An acoustic neuroma – also known as a vestibular schwannoma – is a slow-growing, benign tumor located on the vestibular cochlear nerve, which is the nerve that connects the ear to the brain. The vestibular cochlear nerve is located behind the ear, right under the brain.
It can present with hearing loss, especially difficulty understanding words, but patients can also have normal hearing. Even though it is a growth on the balance nerve, patients rarely complain of dizziness or imbalance until the tumor becomes very large. It is often discovered on routine head MRI scans.
Acoustic neuroma tumors are classified as small, medium, and large. Treatment is personalized based on tumor size, hearing status, and patient age and health status. Treatment options include observation with serial MRI scans and hearing tests, radiation (stereotactic, gamma knife, or radiosurgery), and skull base microsurgery.
Because these tumors are very slow-growing overall but have unpredictable growth rates in the particular instance, it is prudent that, if the patient and physician opt for radiation, the tumor is observed initially with serial MRI scans. Radiation can be instituted if the tumor demonstrates growth. This is because radiation halts tumor growth and does not remove the tumor, and radiation has significant potential side effects, including hearing loss, facial weakness, dizziness, etc.
Acoustic neuroma surgery options include suboccipital craniectomy, middle fossa craniectomy, and translabyrinthine craniectomy for tumor removal. Surgical removal is geared toward total tumor removal with preservation of facial nerve function and hearing preservation where possible. Acoustic neuroma surgery is performed with complete real-time cranial nerve monitoring including hearing nerve and facial nerve monitoring.