Acoustic neuroma, also known as vestibular schwannoma, is a noncancerous and usually slow-growing tumor that develops on the main (vestibular) nerve leading from your inner ear to your brain. Branches of this nerve directly influence your balance and hearing, and pressure from an acoustic neuroma can cause hearing loss, ringing in your ear and unsteadiness.
Acoustic neuroma usually arises from the Schwann cells covering this nerve and grows slowly or not at all. Rarely, it may grow rapidly and become large enough to press against the brain and interfere with vital functions.
Treatments for acoustic neuroma include regular monitoring, radiation and surgical removal.
Signs and symptoms of acoustic neuroma are often subtle and may take many years to develop. They usually arise from the tumor’s effects on the hearing and balance nerves. Pressure from the tumor on adjacent nerves controlling facial muscles and sensation (facial and trigeminal nerves), nearby blood vessels, or brain structures may also cause problems.
As the tumor grows, it may be more likely to cause more noticeable or severe signs and symptoms.
Common signs and symptoms of acoustic neuroma include:
- Hearing loss, usually gradual — although in some cases sudden — and occurring on only one side or more pronounced on one side
- Ringing (tinnitus) in the affected ear
- Unsteadiness, loss of balance
- Dizziness (vertigo)
- Facial numbness and very rarely, weakness or loss of muscle movement
In rare cases, an acoustic neuroma may grow large enough to compress the brainstem and become life-threatening.
When to see your doctor
See your doctor if you notice hearing loss in one ear, ringing in your ear or trouble with your balance.
Early diagnosis of an acoustic neuroma may help keep the tumor from growing large enough to cause serious consequences, such as total hearing loss or a life-threatening buildup of fluid within your skull.