Averting Acoustic Neuroma

You are experiencing ringing in your left ear. You feel dizzy and off-balance. You have recurring bouts of vertigo. You could have acoustic neuroma.

An acoustic neuroma, or more accurately called a vestibular schwannoma, is a benign, slow-progressing tumor that develops on the main nerve that controls balance and hearing which runs from the inner ear to brain. It is a very uncommon condition, but an acoustic neuroma can progress so quickly that it crushes the brainstem and can be fatal.

An acoustic neuroma grows on the cochleo-vestibular nerve (the eighth cranial nerve). This nerve allows a person to hear and is joined to the balance center inside the ear. It carries sound and balance information from the ear to the brain. For that reason, the main signs of an acoustic neuroma are hearing loss and tinnitus (ringing in the ears).

Most people with acoustic neuroma suffer from hearing loss when they have formal tests of their hearing. However, many of these people haven’t sighted the loss.

The tumor is usually assessed with imaging, such as an MRI that is often executed because a patient noted hearing loss in one ear. With improvements in technology and imaging availability, tumors are being diagnosed when they are smaller and causing fewer, if any, symptoms.

Increasingly, acoustic neuromas are being identified as incidental findings when people have an MRI for unrelated reasons, such as chronic headache, multiple sclerosis or even during surveillance imaging for another unrelated tumor.

Most acoustic neuromas grow slowly, although the growth rate fluctuates for each person and may vary from year to year. Some acoustic neuromas stop growing, and a few even spontaneously get smaller. The tumor does not invade the brain, but it may push against it as it gets larger.

Symptoms of an acoustic neuroma typically include loss of hearing in one ear; ringing in the ear or tinnitus and wobbliness while walking. Occasionally, facial numbness or tingling may occur.

A tumor can forestall the normal flow of fluid between your brain and spinal cord, so that fluid builds up in your head. This condition is called hydrocephalus.

Treatment varies depending on the size and growth of the acoustic neuroma, symptoms and your personal preferences.

The three most common treatment options are as follows.

If you have a small acoustic neuroma that isn’t growing or is growing slowly and causes few or no signs or symptoms, your health care professional may decide to watch it. Recent studies indicate that more than half of small tumors don’t grow after initial diagnosis, and a small percentage even shrink. Observation involves regular imaging and hearing tests, usually every six to 12 months at first.

Stereotactic radiosurgery may be used if the acoustic neuroma is growing, with the goal of preventing further tumor growth. With stereotactic radiosurgery, a highly precise single dose of radiation is delivered to the tumor. The procedure’s success rate at stopping tumor growth is usually greater than 90 percent.

The final option is open surgery. Surgical elimination typically is recommended when the tumor is large or growing rapidly. This is a complex procedure, often performed by a team of at least two surgeons. Surgery seeks to get rid of as much of the tumor as possible, while preserving the function of important nearby nerves and brain structures. Surgery risks include damage to the facial nerve.

Research in peripheral nerve tumors is ongoing in general. But, based on long-term data, there appears to be little difference in results no matter which treatment is chosen for smaller tumors. Talk with your health care team to make sure you are being watched appropriately for your situation.