An acoustic neuroma, also known as a vestibular schwannoma, is a benign growth that occurs along the 8th cranial nerve. This nerve actually consists of two separate nerves, the vestibular nerve and the cochlear nerve. The vestibular nerve controls balance, while the cochlear nerve is responsible for hearing. Acoustic neuromas usually arise from the cells of the 8th cranial nerve within the internal auditory canal. Most tumors arise on their own without any known cause. Patients with neurofibromatosis type II (NF2), a hereditary condition, may have an acoustic neuroma on both sides. Their tumors tend to be more aggressive than patients without NF2.
SYMPTOMS OF ACOUSTIC NEUROMA
The symptoms of acoustic neuroma typically include hearing loss, ringing in the ears, dizziness, balance problems, or sensation of fullness or pressure in the ears. In addition, very large tumors can sometimes cause facial numbness or paralysis of one side of the face.
TREATMENT OPTIONS FOR ACOUSTIC NEUROMA
Acoustic neuromas are occasionally discovered incidentally on an MRI. Because these tumors are benign and sometimes grow extremely slowly, observation may be the best choice if the tumor causes no symptoms. However, if it appears as though the patient will need to be treated during the patient’s normal life expectancy, it is usually best to treat the tumor while it is as small as possible. Treatment options include Microsurgical Removal and Radiosurgery.
Microsurgical removal of acoustic neuroma
Microsurgical removal is a surgical procedure involving a several hour procedure to remove the tumor in its entirety. A variety of treatment approaches can be utilized. Surgery is done under general anesthesia, and the patient usually stays in the hospital for several days postoperatively. Possible complications include hearing loss, imbalance, vomiting, decreased mental alertness due to development of a blood clot causing an obstruction to the flow of cerebrospinal fluid, cerebrospinal fluid leak, and meningitis, an infection of the linings of the brain. It is only possible to save some hearing in approximately half of the most favorable cases, even when operated by the most skilled surgeons. The chance of recurrence with complete surgical removal is very low.
Radiosurgery for acoustic neuroma
Radiosurgery is a non-invasive, radiation based treatment that presents itself as a compelling alternative to the treatment of bening and malignant tumors. It was originally used for treatment of acoustic neuromas in the late 1960’s. Since that time more than 10,000 acoustic neuroma patients have been treated with this technique worldwide. Radiosurgery with the Cyberknife System is a very accurate treatment solution for acoustic neuromas that uses high doses of radiation delivered to the tumor with sub-millimeter precision and with little harm to important surrounding sensitive structures.