Description

An acoustic neuroma is a noncancerous tumor that develops on the main nerve leading from the inner ear to the brain. This nerve is called the vestibular nerve. The branches of the nerves directly affect balance and hearing. The pressure from an acoustic neuroma can cause hearing loss, ringing in the ears, and trouble with balance. Another name for an acoustic neuroma is a vestibular schwannoma.

An acoustic neuroma develops from the Schwann cells that covers the vestibular nerve. An acoustic neuroma is generally slow growing. In rare cases, it can grow quickly and become large enough to press against the brain and affect the vital functions.

Treatment for an acoustic neuroma include surveillance, radiation, and surgical excision.

Symptoms

The symptoms of an acoustic neuroma are often easy to lose and can take years to develop. The symptoms may occur due to tumor of the effects on the hearing and balance nerves. The tumor may also put pressure on the nerves that control the facial muscles, known as the facial nerve, and the feeling, known as the trigeminal nerve. The blood vessels or of the structures of the brain can also be affected by an acoustic neuroma.

As the tumor grows, it may be more likely to cause more noticeable or worsen symptoms.

The common symptoms of an acoustic neuroma include:

  • Hearing loss, usually slowly over months to years. In rare cases, the hearing loss can be sudden. The hearing loss typically occurs on one side or is worse on one side.
  • Ringing in the affected ear, known as tinnitus.
  • Loss of balance, or does not feel stable.
  • The dizziness.
  • Facial numbness and, very rarely, weakness or loss of muscle movement.

Rarely, an acoustic neuroma can grow large enough to compress the brain stem and life-threatening.

When to see your doctor

Consult a health care professional if you experience hearing loss in one ear, ringing in the ears, or problems with balance.

The early diagnosis of an acoustic neuroma can help keep the tumor from growing large enough to cause complications such as total loss of hearing.

Causes

The cause of acoustic neuromas can sometimes be linked to a problem with a gene on chromosome 22. Normally, this gene produces a tumor suppressor protein that helps control the growth of Schwann cells that covers the nerves.

The experts don't know what causes this problem with the gene. Often there is no known cause of an acoustic neuroma. This change in the gene is inherited in people with a rare disease called neurofibromatosis type 2. People with neurofibromatosis type 2 usually have a growth of tumors on the hearing and balance nerves on both sides of the head. These tumors are known as bilateral vestibular schwannomas.

Risk factors

The Neurofibromatosis type 2

The only confirmed risk factor for acoustic neuroma is to have a father with the rare genetic disorder neurofibromatosis type 2. However, the neurofibromatosis type 2 represents only about 5% of acoustic neuroma cases.

A hallmark of neurofibromatosis type 2 is the non-cancerous tumors in the balance of nerves on both sides of the head. The tumors can also develop in other nerves.

Neurofibromatosis type 2 is known as an autosomal dominant disorder. This means that the gene associated with the disorder can happen to a child by one of their parents. Each child of an affected parent has a 50-50 chance of inheriting.

Complications

An acoustic neuroma can cause permanent complications, including:

  • The hearing loss.
  • Facial numbness and weakness.
  • Balance problems.
  • Ringing in the ear.

Larger tumors can press on the brain stem, which sometimes impede the flow of cerebrospinal fluid between the brain and the spinal cord. Fluid can build up in your head, a condition known as hydrocephalus. This increases the pressure within the skull.

Diagnosis

An acoustic neuroma is often difficult to diagnose in the early stages because the symptoms can be easy to overlook, and it develops slowly over time. Common symptoms such as hearing loss are also associated with many other middle and inner ear problems.

After asking questions about your symptoms, a member of your health care team takes out an ear exam. You may need the following tests:

  • The hearing test, known as the audiometry.This test is conducted by a hearing specialist called an audiologist. During the test, the sound is directed to one ear at a time. The audiologist presents a variety of sounds of different pitches. Will indicate each time you hear the sound. Each tone is repeated at weak levels to find out when you can barely hear. The audiologist can also present a number of words to test your hearing ability.
  • The projection image. Magnetic resonance imaging (MRI) with contrast medium that is generally used to diagnose an acoustic neuroma. This imaging test can detect tumors as small as 1 to 2 millimeters in diameter. If MRI is not available or you may not have a magnetic resonance imaging, computed tomography (CT) may be used. However, the CT scan may miss small tumors.

The hearing test, known as the audiometry. This test is conducted by a hearing specialist called an audiologist. During the test, the sound is directed to one ear at a time. The audiologist presents a variety of sounds of different pitches. Will indicate each time you hear the sound. Each tone is repeated at weak levels to find out when you can barely hear.

The audiologist can also present a number of words to test your hearing ability.

Treatment

Your acoustic neuroma treatment may vary, depending on:

  • The size and rate of growth of acoustic neuroma.
  • Your health in general.
  • Their symptoms.

There are three treatment approaches for acoustic neuroma: the surveillance, surgery or radiation therapy.

Monitoring

You and your health care team may decide to monitor an acoustic neuroma if it is small and is not growing or is growing slowly. This may be an option if the acoustic neuroma causes few or no symptoms. The monitoring may also be recommended if you're an older adult or if you're not a good candidate for more aggressive treatment.

While being monitored, you'll need regular image and hearing tests, usually every 6 to 12 months. These tests can determine if the tumor is growing and how quickly. If the tests show that the tumor is growing or if the tumor gets worse symptoms or other problems, you may need to have surgery or radiation.

Surgery

You may need surgery to remove an acoustic neuroma, particularly if the tumor is:

  • Continues to grow.
  • Very large.
  • The cause of the symptoms.

The surgeon may use one of several techniques for the removal of an acoustic neuroma. The technique of surgery depends on the tumor size, their hearing status, and other factors.

The goal of surgery is to remove the tumor and preserve the facial nerve to prevent paralysis of the muscles of the face. The removal of the whole tumor may not always be possible. For example, if the tumor is very close to important parts of the brain or the nerves of the face, only a portion of the tumor can be removed.

The surgery for an acoustic neuroma is performed under general anesthesia. The surgery involves the removal of the tumor through the inner ear, or through a window in his skull.

Sometimes the removal of the tumor can worsen symptoms if you have hearing, balance and facial nerves are irritated or damaged during operation. The hearing may be lost on the side where the surgery is performed. The balance is usually affected temporarily.

Complications can include:

  • Filtration of the fluid that surrounds the brain and spinal cord, known as the cerebrospinal fluid. A leak can happen through the wound.
  • The hearing loss.
  • Facial weakness or numbness.
  • Ringing in the ear.
  • Balance problems.
  • Persistent headache.
  • Rarely, an infection in the cerebrospinal fluid, known as meningitis.
  • Very rarely, a stroke, or cerebral hemorrhage.

Radiation therapy

There are several types of radiation therapy used for the treatment of an acoustic neuroma:

  • Stereotactic radiosurgery.A type of radiation therapy known as stereotactic radiosurgery may try an acoustic neuroma. It's often used if the tumor is small, less than 2.5 centimeters in diameter. The radiation therapy may also be used if you are an older adult or are unable to tolerate surgery for health reasons. Stereotactic radiosurgery, such as Gamma knife and CyberKnife, uses many small gamma rays to deliver a targeted dose of radiation to a tumor. This technique offers a treatment without damaging the surrounding tissue or to make an incision. The aim of stereotactic radiosurgery is to stop the growth of a tumor, to preserve the facial nerve function and, possibly, to preserve the hearing. It can take weeks, months or years before you notice the effects of radiosurgery. Your health care team monitors your progress with follow-up imaging studies and tests of hearing. The risks of radiosurgery include: Hearing loss.Ringing in the ear.Facial weakness or numbness.Balance problems.Continued growth of the tumor.
  • The hearing loss.
  • Ringing in the ear.
  • Facial weakness or numbness.
  • Balance problems.
  • Continued growth of the tumor.
  • Fractionated stereotactic radiotherapy. Fractionated stereotactic radiotherapy (SRT) provides a small dose of radiation to the tumor through multiple sessions. SRT is done to slow the growth of the tumor without damaging the surrounding brain tissue.
  • The proton therapy. This type of radiation therapy using beams of high-energy positively charged particles called protons. The proton beams are delivered to the affected area of the dose for the treatment of tumors. This type of therapy reduces the radiation exposure to the surrounding area.

Stereotactic radiosurgery. A type of radiation therapy known as stereotactic radiosurgery may try an acoustic neuroma. It's often used if the tumor is small, less than 2.5 centimeters in diameter. The radiation therapy may also be used if you are an older adult or are unable to tolerate surgery for health reasons.

Stereotactic radiosurgery, such as Gamma knife and CyberKnife, uses many small gamma rays to deliver a targeted dose of radiation to a tumor. This technique offers a treatment without damaging the surrounding tissue or to make an incision.

The aim of stereotactic radiosurgery is to stop the growth of a tumor, to preserve the facial nerve function and, possibly, to preserve the hearing.

It can take weeks, months or years before you notice the effects of radiosurgery. Your health care team monitors your progress with follow-up imaging studies and tests of hearing.

The risks of radiosurgery are:

  • The hearing loss.
  • Ringing in the ear.
  • Facial weakness or numbness.
  • Balance problems.
  • Continued growth of the tumor.

Supportive therapy

In addition to treatment to remove or stop the growth of tumor, supportive therapies can help. Supportive therapies address the symptoms or complications of an acoustic neuroma and its treatment, such as dizziness or balance problems.

Cochlear implants or other treatments that can be used to hearing loss.

Coping and support

Dealing with the possibility of hearing loss and facial paralysis can be very stressful. Deciding which treatment would be best for you, you can also be a challenge. These suggestions can help:

  • Learn more about acoustic neuromas. The more you know, the better prepared you can be to make good decisions about treatment. In addition to talking with your health care team and your audiologist, you may want to talk with a counselor or social worker. Or you may find it helpful to talk with other people who have had an acoustic neuroma. This can help you learn more about their experiences during and after treatment.
  • Maintain a strong support system.Family and friends can help you as you go through this difficult time. Sometimes, however, you may find that the concern and understanding of other people with an acoustic neuroma particularly comforting. Your health care team or of a social worker may be able to put you in touch with a support group. Or you may find a person or a group of on-line support through the Acoustic Neuroma Association.

Maintain a strong support system. Family and friends can help you as you go through this difficult time. Sometimes, however, you may find that the concern and understanding of other people with an acoustic neuroma particularly comforting.

Your health care team or of a social worker may be able to put you in touch with a support group. Or you may find a person or a group of on-line support through the Acoustic Neuroma Association.

Preparing for your appointment

First you can see a health care professional. This person can refer you to a doctor trained in ear, nose and throat conditions. Or you may be referred to a doctor trained in brain and nervous system surgery, known as a neurosurgeon.

Because there's often a lot to talk about during your appointment, it is a good idea to be well prepared. Here's some information to help you prepare and get a good idea of what to expect.

What you can do

  • Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Make a list of all medications, vitamins or supplements you are taking.
  • Ask a family member or a friend to join you, if possible. Sometimes it can be difficult to remember all the information provided to you during an appointment. Someone who comes with you may remember something that you missed or forgot.
  • Write questions to ask their health care team.

Prepare a list of questions will help you make the most of your time. For an acoustic neuroma, some basic questions to ask include:

  • What is likely causing my symptoms?
  • There are other possible causes of the symptoms?
  • What kinds of tests do I need?
  • What treatment options are available?
  • What you recommend for me?
  • What is the probability of side effects of each treatment option?
  • What happens if I do nothing?
  • Are there brochures or other printed material that I can take my house? What sites do you recommend to visit?

In addition to the questions you have prepared, do not hesitate to ask for any present during your appointment.

What to expect from your doctor

You will be asked a series of questions. Be prepared to respond to them can give more time to go through any of the points I need to clarify. You may ask:

  • When did you first begin experiencing symptoms?
  • The symptoms been continuous or occasional?
  • How bad are the symptoms?
  • Do you have any family members with an acoustic neuroma?
  • At your current level, you can hear in the affected ear? For example, you can use the ear on the phone? Does the ear help to establish where a sound is coming from?
  • Do you have regular headaches now or has had in the past?
Symptoms and treatment of Acoustic neuroma