They are also known as acoustic neuroma. It is a benign tumor that affects the nerves from the inner ear to the brain.
It prevents the nerves responsible for hearing and balance from functioning correctly, which causes hearing loss and tinnitus (ringing in the ears).
In later stages, the acoustic neuroma can affect the nerves of the cerebellum and brainstem and can increase pressure in the brain, which can be life-threatening. Acoustic neuroma is also known as acoustic neurinoma, vestibular schwannoma, and auditory tumor.
A layer of cells, called Schwann cells, covers almost all healthy nerves. Schwann cells provide isolation and support for nerve impulses; an acoustic neuroma occurs if they start multiplying too fast.
Treatment options include:
Stereotactic radiosurgery: the doctor can accurately deliver the radiation to the tumor without cutting the patient. A light head frame is attached to the patient’s scalp, desensitized.
The tumor is precisely localized with the help of image scans: the scans help determine exactly where to apply radiation beams. The patient may experience neck stiffness and nausea.
Microsurgical removal involves removing a tumor through an incision in the skull. It is carried out under general anesthesia. In approximately 95 percent of cases, surgery controls cancer.
If the tumor is tiny and the nerve damage is minimal, it can save hearing and improve symptoms. Rarely are parts of cancer that may be left behind if the surgeon thinks there may be a risk of nerve damage. If this is the case, radiation therapy can be used to terminate them.
Radiation therapy: Radiation therapy can be used instead of conventional surgery to reduce the size or limit tumor growth. It is sometimes used after surgery to remove any remaining signs of cancer. The radiation is carefully directed to minimize damage to the tumor’s healthy tissue.
Radiosurgery: this type of treatment delivers radiation directly to the tumor. Imaging scans are used to locate the tumor. A frame is attached to the patient’s scalp to achieve this treatment, which can cause stiffness or nausea.
Monitoring and MRI: As many acoustic neuromas do not grow, continuous monitoring may mean no treatment is required. In this case, MRI (magnetic resonance) scans can determine the growth of the tumor.
After surgery, a doctor will monitor the patient’s recovery and control the recurrence of symptoms.
Potential for hearing loss
Some patients have a permanent degree of hearing loss after surgery. This usually depends on the size of the tumor. The risk is greater if the cancer is more than 1.5 centimeters wide.
If a patient has neurofibromatosis type 2 and if the tumors have developed in both acoustic nerves, the patient may not be able to hear with both ears after the surgery.
Causes of acoustic neuroma
- Genealogical chart
- Family history and genealogy are significant risk factors for acoustic neuroma.
- The exact cause of the acoustic neuroma is unclear. According to the American Hearing Research Foundation, about 95 percent of cases are sporadic, with no known reason.
The risk factors seem to include
Age: most people develop acoustic neuroma between 30 and 60 years.
Family history of neurofibromatosis type 2: about 5 percent of people with acoustic neuroma have neurofibromatosis type 2 (NF-2), in which a person develops acoustic neuromas in both auditory nerves.
Exposure to radiation: there is a slight possibility that exposure to low doses of radiation to the head and neck during childhood may increase the risk
In this case, doctors prefer to delay surgery as long as possible.
Symptoms of acoustic neuroma
Symptoms of acoustic neuroma commonly include hearing loss.
The location of the tumor in the inner ear means that there are various potential symptoms. These include:
Hearing loss: One of the first symptoms of an acoustic neuroma is the gradual loss of hearing in one ear, while the hearing in the other is still expected. Unilateral hearing loss occurs in 90 percent of patients with this condition.
Tinnitus: more than 80 percent of patients will also have tinnitus or tinnitus in the affected ear.
Earache: there may be an earache in some cases.
Dizziness, loss of balance, and vertigo: the person can experience these symptoms if the tumor is affected in the inner ear.
Loss of sensitivity: The local cranial nerves may be affected if a large tumor develops and compresses a part of the brainstem. The trigeminal nerve can be affected, leading to loss of sensation on one side of the face and mouth. The posterior half of the tongue may lose its sense of taste.
Headaches: larger tumors can increase pressure in the brain, causing headaches, vomiting, and altered consciousness.
Vision problems: in exceptional cases, vision problems occasionally occur.