An acoustic neuroma is a rare, noncancerous (benign) brain tumour (growth). The tumour which grows on a nerve in the brain near to the ear can cause problems with hearing and balance, and can cause tinnitus (ringing in the ears). In most cases, the cause is unknown. However, some acoustic neuromas are associated with the disease neurofibromatosis type 2. Acoustic neuromas are slow-growing and are rarely life-threatening. They do not spread to distant parts of the body. Treatment is usually with surgery, but radiotherapy can also be used. A degree of permanent deafness in one ear is usual after treatment for an acoustic neuroma.
An acoustic neuroma is a rare type of brain tumour (growth). It is a benign (noncancerous) tumour.
The tumour grows along a nerve in the brain (a cranial nerve) that is called the acoustic or vestibulocochlear nerve. This nerve controls your sense of hearing and balance.
Acoustic neuromas grow from a type of cell called a Schwann cell. These cells cover and insulate nerve cells. This is why the tumour is also called a vestibular schwannoma.
Acoustic neuromas tend to grow very slowly and they don't spread to distant parts of the body. Sometimes they are too small to cause any problems or symptoms. Bigger acoustic neuromas can interfere with the function of the vestibulocochlear nerve.
The cause of most acoustic neuromas is unknown.
About 7 out of every 100 acoustic neuromas are caused by neurofibromatosis type 2 (NF2). NF2 is a very rare genetic disorder that causes benign tumours of the nervous system. It affects about 1 in 350,000 people. Almost everyone with NF2 develops an acoustic neuroma on both acoustic nerves (ie, bilateral tumours). People with NF2 can also get benign tumours on the spinal cord and the coverings of the brain.
Acoustic neuromas are rare. About 13 people in every million are diagnosed each year with an acoustic neuroma in the UK.
Brain tumours themselves are rare. Brain tumours can be benign (noncancerous) or malignant (cancerous). Brain tumours are divided into two main groups:
Acoustic neuromas account for about 8 in 100 primary brain tumours. They are more common in middle-aged adults, generally between the ages of 30 and 60 years and extremely rare in children.
Acoustic neuromas seem to be more common in women than men.
A small acoustic neuroma may cause no symptoms. If you do get symptoms from an acoustic neuroma, these may develop very gradually, as the tumour is so slow-growing.
The symptoms that an acoustic neuroma can cause are very common in the general population. Remember that acoustic neuromas are very rare. You should see your doctor if you have any of these symptoms, but they are more likely to be due to other conditions than a brain tumour.
The most common symptoms of an acoustic neuroma are:
Other, common symptoms of acoustic neuroma include:
Less common symptoms of acoustic neuroma are:
Acoustic neuromas can be difficult to diagnose. This is partly because they are so rare, and partly because lots of other conditions can cause similar symptoms.
If your GP suspected that you had an acoustic neuroma from your symptoms, you would probably be referred to an ear, nose and throat (ENT) surgeon in a hospital.
You may be referred to an ENT surgeon because of one of your symptoms, and during investigations, an acoustic neuroma might be suspected and found. This is particularly the case if you have recent-onset sensorineural (nerve-related) hearing loss in one ear.
The best test to diagnose an acoustic neuroma is a magnetic resonance imaging (MRI) scan of the brain. An MRI scanner uses a strong magnetic field and radio waves to take a detailed picture of your brain, and of the structures inside it. It is a painless and non-invasive test, but it can be noisy and can make you feel claustrophobic. No X-rays are used (so it is different to a computed tomography (CT) scan that does use X-rays). An MRI scan of the brain can take up to 45 minutes to complete. The pictures are like very thin slices of the brain, and provide detailed information. Some people cannot have an MRI scan. This is usually because of metal implants in the body - such as pacemakers or clips in the brain from brain aneurysm surgery. Contrast is a special dye that is injected into a vein in the arm, during an MRI scan. It helps show up small tumours in the brain on MRI scan. If you have had a previous allergy to the contrast, called gadolinium, or if you have renal (kidney) failure, you may be unsuitable to have an MRI scan with contrast dye. (See separate leaflet called MRI Scan' for more information).
Hearing tests may also be performed if an acoustic neuroma is suspected. This is because one of the most common symptoms of an acoustic neuroma is hearing loss. If an acoustic neuroma is found on a scan, it is useful to know what your hearing in both ears is like before treatment.
If you have a very small acoustic neuroma, your doctors might decide that the best approach is to observe and monitor it closely. This is because acoustic neuromas are very slow-growing and may not cause any symptoms for a long time. Remember, acoustic neuromas are not malignant and do not spread, so it is quite safe to watch things for a while. Also, treatments can have complications and side-effects, so the risks and benefits of treatment have to be balanced. If observation is recommended, your condition will be monitored with regular scans.
The main treatments for acoustic neuroma are:
The treatment you are offered will depend on:
The results of the tests and scans you have can also help to determine which type of treatment is best for you and your tumour.
Either a neurosurgeon (brain surgeon) or an ENT surgeon can operate to remove an acoustic neuroma, depending on its size and location on the vestibulocochlear nerve in the brain. The surgery is carried out under a general anaesthetic. Most people with acoustic neuroma are treated with surgery, and about 95 in 100 tumours can be removed completely.
Occasionally (about 5 cases in every 100), a small part of the tumour is left behind. This is usually because it is technically too difficult to remove the whole tumour and/or there is a risk of causing more damage to the nerve or other nearby structures.
If some of the acoustic neuroma is left remaining, it can often be treated with radiotherapy.
After surgery for an acoustic neuroma, you will probably have to remain in hospital for a few days for monitoring. You should be fully recovered within 6-12 weeks, and, if your tumour was completely removed, you should not need any more treatment.
Radiotherapy is a type of treatment generally used for tumours (both benign and malignant). This treatment is given by a clinical oncologist (cancer specialist).
Radiotherapy may completely destroy a tumour, or it may shrink it. It uses high-energy beams of radiation, focused on the tumour. Radiotherapy is commonly used in cancer treatments, especially brain tumours.
Radiotherapy treatment is planned using MRI scans. Your oncologist determines how best to direct the radiotherapy beams on to the tumour, whilst avoiding normal healthy tissue, to minimise damage. You will usually have several sessions of radiotherapy treatment. (See separate leaflet called 'Radiotherapy' for more information.)
Newer types of radiotherapy are increasingly being used for the treatment of brain tumours. One such treatment is called CyberKnife®. Here, radiotherapy is given using a radiotherapy machine on a robotic arm. No frame is needed to hold your head in position, but X-rays are constantly taken during the treatment. This ensures that if there has been the slightest movement, the radiotherapy beams are directed back on target. It is also known as stereotactic radiotherapy.
This is a newer type of treatment that can be used for acoustic neuromas. Stereotactic radiosurgery involves delivering a very precise single dose (usually) of radiation to an extremely well-defined area within the brain - where your acoustic neuroma is.
Stereotactic means locating a point using three-dimensional (3D) co-ordinates. In this instance, the point is the acoustic neuroma tumour within the brain. A metal frame (like a halo) is attached to your scalp and a series of scans are performed to show the exact location of the tumour.
SRS can be given with a normal radiotherapy machine, the CyberKnife® machine or with a technique known as gamma knife treatment. It is used where neurosurgery is thought to be too risky in terms of the chances of complications (such as brain or nerve damage).
SRS is a very specialised type of treatment and is only available in some large hospitals, usually ones with both neurosurgery and oncology centres.
The main advantage of this treatment is to prevent tumour growth and preserve any residual hearing. It tends to shrink rather than remove or destroy the acoustic neuroma. It can be used for very small tumours.
Complications can be thought of as:
Fewer than 5 in every 100 acoustic neuromas recur (come back). So it is uncommon, but possible. It is more likely if you have NF2. It could cause any of the symptoms mentioned earlier, or any of the complications.
After treatment for acoustic neuroma you will generally be followed up in an outpatient clinic to check for any symptoms or signs of a recurrence.
If you hold a Group 1 entitlement driving licence (car or motorbike) then you do not need to notify the DVLA of your condition, unless you experience sudden and disabling giddiness.
If you hold a Group 2 entitlement driving licence (lorries and buses), you also do not need to inform the DVLA of your condition, unless you experience disabling giddiness or the condition is bilateral (affects the left and right acoustic nerve).
The outlook is generally very good, particularly as it is a benign tumour. It is generally very suitable for treatment and complications are uncommon. A degree of hearing loss in one ear after treatment, should, however, be expected.
A site designed and developed by people affected by acoustic neuroma. There are public areas to the website and an opportunity to become a member of the association.
Formerly the RNID, they are a charitable organisation working on behalf of the UK's 9 million deaf and hard of hearing people. The website offers support, information and even an online shop for products to assist people with impaired hearing.
A UK-based organisation offering support and information for people affected by the diseases neurofibromatosis 1 and 2.