About Acoustic Neuromas
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
All patients with acoustic
neuromas are seen promptly. Same- and next-day appointments are often
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
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.
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 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
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.
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
can be attempted in patients with normal or near-normal hearing and small
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
- 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
- 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.
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.
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.