Symptoms

An acoustic neuroma may not cause any obvious symptoms at first.

Any symptoms tend to develop gradually and often include:

• hearing loss that usually only affects 1 ear
• hearing sounds that come from inside the body (tinnitus)
• the sensation that you are moving or spinning (vertigo)

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 hearing loss or other neurologic symptoms, it is important to keep track of them. This can help your doctor diagnose your problem.

Diagnosis

Your doctor will want a detailed history of your symptoms. If you have a neuroma, you will probably need a hearing test. You may need other tests as well:

• Brain stem auditory evoked response tests can check both neurological and hearing function.
• Electronystagmography detects changes in eye movement that may be caused by inner ear problems.
• MRI and CT scans can give your doctor an image of the inside of your head.

Causes

The only known risk factor for acoustic neuroma is having a parent with the genetic disorder neurofibromatosis 2 (NF2). Most of these tumours appear spontaneously. They occur in people with no family history of the disease.

Scientists still do not understand why some people get these tumours. Some risk factors might include:

• loud noises
• a parathyroid neuroma, which is a benign tumour of the thyroid
• exposure to low levels of radiation during childhood

There are several different treatment options for an acoustic neuroma, depending on the size and position of your tumour, how fast it is growing and your general health.

The main options are:

• monitoring the tumour – small tumours often just need to be monitored with regular MRI scans, and the treatments below are generally only recommended if scans show it is getting bigger
• brain surgery – surgery to remove the tumour through a cut in the skull may be carried out under general anaesthetic if it is large or getting bigger
• stereotactic radiosurgery – small tumours, or any pieces of a larger tumour that remain after surgery, may be treated with a precise beam of radiation to stop them from getting any bigger

All these options carry some risks. For example, surgery and radiosurgery can sometimes cause facial numbness or an inability to move part of your face (paralysis).

Speak to your specialist about the best option for you and what the benefits and risks are.

Large acoustic neuromas can be serious because they can sometimes cause a life-threatening build-up of fluid in the brain (hydrocephalus). But it is rare for them to reach this stage. Many grow very slowly or not at all, and those that grow more quickly can be treated before they become too big.

Even with treatment, symptoms such as hearing loss and tinnitus can persist and affect your ability to work, communicate and drive. These problems may need additional treatment.

An acoustic neuroma can occasionally return after treatment. This is thought to happen to around 1 in every 20 people who have had surgical removal.

You will probably continue having regular MRI scans after any treatment to check if the tumor is growing again or coming back.