Acoustic neuroma

Also called Vestibular schwannoma

A slow-growing benign tumour on the hearing and balance nerve. One-sided hearing loss or tinnitus is the sign, and it needs a scan.

What it is

A benign, slow-growing tumour on the nerve carrying hearing and balance from the inner ear to the brain.

It is not cancer and it does not spread, but it grows in a confined space, and a large one presses on the brainstem, the facial nerve and the nerves supplying sensation to the face.

**The practical message is about asymmetry.** Hearing loss and tinnitus affecting one ear noticeably more than the other is the presentation, and it is frequently attributed to age, wax or noise exposure. One-sided sensorineural hearing loss warrants an MRI, and that referral is the whole of early diagnosis.

Sudden one-sided hearing loss is a separate emergency in its own right, needing assessment within days for steroid treatment.

Management is often watching with serial scans, because many grow very slowly or not at all, particularly in older people. Otherwise treatment is stereotactic radiosurgery or microsurgery, both of which carry risks to hearing and to the facial nerve.

Neurofibromatosis type 2 causes tumours on both sides, usually presenting in younger people, and is a different situation requiring specialist care. See neurofibromatosis.

Signs you might notice

Gradual hearing loss in one ear, often first noticed on the telephone.

Tinnitus in one ear.

Difficulty understanding speech in that ear, out of proportion to the measured hearing loss.

Unsteadiness or vague imbalance, rather than spinning vertigo.

Later: numbness or tingling of the face, facial weakness, difficulty swallowing, headache.

Urgent: sudden hearing loss in one ear, which needs assessment within days regardless of cause.

Also urgent: facial weakness, facial numbness, severe headache with vomiting, or worsening unsteadiness.

Any one-sided hearing loss or one-sided tinnitus should lead to audiology assessment and consideration of an MRI.

How it can affect day-to-day life

Being told there is a brain tumour, and then that nobody is going to treat it, is very hard, and watchful waiting is the correct approach for many people. Explaining the reasoning properly is the difference between reassurance and terror.

Single-sided deafness is more disabling than people expect: locating sound becomes impossible, and following conversation in noise is exhausting. Hearing solutions exist, including CROS aids and bone-anchored devices, and are frequently not offered.

Balance usually compensates well over months, because the brain adapts, and vestibular rehabilitation speeds that.

Facial nerve function is the main risk of treatment, and the trade-off between hearing preservation, facial function and tumour control should be discussed explicitly with a skull base team.

Dry eye after facial weakness is a genuine risk to sight and needs proper eye care.

Scan anxiety before each surveillance MRI is common and worth naming.

Supporting someone well

Get one-sided hearing loss or tinnitus assessed, and ask about an MRI.

Treat sudden one-sided hearing loss as urgent; steroids work best started early.

Ask about hearing solutions for single-sided deafness; they exist and are under-offered.

Ask for vestibular rehabilitation for imbalance.

Ask for referral to a skull base multidisciplinary team for treatment decisions.

Ask about the risks to facial nerve function and hearing before choosing between options.

Protect the eye carefully if there is facial weakness.

Keep surveillance scans, and ask for support with scan anxiety.

Where to get help

A GP practice for audiology referral; ENT and a skull base service for management.

Urgent ENT assessment for sudden one-sided hearing loss.

RNID for hearing support, including single-sided deafness.

Brain Tumour Charity and brainstrust support people with benign brain tumours too.