Conditions

Vestibular Schwannoma (Acoustic Neuroma)

Also known as: Acoustic neuroma · Vestibular nerve schwannoma · Cerebellopontine angle tumor

A vestibular schwannoma is a benign tumor that grows on the balance nerve between the inner ear and the brain. Most grow slowly, and the right management depends on the size of the tumor, your hearing, your symptoms, and your goals.

What it is

A vestibular schwannoma is a benign tumor that arises from the Schwann cells insulating the eighth cranial nerve, which carries hearing and balance information from the inner ear to the brain. Most arise from the vestibular (balance) division of that nerve — the origin of the name — though some involve the cochlear (hearing) division. Because the nerve travels through a narrow bony channel and passes near the facial nerve, even a small tumor can produce noticeable symptoms.

Most vestibular schwannomas grow slowly, and some do not grow at all over years of observation. They occur sporadically in the large majority of cases. Tumors on both sides are uncommon and raise the possibility of an underlying genetic condition, which changes how the tumor is evaluated and followed.

Symptoms

The most common presentation is gradual hearing loss in one ear, often noticed first on the telephone or in a noisy room. Other symptoms include:

  • Asymmetric hearing loss — hearing that is measurably worse in one ear
  • Tinnitus — ringing, hissing, or buzzing, usually on the affected side
  • Imbalance or unsteadiness, more often a vague sense of being off than true spinning vertigo
  • A feeling of fullness in the affected ear
  • Facial numbness or tingling, which suggests a larger tumor contacting the trigeminal nerve
  • Facial weakness, which is uncommon at presentation and generally indicates a larger tumor

Sudden hearing loss in one ear can also be a presenting sign. Because the symptoms develop gradually and are easy to attribute to age or wax, many vestibular schwannomas are found only after an asymmetry shows up on a hearing test.

How it is diagnosed

Evaluation usually begins with a complete audiogram, which documents the pattern and degree of hearing loss and compares the two ears. Asymmetric sensorineural hearing loss is the finding that most often prompts imaging.

MRI with gadolinium contrast is the definitive test. It shows the tumor, its size, and its relationship to the internal auditory canal, the brainstem, and the surrounding cranial nerves. Tumors too small to be seen on a standard CT scan are readily visible on a dedicated MRI protocol.

Additional testing — balance function studies, or a full cranial nerve assessment — may be added depending on the size of the tumor and the symptoms.

Management options

There are three established approaches, and the best choice depends on tumor size, growth on serial imaging, hearing status, age, overall health, and personal preference.

Observation. Serial MRI scans and hearing tests track the tumor over time. This is frequently the right first step for small tumors that are causing limited symptoms, since a substantial proportion grow slowly or not at all. Observation is an active strategy, not a decision to do nothing — the point is to intervene if and when the tumor demonstrates that it needs treatment.

Stereotactic radiosurgery. Focused radiation delivered in a single session or a small number of sessions, with the goal of stopping growth rather than removing the tumor. It is most often used for small and medium tumors. See Gamma Knife stereotactic radiosurgery for more detail.

Microsurgical removal. Surgery to remove the tumor, approached through the mastoid bone, behind the ear, or above the ear canal depending on tumor size, position, and whether hearing preservation is a realistic goal. Larger tumors, tumors compressing the brainstem, and tumors that continue to grow after other treatment are the usual indications. Facial nerve function is monitored throughout the operation.

For patients who lose hearing on the affected side, several rehabilitation options exist, including osseointegrated hearing devices and, in selected cases, cochlear implantation.

What to expect at your visit

Bring any prior hearing tests and imaging, including the actual MRI images rather than only the report if you can obtain them. A typical consultation includes a review of your history and symptoms, an ear examination, a cranial nerve examination, and a detailed discussion of the imaging. The goal of the first visit is a shared understanding of what the tumor is doing and what the realistic options are — not necessarily an immediate decision.

Common questions

Is a vestibular schwannoma cancer?

No. Vestibular schwannomas are benign, meaning they do not invade surrounding tissue or spread elsewhere in the body. They are still treated carefully because they sit in a confined space next to the hearing, balance, and facial nerves, and because larger tumors can press on the brainstem.

Do all vestibular schwannomas need to be treated right away?

No. Many are small, slow-growing, and cause few symptoms, and the safest initial approach is often observation with periodic MRI scans and hearing tests. Treatment is recommended when a tumor is growing, when it is large enough to affect nearby structures, or when symptoms warrant it.

Will I lose my hearing?

It depends on the size and position of the tumor, how much hearing you have at the outset, and which management approach is chosen. Hearing preservation is an explicit goal in some situations and is not achievable in others. This is one of the central topics to discuss during your consultation.

What is the difference between an acoustic neuroma and a vestibular schwannoma?

They are the same tumor. "Vestibular schwannoma" is the more precise term - the growth is a schwannoma rather than a neuroma, and it most often arises on the vestibular (balance) division of the eighth cranial nerve rather than the hearing division that "acoustic" refers to. "Acoustic neuroma" is the older, more familiar name and remains in wide use.

Where can I see a specialist for vestibular schwannoma in Colorado?

Dr. Ashley Nassiri evaluates vestibular schwannoma, also called acoustic neuroma, at UCHealth University of Colorado Hospital, on the University of Colorado Anschutz Medical Campus in Aurora, Colorado, in the Denver metropolitan area. She is a fellowship-trained neurotologist and skull base surgeon, and appointments are arranged through UCHealth.

Related

Gamma Knife Stereotactic Radiosurgery Cochlear Implantation Hearing Loss

Where this care is provided

Dr. Ashley Nassiri is a fellowship-trained neurotologist and skull base surgeon at UCHealth University of Colorado Hospital, on the University of Colorado Anschutz Medical Campus in Aurora, Colorado, in the Denver metropolitan area. Patients seeking evaluation for vestibular schwannoma (acoustic neuroma) can schedule by calling the clinic below or through UCHealth. There is also an overview of what a neurotologist treats and when to ask for a referral.

Call 720-848-2820 UCHealth provider page

UCHealth Ear, Nose and Throat Clinic – Anschutz Outpatient Pavilion, Aurora, Colorado

This page provides general information about a medical condition or procedure and is not medical advice. It is not a substitute for evaluation by a qualified clinician, and it cannot account for the specifics of any individual case. If you have symptoms that concern you, seek care directly.