Acoustic neuromas are a type of tumor that arise from Schwann cells. Schwann cells are designed to cover and protect nerves in the body. Typically an acoustic neuroma will develop on the vestibular nerve, which runs into the ear. Acoustic neuromas, though rare, are one of the more common types of brain tumors.
Symptoms
In 90 percent of all patients, the earliest symptom is a loss of hearing in one ear, explains the Acoustic Neuroma Association. This hearing loss my occur concurrently with a ringing in the affected ear, known as tinnitus. The hearing loss usually progresses slowly, so patients often ignore it. Patients may also have a sensation of fullness in the affected ear. As the tumor continues to grow, it may affect the nerves that regulate balance, leading to unsteadiness, loss of balance and vertigo. The tumor can also press on the trigeminal nerve, leading to facial pain and tingling.
Causes
The two different kinds of acoustic neuromas are sporadic and inherited. The sporadic form, which is the most common, does not have a known cause. Some studies have linked acoustic neuromas with the use of cellular phones or prolonged exposure to loud noises, though there is not enough evidence to fully support those things as risk factors. The inherited form is due to a genetic condition known as neurofibromatosis II.
Diagnosis
One common test that is used to diagnose an acoustic neuroma is called conventional audiometry. This test measures the ability of the patient to hear a variety of sounds at different pitches and volumes. Patients with acoustic neuromas often have lost their ability to hear high-pitched sounds. Abnormal audiometry results can be followed up with more sensitive testing, such as an MRI scan. The MRI will be able to show the development of a large tumor in one ear.
Complications
If untreated, acoustic neuromas can permanently damage any nerves that are pinched by the tumor. This can lead to permanent hearing loss as well as problems with balance and facial pain. Another serious complication of an acoustic neuroma is an increase in the pressure inside the skull. This condition, known as hydrocephalus, can cause severe headaches, confusion and is ultimately fatal if not treated.
Treatment
Small acoustic neuromas that are growing slowly and not causing any symptoms may simply be monitored, the Mayo Clinic explains. Stereotactic radiosurgery can be used to destroy tumors that are causing symptoms. With this procedure, radiation is focused so that it only hits the tumor, destroying it. Traditional surgery can remove tumors that are pinching nerves in the face and ear.
