Acoustic Neuroma
(Neurilemoma; Vestibular Schwannoma; Acoustic Schwannoma)
Definition
An acoustic neuroma is a tumor that grows on the nerve of the ear. This nerve runs from your brainstem to the ear and plays a role in hearing and in maintaining your balance. This is a benign tumor, which means it is not cancerous. However, this condition can still cause serious problems if the tumor is large enough to put pressure on your brainstem.
Copyright © Nucleus Medical Media, Inc.
Causes
A tumor is caused by the abnormal growth of cells. This growth is determined by genes of the cells. An acoustic neuroma is caused by a problem with specific genes. It is not clear what causes the problem with the genes. Some environmental factors may play a role.
Risk Factors
Acoustic neuroma is most common in people aged 30-60 years old. Factors that may increase your chance of acoustic neuroma include:
- History of neurofibromatosis type 2 (NF2)—a condition that leads to growth of tumors on nerves
- Family history of NF2
- Long-term exposure to loud sounds
Symptoms
An acoustic neuroma grows slowly. Symptoms will be minor at first, then worsen over time as the tumor grows. The first symptoms of an acoustic neuroma include:
- Gradual hearing loss in one ear
- Decrease in sound discrimination, especially when talking on the telephone
- Ringing in the affected ear—tinnitus
As the neuroma grows larger, symptoms may include:
- Balance problems
- Facial numbness and tingling
- Weakness of the facial muscles on the side of the tumor
If headaches or mental confusion occur, the tumor may be life threatening. Call your doctor right away.
Diagnosis
You will be asked about your symptoms and medical history. Your ears will be examined. Tests of your nervous system will also be done. There are a number of conditions that can affect your hearing, including the very common ear infection. Acoustic neuroma may only be diagnosed after results from tests such as:
- MRI scan of head
- CT scan of head
- Audiogram—hearing test
- Auditory brainstem response test
Treatment
Treatment depends on your age, general health, the size and location of the tumor, and its rate of growth. Treatment may include:
Observation
Tumors may stay very small and cause few problems. In this case, the tumor may not need treatment. The doctor will monitor it for any changes. This is approach is common among people over age 70.
Microsurgical Removal
If the tumor is causing problems or is growing large it may need to be removed. The type of surgery depends on the size and location of the tumor. Complications of surgery may include permanent hearing loss and/or paralysis of facial muscles on the affected side.
Radiation Therapy
Radiation therapy is the use of radiation to kill cells and shrink tumors. It may also stop further growth of the tumor. Radiation may be used when tumors are small and surgery is not possible. This method may preserve hearing. The radiation may be given over several treatments or as 1 large dose.
A procedure called stereotactic radiosurgery may be used. This surgery uses a focused beam of radiation to destroy tumor tissue in and around the brain.
Prevention
There are no current guidelines to prevent acoustic neuroma.
RESOURCES:
Acoustic Neuroma Association
https://www.anausa.org
American Academy of Audiology
https://www.audiology.org
CANADIAN RESOURCES:
Canadian Academy of Audiology
https://canadianaudiology.ca
The College of Family Physicians of Canada
http://www.cfpc.ca
REFERENCES:
Acoustic neuroma. American Hearing Research Foundation. Available at: http://american-hearing.org/disorders/acoustic-neuroma. Accessed September 5, 2019.
Acoustic neuroma. VEDA website. Available at: http://vestibular.org/acoustic-neuroma. Accessed September 5, 2019.
What is acoustic neuroma? Acoustic Neuroma Association website. Available at: https://www.anausa.org/learn-about-acoustic-neuroma/what-is-acoustic-neuroma. Accessed September 5, 2019.
Last reviewed September 2019 by EBSCO Medical Review Board Donald W. Buck II, MD Last Updated: 8/11/2020
