A diagnosis of a vestibular schwannoma, also called an acoustic neuroma, can feel overwhelming. While the tumor is noncancerous, it develops in a delicate area near the brain that controls hearing, balance, and facial movement. If left untreated, larger tumors can lead to serious complications.

The good news is that vestibular schwannomas are often slow growing. Many people have excellent outcomes with personalized treatment and ongoing monitoring.

Nebraska Medicine neurosurgeon Mithun Sattur, MBBS, explains what vestibular schwannomas are, the symptoms to look out for, and how treatment is tailored to each patient.

What is a vestibular schwannoma?

A vestibular schwannoma is a benign tumor that develops from the balance portion of the eighth cranial nerve, also called the vestibulocochlear nerve. 

“The tumor usually originates from the vestibular, or balance, portion of the nerve rather than the hearing portion,” says Dr. Sattur.

Unlike cancer, these tumors do not spread to other parts of the body. However, because they grow in a confined space near the brainstem and important cranial nerves, they can still cause significant neurological symptoms as they enlarge.

Where do vestibular schwannomas develop?

Vestibular schwannomas form in the skull base, where the hearing, balance, and facial nerves travel from the inner ear to the brain. 

The tumor typically begins inside a narrow bony canal deep within the ear. As it grows, it can extend toward the brain, placing pressure on nearby structures, including:

• The hearing nerve
• The balance nerve
• The facial nerve
• The cerebellum, which helps coordinate movement and balance
• The brainstem, which controls vital body functions

What causes vestibular schwannomas?

Researchers believe most vestibular schwannomas develop because of a mutation in the NF2 tumor suppressor gene. It’s unknown why this mutation occurs in most people. 

Studies haven’t found a clear link between cellphone use and vestibular schwannoma development.

Who is at risk?

Most vestibular schwannomas occur without an identifiable cause or preventable risk factor. 

A small number of patients have a genetic condition called Neurofibromatosis Type 2 (NF2). People with NF2 may develop vestibular schwannomas on both sides and often have multiple tumors involving the brain or spine, along with a family history of the condition.

What are the symptoms of a vestibular schwannoma? 

Because vestibular schwannomas usually grow slowly, symptoms often develop gradually over months or even years.

Common vestibular schwannoma symptoms include:

• Hearing loss in one ear
• Ringing in one ear (tinnitus)
• Difficulty understanding speech, especially in noisy settings
• Problems with balance or unsteadiness
• Vertigo
• Facial numbness
• Facial weakness

Some people experience sudden sensorineural hearing loss as their first symptom. It’s an unexplained loss of hearing over 72 hours or less, often in one ear.

“The severity of symptoms doesn’t always match the size of the tumor,” says Dr. Sattur. “Even relatively small tumors can cause significant hearing changes.”

When to see a doctor

You should seek medical evaluation if you experience:

• Persistent ringing in one ear
• Hearing loss that’s worse on one side
• Unexplained balance problems
• Frequent vertigo
• Facial numbness
• Sudden hearing loss

Sudden hearing loss is considered a medical urgency and should be checked promptly. 

How is vestibular schwannoma diagnosed?

The gold standard for diagnosis is an MRI of the brain with contrast, which allows physicians to clearly see the tumor.

Additional testing often includes a hearing test (audiometry) and balance testing (vestibular testing), when appropriate. These tests help determine how the tumor affects hearing and balance and guide treatment decisions.

What are the treatment options?

Treatment depends on many factors, including the size of the tumor, whether it’s growing, your symptoms, and your overall health.

There are three primary treatment approaches.

Observation

Not every vestibular schwannoma requires immediate treatment.

If the tumor is small, causing minimal symptoms, and not growing, doctors may recommend regular MRI scans, hearing evaluations, and ongoing monitoring for changes.

Stereotactic radiosurgery

Focused radiation treatments, such as Gamma Knife® or CyberKnife®, can stop or slow tumor growth without surgery.

Radiation does not remove the tumor. The goal is to prevent further growth. Because changes occur gradually, long-term imaging is still needed after treatment.

Microsurgical removal

Larger tumors, tumors causing pressure on the brainstem, or tumors that continue to grow may require surgery through a craniotomy. 

One of the most important considerations is protecting the facial nerve, often attached to the tumor.

In select situations, a medication called bevacizumab may also be considered.

What is recovery like? 

Recovery depends on the treatment used. 

After surgery, patients typically spend several days in the hospital. They then begin recovery in the intensive care unit and may require inpatient rehabilitation to help with strength and balance.

Recovery may take several weeks, especially after removal of larger tumors. Temporary or permanent facial weakness can occur because of the close relationship between the tumor and the facial nerve.

Will hearing and balance improve?

Unfortunately, hearing usually continues to decline over time in the affected ear, even if the tumor is stable or treatment is successful. 

Treatment may preserve useful hearing in some patients, but it rarely restores hearing that’s already been lost. 

Balance, however, often improves. The brain can start compensating for reduced balance function, especially with vestibular rehabilitation therapy, balance exercises, and physical therapy. 

Patients with hearing loss may benefit from traditional hearing aids, bone-conduction hearing devices, cochlear implants, or auditory brainstem implants for complex cases.

Possible long-term complications

Depending on the size of the tumor and treatment, complications can include:

• Permanent hearing loss
• Tinnitus
• Balance difficulties
• Facial weakness or numbness
• Dry eye from facial nerve dysfunction

Surgery also carries a risk of cerebrospinal fluid leakage, while radiation requires continued monitoring for delayed nerve injury.

Living with a vestibular schwannoma

The outlook for people with vestibular schwannoma is generally very good. Because these tumors are benign, treatment is usually successful at controlling growth. The focus is on preserving hearing, facial nerve function, balance, and quality of life. 

Living with one-sided hearing loss can make everyday situations more challenging. Some find it harder to follow conversations and maintain balance in busy settings. Some also experience fatigue, anxiety about follow-up scans, or persistent tinnitus. 

Fortunately, vestibular rehabilitation, hearing technologies, and individualized treatment plans can help patients continue working, driving, and enjoying daily activities.

“The diagnosis doesn’t automatically mean you need surgery,” says Dr. Sattur. “Treatment should be individualized to control the tumor while preserving hearing, facial function, balance, and quality of life for as long as possible.”