Introduction to Acoustic Neuroma
An acoustic neuroma (or vestibular schwannoma) is a benign mass that grows on the vestibulocochlear nerve.
What is Acoustic Neuroma?
An acoustic neuroma (or vestibular schwannoma) is a benign mass that grows on the vestibulocochlear nerve. Acoustic neuroma can result in an array of symptoms that vary depending on the size of the abnormality. The condition is rare, with around 2 people out of every 100,000 in the population being diagnosed each year. Acoustic neuromas are not typically life-threatening, but they can cause hearing loss and therefore affect your ability to communicate with those around you. If you are experiencing symptoms associated with the condition, see an ENT specialist or a GP.
What causes an Acoustic Neuroma?
An acoustic neuroma is caused by growth on special insulating cells known as Schwann cells, which line the vestibulocochlear nerve. The only known risk factor for developing an acoustic neuroma is a rare hereditary disease known as neurofibromatosis type 2. However, this disease is only responsible for around 1 in 20 acoustic neuromas.
What are the symptoms of an Acoustic Neuroma?
Symptoms associated with acoustic neuromas largely depend on their size. Acoustic neuromas usually grow very slowly, and as such, symptoms tend to develop slowly. There may be periods where you experience no symptoms. As the neuroma grows, you may develop hearing loss or tinnitus. In addition, you may experience vertigo, the feeling that the world is moving around you. If the neuroma grows quite large, it can affect other nerves in the head, resulting in facial numbness. Furthermore, you may experience a loss in physical co-ordination and headaches.
How is an Acoustic Neuroma treated?
Treatment of acoustic neuroma depends on your own health, and the nature of the acoustic neuroma. If the neuroma is small and growing only slowly, the best option may be to do nothing, and closely monitor its development, especially since many of the treatment options have significant risks associated with them.
Microsurgery may be considered to remove the neuroma. This involves being put to sleep with general anaesthetic, making an incision in the skull, and taking out the mass. Hearing is almost always lost immediately following the procedure, and there may be additional damage to one of the nerves that runs next to the vestibulocochlear nerve. This nerve, known as the ‘facial nerve,’ controls muscles that allow facial movement and expression. Therefore, damage to this nerve can result in a face droop on one side, difficulty closing your eyelid on one side, and drooling of saliva. In some people, these issues get better. However, in others they are permanent.
An alternative option in some patients is stereotactic radiosurgery. This involves giving a highly accurate dose of radiation to the neuroma. Though it does not get rid of the mass, it can slow down its development. Following the procedure, around 1 in 3 people will experience hearing loss and around 1 in 100 will experience facial paralysis.