An acoustic neuroma is a rare, benign tumor that occurs on a nerve that connects the brain to the inner ear. It is usually a very slow-growing tumor. Although an acoustic neuroma is noncancerous and will not spread throughout the body, they can grow to become quite large. When this happens, it can damage parts of the brain. This is due to the fact that the branches in the nerve that runs from the brain to the inner ear are directly associated with your hearing and balance. If the acoustic neuroma becomes big enough, it can place significant pressure on the nerve which may result in hearing loss. It is estimated that about ten out of every one million people are diagnosed with an acoustic neuroma each year.
An acoustic neuroma may also be known as a vestibular schwannoma or a neurilemmoma. It may grow very slowly or it may not grow at all. The signs and symptoms of an acoustic neuroma are directly related to the pressure the tumor puts on the main nerve the runs from the brain to the inner ear. This pressure will also affect other nerves, parts of the brain, or blood vessels that are close by.
The signs and symptoms of an acoustic neuroma are often more significant as the tumor grows. This is not to say that symptoms won’t appear if the tumor does not grow, or will appear more significantly if the tumor does grow. The signs and symptoms of an acoustic neuroma and the size of the tumor are not correlated. If a person does experience signs and symptoms with an acoustic neuroma, they may experience signs and symptoms such as hearing loss (which is usually gradual, although some people may experience sudden hearing loss; may also only occur on one side or be more apparent on one side), ringing in the ear that is affected by the condition (also known as tinnitus), a feeling of unsteadiness or a loss of balance, a feeling of dizziness (also known as vertigo), feeling numb in the face, and in some rare cases, a feeling of weakness.
Acoustic neuromas can be difficult to identify in the early stages of the condition because the signs and symptoms may be related to other ear conditions. To test for and diagnose an acoustic neuroma, your doctor may do a hearing test called an audiometry or an MRI or CT scan. Treatments for an acoustic neuroma may include having regular MRIs to check on the growth of the tumor, having radiation to slow the growth of the tumor or kill it, or having surgery to completely remove the tumor.