An acoustic neuroma — also known as vestibular schwannoma or neurilemmoma — is a noncancerous (benign) tumor on the eighth cranial nerve, the vestibulocochlear nerve. This nerve leads from the brainstem to the ear and is involved in hearing and maintaining balance.
The more precise term for this tumor is “vestibular schwannoma,” because it involves the vestibular portion of the nerve, not the acoustic (cochlear) portion, and it arises from Schwann cells rather than from neurons.
Acoustic neuromas are usually solitary tumors that grow slowly over a period of years, expanding in size at their site of origin.
The earliest symptoms of an acoustic neuroma include gradual hearing loss and ringing in the affected ear. Balance problems often arise as the tumor grows.
Larger tumors that compress the adjacent brainstem may affect other local cranial nerves, leading to facial weakness, numbness and tingling, and impaired sensation in the face and mouth on the involved side.
Depending on the exact location of the acoustic neuroma, the UPMC Acoustic Neuroma Center offers several microsurgical approaches, endoscopic assisted approaches, as well as Gamma Knife® radiosurgery.
The cause of most acoustic neuromas is not known. In a minority of cases, acoustic neuroma may be caused by a rare genetic disorder, called neurofibromatosis type 2, which produces benign tumors of the nervous system.
There are no known risk factors for acoustic neuroma.
Acoustic neuroma symptoms may include:
Larger acoustic neuromas may compress the adjacent brainstem and affect other local cranial nerves. This can result in patients experiencing the following symptoms:
Doctors use MRI or CT scans to diagnose and confirm the presence of an acoustic neuroma.
Other diagnostic tests may include:
The UPMC Acoustic Neuroma Center offers a wide array of treatment options for acoustic neuromas. Our multidisciplinary team of neurosurgeons and neurotologists works together to offer each patient a personalized treatment plan. Treatment for acoustic neuroma depends on your age and general health, as well as the tumor's size, location, and rate of growth.
If the tumor is very small and you have no serious symptoms, the doctor may decide simply to monitor its growth. This conservative route is common among people over age 70.If the patient is experiencing more serious symptoms, surgery may be recommended by the doctor.
As the acoustic neuroma grows, or if hearing becomes impaired, removal of all or part of the tumor may be necessary.
The surgical approach depends on the size and location of the tumor.
Microsurgical approaches for acoustic neuromas, all available at the UPMC Acoustic Neuroma Center, include:
In all cases, we perform neurophysiological monitoring of cranial nerves, especially the seventh cranial nerve (facial nerve).
The experts at the UPMC Acoustic Neuroma Center may recommend a combination of surgical and non-surgical treatments to treat your acoustic neuroma. Our goal is to maximize the benefits of surgery, while minimizing risks.
Gamma Knife radiosurgery is a painless procedure that uses hundreds of highly focused radiation beams to target tumors and lesions within the brain, with no surgical incision.
Gamma Knife may be the first treatment option for an acoustic neuroma, particularly in cases where the tumor is not causing mass effect.
Gamma Knife may be used as an additional treatment after partial surgical removal for large acoustic neuromas. UPMC doctors use this treatment to prevent further growth of the tumor and maintain current neurological and hearing functions.
As the nation's leading provider of Gamma Knife procedures, UPMC has treated more than 15,000 patients with brain tumors, vascular malformations, pain, and other functional problems.
Case Study: Trigeminal Schwannoma
Read how UPMC surgeons were able to treat a trigeminal schwannoma using several techniques, including EEA.