Acoustic Neuroma (Vestibular Schwannoma): Symptoms and Treatment in the UK

An acoustic neuroma, medically known as a vestibular schwannoma, is a non-cancerous (benign) brain tumour. It develops on the eighth cranial nerve, which is responsible for transmitting sound and balance information from the inner ear to the brain. Because these tumours grow from the 'Schwann cells' that insulate the nerve fibres, they are technically schwannomas.

In the UK, acoustic neuromas are relatively rare, affecting roughly 1 in 100,000 people each year. They are most commonly diagnosed in adults between the ages of 30 and 60. Unlike malignant brain tumours, an acoustic neuroma is slow-growing and does not metasatise (spread) to other organs. However, if left untreated over many years, their size can eventually put pressure on critical brain structures or other nearby nerves, such as those controlling facial movement.

Because acoustic neuromas grow very slowly, symptoms can be subtle and may develop over several years. Many patients initially attribute their symptoms to age or general congestion. The primary indicators, as noted in NHS clinical guidance, include:

• Unilateral hearing loss: This is the most common early sign, occurring in about 90% of cases. It usually affects only one ear and is gradual, though in rare cases it can be sudden.
• Tinnitus: A persistent ringing, buzzing, or hissing sound specifically in the affected ear.
• Vertigo and imbalance: You may feel unsteady on your feet or experience a sensation that the room is spinning, though severe vertigo is less common than general instability.
• Facial numbness: If the tumour grows large enough to press on the trigeminal nerve, you might experience tingling or numbness in your face.

It is important to note that having these symptoms does not automatically mean you have a tumour; many common conditions, such as earwax build-up or ear infections, present similarly.

In the vast majority of cases, the cause of an acoustic neuroma is unknown. There is no evidence currently to suggest that mobile phone use, loud noise, or lifestyle factors contribute to the development of these tumours. Clinical research in the UK usually classifies these as 'sporadic' instances.

The only confirmed risk factor is a rare genetic condition called Neurofibromatosis type 2 (NF2). People with NF2 often develop acoustic neuromas on both sides (bilateral tumours). NF2 is an inherited condition usually diagnosed in young adulthood. If you have a family history of NF2 and notice hearing changes, early medical screening is essential.

If you present to a GP with one-sided hearing loss or persistent tinnitus, they will follow clinical pathways aligned with NICE (National Institute for Health and Care Excellence) guidelines. The diagnostic process typically follows these stages:

1. Initial Hearing Test (Audiology)

An audiogram is used to measure how well you hear different pitches and volumes. If the test shows significant 'sensorineural' hearing loss in one ear compared to the other, further investigation is required.

2. MRI Scan

An MRI scan of the brain and internal auditory canals is the 'gold standard' for diagnosing an acoustic neuroma. It can detect even very small tumours (a few millimetres in size). In some cases where an MRI is not possible, a CT scan with contrast may be used.

3. Specialist Referral

Following a diagnosis, you will be referred to an ENT (Ear, Nose, and Throat) specialist or a neurosurgeon who specialises in skull-base tumours to discuss management options.

Treatment in the UK is tailored to the individual, taking into account the size of the tumour, the rate of growth, your age, and your overall health. There are three main strategies:

• Active Monitoring (Watch and Wait): Small tumours that aren't causing significant symptoms may simply be monitored with annual MRI scans. Many of these tumours grow so slowly that treatment is never actually necessary during the patient's lifetime.
• Stereotactic Radiosurgery (Gamma Knife): This is a non-invasive treatment that uses precise beams of radiation to stop the tumour from growing. It is often used for small to medium-sized tumours.
• Neurosurgery: Surgery might be recommended if the tumour is large, growing rapidly, or causing severe symptoms. The goal is to remove as much of the tumour as possible while preserving facial nerve function.

If you are experiencing new or persistent hearing changes, speaking to an online GP can be an excellent first step. While an online doctor cannot perform an MRI or a physical hearing test, they can provide a clinical review of your symptoms and history. During a consultation, a GP can:

• Discuss the nature of your tinnitus or hearing loss to determine if it requires urgent referral.
• Review whether your symptoms might be caused by more common conditions like Eustachian tube dysfunction or infection.
• Provide clinical advice on the next steps for seeking an audiometry test or an ENT referral via the NHS or private pathways.
• Offer guidance on managing the anxiety associated with new vestibular or neurological symptoms.

Seeking an expert opinion early ensures that potential issues are identified promptly, giving you peace of mind and a clear plan for investigation.