Acoustic Neuroma
Pronounced: Ah-COO-stic New-ROH-mah
(Neurolemmoma, Vestibular Schwannoma)
Definition |
Causes |
Risk Factors |
Symptoms |
Diagnosis |
Treatment |
Prevention |
Organizations
Definition
An acoustic neuroma is a benign (non-cancerous) tumor on the eighth cranial nerve leading from the brainstem to the ear. This nerve is involved in hearing and maintaining equilibrium. Acoustic neuromas grow relatively slowly.
Causes
The exact cause of an acoustic neuroma is unknown.
Risk Factors
A risk factor is something that increases your chances of getting a disease or condition.
- Age: 30-60
- Sex: Female
- History of the disease neurofibromatosis (for bilateral neuromas only, which are very rare)
Symptoms
The first symptoms of an acoustic neuroma include:
- Gradual hearing loss in one ear
- Decrease in sound discrimination
- Ringing in the ears, called tinnitus
As the neuroma gradually enlarges, symptoms may include:
- Balance problems
- Facial numbness and tingling
- Weakness of the facial muscles
Finally, if headaches or mental confusion occurs, the tumor may be life threatening. A doctor should be contacted immediately.
Diagnosis
The doctor will ask about your symptoms and medical history, and examine your ears and nervous system. Tests may include:
- Audiogram – A test that measures hearing in both ears.
- Auditory Brainstem Response Test (ABR, BAER, or BSER) – A test that measures the rate of electric impulses traveling from inner ear to brainstem. A slowed or absent impulse may indicate the presence of an acoustic neuroma.
- MRI Scan – A test that uses magnetic waves to make pictures of the inside of the body.
- CT Scan – A type of x-ray that uses a computer to make pictures of the inside of the body.
Treatment
Treatment depends on your age, general health, the size and location of the tumor, and its rate of growth. Treatment may include:
Observation – If the tumor is very small, your doctor may just monitor its growth. This is common among people over age 70.
Microsurgical Removal – As the tumor grows and/or hearing becomes impaired, removal of the tumor may be necessary. The surgical approach 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 (or Radiotherapy) – The use of radiation to kill cells and shrink tumors. Radiation may be used when tumors are small and surgery is not possible. This method may preserve hearing.
Prevention
There are no guidelines for preventing the development of an acoustic neuroma because the cause is not usually known.
Organizations
Acoustic Neuroma Association
http://www.anausa.org/
American Academy of Audiology
http://www.audiology.org
SOURCE:
Acoustic Neuroma Association
Last reviewed January 2002 by Medical Review Board
