Acoustic Neuroma

What is acoustic neuroma?

An acoustic neuroma is a rare benign (non cancerous) tumour that grows around the acoustic nerve (or vestibulocochlear nerve) that connects the ear to the brain and transmits information about sound and balance. The neuroma actually arises from cells called Schwann cells that cover the nerve, rather than from the nerve itself, and is therefore correctly called a vestibular schwannoma.

Symptoms

Invariably the acoustic neuroma develops only on one side of the head, causing symptoms to occur in that ear. These may include:

• Unilateral (one-sided) hearing loss
• Tinnitus
• Vertigo
• Headaches, facial numbness, deterioration of sight and loss of co-ordination are late symptoms

Causes and risk factors

Most people are between the ages of 40 and 60 when an acoustic neuroma is discovered, but why they develop one in the first place is unclear.

Treatment and recovery

Acoustic neuroma is a non-cancerous growth, which means it won’t spread to and damage other parts of the body. But it can continue to grow where it is, inside the skull.

It’s important to have it removed because although it grows slowly it can press on the nerves and part of the brain, causing permanent damage. This may result in hearing loss, poor balance and coordination, weakness in the muscles of the face and pain.

When a neuroma is suspected, diagnosis can be confirmed using a CT (computerised tomography) or MRI (magnetic resonance imaging) scan. These can also show the size and position of the tumour.

Most acoustic neuromas are surgically removed, after which many of the symptoms should disappear. This is more likely to be the case when the neuroma is small. Larger neuromas may have done irreversible damage to the brain and nerves before or during surgery.

Many patients have already lost a significant amount of hearing prior to surgery and this is not something that can be reversed although 40 per cent of patients who had tinnitus (ringing in the ears) noticed an improvement in that symptom after surgery.

This is why it’s best to treat an acoustic neuroma sooner rather than later. However, because they’re slow growing, only 1-2mm a year, very small neuromas may initially be just carefully monitored.

Stereotactic Radiotherapy (‘gamma knife’) may also be used to treat an acoustic neuroma.

BBC Health