An acoustic neuroma grows in the acoustic nerve, the eighth cranial nerve in the brain – a nerve also known as the vestibulocochlear nerve. This nerve is responsible for controlling hearing and balance.

Acoustic neuroma causes

The cause of acoustic neuroma is usually not known. A few people who have an acoustic neuroma also have a rare inherited condition called neurofibromatosis type 2. But for most people, there is no obvious cause.

Acoustic neuroma symptoms

Usually acoustic neuromas grow very slowly. This means there may not be any symptoms in the early stages when the tumour is small.

Many people say they notice some loss of hearing and tinnitus, or ringing in the ears. Usually one ear is affected, but both ears can be involved if the person has neurofibromatosis type 2.

Whether or not there are any other symptoms can depend on the size of the tumour and how hard it presses on the eighth cranial nerve. Some people with an acoustic neuroma get:

• dizziness or vertigo, which is a feeling that the space around you is spinning
• loss of balance
• headache
• facial numbness or tingling
• blurred vision
• problems coordinating limbs on one side of the body

Acoustic neuroma diagnosis

If your doctor suspects you have acoustic neuroma, they might send you for tests such as hearing tests and magnetic resonance imaging, or MRI. An MRI allows your doctor to see if there’s a tumour, and its size and position if there is one.

Acoustic neuroma treatment

The options for treatment include:

• no treatment – just monitoring the tumour growth and related symptoms
• surgery – to cut out the tumour
• stereotactic treatment – this procedure sends focused radiation to the tumour to stop it from growing

Which treatment you have depends on the size and location or the tumour, your symptoms, your age and general health, and what you want.

Even though acoustic neuromas are not cancerous, they can be disruptive and cause lasting hearing and balance problems. If they’re not treated, some acoustic neuromas can cause serious, permanent damage to nerves. If you have any of the symptoms listed above, see your doctor as soon as possible.