Acoustic neuromas are a type of tumour that develop on the nerve between the inner ear and the brain. They are benign (noncancerous) and grow slowly but can affect hearing and balance. They develop on the nerve known as the vestibular nerve from cells called Schwann cells. Schwann cells create protective membranes for brain cells, also known as neurons. For this reason, they can also be called vestibular schwannomas.
Common symptoms of an acoustic neuroma are:
Symptoms of an acoustic neuroma usually take years to show and can be easy to miss. The longer someone has an acoustic neuroma, the more likely they are to notice symptoms that affect not just their hearing, but sensation in the face and ability to move the facial muscles. Acoustic neuromas rarely get big enough to become life-threatening.
Acoustic neuromas are linked to genetic mutations on the 22nd chromosome. The 22nd chromosome has a gene that helps regulate the growth of Schwann cells. When that gene is mutated, acoustic neuromas are more likely to occur. This genetic mutation is often inherited as part of a genetic disorder called neurofibromatosis 2. However, most acoustic neuromas have no obvious cause.
The only known risk factor for acoustic neuromas is having a parent with neurofibromatosis 2.
A doctor will diagnose acoustic neuroma with a combination of information about your medical history, current and past symptoms, and ear exams.
Some diagnostic tests that may be performed include:
Complications of an acoustic neuroma include permanent hearing loss and tumours large enough that they press on the brain stem. This can cause a buildup of fluid around the brain that can be life-threatening.
The treatment of an acoustic neuroma is based on the current size and rate of growth of the tumour, the overall health of the patient, and the current symptoms.
Treatment options include:
Supportive care can also be used to treat the symptoms of acoustic neuroma and improve the quality of life of patients living with it.