An acoustic neuroma is a noncancerous growth that grows from the 8th or vestibulo-cochlear nerve, which is responsible for hearing. It is linked to production of an abnormal protein called merlin. It grows very slowly over a long period of time and enlarges to the point that it can be detected on x-rays or an MRI.
Symptoms
The symptoms of acoustic neuroma vary depending on the size and location of the growth or tumor. As these grow slowly, symptoms rarely present themselves before the age of 30. Once they do appear, they present as hearing loss, tinnitus (ringing of the ears), vertigo (dizziness), imbalance or dysequilibrium (difficulty with balance), fullness or pressure in the ears and, for large tumors, facial numbness or paralysis. Less common symptoms are difficulty understanding speech, headache or temporary vision abnormalities.
Causes and Incidence
Acoustic neuromas are thought to be caused by a gene defect that normally prevents tumors from growing. The defect covers all ethnic backgrounds and races, but predominantly affects women. Most are diagnosed between 30 and 60 years of age. These tumors appear in 2.5 percent of the population.
Diagnosis
Routine auditory tests can confirm that you have a hearing problem, generally in only one ear. Once acoustic neuroma is suspected, an auditory brainstem response test (ABR, BAER, BSER) may be done. In addition, a test for equilibrium and balance (electronystagmography) may be requested, and finally a CT or MRI of the head will positively confirm the diagnosis. The tumor is invariably found at the base of the brain.
Treatment
Treatment typically is removal of the tumor with surgery. The earlier the tumor is detected, the better the chance of removing the whole thing. If you already have a hearing loss, that cannot be restored.
If the entire tumor cannot be removed, radiation therapy may be performed, though this is generally reserved for elderly patients who cannot tolerate surgery. It is also used if the entire tumor cannot be removed.
Complications
If you do not detect this early, treatment can result in paralysis of the facial muscles on the affected side and, after radiation therapy, nerve damage, loss of hearing and paralysis of the face.
Visit Your Doctor
If you experience sudden hearing loss, worsening hearing loss or dizziness, contact your physician for an evaluation.
Tags: hearing loss, acoustic neuroma, cannot removed, entire tumor, entire tumor cannot, have hearing, radiation therapy