An acoustic neuroma is a slow-growing tumor of the nerve that connects the ear to the brain. This nerve is located behind the ear right under the brain.
An acoustic neuroma is benign, which means it does not spread to other parts of the body or invade the tissue around it. However, it can damage several important nerves as it grows.
Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor
An acoustic neuroma is believed to occur when there is a defect in a gene that normally prevents tumors from forming. The cause of the genetic defect is not known. However, acoustic neuroma can be linked with the genetic disorder neurofibromatosis type 2 (NF2).
Acoustic neuromas are relatively uncommon.
The symptoms vary based on the size and location of the tumor. Because the tumor grows so slowly, symptoms usually start after the age of 30.
Common symptoms include:
Less common symptoms include:
The health care provider may diagnose an acoustic neuroma based on your medical history, an examination of your nervous system, or tests.
Often, the physical exam is normal at the time the tumor is diagnosed. Occasionally, the following signs may be present:
The most useful test to identify an acoustic neuroma is an MRI of the head. Other useful tests to diagnose the tumor and tell it apart from other causes of dizziness or vertigo include:
Depending on the size and location of the tumor, you and your health care provider must decide whether to watch the tumor (observation) or try to remove the tumor.
Many acoustic neuromas are small and grow very slowly. Small tumors with few or no symptoms may be followed. Regular MRI scans will be done.
If they are not treated, some acoustic neuromas can damage the nerves involved in hearing, as well as the nerves responsible for movement and feeling in the face. Very large tumors can lead to a buildup of fluid (hydrocephalus) in the brain, which can be life-threatening.
Removing an acoustic neuroma is more commonly done for:
Surgery is done to remove the tumor and prevent further hearing loss or other nerve damage.
Stereotactic radiosurgery focuses high-powered x-rays on a small area. It is considered to be a form of radiation therapy, not a surgical procedure. It may be used:
Removing an acoustic neuroma can damage nerves, causing loss of hearing or weakness in the face muscles. This damage is more likely to occur when the tumor is next to or around the nerves.
An acoustic neuroma is not cancer. The tumor does not spread (metastasize) to other parts of the body. However, it may continue to grow and press on important structures in the skull.
People with small, slow-growing tumors may not need treatment.
Once hearing loss occurs, it does not return after surgery.
Call your health care provider if you experience new or worsening hearing loss or vertigo (dizziness).
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Sweeney P, Yajnik S, Hartsell W, Bovis G, Venkatesan J. Stereotactic radiotherapy for vestibular schwannoma. Otolaryngol Clin North Am. 2009;42:655-663.