Acoustic Neuroma

Our conservative course of action is regular observation for patients who have small tumors (less than 2 cm) and who are experiencing few symptoms that are not affecting hearing or quality of life. This involves a second MRI 6 months after diagnosis, followed by annual imaging to monitor tumor size, growth, and symptoms. These tumors may appear to remain unchanged over many years but It is important to note however that hearing loss often progresses even though small tumors may not show any growth.

For larger or symptomatic tumors that require a more aggressive approach, patients may receive advanced-technology focused radiosurgery or stereotactic radiotherapy, or fractionated radiation which targets tumor tissue while sparing the surrounding areas of healthy brain. This nonsurgical treatment is typically done in an outpatient setting where radiation may be administered as a single dose or in multiple or fractionated doses.

For those who may be candidates for minimally invasive surgery, our team of experienced surgeons use keyhole and endoscopic approaches to make acoustic neuroma surgery safer, less invasive, and more effective to optimize clinical outcomes.

For tumors under 2.5 cm, either surgery or radiosurgery are reasonable treatment options. For tumors over 2.5 cm, surgical removal is generally recommended.

Treatment for acoustic neuromas by surgical removal is through a keyhole retrosigmoid craniotomy, a middle cranial fossa, or a translabyrinthine minimally invasive route using an endoscope and micro-instrumentation. The choice of approach depends upon the tumor location. Tumor adherence to critical structures dictates how much tumor can be safely removed, and in some cases, not all tumor tissue can be removed. In some patients in whom only a sub-total tumor removal is possible through neurosurgery, radiosurgery or stereotactic radiotherapy may be effectively used to control further tumor growth. Chemotherapy is generally not used for treating acoustic neuromas.

• The retrosigmoid approach to treat acoustic neuroma (also known as the retromastoid approach) uses a small window behind the ear to reach and remove the acoustic neuroma. This approach is augmented with the use of the endoscope, resulting in minimal cosmetic or soft-tissue damage and relatively quick patient recovery. In this approach the inner ear structures can remain intact to preserve hearing. Patients with functional hearing and small tumors (under 2 cm) that do not extend deep into the internal auditory canal can benefit from this approach. For patients with a history of headaches we avoid retrosigmoid surgery as there is a low risk of chronic headache with this approach.
• The middle cranial fossa surgical approach for acoustic neuroma involves a small opening above the ear for small tumors (less than 1.7 cm) that are typically confined to the internal auditory canal. This procedure aims for long-term hearing preservation in patients with functional hearing. Using this minimally invasive approach, the neuroma can be reached from above without disturbing the structures of the inner ear.
• The translabyrinthine approach for acoustic neuroma is performed through a small incision behind the ear. This treatment modality offers the most direct route and widest view of the skull base. It is the preferred approach for larger tumors (greater than 2 cm) where hearing loss has progressed or where hearing preservation is unlikely.

The benefits of minimally invasive surgery compared to open surgery are:

• Fewer headaches
• Less disruption to surrounding brain tissue
• 1-2 nights in the hospital
• Less disruption to patients’ day to day life

When surgical treatment is necessary, factors such as tumor size, the microsurgical technique used, and the use of intraoperative nerve monitoring play crucial roles in minimizing the risk of facial nerve paralysis after surgery. It is important to discuss with your physician the potential risk of facial nerve injury. It is recommended to consult with our facial nerve reconstructive surgeon to understand your options for facial nerve preservation or tumor-related facial paralysis rehabilitation.

In some patients with AN, facial paralysis may develop prior to diagnosis/treatment due to compression of the facial nerve. This can be because of the size and/or location of the tumor since the facial nerve (7th cranial nerve) and 8th cranial nerve are located very close together. If the acoustic neuroma has caused facial nerve damage resulting in facial paralysis, our facial reanimation and plastics reconstructive surgeon is also included in the treatment team. Treatment options for AN-related facial paralysis may vary and are dependent on the health of the facial nerve. We recommend a consultation with our facial reanimation expert right after surgery to create a plan to manage the paralysis.

Balance therapy is an integrated component of your care. Vestibular status is assessed before and after your procedure by physical therapists with expertise in issues related to balance and dizziness. Our vestibular rehabilitation program is composed of a series of balance training exercises that are individually tailored for each patient. These exercises promote the patient’s vestibular system to compensate for the balance disorder. Our specialists work in conjunction with the Performance Therapy department at Providence Saint John’s Health Center to provide balance therapy services to our patients.

Some acoustic neuromas can grow very large and cause major brain / brainstem compression which could affect major neurological problems over time.

Acoustic neuromas can cause hearing loss, facial numbness, pain or weakness, headaches, imbalance, swallowing difficulties and weakness.

Large acoustic neuromas are treated with surgical resection. Small acoustic neuromas can be treated with surgery or stereotactic radiosurgery, though some can be observed to see if they may grow or cause neurological deficits.

Some can cause headaches and/or facial pain.

No, acoustic neuromas don’t spread.

Acoustic neuromas are diagnosed by MRI and audiogram.

A nerve sheath tumor is treated by surgical resection (removal).

Yes, most often acoustic neuromas are benign (noncancerous).

Yes, acoustic neuroma is considered a brain tumor.

Acoustic neuromas are not cancerous.

Yes, acoustic neuroma patients are at risk for facial nerve paralysis. Factors include size of tumor, location, and growth rate. Some patients may develop facial paralysis prior to diagnosis/treatment due to compression of the facial nerve.. If the facial nerve is injured as a result of removal of the acoustic neuroma, patients may experience facial paralysis after surgery and it is essential to consult a facial reanimation expert immediately and create a plan to manage the paralysis.

Excellent when detected early and managed appropriately. Most patients enjoy good long-term outcomes and quality of life.