Vestibular Schwannoma

Vestibular Schwannoma is a benign tumor of the inner ear. It grows very slowly and develops from the nerves that contribute to hearing and balance. There are estimated between 13 and 20 annual cases per million. This tumor is a result of an overproduction of Schwann cells that wrap around nerve fibers. While these cells grow, it pushes and adds pressure to these nerves. It may cause unilateral or bilateral hearing loss or ringing in one's ears, dizziness, or a loss of balance. Some symptoms of Vestibular Schwannoma are facial drooping on one side, unsteady walk, or a dilated pupil on one side. If the tumor goes untreated, it may grow large enough to put pressure on the facial nerve and cause numbness in one side or both of the face. It is a tumor that connects the ear to the brain. If it continues to grow even more, the tumor may press against the brain and could potentially become life threatening.

Early detection of Vestibular Schwannoma may be difficult due to subtle symptoms that the person may not realize. MRI with contrast is the best way to visualize this pathology but CT may also be used.

Unilateral Vestibular Schwannoma accounts for about 8% of all skull tumors. Symptoms may occur at any age but they usually appear anywhere from 30 to 60 years old. Bilateral Vestibular Schwannoma affects both hearing nerves and may be associated with a genetic disorder called Neurobibromatosis Type 2. Some scientists believe that unilateral and bilateral Vestibular Schwannoma comes from a loss of function of the gene on chromosome 22. This has an affect on the production of Schwann cells.

Treatment may be, but not limited to, surgical removal, radiation, and monitoring. The majority of cases where patients have Vestibular Schwannoma, the tumor is surgically removed. Sometimes, the growth is growing over the nerve and the nerve will have to be removed as well. This can make symptoms worse and a patient will not be able to recover from this. Radiation may be used to reduce the size and growth if the tumor to prevent it from getting bigger and causing further complications. The last is monitoring. Sometimes the growth is not worth removing if it is not causing harmful symptoms to the patient. At this point, they monitor the growth to see if it is progressively getting worse.

National Institute on Deafness and Other Communication Disorders (June, 2010) Vestibular schwannoma (acoustic neuroma) & neurofibromatosis. Retrieved from http://nidcd.nih.gov/health/hearing/acoustic_neuroma.html