In some cases, an acoustic neuroma may be so small that it does not cause symptoms and merely requires monitoring. This is especially likely for elderly patients or others who may not be good candidates for treatment. Such patients are likely to undergo periodic testing to determine whether the tumor is growing.

A typical periodic testing plan might include initial magnetic resonance imaging (MRI) testing after six months, then testing at intervals of a year or even up to five years for tumors that appear to be under control. While monitoring may be the best approach, there is always the slight risk that the tumor could grow rapidly and damage the hearing before it becomes obvious that other treatments are necessary.

Patients who experience symptoms usually require treatment. Radiation therapy can be used to shrink or eliminate the tumor. A technique called gamma-knife radiosurgery allows the physician to deliver the radiation without making an incision. The procedure is performed under a local anesthetic on an outpatient basis. Risks associated with radiation therapy include facial numbness or weakness, but this usually is temporary.

The results of this therapeutic technique sometimes take weeks, months or even years to fully manifest. In the meantime, the patient will be monitored regularly to see if the tumor has been arrested. Because acoustic neuromas are not cancerous, they pose no health risk to a patient if they remain small and do not grow.

In other cases, traditional surgery may be necessary to remove the tumor. This usually is recommended for patients in danger of losing their hearing or of experiencing facial paralysis. This type of surgery is performed under general anesthesia and requires an incision in the skull. Patients typically have to spend several days in the hospital and may require an extended recovery period of 6 to 12 weeks.

Surgical treatment does carry some risks, including potential loss of hearing or facial-nerve dysfunction. However, these risks can be reduced in some patients who are candidates for a partial removal of a tumor, which is less invasive than full removal. Other side effects sometimes associated with surgery include:

• Balance difficulties
  
  
• Excessive eye dryness
  
  
• Facial weakness
  
  
• Headaches
  
  
• Ringing of the ears (tinnitus)

Some patients experience leakage of cerebrospinal fluid through the surgical incision or the nose. If this occurs, it should be reported to a physician immediately.