What is an Acoustic Neuroma?
An acoustic neuroma (sometimes termed a vestibular schwannoma or neurolemmoma) is a benign tissue growth that arises on the eighth cranial nerve leading from the brain to the inner ear. This nerve has two distinct parts - sound and balance. Acoustic neuromas usually grow slowly over a period of years. They expand in size at their site of origin and when large can displace normal brain tissue.
Is the cause known?
No. However, many theories exist. Acoustic Neuromas can result from a genetic abnormality - a spontantias mutation on Chromosome 22.
What is the incidence?
Recent publications suggest that the incidence of acoustic neuromas is rising. This is because of advances in MRI scanning both on incidental scans and for patients experiencing symptoms. Studies in Denmark published in 2004 show the incidence is 17.4 per million or close to 2 persons per 100,000. Most acoustic neuromas are diagnosed in patients between the ages of 30 and 60.
What are the symptoms?
Early symptoms are often overlooked. The first symptom in 90% of cases is hearing loss in one ear, often accompanied by unilateral tinnitus. The loss of hearing is usually subtle and worsens slowly, although occasionally a sudden loss of hearing is noted. There may be a feeling of fullness in the affected ear. These early symptoms are sometimes mistaken for normal changes of ageing.
How do Audiologists detect Acoustic Neuromas?
Key indicators we look for during a hearing assessment are:
- Asymmetrical hearing loss
- Unilateral tinnitus
- Poor word recognition scores compared to degree of sensorineural hearing loss
- Perceived distortion of sounds when peripheral hearing is normal
What is the treatment for Acoustic Neuromas?
Should a hearing evaluation result in one or more of the above indicators, generally an MRI scan and further investigations by an ENT surgeon are recommended. Once diagnosed, the treatment options are broadly:
- Observation - watch, wait & re-scan
- Microsurgical tumour removal
- Radiation - radiosurgery or radiotherapy
The treatment choice largely depends on the size, shape and position of the tumour.
The information on this website is not intended to be a substitute for professional clinical advice. Diagnosis and treatment of a clinical condition can only be undertaken by a qualified health professional.