An acoustic neuroma is a slow growing, benign tumor that typically develops on your vestibular nerve. Your vestibular nerve carries signals from your inner ear and vestibular system to your brain, controlling balance and dizziness. Sometimes acoustic neuromas grow on your cochlear nerve, which transmits information about sound from your inner ear to your brain. An acoustic neuroma grows from Schwann cells, which is the cell that creates myelin, a material that protects and insulates nerves throughout your body. Most typically, acoustic neuromas occur in women aged 30-60, and arise from unknown cause.
Symptoms & Diagnosis
Because of the slow growing nature of an acoustic neuroma, it can often be difficult to diagnose. Symptoms often build up slowly and begin with hearing loss and dizziness. If it grows large enough, it may press on other nerves or your brainstem and worsen symptoms. These are also difficult to diagnose because the typical symptoms are common in other types of vestibular disorders. Symptoms include some, or all, of the following:
- tinnitus (ringing in your ear)
- hearing loss
- aural fullness (feeling stuffed up or like you have water in your ear)
- loss of balance
- vertigo (dizziness, lightheadedness, or like your brain is spinning)
- double vision
- nausea and/or vomiting
- numbness/tingling in your face
Any, or all, of these symptoms can occur with an acoustic neuroma as well as other vestibular or central nervous system disorders. It is important that you and your healthcare provider rule out all other diagnoses before getting to acoustic neuroma. The first tests that will likely be done are a hearing test and an ear exam. Then, if an acoustic neuroma is still suspected you will receive an MRI and/or a CT scan.
For an MRI, you will likely be injected with contrast dye prior to your scan. This will help show your physician a 3D image of the soft tissues in your brain, and help the tumor be differentiated from the rest of your brain tissue.
The CT scan will provide a 3D image of your brain as well, and is used if you have metal in your body, or any other reason you can’t have an MRI. You may be given an injection of contrast dye to help enhance the image as well. If you have a positive CT or MRI scan, your healthcare provider will provide you with a few treatment options depending on your specific needs.
There are a few ways your healthcare team may choose to handle your acoustic neuroma once you receive your diagnosis. The best choice is always the one that you make with the assistance of your treatment team. You and your team should always make sure to consider all options before coming to a decision. The three most common forms of treatment are observation, surgical removal, or radiation. These three choices are incredibly different, so let’s break them down together to help with your decision
Observation is usually the choice best suited for people who have very small or slow growing tumors, or those without symptoms. Acoustic neuromas do not always require immediate treatment, so if your providers make this recommendation don’t be worried that you aren’t taking a more significant action — you’re likely making the best decision for yourself!
You may need surgery or radiation therapy in the future if the tumor grows or you develop symptoms, but in this case that can be reserved for the future!
Surgical removal of an acoustic neuroma is a procedure done under a microscope, a microsurgery, for partial or full removal of the mass. You and your surgeon can decide on if a partial or total removal of the neuroma is right for you. A partial removal indicates only removing a portion of the tumor in order to decrease the complication rate and decrease risk of facial paralysis or hearing loss. However, with a partial removal you may have to undergo another surgery in the future if the tumor returns. The other option is a total removal of the tumor. In a total removal, your surgeon will remove the entire neuroma while also trying to preserve hearing and avoid facial paralysis.
The final option, radiation therapy, has increased in accuracy and dependency with recent technology. People can now use radiation therapy to reduce the size of the neuroma and slow or even stop growth. Depending on your case, it can take one or many treatments before results are seen, but this treatment can be done in an out-patient setting like a regular trip to the doctor. The concept is the direct radiation specifically at the tumor, sparing the tissue around it, to stop growth and decrease the tumor’s size.
Physical therapy is a vital part of your treatment once you are diagnosed with an acoustic neuroma. Your physical therapist should have a background and understanding of vestibular care, and will help treat your symptoms! You can start before, during, or after your other medical treatments depending on what you decide with your healthcare team. Vestibular Rehabilitation Therapy will help to increase your balance, decrease dizziness, and improve your overall vestibular function. In patients who underwent surgery, those who received direct instruction to improve their vestibular system post-operation had significantly improved balance compared to the group who received general instruction about vestibular rehabilitation (2). Your physical therapist should understand your personal goals, and work with you to determine the best course of treatment with you!
(1) National Organization for Rare Disorders (NORD). (2016). Acoustic Neuroma. Retrieved August 18, 2020, from https://rarediseases.org/rare-diseases/acoustic-neuroma.
(2) Vereeck L, Wuyts FL, Truijen S, De Valck C, Van de Heyning PH. The effect of early customized vestibular rehabilitation on balance after acoustic neuroma resection. Clin Rehabil. 2008;22(8):698-713. doi:10.1177/0269215508089066. https://pubmed.ncbi.nlm.nih.gov/18678570/.