Acoustic Neuroma
Table of Contents
What is Acoustic Neuroma?
An acoustic neuroma (also called a vestibular schwannoma) is a benign, slow-growing tumor that grows off the eighth cranial nerve, called the vestibulocochlear nerve. The eighth cranial nerves (one on the right and one on the left) are your hearing and balance nerves, which often explains the symptoms people develop as these tumors grow. Acoustic neuromas are noncancerous tumors so they do not spread or metastasize to other parts of the body.
Because acoustic neuromas can grow slowly, they can stretch or press on any structures in their neighborhood including the balance nerves, hearing nerve and the nerve that moves the muscles of the face (the facial nerve). If an acoustic neuroma grows beyond an inch, it can push on the brainstem. The trigeminal nerve (responsible for feeling the face) and other cranial nerves can then cause symptoms.
In addition, because these tumors are located along the nerves that travel from the ear to the brain, they tend to be found in the inner ear canal, they can damage the function of the middle and inner ear.
How Does Acoustic Neuroma Develop?
Acoustic neuromas arise from special cells called Schwann cells, which surround and insulate the vestibulocochlear nerve. They typically grow slowly and do not spread to other body areas, but they can lead to acoustic neuroma symptoms by pressing on the nerves or surrounding tissues in the area.
Most of the time, patients complain of hearing loss that affects only one ear. People often don’t even notice an issue for years due to the slow-growing nature of these tumors. Due to the hearing issues, many patients will seek out the help of a hearing specialist such as an ENT doctor first. Less commonly, people will complain of balance problems that also develop very slowly, if at all. Because acoustic neuromas grow slowly, doctors typically diagnose them in patients between 30 and 60 years old. Unless the tumor is quite large, it’s seldom life-threatening.
Most patients will only have one nerve affected (the cranial nerves are paired, one on each side of the body), but some patients with a rare condition called Neurofibromatosis Type 2 may have tumors on both sides, which affects both ears. The cause of most acoustic neuroma cases is unknown but could be related to an issue with a gene on chromosome 22.
What Are the Symptoms of Acoustic Neuroma?
Acoustic neuroma symptoms can be mild, so many patients ignore them until they become obvious. Possible symptoms from a growing acoustic neuroma can include:
- Hearing loss and/or ringing one ear
- Vertigo
- Balance issues and difficulty walking
- Facial numbness and weakness
- Hydrocephalus (a buildup of fluid in the brain)
How Acoustic Neuroma is Diagnosed
Depending on a patient’s symptoms, a doctor will often examine the patient’s ear and perform a hearing test. If these examinations demonstrate loss of hearing on one side, most doctors will order either a CT scan or a magnetic resonance scan (MRI) of the brain with contrast, to see if there is anything visible around the hearing nerve.
Acoustic Neuroma Treatment
Acoustic neuroma treatment is usually elective. This means patients typically have time to learn about their options and seek second opinions before making a decision.
To recommend the best approach, an experienced brain surgeon carefully reviews all test results and imaging. Key factors considered include:
Age, current medications, overall health, and personal goals
Hearing test results
High-resolution MRI findings, including tumor size, location, and growth over time
Current symptoms and how they are changing
After reviewing these factors, you and your doctor will discuss the most appropriate acoustic neuroma treatment options. These may include:
Gamma Knife Treatment (Stereotactic Radiosurgery)
Gamma Knife uses 192 small beams of radiation to treat the tumor with no incisions or hospital stay. Gamma Knife is typically recommended for tumors less than 2.5 cm that are not causing significant pressure on the brainstem. This option is a game-changer for patients who wish to resume normal life quickly following an acoustic neuroma diagnosis.
Traditional Acoustic Neuroma Surgery
Traditional surgery is an excellent treatment option when reducing the size of the acoustic neuroma is absolutely necessary. For younger patients with larger tumors, traditional surgery may be the preferred option. Gamma Knife treatment can treat the remaining fragments in cases where a small amount of tumor needs to be left behind.
Conservative “Watchful Waiting” Approach
It’s very important to mention that not every patient will require acoustic neuroma treatment (for example, those who have small, asymptomatic tumors). Doctors will instead monitor these patients for tumor growth on a structured follow-up schedule. If, over time, a smaller acoustic neuroma grows, then Gamma Knife is a great option at some point “down the road.”
Not Sure Which Acoustic Neuroma Treatment Is Right for You?
A consultation with the team at Valley's Gamma Knife Center can help you understand your options and feel more confident about your next steps. Call us at 201-634-5610 to schedule an appointment today.
Schedule an AppointmentAuthors:
William Cobb, MD, PhD, FAANS
Dr. William Cobb is a board-certified neurosurgeon that specializes in Neurosurgery, Neuro-Oncology, brain and spine tumor treatment, as well as Gamma Knife Radiosurgery. He is the Director of Neurosurgical Oncology at The Valley Hospital. Dr. Cobb is experienced in treating patients with many types of brain tumors, as well as trigeminal neuralgia and brain metasteses.
Rupa G. Juthani, MD
Dr. Rupa Juthani is a board-certified neurosurgeon that specializes in endoscopic pituitary and skull base surgery, brain tumor treatment, trigeminal neuralgia, Gamma Knife Radiosurgery, and more. She is the Sub-Specialty Medical Director of Endoscopic Skull Based Surgery at The Valley Hospital. Dr. Juthani is experienced in treating patients with various brain tumors, trigeminal neuralgia, acoustic neuroma, and more.
Get Your Questions Answered, By a Real Person.
Our Patient Liaisons are here to help you understand your next step. After discussing your specific case, they can help you navigate your medical records, answer insurance questions, and connect you with one of our nurses, at no charge to you.
For your convenience and safety, we offer both virtual and in-person consultations. Reach out today (201) 634-5610.
