Acoustic Neuroma

The acoustic neuroma program at UT Southwestern Medical Center is one of the highest-volume centers in the United States and offers state-of-the-art treatment options. Research shows that clinical outcomes for patients with acoustic neuromas are better at high-volume centers than at low-volume centers.

Our team of doctors are fellowship-trained in the advanced treatment of acoustic neuroma. A team approach consisting of neurotologists (specialists in neurological disorders of the ear), neurosurgeons, and radiation oncologists are utilized for acoustic neuroma management given the anatomic complexity of the lateral skull base. This team-oriented approach results in improved outcomes in patients with acoustic neuroma. Audiologists and physical therapists are involved in managing hearing and balance symptoms, which are common in patients with acoustic neuroma.

A unique feature of the acoustic neuroma program at the UT Southwestern is our monthly skull base conference. During this conference, patients with an acoustic neuroma and other skull base tumors are presented to the group, and a management plan is finalized. The multidisciplinary skull base team's management recommendations are based on the extensive clinical experience of the UT Southwestern physicians and the latest published treatment recommendations.

About Acoustic Neuromas

An acoustic neuroma is a benign (nonmalignant) tumor that originates on the nerves affecting hearing or balance. These nerves are located deep in the skull and are very close to other important structures.

Because the tumor involves these particular nerves, patients usually experience hearing loss, ringing in the ear, or problems with balance. Larger tumors can cause facial numbness, headaches, and the accumulation of fluid around the brain that can be fatal if left untreated. 

Diagnosis and Evaluation

When a patient is seen at UT Southwestern for a possible acoustic neuroma, the evaluating physician will gather information about the size and shape of the tumor, the current level of hearing, and any previous treatments. We then confer with the multidisciplinary acoustic neuroma team, and together we will formulate a personalized treatment plan.

All patients with acoustic neuromas are seen promptly. Same- and next-day appointments are often available. 

Treatment for Acoustic Neuromas

Treating acoustic neuromas can be complex because of the anatomy and other individual factors involved. At UT Southwestern, we use a multidisciplinary approach involving a neurotologist (specialist in neurological disorders of the ear), a neurosurgeon, and, when appropriate, a radiation oncologist for the best possible outcomes. Treatments include observation, radiosurgery (radiation therapy), and surgery.

Observation

Small tumors and some medium tumors can be observed with regular MRIs. If initial scans do not show tumor growth, an annual MRI is usually then required to ensure there’s no further development. If initial scans show the tumor has grown, further treatment is indicated.    

Observation is not recommended for young patients or patients with large tumors. Hearing loss is possible during the observation period and can be sudden in some cases.

Radiosurgery

Radiosurgery is the precise use of radiation with the goal of stopping tumor growth. Generally, the tumor should show signs of growth via multiple MRIs before the tumor is treated with radiosurgery.    

The procedure is performed on an outpatient basis and is well tolerated, although some patients experience temporary headache and nausea.

The risks of radiosurgery include continued tumor growth, facial numbness, hearing loss, dizziness, ringing in the ear, facial paralysis or twitching (rare), and fluid buildup around the brain.

If the tumor needs to be removed after radiosurgery because of continued tumor growth, complications (such as facial weakness) tend to be more common. Also, there is a small risk of the tumor turning malignant (cancerous), estimated to be 1 in 1,000 cases over a 30-year period.

Surgery

Because of the anatomical complexities involved with the surgical removal of an acoustic neuroma, we use a team approach to treatment, including a neurotologist, neurosurgeon, and audiologist.    

Hearing preserva­tion can be attempted in patients with normal or near-normal hearing and small tumors.

We determine the most appropriate surgical approach based on multiple factors such as tumor size, tumor location, and hearing status. Depending on the tumor location and type of surgery, we monitor facial nerves and hearing nerves during the procedure.

• Translabyrinthine approach: This is the most common approach for removing an acoustic neuroma. An incision is made behind the ear, and the bone behind the ear is removed. Next, the labyrinth is removed, allowing a wide view of the tumor. Because the labyrinth is removed, total hearing loss is expected; however, with this approach, the brain does not require retraction and the largest tumors can be removed. Fat from the abdomen is used to fill in the surgical defect.
• Middle fossa approach: We use the middle fossa approach to remove small tumors in patients with good hearing. An incision is made above the ear, and a small piece of the skull is removed that will be placed back with small titanium plates. The temporal lobe of the brain is retracted, and the bone over the internal auditory canal is removed, allowing access to the tumor that is then removed. The goal of the middle fossa approach is hearing preservation, which is achieved in approximately 60 percent of cases.
• Retrosigmoid approach: The retrosigmoid approach is also used for small to medium tumors that have developed primarily in the brain cavity rather than in the internal auditory canal. We make an incision behind the ear and remove a small piece of the skull, allowing a wide view of the brain cavity. We then remove the tumor. Hearing preservation is sometimes possible with the retrosigmoid approach.

Total removal of a tumor is always the initial goal of surgery. If the tumor is adherent to the facial nerve or other vital structures, a small piece of tumor can be left behind to prevent complications. These small tumor remnants rarely grow; however, it is important to get an annual MRI to confirm.

Hearing Impairment and Acoustic Neuromas

The natural course of an untreated acoustic neuroma is hearing loss in the affected ear. Surgery or radiosurgery can also result in hearing loss. Many patients adjust well to hearing in only one ear. Other patients are more bothered with hearing loss and can consider a few options.    

One option is to wear a CROS (contralateral routing of sound) hearing aid, which consists of a hearing aid in the ear with poorer hearing that transmits sounds to a hearing aid in the other ear.

Another option is a bone-anchored hearing device, which is a surgically implanted abutment that attaches to an external sound processor. The sound is then routed through the bones of the skull into the good ear. The surgical procedure takes about 45 minutes and is performed as a day surgery. 

Research and Clinical Trials

UT Southwestern conducts clinical trials aimed at improving the diagnosis and treatment of brain conditions such as acoustic neuromas. Talk with our doctors to see if a clinical trial is available.