What is an acoustic neuroma?
An acoustic neuroma, also called a vestibular schwannoma, is a benign (non-cancerous) and usually slow-growing tumor that develops on the eighth cranial nerve that runs from your inner ear to your brain, which controls your sense of hearing and balance. This type of tumor accounts for fewer than 5 percent of all tumors within the skull, with between 2,500 and 3,000 cases diagnosed in the U.S. each year. Typically, you develop an acoustic neuroma on only one side, causing hearing loss, buzzing, or ringing in just one ear and sometimes dizziness.
Causes of acoustic neuroma
A gene on chromosome 22 normally produces a protein that controls the growth of the cells that produce myelin, which covers the nerves. When the gene malfunctions, acoustic neuromas grow out of that covering, made up of Schwann cells. It’s unclear what causes the malfunction, although in about 5 percent of cases it is inherited as part a rare disorder called neurofibromatosis type 2.
Acoustic neuroma treatment options
Depending on the severity of your symptoms, your best option may be monitoring your acoustic neuroma if it doesn’t seem to be growing or is growing slowly. Hearing and imaging tests every six to 12 months can help determine if the tumor is progressing and treatment is necessary.
If you do need treatment, there are several options available:
Gamma Knife radiosurgery, which is actually not a surgery but a form of highly focused radiation therapy, should be one of the treatments considered first. Gamma Knife successfully treats 92 to 97 percent of all cases by first shrinking the tumor and then by preventing it from growing again.
The majority of acoustic neuroma tumors up to 3 centimeters qualify for treatment with Gamma Knife. If you are interested in Gamma Knife treatment, talk to your physician or consider scheduling a consultation with a physician affiliated with Rocky Mountain Gamma Knife Center who specializes in this treatment.
Open neurosurgery: Surgery is sometimes needed for certain large acoustic neuromas or chosen in other special situations, such as in cancer-prone individuals. Surgery requires a hospital stay and is performed under general anesthesia. The tumor may be removed through the inner ear, or through the skull. If the acoustic neuroma is located on a vital area of the brain, it may not be possible to remove the entire tumor. In that case Gamma Knife radiosurgery can be used to treat the remaining tumor. Risks associated with neurosurgery for acoustic neuromas include hearing loss and damage to the facial nerve, infection, and spinal fluid leak. Generally, the larger the tumor, the greater the risk of some or total hearing loss.
Learn about gamma knife treatment for acoustic neuromas at Rocky Mountain Gamma Knife Center.
Learn about other treatment options for acoustic neuromas.