Non-cancerous tumors called acoustic neuromas or vestibular schwannomas grow on the vestibular nerve that connects the brain to the inner ear. These rare tumors grow very slowly; some do not grow at all. The vestibular nerve regulates the body’s balance and hearing, and the tumors result from abnormal growth in the nerve’s Schwann cells, which help to insulate the nerve fibers and provide them with support.
Acoustic Neuroma Symptoms
There are several symptoms that can help to identify an acoustic neuroma, and they can differ based on the location and size of the growth. Some of these symptoms include the following:
- Loss of balance and, sometimes, vertigo
- Sudden or progressive hearing loss
- Tinnitus, or ringing in an ear that is affected
In some cases, people with acoustic neuromas may also feel numbness in the ear or the face and experience headaches or dizziness. In general, acoustic neuromas do not cause facial paralysis; a facial nerve tumor, called a schwannoma, is more likely to be associated with facial paralysis or weakness.
Diagnosis of an Acoustic Neuroma
The most common and effective way to diagnose acoustic neuromas is through an MRI (magnetic resonance imaging). Doctors can also use hearing tests, equilibrium tests and balance tests to help determine the originating nerve of acoustic neuromas.
Treating Acoustic Neuromas
In some case, a physician may recommend monitoring the tumor and its development rather than pursuing treatment immediately. This is especially the case if the neuroma is not causing serious symptoms and is small in size. If the tumor is larger or symptomatic, stereotactic radiosurgery may be recommended. This procedure aims to protect nerve function and hearing, and works by targeting the tumor directly with a precise beam of radiation. This painless, non-invasive procedure poses a reduced risk of damage to healthy nerves and hearing than traditional surgery, and the full results should be apparent several months after the treatment.
In the case of very large neuromas, however, traditional surgery under general anesthesia may be necessary. The neuroma is removed through the inner ear or through a small opening made in the skull. At times, the neuroma may be too close to nerves and other brain structure to be fully removed safely. The outcomes of treatment depend on the size and position of the neuroma as well as the patient’s overall health situation.
Prognosis for Patients with Acoustic Neuromas
As non-cancerous tumors, neuromas do not spread to other areas of the body or organ systems. They can continue to develop and may press on important areas of the brain, causing pressure. After a surgery for an acoustic neuroma, people are recommended to receive follow-up MRIs at one, two, five and 10 years after their surgery. These scans serve to confirm that the tumor has not continued to grow or grown back.