Acoustic Neuroma (Vestibular Schwannoma)
An acoustic neuroma, more accurately termed a vestibular schwannoma, is a benign tumour arising from the Schwann cells of the vestibular nerve.
What is an Acoustic Neuroma?
An acoustic neuroma, more accurately termed a vestibular schwannoma, is a benign tumour arising from the Schwann cells of the vestibular nerve. It is one of the two branches of the vestibulocochlear nerve responsible for hearing and balance. This nerve runs from the inner ear to the brain, and the tumour typically develops in a narrow bony canal, called the internal auditory canal, or in the space where this nerve meets the brainstem and cerebellum, the cerebellopontine angle (CPA).
Acoustic neuromas are the most common type of tumour found in this part of the brain. They usually grow slowly, are not cancerous and typically occur on one side. Bilateral acoustic neuromas are characteristic of a genetic condition, neurofibromatosis type 2 (NF2). Treatment options include observation, microsurgical resection, and stereotactic radiosurgery. The best option depends on the size of the tumour, symptoms, age, and personal preferences.
At One Brain and Spine, our Melbourne neurosurgeons work closely with otolaryngologists (ENT surgeons) and radiation oncologists in a multidisciplinary skull base team to provide optimal, individualised care.
What Causes Acoustic Neuromas?
Most acoustic neuromas develop without any known cause. A small number are linked to:
- Neurofibromatosis type 2 (NF2) – a genetic condition that causes tumours to grow on the hearing nerves on both sides, as well as other types of tumours. This accounts for only a small proportion of cases.
- Previous radiation to the head – a rare and uncommon risk factor.
Symptoms of an Acoustic Neuroma
Symptoms happen because the tumour presses on the hearing and balance nerve, and as it grows larger, on nearby nerves and brain structures. Symptoms usually develop gradually, over months to years.
Hearing Loss
Loss of hearing in one ear is the most common first symptom, affecting the majority of patients. It can be subtle at first and easily mistaken for normal age-related hearing loss. Sudden unilateral hearing loss warrants urgent MRI to exclude an acoustic neuroma.
Tinnitus
Many patients notice ringing or buzzing in one ear (tinnitus), and this is often the very first symptom they notice. It's usually a constant, high-pitched sound.
Balance Disturbance
Feeling unsteady, off-balance, or occasionally dizzy is common. Acute severe vertigo (similar to Meniere's disease) is less typical.
Facial Symptoms – Numbness and Weakness
As the tumour grows, it can press on nearby nerves, causing numbness or tingling in the face, and in more advanced cases, facial weakness.
Brainstem and Cerebellar Compression
Large tumours can compress the brainstem and cerebellum, causing significant gait disturbance, headache from raised intracranial pressure, and, rarely, hydrocephalus.
How is an Acoustic Neuroma Diagnosed?
- MRI brain with contrast – this is the key test for diagnosing an acoustic neuroma. It can pick up even very small tumours.
- Audiogram (hearing test) – documents the pattern and degree of hearing loss. This will typically show asymmetric sensorineural hearing loss.
Treatment Options for Acoustic Neuroma
Observation
Small, incidentally discovered acoustic neuromas, particularly in older patients or those with limited symptoms, may be safely managed with surveillance. This would typically involve MRI monitoring every 6–12 months. Many small acoustic neuromas grow very slowly or not at all. Intervention is recommended if there is documented growth or worsening symptoms.
Stereotactic Radiosurgery (SRS)
SRS is an excellent treatment for small to medium sized acoustic neuromas. It uses precisely focused radiation to stop the tumour from growing and is successful in most cases. It often preserves hearing better than surgery and avoids the risks of an operation. It doesn't remove the tumour but stops it from growing further. This is often the preferred option for smaller tumours, especially for older patients or those wanting to protect their remaining hearing.
Microsurgical Resection
Surgery is recommended for large tumours causing brainstem compression or hydrocephalus, rapidly growing tumours, cystic tumours not suitable for SRS, and in younger patients with large tumours. Surgical approaches are used depending on tumour size, tumour morphology / location, hearing status, and surgeon preference.
- Retrosigmoid (suboccipital) approach – allows hearing preservation in selected patients
- Translabyrinthine approach – sacrifices hearing but provides excellent facial nerve exposure.
- Middle fossa approach – uncommon approach. Used for small intracanalicular tumours.
Frequently Asked Questions — Acoustic Neuroma Melbourne
Will I go deaf if I have an acoustic neuroma?
Not necessarily. Many patients already have significant hearing loss at diagnosis. Even if hearing is lost in the affected ear, most people adapt well over time, and hearing aids or specialised hearing devices can help.
Will an acoustic neuroma affect my facial nerve?
For most patients with small to medium-sized tumours, facial nerve function is well preserved, whether treated with surgery or radiation. Protecting the facial nerve is always a key goal of treatment at One Brain and Spine.
Do all acoustic neuromas need treatment?
No. Small tumours that are stable or growing very slowly, especially in older patients, can often be safely monitored with regular MRI scans rather than treated straight away. Treatment is usually recommended if the tumour is growing, symptoms are getting worse, or it's pressing on important structures.
What is the difference between Gamma Knife and surgery for an acoustic neuroma?
Gamma Knife is a form of stereotactic radiosurgery, which uses targeted radiation to treat tumours and controls tumour growth in most small to medium tumours without surgery. In appropriately selected cases it preserves facial nerve function and hearing better than surgery. Surgery removes the tumour directly. It is preferred treatment in larger tumours, younger patients, or those not suitable for radiosurgery. Your neurosurgeon will discuss which approach is most appropriate for your situation.
Why Choose One Brain and Spine for Acoustic Neuroma in Melbourne?
One Brain and Spine is a specialist neurosurgical group practice in Melbourne, bringing together extensive expertise in brain, spinal, and peripheral nerve surgery. Our team has particular strength in neuro-oncology surgery, delivering multidisciplinary care using the latest technology available in Australia. We are committed to providing comprehensive, patient-focused treatment through:
- Specialist neuro-oncology neurosurgeons – internationally fellowship-trained with subspecialty cranial surgery expertise
- Advanced technology – including intraoperative navigation, neuromonitoring, and state-of-the-art microsurgical techniques
- Multidisciplinary care – close collaboration with otolaryngologists (ENT surgeons) and radiation oncologists to ensure optimal outcomes
- Patient-centred approach – compassionate care with clear explanations of your diagnosis and all available treatment options
- All major health funds accepted