain, causing headaches and changes to your eyesight.
Tests for acoustic neuromas
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Your doctors need to find out as much as possible about the type, position and size of the tumour so they can plan your treatment. You may have a number of tests and investigations.
You will have a range of hearing tests (audiometry) and sometimes a test is done to check your sense of balance. The doctor will examine you thoroughly and also test your reflexes and the power and feeling in your arms and legs.
CT (computerised tomography) scan
A CT scan takes a series of x-rays that build up a three-dimensional picture of the inside of the head. The scan is painless but takes a few minutes. CT scans use small amounts of radiation, which will be very unlikely to harm you or anyone you come into contact with.
You may be given an injection of a dye, which allows particular areas to be seen more clearly. This may make you feel hot all over for a few minutes. If you are allergic to iodine or have asthma, you could have a more serious reaction to the injection, so it’s important to let your doctor know beforehand.
MRI (magnetic resonance imaging) scan
This test uses magnetism to build up a detailed picture of areas of your body. Before the scan you may be asked to complete and sign a checklist. This is to make sure it’s safe for you to have an MRI scan.
Before having the scan, you’ll be asked to remove any metal belongings including jewellery. Some people are given an injection of dye into a vein in the arm. This is called a contrast medium and can help the images from the scan show up more clearly. During the test you will be asked to lie very still on a couch inside a long cylinder (tube) for about 30 minutes. It’s painless but can be slightly uncomfortable, and some people feel a bit claustrophobic during the scan. It’s also noisy, but you’ll be given earplugs or headphones.
The diagnosis of an acoustic neuroma is usually obvious from the MRI brain scan.
Treatment for acoustic neuromas
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The treatment you have will depend on the size of the tumour, how the symptoms are affecting you and your general health. The main treatments are radiotherapy or surgery.
A team of specialists will plan your treatment. This will usually include a surgeon who specialises in operating on conditions of the nervous system (neurosurgeon), and a specialist ear, nose and throat (ENT) surgeon (called a neuro-otologist), a cancer doctor (oncologist) and a specialist nurse.
They will explain the aims of your treatment, the benefits and disadvantages, and possible risks. Deciding on the treatment that is right for you is a decision you make in partnership with your doctor. Make sure you have enough information and time to help you make any treatment decisions.
If the tumour is small and causing only mild symptoms, you may not need treatment straightaway. Acoustic neuromas tend to be very slow-growing and it may be a long time before you need treatment. You will have regular scans to make sure the tumour is not growing. This can be a good option when the effects of surgery or radiosurgery (see below) outweigh the risk of an acoustic neuroma affecting your health.
Radiotherapy treatment uses high energy rays to destroy the tumour cells. Acoustic neuromas are treated with a targeted radiotherapy called stereotactic radiotherapy. You have this as a course of treatment over a number of daily sessions from Monday to Friday.
Several beams of radiation are given from different angles, overlapping at the tumour. This gives a high dose to the tumour and very low doses to surrounding healthy tissue so helps to reduce side effects.
These treatments reduce the risk of permanent effects such as hearing loss and facial nerve damage that you get with surgery. But some people may still have some hearing loss and occasionally some damage to the facial nerve.
You have this type of stereotactic radiotherapy as a single session of high-dose focused treatment. This is often the treatment for smaller tumours, as there are likely to be fewer side effects than with surgery. It is sometimes called gamma knife treatment, named after the machine that’s used. It doesn’t involve any surgery.
Surgery is usually only used to remove larger tumours as an operation is likely to have more side effects than stereotactic radiotherapy or radiosurgery.
Your surgeon will explain what it involves and what the possible complications and risks are. The operation is done through the skull. Sometimes they leave a tiny part of the tumour to try to avoid damaging the facial nerve. Any tumour that is left behind can be treated with stereotactic radiosurgery.
Surgery will usually cause hearing loss in the affected ear. Your surgeon may talk to you about being fitted with a special type of hearing aid, which diverts sounds from the affected ear to your other ear. You will usually see a hearing specialist for expert help and advice.
Doctors may delay surgery, if possible, in people who have large tumours of both acoustic nerves because of the risk of total hearing loss. You will have MRI scans to monitor the tumours. Occasionally, they operate on one side first. If you can hear with this ear after surgery, you then have the other side operated on. If hearing is lost during the first operation it may be possible to delay surgery on the second tumour, or to use radiotherapy.
Sometimes surgery may damage the facial nerve. This can cause numbness or drooping (palsy) of one side of the face, which is sometimes permanent. It can affect actions like chewing and blinking. A physiotherapist will show you exercises and massage that you can do to help improve this. Some people also get a dry eye. Eye drops will help with this. If necessary, your doctor can refer you to an eye specialist. The British Acoustic Neuroma Association has more information (details below).
You may find the idea of a tumour affecting your brain extremely frightening. You may have many different feelings, including anxiety, anger, fear or feeling low or depressed. Many people go through these in coping with their illness.
It’s important to get the support you need. You may find it helpful to talk things over with family and close friends or your doctor or nurse. You can also talk to one of our cancer support specialists. Sometimes people need more help to cope with difficult feelings of anxiety or depression. Your doctor can refer you to a counsellor or psychologist for more support.
British Acoustic Neuroma Association
The British Acoustic Neuroma Association gives information and support for people with acoustic neuroma. It has a network of local branches throughout the UK.
The Neuro Foundation
The Neuro Foundation offers information and advice about neurofibromatosis.
This information has been compiled using a number of reliable sources, including:
Thank you to Mr Robert Bradford, Consultant Neurosurgeon who reviewed this information.
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