An acoustic neuroma is a benign tumor of the cranial nerve that connects the inner ear and the brain. Though noncancerous and typically slow growing, it can affect both hearing and balance, and may cause hearing loss, tinnitus and dizziness. In rare cases, tumors may become large enough to press against the brain, interfering with vital processes and even leading to death.
A small percentage of acoustic neuromas are the result of an inherited disorder called neurofibromatosis type II (NF2), associated with a malfunctioning gene on chromosome 22. This genetic disorder often causes benign tumors to develop on the balance nerves on both sides of the head. More often than not, acoustic neuromas are classified as sporadic, meaning their exact cause is unknown. There is some evidence of a connection between exposure to low-dose radiation of the head and neck during childhood, and the development of acoustic neuromas.
There are no known risk factors for acoustic neuromas other than having a parent with NF2. If this is the case, children have a 50% chance of inheriting the condition themselves.
Acoustic neuromas, sometimes called vestibular schwannomas, usually grow very slowly (or not at all). Because of this, symptoms early on are often difficult to spot. Patients may notice gradual hearing loss that is sometimes accompanied by tinnitus. If the tumor continues to grow, additional symptoms are likely to develop. These include dizziness and vertigo, facial numbness and weakness, a tingling sensation in the face, changes in taste, hoarseness, difficulty swallowing, headaches and confusion. Early diagnosis and treatment can help prevent more serious symptoms.
The patient’s otolaryngologist can diagnose an acoustic neuroma primarily through a review of their symptoms in conjunction with a hearing test and imaging scans (CT or MRI). Because growth of the tumor is usually very slow, many times the patient’s doctor will simply want to monitor the tumor’s progress over time, especially when few symptoms are present. Regular imaging tests every six to 12 months can track any growth.
Surgery may be an option for tumors that are growing or causing symptoms. Gamma Knife radiosurgery delivers radiation without the need for an incision, but results can take a long time. More invasive surgery may be required, especially if the tumor is growing close to the brain or facial nerve.
Call Southern Utah Ear, Nose, Throat, Allergy, and Facial Plastics at (435) 628-3334 for more information or to schedule an appointment.