Bilateral Acoustic Neuroma
Bilateral acoustic neuromas affect both hearing nerves and are usually associated with a genetic disorder called neurofibromatosis type 2 (NF2). Half of affected individuals have inherited the disorder from an affected parent and half seem to have a mutation for the first time in their family. Each child of an affected parent has a 50 percent chance of inheriting the disorder.
Unlike those with a unilateral acoustic neuroma, individuals with NF2 usually develop acoustic neuroma symptoms in their teens or early adulthood. In addition, people with NF2 usually develop multiple brain- and spinal cord-related tumors. They can also develop tumors of the nerves associated with:
- Eye and facial movement
- Facial sensation.
Determining the best way to manage bilateral acoustic neuromas as well as the additional nerve, brain, and spinal cord tumors is more complicated than deciding how to treat a unilateral acoustic neuroma. Further research is needed to determine the best treatment for individuals with neurofibromatosis type 2.
(Click Acoustic Neuroma Gene for more information on the gene responsible for neurofibromatosis type 2.)
No one knows the exact causes of acoustic neuroma. Doctors cannot always explain why one person gets the condition and another does not. However, acoustic neuroma research has shown that people with certain risk factors for this condition are more likely than others to develop it. A risk factor is anything that increases a person's chance of developing a disease.
Specific risk factors include:
- Family history of neurofibromatosis type 2.