Questions frequently asked about neurinoma

When is partial or total resection of an acoustic neuroma performed?

The goal of surgery is total removal of the tumor without complications. Regardless of the size of the acoustic neuroma, partial resection is rarely indicated. In certain situations, such as in treating disorders of the brain centers that control breathing, blood pressure, or heart function, it may be necessary to shorten the procedure. In this case, partial resection of the tumor is preferred, thus allowing the brain to restore vital functions. If there is residue from the acoustic neuroma, the tumor can grow back and cause symptoms. In this situation, a new procedure can be performed with less risk of compromising vital functions. If a partial removal is to be performed, the patient will be informed.

It is not uncommon for the first surgery to reduce the size of the tumor and separate the tumor from vital brain centers. It can be completely removed later in a second procedure. In most cases, we wait for 4 to 6 months to operate again and remove the residual acoustic neuroma. As a precaution, some cases can be observed over several years so that, if the residual acoustic neuroma begins growing again, the need for a second procedure can be reconsidered.

What are the risks and complications of acoustic neuroma surgery?

The most common treatment for acoustic neuroma is surgical removal. In general, the chance of complications is lower when the neuroma is smaller and the surgery time is shorter. As the tumor increases in size, the risk of complications also increases. The earlier it is diagnosed and removed, the less likely it is that serious complications will occur. The risk that accompanies this type of surgery is lower than the risk of letting the acoustic neuroma grow without proper treatment.

Deafness – With small tumors, it may be possible to save hearing even after resection of the acoustic neuroma. With large tumors, however, deafness may occur in the affected ear. Fortunately, hearing will remain normal in the unaffected ear.

Tinnitus – After surgery, tinnitus usually remains the same as it was before surgery. In 10% of patients, tinnitus may become more noticeable.

Taste Disorder and Dry Mouth – These are not uncommon for a few weeks after the surgical procedure, and in 5% of patients these symptoms may be prolonged.

Dizziness and Imbalance – In acoustic neuroma surgery, it is necessary to remove part or all of the vestibular nerve and, in some cases, the part of the inner ear responsible for balance. Since the tumor often damages the balance mechanism, tumor removal tends to improve symptoms of imbalance and dizziness that were present before operating. Dizziness is common after the procedure and can be significant for a few days. Dizziness and imbalance continue into the period in which the good ear learns to compensate, usually for a period of 1 to 4 months.

Some patients may notice symptoms of imbalance for several years, especially when fatigued. Occasionally, the blood supply to the part of the brain responsible for coordination (the cerebellum) is reduced by the tumor or by the resection of the acoustic neuroma itself. Difficulty coordinating the arm and leg (ataxia) may occur. This complication is extremely rare.

Facial Paralysis – Acoustic neuromas are in close contact with the facial nerve, which is responsible for closing the eye, as well as for moving the facial expression muscles. Temporary facial paralysis may occur after acoustic neuroma resection, and weakness may persist for 6 to 12 months, though few patients have permanent facial weakness. Facial paralysis can result from swelling or nerve damage. This swelling is common due to the fact that the nerve is compressed and distorted by the tumor in the internal auditory canal.

Careful tumor removal using an operating microscope and monitoring the facial nerve often results in preservation of the nerve. Stretching of the facial nerve can also result in swelling and lead to temporary facial paralysis. In these cases, facial nerve function is closely monitored over the months after the procedure. If it is certain that facial nerve function will not recover over time (just 1% to 2% of cases), a second surgery can be performed to connect the facial nerve with a nerve in the neck (hypoglossal-facial anastomosis).

In 1% to 2% of cases, the facial nerve passes through the middle of the acoustic neuroma. Also, the tumor may originate in the facial nerve itself, which is known as facial neuroma. In these situations, it is necessary to remove part or all of the nerve for tumor resection. When this is needed, the facial nerve can be immediately reattached by way of a “bridge” procedure by connecting it with another nerve in the neck that provides skin sensation.

When it is not possible to “bridge” the facial nerve, a second surgery may be performed to reanimate the face. One type is hypoglossal-facial anastomosis, connecting the nerve of the tongue with the nerve of the face. Another option is facial resuscitation surgery in which the temporal (chewing) muscle is connected to the muscles of the face to aid in movement.

Eye Care – The nerve fibers responsible for tears are closely related to the facial nerve. Facial paralysis can lead to a dry, unprotected eye. Through evaluation with an ophthalmologist it is possible to address this problem. It may be helpful to use artificial tears, and to protect the eye with tape, lubricants, and an eye patch. When facial paralysis is prolonged, the ophthalmologist may use an eye closure system, a gold weight, or contact lenses. This keeps the eye lubricated and improves comfort and appearance.

Other muscle weaknesses – In rare cases, the acoustic neuroma may be in contact with the nerves that extend to the muscles of the eye, face, mouth, and throat. These affected areas can result in double vision, or tingling in the throat, face, or tongue, shoulder weakness, voice weakness, or difficulty swallowing. Though these problems can be permanent, they are extremely rare.

Headache in the postoperative period – Soon after resection of the acoustic neuroma, that is, in the postoperative period, headache is common. In some cases, this headache can be prolonged.

Lower back pain – This pain can occur due to inflammation of the structures of the spine in the space where the nerves are located. This issue is temporary and responds well to local heat treatment and physical therapy.

Brain complications – Acoustic neuromas are located in an area close to the vital centers of the brain that control breathing, blood pressure, and heart function. As the tumor grows, it adheres to these brain centers and intertwines with blood vessels that irrigate these brain areas. Delicate surgery using an operating microscope usually allows the vital brain centers to avoid being affected. If there is a disturbance in the blood supply to these areas, serious complications such as loss of muscle control and paralysis can occur. These complications are extremely rare.

Postoperative spinal fluid leak – In acoustic neuroma surgery, temporary leakage of cerebrospinal fluid (the fluid that surrounds the brain) may occur. Before completing the surgical procedure, this leak is closed with fat removed from the abdomen. This is very rare, but occasionally this opens and a second small surgery is needed to close it properly. On average, CSF leak occurs in less than 1% of our patients.

Postoperative bleeding and brain swelling – Bleeding and brain swelling can occur after surgery. In these cases, a second procedure may be needed to reopen the incision, remove the clotted blood, and allow the brain to regain its form. This is extremely rare in our patients.

Postoperative infection – Infections occur in less than 1% of patients after surgery. This can occur in the form of meningitis, which is an infection of the fluid and tissue surrounding the brain. When this complication occurs, hospitalization can be prolonged due to the treatment that must be carried out with high doses of antibiotics.

Blood transfusion reaction – Blood transfusion may be required during surgery for acoustic neuroma, though transfusion reactions are extremely rare. In some cases, even before surgery, a bag of the patient’s own blood may be stored for future use.