Vestibular schwannoma (acoustic neuroma) is a benign, usually slow-growing tumor arising from the balance nerve. One-sided hearing loss and ringing in the ear are its most common symptoms.
What is a vestibular schwannoma?
A vestibular schwannoma is a benign tumor that develops from the Schwann cells covering the balance (vestibular) portion of the eighth cranial nerve, which runs from the inner ear to the brainstem. It is also commonly known as an "acoustic neuroma".
The tumor begins in the internal auditory canal and, as it grows, can extend into the area between the brainstem and the cerebellum (the cerebellopontine angle). It is usually one-sided; tumors on both sides are associated with a genetic condition called neurofibromatosis type 2.
Symptoms
- One-sided, usually gradually progressive hearing loss
- Ringing in the ear (tinnitus)
- Imbalance and dizziness
- A feeling of fullness in the ear
- With large tumors, facial numbness, facial muscle weakness and headache
Diagnosis
Contrast-enhanced MRI of the internal auditory canals is the most valuable investigation. Audiometry is performed to determine hearing levels. Treatment decisions take into account tumor size, growth rate, hearing status and the patient's age.
Treatment Approach
- Observation: Small tumors that are not growing can be monitored with regular MRI and hearing tests, especially in older patients.
- Radiosurgery (Gamma Knife): A frequently used option for small and medium-sized vestibular schwannomas. The aim is to stop tumor growth while preserving facial nerve and hearing function as far as possible.
- Surgery: Large tumors, those compressing the brainstem or those growing rapidly are removed by microsurgery, with facial nerve function monitored during the operation (neuromonitoring).