Acoustic Neuroma (Vestibular Schwannoma)

Acoustic neuroma, also known as vestibular schwannoma is a benign growth that may cause hearing loss and imbalance in some people. Read on to learn more.

What is Acoustic Neuroma? 

Acoustic neuroma (also called vestibular schwannoma) is a non-cancerous growth that develops on the eighth cranial nerve, which connects the inner ear with the brain. One part of this nerve, known as the cochlear division, transmits sound, while the other, the vestibular division, sends balance information from your inner ear to brain. In most cases, the condition affects one’s hearing and balance.

Acoustic neuromas usually grow at a slow pace, expanding by one to three millimetres per year. However, some may grow by more than five millimetres every year. In some nine to 21 percent of patients, the growth can remain inert for several years, and in a small proportion of patients (six to 15 percent), its growth can even regress with time. 

What Causes Acoustic Neuroma?

The exact cause of acoustic neuroma is currently unknown. However, it is thought that there may be a hereditary factor involved for patients with both sides of their eighth cranial nerve affected.

Symptoms of Acoustic Neuroma

Over 90 percent of patients with acoustic neuroma experience one-sided deafness, often accompanied by tinnitus — the perception of noise or ringing in the affected ear. The deafness may be gradual or sudden. A common pattern of deafness among those with acoustic neuroma is lower speech discrimination, which is the ability to understand words when listening to someone speak on the telephone.

Dizziness and balancing problems may occur early in the growth of the tumour, and can worsen as the vestibular division continues to deteriorate. If large enough, the tumour may grow on other cranial nerves and cause facial numbness, weakness of the facial muscles or swallowing problems. Some people may experience an unsteady gait brought on by the pressure placed on the cerebellum. Acoustic neuromas that are very large may also cause headaches.

Confirming the Presence of Acoustic Neuroma

Doctors may help to diagnose the condition by conducting auditory tests that reveal lower speech discrimination and hearing loss. Another way to diagnose the condition is through an Magnetic Resonance Imaging (MRI) scan.

Acoustic Neuroma Treatment Methods

The treatment method that your doctor prescribes will depend on the severity of your condition. A large tumour that may cause severe brain compression will most likely require surgical treatment, while smaller tumours may be treated using radiation.


An acoustic neuroma can be removed through a surgical procedure if it is large enough and severely affecting your facial movements and hearing. At times, the entire tumour may not be completely removed if the tumour is too close to critical parts of the brain or facial nerves. There may be complications associated with the surgical removal of an acoustic neuroma, including hearing loss, facial weakness and paralysis, double vision, swallowing problems, mouth dryness, and unsteadiness. The likelihood of unexpected complications is generally low but include infection, bleeding, stroke, seizures, paralysis of limbs, coma and death.

Do note that there may be complications associated with the surgical removal of an acoustic neuroma, including the following:

Hearing loss
Facial weakness or numbness
Ringing in the ear
Balancing problems
Persistent headaches 

Radiation Therapy

For radiation therapy, the exact location of the tumour is required as the treatment will send targeted beams of radiation at the tumour from different directions. A CT scan and MRI scan of the head will be required beforehand. 

To continue learning about acoustic neuroma (vestibular schwannoma) treatment methods, click here.

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