Vestibular schwannoma (acoustic neuroma) 

A vestibular schwannoma is also called an acoustic neuroma. It starts in cells called Schwann cells. Schwann cells cover and support the hearing and balance nerve.

Vestibular schwannomas develop from the covering of the nerve that connects the inner ear to your brain. This is called the acoustic or vestibulocochlear nerve. It controls your hearing and balance. The main nerve that controls facial movement (the facial nerve) runs next to it. 

A vestibular schwannoma usually only affects the hearing and balance nerve on 1 side of the head. Rarely, it can develop on both sides. This can happen if you have a rare genetic condition called NF2-related schwannomatosis.

A vestibular schwannoma is not cancer. It is described as a benign tumour because it cannot spread into the brain. But a benign tumour can cause problems if it grows and presses on surrounding tissue. 

If the tumour grows large enough to put pressure on the brain and brainstem, it can affect nearby nerves or important functions of the brain.

Vestibular schwannomas are most common in people aged between 40 and 60, but they can affect people of any age.

The cause of vestibular schwannomas is unknown in most cases, but research is being done to find out more.

NF2-related schwannomatosis is a rare inherited (genetic) condition. It used to be called neurofibromatosis Type 2.

In a very small number of people, vestibular schwannoma is linked to NF2-related schwannomatosis. In this situation, tumours can develop on the hearing and balance nerves on both sides of the head.

NF2-related schwannomatosis is usually diagnosed in younger people. If your doctor thinks that you may have NF2-related schwannomatosis, you may be referred to genetic specialists for more tests.

Your treatment may depend on:

• the size of the tumour
• how the symptoms are affecting you
• your general health.

If the tumour is small, your doctor may suggest active monitoring until treatment is needed. This is also called active surveillance. This is when they monitor the tumour for any growth.

If treatment is needed, the main treatments for vestibular schwannoma are:

• a type of radiotherapy called stereotactic radiosurgery (SRS)
• surgery.

A team of specialists will plan your treatment. Your specialist doctor and nurse will explain the aims of your treatment and what it involves. They will talk to you about the benefits and risks of different treatment types. They will also explain the side effects.

You may be given a choice of treatment options. You will have time to talk about this with your hospital team before you make any treatment decisions. You will usually have plenty of time to think about the choices. This helps you to make an informed decision.

You will need to give permission (consent) for the hospital staff to give you the treatment. Ask questions about anything you do not understand or feel worried about. Tell your specialist if you need more information or more time to decide on a treatment.

Because a vestibular schwannoma develops on the hearing and balance nerve, one of the main symptoms of the tumour is loss of hearing on that side. Hearing loss can vary in different people. It can happen slowly, over years, or may happen more quickly. It does not always depend on the size of the tumour. Some small tumours can cause hearing loss and some large tumours might not cause hearing loss.

How treatment might affect your hearing varies depending on the type of treatment and your individual situation. The aim of any treatment is to control the tumour and stop it growing or remove it. If hearing has already been lost, treatment is not able to improve hearing. If you still have some hearing, treatment may be able to preserve hearing. Your doctor can explain more about your specific situation and how any treatment might affect your hearing.

It may be possible to manage hearing loss with a hearing aid. This will depend on the type and level of hearing loss. You will usually see a hearing specialist (audiologist) or ear, nose and throat (ENT) specialist for expert help and advice.

Active monitoring means regularly checking the tumour to find out whether it is growing. It also helps you and your doctors know how slowly or quickly it may be growing.

If the tumour is small, your doctor may suggest monitoring the tumour for growth. Vestibular schwannomas are usually slow-growing and sometimes do not grow at all. Some may never need treatment. Or sometimes, treatment can be delayed until it is needed. 

Some treatment can cause side effects and some of these may be permanent. Your doctor will always consider whether the benefits of the treatment outweigh any side effects, and discuss this with you to help make a decision.

Instead of starting treatment, you may have regular scans to check for changes in the size of the tumour. Your specialist team will explain the results of the scans. They will also monitor your hearing. These help your doctor know if, or when, to recommend treatment.

Talk to your doctor or specialist nurse if you are worried about any symptoms. They will explain the benefits and risks of active monitoring. Even if the tumour has not grown, your symptoms can still change over time. They will talk about the different ways of managing any symptoms.

Radiotherapy uses high-energy rays to destroy the tumour cells. You may have radiotherapy to stop a tumour growing. Sometimes it can also shrink it.

A vestibular schwannoma is usually treated with a type of radiotherapy called stereotactic radiotherapy (SRT). SRS can be given using different types of radiotherapy machines. These include:

• Gamma Knife™
• Cyberknife™
• Linear accelerator (LINAC).

The radiotherapy machine directs radiation beams from different angles, so they cross over at the tumour. This gives a high dose of radiation to the tumour while limiting the dose to the surrounding areas.

You may have radiotherapy in the following ways:

• As a single treatment – this is called stereotactic radiosurgery (SRS) and it is often used to treat smaller tumours.
• Over 3 to 5 sessions, spread over 1 to 2 weeks. This is called stereotactic radiotherapy (SRT).
• Over 25 to 30 sessions, given once daily from Monday to Friday for 5 to 6 weeks. This may be given for larger tumours.

Your specialist doctor will explain how long treatment will last and the type of radiotherapy you will have.

Side effects of radiotherapy

The possible side effects of radiotherapy can depend on:

• the size of the tumour
• your symptoms
• your general health
• the type of radiotherapy you are having.

Your radiotherapy team will explain about the treatment, the possible side effects in your individual situation and how to manage them.

If you are having stereotactic radiosurgery (SRS) for vestibular schwannoma, side effects are usually mild and easy to manage. Some people may not notice any side effects.

If you are having radiotherapy over a few weeks, you may have more side effects. It is normal to feel tired after treatment. This usually improves over time.

Treatment can also sometimes cause weakness on the affected side of the face. This is because the nerve that controls movement in the face (the facial nerve) sits very close to the hearing and balance nerve. If this happens, it is usually mild and temporary. Sometimes it can be permanent. Your team will explain more about this when you sign your consent form before your treatment.

Rarely, radiotherapy can cause fluid to build up around the brain. This is called hydrocephalus. This is more likely to happen with larger tumours. Symptoms can include a headache, feeling sick and loss of balance. If you notice these or feel unwell, tell your specialist doctor, nurse or radiographer straight away. Symptoms can be improved by draining the fluid. We have more information about surgery to drain fluid from the brain. 

Tell your radiotherapy team straight away if your side effects get worse during or after treatment.

We have more information about radiotherapy to the brain, possible side effects and how to manage them..

Surgery for a vestibular schwannoma involves removing all or part of the tumour. Sometimes the surgeon may need to leave a small part of the tumour to avoid damaging nearby nerves. The surgery will depend on:

• the size of the tumour
• your symptoms
• whether you have any other health problems
• your preferences.

Your surgeon will explain the type of surgery and the possible risks. They will give you information about what to expect before and after your operation. The doctors and nurses will monitor you carefully after your operation.

You may be able to have SRS or other types of radiotherapy if:

• it has not been possible to remove most or all of the tumour
• it begins to grow back after surgery. 

Side effects of surgery

Surgery is likely to have more immediate side effects than SRS. You will need to stay in hospital for a few days afterwards.

After surgery, you may:

• have headaches
• have nausea
• feel dizzy
• notice that your balance is affected.

These usually improve in the weeks after surgery.

You may also feel very tired. It can take 2 to 3 months to start to feel better.

Surgery may cause hearing loss in the affected ear. If your hearing has not been badly affected by the tumour before the surgery, your surgeon may sometimes be able to preserve your hearing. Before you have surgery, your surgeon will explain if this might be possible in your situation. They will also explain what to expect after your surgery.

Sometimes, surgery can damage the facial nerve on the side of the face affected. This can cause drooping (palsy) of 1 side of the face. This is usually temporary. It can affect actions like smiling, chewing and blinking. It can take time for the facial nerve to recover.

The surgeon will carefully monitor the facial nerve during the surgery. They will try to reduce the risk of facial nerve damage as much as possible. If the damage is permanent, there are usually other procedures available that can be done to help with the weakness.

If the facial nerve is affected, you may have difficulty fully closing your eye. If you get a dry eye, using eye drops will help with this. If needed, your doctor can refer you to an eye specialist.

We have more information about help with recovering from surgery.