What Is Acoustic Neurinoma?
Acoustic neurinoma is a benign (non-spreading) tumor. Other names for an acoustic neurinoma are vestibular schwannoma, acoustic neuroma and acoustic neurilemoma. This tumor develops on a cranial nerve that extends from the brain to the inner ear. The tumor develops when cells that cover the nerve fibers multiply too much and form a tumor. The growth takes place slowly over time.
Frequency of Acoustic Neurinoma
The National Institute on Deafness and Other Communication Disorders says that one out of every 100,000 people each year develops this type of neurinoma. Studies published in Denmark in 2004 show that the incidence of acoustic neurinoma is 17.4 people per million people which translates to almost two people in every 100,000 people.
What Causes Acoustic Neurinoma
A definitive cause is not known, but some experts believe it may be caused by a malfunctioning gene on chromosome 22. At the same time, some studies have suggested that constant exposure to loud noise could be a contributing factor. While the unilateral type (one ear) of acoustic neurinoma is not hereditary, there is a bilateral type (both ears) that is hereditary, and is associated with neurofibromatosis type 2 (NF 2), a genetic condition.
Effects of Acoustic Neurinoma
As the tumor grows bigger, its size can cause problems with hearing, balance, and facial muscles. Facial weakness or facial paralysis can occur, too. Pressure on the hearing and balance nerves can result in hearing loss in one or both ears. (Dizziness, balance problems, and tinnitus can also result.)
These effects also help diagnose the presence of an acoustic neurinoma. Hearing, balance, and facial problems are clues to the existence of an acoustic neurinoma. Other diagnostic techniques include ear exams, the use of magnetic resonance imaging (MRI), and hearing tests.
Treatment of Acoustic Neurinoma
Surgery and radiation are the two primary ways to remove an acoustic neurinoma. It is important to get an acoustic neurinoma removed because if it grows too big, in addition to the other effects described above, it can press on the brainstem or cerebrullum so much that death is a risk. It's best to remove the tumor early on, so that a person's hearing may be salvaged.
Support for People with Acoustic Neurinoma
The Acoustic Neuroma Association has support groups in several states, and holds a national conference (symposium) on acoustic neuroma.
Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis. National Institute on Deafness and Other Communication Disorders. http://www.nidcd.nih.gov/health/hearing/acoustic_neuroma.asp. Accessed March 2011.
What is Acoustic Neuroma. Acoustic Neuroma Association. http://www.anausa.org/index.php?option=com_content&view=article&id=114:what-is-acoustic-neuroma&catid=45:overview&Itemid=206. Accessed March 2011.