What is it?
An acoustic neuroma is a benign, usually slow-growing tumor that develops from the balance and hearing nerves supplying the inner ear.
As the acoustic neuroma grows, it presses against the hearing and balance nerves, usually causing unilateral (one-sided) or asymmetric hearing loss, tinnitus (ringing in the ear) and dizziness/loss of balance.
As the tumor grows, it can interfere with the face -sensation nerve causing facial numbness and can also cause facial weakness or paralysis on the side of the tumor. If the tumor becomes large, it will eventually press against nearby brain structures, becoming life threatening.
What are the symptoms?
You may have one or several of these symptoms, and they may be mild to severe, depending upon the location and size the acoustic neuroma:
-- Loss of hearing in one ear
-- Buzzing or ringing in the ear
-- Facial paralysis
-- Loss of facial sensation
-- Difficulty swallowing
-- Impaired eye movement
-- Taste disturbances
How is a patient diagnosed?
Once symptoms appear, a thorough ear examination and hearing test (audiogram) are essential to diagnose an acoustic neuroma.
In addition, CT scans, enhanced with intravenous dye (contrast), and MRIs are critical in the early detection of an acoustic neuroma. They are also helpful in determining the location and size of a tumor and in planning its microsurgical removal.
How is it treated?
Because an acoustic neuromas grows slowly, treatment may not be necessary for some. Instead, the doctor will examine patients over time and treat the tumor only if it increases in size or causes hearing deterioration or other problems.
The most common and effective treatment is partial or complete microsurgical removal of an acoustic neuroma. There are several surgical approaches, and your doctor will discuss the method that is best for you. Generally speaking, patients can expect to remain in the hospital from four to seven days and should allow four to six weeks for recovery. The removal of tumors affecting the hearing, balance or facial nerves can make the patient's symptoms worse because sections of these nerves may also need to be removed with the acoustic neuroma.
Stereotactic radiosurgery may be appropriate for acoustic neuroma patients who may also benefit from radiation, either conventional or focused, such as the CyberKnife® Robotic Radiosurgery System at Sentara, which delivers image-guided radiation.
This treatment arrests tumor growth or may cause it to shrink but will not remove the tumor entirely. For this reason, follow-up examinations (including periodic MRIs) and observation are important to make sure the acoustic neuroma remains under control. Radiosurgery can be conducted on an outpatient basis. Many patients return home a few hours after treatment and resume their normal activities with a minimum of side effects.
Radiation therapy is sometimes the preferred option for elderly patients, patients in poor health, patients with bilateral acoustic neuroma (tumor affecting both ears) or patients whose tumor is affecting their only hearing ear.
What research is being done?
For the latest news on acoustic neuroma, visit MedlinePlus, run by the U.S. National Library of Medicine and the National Institutes of Health.
-- National Institute on Deafness and other Communication Disorders
-- Acoustic Neuroma Association