An acoustic neuroma is a rare type of benign (non-cancerous) brain tumor that is characterized as slow-growing. It occurs when there is an overproduction of Schwann cells, which are the cells that cover and protect certain types of nerves in the brain and spine.

The overgrowth of Schwann cells can form a tumor on the cranial nerve at the point where the ear is connected to the brain. As this tumor develops, it can push against the brain and facial nerves, which may affect hearing and balance. The larger the tumor, the more problems it can cause with these and other vital bodily functions. The specialized team of caregivers at Mischer Neuroscience Institute is experienced in the diagnosis and treatment of patients with acoustic neuromas of all sizes, no matter how complex.

Types of Acoustic Neuroma

There are two types of acoustic neuromas. The most common is called a unilateral acoustic neuroma, which means it only affects one ear. While a unilateral acoustic neuroma can occur at any age, in most cases, it occurs in adults between the ages of 30 and 60.

Bilateral acoustic neuroma affects both ears and is caused by a very rare genetic (inherited) condition called neurofibromatosis-2 (NF2). This type typically develops in the teenage years and into early adulthood.

What Causes Acoustic Neuroma?

Unilateral acoustic neuroma, which is the most commonly diagnosed type, has no known cause. Although studies have been conducted to determine if there is a link between environmental factors (frequent exposure to loud noises, high doses of radiation in the head and neck area), no conclusive evidence of correlation has been discovered.

Bilateral acoustic neuroma, which affects fewer than 5% of diagnosed patients, has shown to be caused by neurofibromatosis-2. People with this genetic condition may also develop multiple brain and spine tumors in addition to bilateral acoustic neuroma.

Symptoms of Acoustic Neuroma

The symptoms of acoustic neuroma can often mimic other conditions, making it difficult to diagnose accurately at first glance in many cases. Because it develops in the inner ear, the most common symptoms involve hearing and balance difficulty and include one or more of the following symptoms:

  • Hearing loss in the tumor ear, particularly at high frequencies. Usually the hearing loss has become progressively worse
  • Feeling of fullness in the tumor ear
  • Loss of balance, feelings of unsteadiness, and sometimes dizziness or vertigo
  • Headache
  • Facial numbness or tingling on the side of the tumor ear


An accurate and early-as-possible diagnosis coupled with the appropriate treatment is important for patients suffering from an acoustic neuroma, or any other neurological condition. Although symptoms may develop gradually, the tumor can become life-threatening and affect vital functions if left untreated. Since the symptoms of acoustic neuroma are similar to other, less serious conditions, in can be difficult to diagnose early. Most patients are referred to the Brain Tumor Center by their physician after they experience worsening of the symptoms above.

The team of board-certified neurological specialists at the Brain Tumor Center at Mischer Neuroscience Institute have extensive experience and are highly trained across multiple medical specialties, including neurology, oncology and neurosurgery. Our team uses a number of methods to diagnose patients who may have an acoustic neuroma, including:

  • Hearing tests
  • Equilibrium and balance tests
  • Neurological exams of the eyes, vision, muscle strength and reflexes
  • MRI scan(s)
  • CT scan(s)


Patients who are diagnosed with acoustic neuromas are often shocked, frightened and confused about what may lie ahead. Rest assured, at the Brain Tumor Center, we are committed to providing you and your family with compassionate care and the most advanced treatments every step of the way.

Some cases may require watchful waiting, with specialists tracking the growth of the tumor over time, while other more complex cases require surgical removal and radiation. Physician leaders from across all specialties meet weekly for our Tumor Board review. Here, cases are extensively reviewed to ensure our patients benefit from the full spectrum of expertise offered from a variety of disciplines, and receive the best treatment option that is specific to their unique circumstances.

No matter what course of treatment, our dedicated neurological team is committed to providing every patient with the highest quality outcomes, delivered with care and compassion.

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