What is an Acoustic Neuroma? An acoustic neuroma is a tumor of the cells surrounding the nerve that transmits balance information from the inner ear to the brain. It is not malignant; that is it does not produce cells that travel to other places in the body and start additional tumors. Nonetheless, an acoustic neuroma is a problem because it slowly grows toward the brain’s hearing, breathing, and blood pressure centers and compresses them. Untreated, acoustic neuromas can create serious neurological problems and even become life-threatening.
Normal healthy nerves are covered by a layer of cells called Schwann cells which function the same way that rubber or plastic coating on electrical wires work, providing insulation and support for nerve impulses. When these cells begin to grow and multiply at an abnormal rate, an acoustic neuroma occurs. Acoustic neuromas occur in only 1 out of 100,000 people per year and they generally happen in people who are between the ages of 30 and 60.
What Causes An Acoustic Neuroma? There are no well-defined causes for an acoustic neuroma. Some studiesperformed in the past have linked the tumor with prolonged exposure to loud noise, but this has not been confirmed. Other studies have indicated there maybe a link to radiation, but again this has not been confirmed. The vast majority of tumors are sporadic, meaning there is no genetic inheritance pattern.
What Are The Symptoms Of An Acoustic Neuroma? A symptom is something the patient senses and describes, while a sign is something other people, such as a doctor, notice. For example, drowsiness may be a symptom while dilated pupils may be a sign.
The first symptoms of an acoustic neuroma include gradual hearing loss in one ear with near normal hearing in the other ear, decrease in sound discrimination, especially when talking on the telephone and ringing in the affected ear, called tinnitus. More than 80% of patients have reported tinnitus, most often a unilateral high-pitched ringing like a steam kettle.
How Are Acoustic Neuromas Diagnosed? The gold standard for diagnosing an acoustic neuroma is an MRI scan of the brain. This is often performed with the contrast material, gadolinium, which helps to define the tumor precisely. An audiogram should be performed along with the MRI to test hearing function in both ears. Finally, some patients may undergo an auditory brainstem response test. This test measures the conduction of the electrical impulses along the nerve to the brain. A defect in conduction through this nerve may suggests the presence of a tumor.
What Are The Treatment Options? There are currently three man treatment options and physicians can choose from 1) observation; 2) surgery; or 3) radiation. Left untreated, an acoustic neuroma may cause neurological problems, including facial paralysis which can lead to blindness and brain damage severe enough to cause death. An acoustic neuroma always requires specialized and prompt treatment.
Conclusion. An acoustic neuroma is a complex medical problem requiring skilled care at all stages from diagnosis to rehabilitation. The audiologists and staff at The Hearing Professionals are not medical doctors and we do not give medical advice. We are, however, in a unique position because of the large amount of testing that we do for hearing loss and we are often the first people who will notice the possibility of a medical condition or possible acoustic neuroma.