Acoustic Neuroma: Causes, Symptoms, Treatment, Surgery, Complications
The acoustic neuroma is noncancerous (benign), uncommon tumor which usually grows slowly. Acoustic neuroma develops in the main nerve, which leads from the inner ear to the brain. The branches of this nerve can directly affect your hearing and balance, pressure from the acoustic neuroma might cause hearing loss, unsteadiness and ringing in your ear.
It is also referred as vestibular schwannoma; the acoustic neuroma grows slow or does not grow at all. Well, in a few cases, this tumor can also grow rapidly and become big enough that it can press against the brain. It might also interfere with the vital functions of the brain.
Treatment for acoustic neuroma tumor includes radiation, surgical removal and regular monitoring.
How Common are Acoustic Neuromas?
All sorts of brain tumors are relatively rare. Approximately 20 people out of a million people, every year are diagnosed with acoustic neuroma.
For certain reasons that are still not clear, the tendency of acoustic neuroma is more in women when compared to men. People between the ages of 40 to 60 years are mostly affected. Acoustic neuroma is rare in children.
What are the Causes of Acoustic Neuroma?
Acoustic neuromas is caused — tumors develop on the main balance nerve that leads from the inner ear to the brain — it comes into view that it is malfunctioning gene on chromosome 22. Generally, it is the gene that produces a protein, which helps to control the development of Schwann cells covering the nerves. The reason for gene malfunction is not clear. For now there are no known factors cleared that can get an acoustic neuroma.
Scientists know that the defective gene is hereditary in neurofibromatosis type 2, it is a rare disorder, which usually involves the development of tumors on balance nerves on either side of the head (bilateralAcoustic Neuromas or bilateral vestibular schwannomas).
What are the Symptoms of Acoustic Neuroma?
The symptoms and signs of acoustic neuroma show from the straight effect on the main nerve or by the tumor pressing the adjacent nerves, which are near to brain structures or blood vessels.
When the tumor grows, there are more chances for signs and symptoms. However, the size of the tumor does not determine its effect. There is possibility that the small tumor can cause significant symptoms and signs.
You might experience symptoms and signs of acoustic neuroma, such as:
- Hearing loss, typically gradual,but in some cases are sudden and occurs on either side or more prominent on one side
- Vertigo or Dizziness
- Tinnitus(Ringing) in the affected ear
- Very rarely, weakness or Facial numbness
- Loss of balance or unsteadiness.
In a few cases, the tumor may grow large enough that it can compress the brain stem as well as threaten your life.
When to Visit the Doctor for Acoustic Neuroma?
Visit your doctor if you observe a hearing loss in any of your ear, or trouble with balance or ringing in your ear. If acoustic neuroma is diagnosed at early stages then it might help you to control the growth of tumor so that there no serious consequences, like a total loss of hearing power or a buildup of fluid in the skull that can be life threatening.
Most likely, you start by visiting a general practitioner or family doctor. The doctor might refer you to the doctor who is trained in (otorhinolaryngologist) ear, nose and throat conditions.
Since there is lots of talk when you visit the doctor so, it is better if you are well prepared for it. Below is some information that will help you to get ready for the appointment with the doctor.
- Note down the symptoms that you are experiencing, including the symptoms that are not related to the reason for which you are visiting the doctor.
- Create a list of vitamins, supplements and all medications that you are taking.
- Note down questions that you need to ask the doctor.
What are the Risk Factors for Acoustic Neuroma?
The known risk factor for causing acoustic neuroma is having a parent who has rare genetic disorder neurofibromatosis type 2. However, it only accounts for a small number of cases. The development of benign tumors on both sides of your head on the balance nerve is a hallmark characteristic of neurofibromatosis type 2.
What are the Complications for Acoustic Neuroma?
An acoustic neuroma might also cause a variety of complications that are permanent, including:
- Ringing in the ear
- Weakness and Facial numbness
- Hearing loss
- Difficulties with balance.
What are the Tests Conducted to Diagnose Acoustic Neuroma?
As the acoustic neuroma symptoms build up in a gradual way and the symptoms like loss of hearing can indicate problems in the inner ear, detecting the tumor may be difficult for the doctor. After speaking to the doctor about the symptoms, he or she will examine the inner ear.
The doctor may do the following tests for diagnosing acoustic neuroma:
- Audiometry or hearing test: An audiologist will carry out the test and the patient may hear sounds that are directed to each ear. The audiologist produces a range of sounds and you will have to indicate what kind of sounds are heard. The tones are repeated at various audible levels and this will help in indicating the hearing capacity.
- Scans: Computerized tomography (CT) or Contrasted magnetic resonance imaging (MRI) or head scans may be done to detect acoustic neuroma.
What are the Treatment Options for Acoustic Neuroma?
The treatment for acoustic neuroma may vary based on the growth and its size as well as the symptoms that the patient is experiencing. The doctor may suggest various treatment options for treating acoustic neuroma.
Monitoring the Progress of Acoustic Neuroma
If your acoustic neuroma is small and is slowly growing and there are no signs, the doctor may monitor it as well. The doctor may also suggest carrying out imaging and hearing tests on a regular basis for every six months or more. This will help in determining the whether the tumor is growing or not. You will have to undergo specific treatment if the symptoms are progressive and you are experiencing other difficulties.
Stereotactic Radiosurgery for Treating Acoustic Neuroma
A stereotactic radiosurgery may be recommended by your doctor if acoustic neuroma is detected. However, some large tumors may not be treated by this method.
Stereotactic radiosurgery is done to stop the tumor growth and preserve the function of the facial nerves as well as the hearing. Studies have revealed that certain people lose their hearing ability within 10 years after the surgery has been done.
Gamma Knife radiosurgery is a type of stereotactic radiosurgery and doctors target radiations to the tumor in a precise manner without cutting the skin. A head frame which is lighter in weight is attached to the scalp and the area is number to keep it still during the entire surgery. Using the scans the doctor will find the tumor and the radiations will be directed to that area.
The effects of the surgery may be evidently noticed within years or months or even several weeks. The doctor will carry out several hearing tests and imaging to keep an eye on the progress. Radiosurgery may include risks like facial weakness, hearing loss,facial numbness,ringing in the ear, tumor re-growth or treatment failure and balance problems. Though rare, the radiation may also give rise to cancer in the area that has been treated.
Surgical Removal of Acoustic Neuroma
Acoustic neuroma can also be removed via surgery. Various techniques will be used by your surgeon for its removal based on the patient's preoperative hearing status, tumor size and some additional factors. The motive of the surgery is complete tumor removal, preserving facial nerves so that it is not paralyzed and preserve hearing aid.
The tumor is removed in an anesthetic state through the inner ear or a window that has been incisioned in the skull. In some cases, the tumor may not be entirely removed if it is too close to important brain parts or any facial nerve.
If specific nerves or structures in the skull are affected, the surgery may give rise to complications which may involve worsening of symptoms. The surgical approach will be decided based on the tumor size and the associated risks will be closely linked with it as well.
Following complications may be observed in surgical removal of acoustic neuroma:
- Persistent headache
- Leakage of cerebrospinal fluid through the wound.
- Facial weakness
- Hearing loss
- Brain bleeding or stroke
- Facial numbness
- Balance problems
- Meningitis or cerebrospinal fluid infection.
- Ringing in the ear.
How to Cope with Acoustic Neuroma?
It can be quite stressful to find the treatment and deal with the loss of hearing as well as paralysis of facial muscles. The following suggestions may be quite helpful for coping with acoustic neuroma:
- Self-education about acoustic neuroma: You will be able to make a better approach towards the treatment if you try to know more about the disease. Apart from talking to your audiologist and doctor, you may speak to a social worker or counselor. You may also learn from people who have already suffered from it and this will help you in understanding the consequences better.
- Rely on a strong support system: Friends and family can help you in getting through the tough times. At times, the understanding and concern from people who are suffering from acoustic neuroma may seem comforting.
A social worker or your doctor may help you in connecting with a support group. You may also join online support groups via the Acoustic Neuroma Association.