Acoustic Neuroma (Vestibular Schwannoma)

Causes of acoustic neuromas

Most acoustic neuromas occur sporadically with no known cause or family history. A small percentage of acoustic neuromas (5%) are inherited and associated with neurofibromatosis type 2 (NF2), a genetic disorder. Individuals with NF2 often develop tumors on both sides of the vestibulocochlear (hearing and balance) nerve at a younger age. They also typically develop other types of benign tumors in the brain and spine.

Importantly, there’s no evidence to suggest environmental concerns, such as cellphone use, noise exposure or dietary factors, are linked to the development or growth rate of acoustic neuromas.

Acoustic neuroma symptoms

Although acoustic neuromas form on the balance nerve, they most commonly affect your hearing abilities — not your balance. Symptoms include:

• One-sided or asymmetric (uneven) hearing loss
• Feeling of fullness in the ear
• Tinnitus (ringing in the ear)
• Vertigo
• Balance problems
• Facial numbness or twitching (if the tumor is very large)

With acoustic neuroma, the degree of hearing loss is not always associated with the size of the tumor. Many patients experience few hearing loss symptoms even with a large tumor, while some might not display any symptoms. Some patients lose hearing even when the tumor is very small.

How is an acoustic neuroma diagnosed?

Because symptoms usually develop slowly over time and are often ignored, it can be difficult to diagnose acoustic neuromas (vestibular schwannomas). In patients with significant asymmetric hearing loss, a magnetic resonance imaging (MRI) scan to look for an acoustic neuroma is sometimes advised.

Imaging scans are also recommended for people who experience a sudden drop in their ability to hear; however, the likelihood of having an acoustic neuroma in this case is only about 1%.

Hearing tests might also be recommended. If you have sudden hearing loss or are experiencing asymmetric hearing loss, you should contact the audiology department at the Ohio State Wexner Medical Center to start the process of diagnosing the cause of your hearing issues.

Tumor size, hearing ability, age and overall health are all important factors in determining the best treatment for an acoustic neuroma. Our multidisciplinary team will work with you to select the best approach and provide you with the most optimal outcomes. Management approaches include:

• Treatment through observation - If the tumor is small and you are experiencing few symptoms, you may only need to have the tumor checked annually via an MRI scan. Smaller tumors may grow very slowly or not at all over a period of time. However, your hearing may still decline over time even if the tumor doesn’t grow.
• Stereotactic radiation - Stereotactic radiation is a nonsurgical procedure usually used on a tumor that's growing (determined through multiple MRIs). The radiation, given through one or more outpatient appointments, is aimed precisely through special equipment with the patient in specific positions. This treatment does not require a long recovery and will stop the growth of the tumor in most cases; however, it could adversely affect hearing.
• Microsurgery - Some people choose surgery for their tumor management. This decision is highly individualized and dependent on various factors, including tumor size, tumor location and residual hearing. Your overall health also plays an important role in the decision-making.

At the Ohio State Wexner Medical Center, our treatment team has extensive experience in the three surgical approaches available for acoustic neuromas.

1. The translabyrinthine approach is performed through an incision behind the ear. The surgeon will then remove part of the temporal bone and inner ear to access the tumor. This technique is useful for large tumors or for patients with substantial hearing loss as well as if hearing preservation is unlikely.
2. The retrosigmoid approach is performed through an incision behind the ear but does not involve removal of the inner ear. This approach is useful for people with tumors of all sizes and has a potential to preserve hearing.
3. The middle cranial fossa approach is performed through an incision in front of and above the ear. The inner ear parts are preserved, and the tumor is accessed from above. This surgical approach is ideal for small tumors, tumors located in the internal auditory canal and for patients with good preoperative hearing. The middle cranial fossa approach offers the highest likelihood of long-term hearing preservation.

Resources for patients

Consultation

At Ohio State, our team is committed to creating an individualized, optimized treatment plan for every patient. We are happy to provide an initial consultation with you and your family members to discuss your problem, goals and concerns. We will also review your hearing tests, diagnostic tests (such as MRIs) and any other relevant medical information. Call 614-366-3687 to schedule an appointment.

Support Groups

Many patients with acoustic neuromas seek out advice and support from support groups. The Acoustic Neuroma Association (ANA) is a great resource for patients and has many groups that focus on relevant acoustic neuroma issues, including headaches pre- and post-treatment, young adults, caregivers and facial paralysis. Find a support group and more information on support groups in your area.