What is an Acoustic Neuroma?
An acoustic neuroma, which may also be referred to as a vestibular schwannoma, neurinoma or neurilemmoma, is a benign (non-cancerous), usually slow-growing tumor on the eighth cranial nerve, the main nerve that connects the ear to the brain and controls hearing and balance. Acoustic neuromas grow slowly at their site of origin.
The tumor can push against the brain as it enlarges, but does not invade the brain. Larger tumors can press on the trigeminal nerve or even on the brain stem and cerebellum, threatening vital functions.
Types of Acoustic Neuroma
Two types of acoustic neuromas:
- Unilateral acoustic neuromas — Affect only one ear. This tumor accounts for approximately 8 percent of all tumors inside of the skull. Symptoms may develop at any age, but typically occur between the ages of 30 to 60.
- Bilateral acoustic neuromas — Affect both ears. Bilateral acoustic neuromas are usually associated with a rare genetic disorder, neurofibromatosis-2, and typically develop in the teens or early adulthood. Patients with neurofibromatosis-2 may develop multiple brain and spinal related tumors in addition to bilateral acoustic neuromas.
Acoustic Neuroma Symptoms
The most common first symptom of an acoustic neuroma is hearing loss in the tumor ear. Other symptoms may also include tinnitus (ringing in the ears), dizziness, paralysis of a facial nerve, headaches, and loss of balance.
Treatment for acoustic neuromas includes surgical removal, radiation, including Gamma Knife, and watchful waiting.