Acoustic Neuroma (Vestibular Schwannoma): Symptoms, Diagnosis and UK Care

An acoustic neuroma, medically known as a vestibular schwannoma, is a non-cancerous (benign) and usually slow-growing tumour. It develops on the vestibular nerve, which leads from your inner ear to your brain. This nerve is responsible for both hearing and balance, which is why the symptoms of an acoustic neuroma typically affect these functions.

In the UK, it is estimated that about 1 in 1,000 people will develop an acoustic neuroma in their lifetime. They are most commonly diagnosed in adults aged 30 to 60. Because they are benign, they do not spread to other parts of the body. However, if they grow very large, they can press against the brainstem or the facial nerve, which can lead to more serious complications. NHS and NICE guidance suggest that early identification is key to managing the condition effectively through monitoring or intervention.

The symptoms of an acoustic neuroma are often subtle and can take many years to develop. Because the tumour grows slowly, the brain often compensates for the gradual loss of balance, making the early signs easy to miss or attribute to ageing.

• Hearing loss: This is the most common symptom, occurring in around 95% of patients. It is almost always unilateral (in one ear only) and occurs gradually.
• Tinnitus: This is a ringing, buzzing, or hissing sound in the ear. Like the hearing loss, this usually only affects the ear on the side of the tumour.
• Vertigo and imbalance: You may feel unsteady on your feet or experience a sensation that the room is spinning.
• Facial numbness: If the tumour grows large enough to press on the trigeminal nerve, you may notice tingling or numbness in your face.

Rare Symptoms

In very rare cases, a large tumour can cause headaches, blurred vision, or even difficulty swallowing. If you notice any persistent changes in your hearing or balance, it is important to consult a healthcare professional for an assessment.

The exact cause of most acoustic neuromas remains unknown. Most cases are 'sporadic,' meaning they occur by chance without a clear hereditary link. However, science points to a malfunction in a gene on chromosome 22 that normally helps to control the growth of Schwann cells (the cells that wrap around and support nerves).

There is one known genetic risk factor called Neurofibromatosis type 2 (NF2). This is a rare hereditary disorder that leads to the growth of tumours on the balance nerves on both sides of the head. Only about 5% of acoustic neuromas are associated with NF2. Outside of this genetic condition, there are no proven environmental risk factors—such as mobile phone use or loud noise exposure—that have been definitively linked to the development of these tumours according to current UK health research.

If you present to a GP with one-sided hearing loss or tinnitus, they will follow NICE (National Institute for Health and Care Excellence) guidelines for referral. The diagnostic process usually involves several steps:

• Hearing Test (Audiometry): This is usually the first step to confirm the level of hearing loss and determine if it is sensorineural (related to the inner ear or or nerves).
• MRI Scan: An MRI scan of the brain and internal auditory canals is the 'gold standard' for diagnosing an acoustic neuroma. It can identify tumours as small as 1 or 2 millimetres.
• CT Scan: This may be used if an MRI is not possible (for example, if a patient has a pacemaker), though it is less sensitive for very small tumours.

Once a tumour is confirmed, you will be referred to an ENT (Ear, Nose, and Throat) specialist or a neurosurgeon at a specialist skull-base clinic to discuss management options.

Not every acoustic neuroma requires immediate treatment. Because they grow so slowly, the risks of intervention may sometimes outweigh the benefits. There are three main approaches used in the UK:

1. Active Observation ('Watch and Wait')

If the tumour is small and causing few symptoms, your consultant may recommend regular MRI scans (usually once a year) to monitor its size. If the tumour shows no significant growth, treatment may never be necessary.

2. Surgery

Surgery is often considered for larger tumours or those that are growing quickly. The goal is to remove the tumour while preserving the facial nerve. It is a major operation performed under general anaesthetic, and it usually results in permanent hearing loss in the affected ear.

3. Stereotactic Radiosurgery (Gamma Knife)

This is a non-invasive treatment that uses precisely targeted beams of radiation to stop the tumour from growing. It is often preferred for smaller tumours or for patients who may not be fit for major surgery. It does not remove the tumour but aims to shrink it or keep it stable long-term.

If you are worried about persistent ear symptoms, speaking to a GP online can be a helpful first step. At OnlineDoctor24, our clinicians can discuss your symptoms in detail and help determine the next steps in your care. While an online GP cannot perform a physical hearing test, they can:

• Assess the severity of your tinnitus or hearing loss.
• Review your symptoms against NICE referral criteria.
• Provide clinical advice on the likelihood of different ENT conditions.
• Issue a private referral letter to an ENT specialist for further investigation (such as an MRI or audiometry).
• Recommend self-care strategies for managing dizziness or mild balance issues.

Our service provides a calm, evidence-based environment to address your concerns without the wait times often associated with local surgeries, ensuring you have a clear plan for your ear health.