Acoustic Neuroma: Vestibular Schwannoma

An Acoustic Neuroma is a non-cancerous, usually slow growing, tumour of the VIII cranial nerve. Acoustic neuromas are one of the most common brain tumours affecting approximately 1 in 100,000 persons a year. The tumour is usually located at the base of the brain where the nerve leaves the skull and enters the bony structure of the inner ear.

As Acoustic Neuromas grow very slowly, symptoms are likely to arise after the age of thirty. The more common features are hearing loss, tinnitus and imbalance; less commonly headaches on awakening or on movement, vertigo, pain, numbness of the face or some vision difficulties are reported.

While a physical examination may identify some signs such as unilateral facial drooping, drooling or unsteadiness on walking, an acoustic neuroma is more likely to be diagnosed on a neurological assessment, taking the individual's history and performing other tests such as MRI (magnetic resonance imaging) and hearing tests. The latter may also include tests of balance (electronystagmography and calorics) and a brainstem auditory evoked response (BAER).

Removal of small acoustic neuromas aims to prevent facial paralysis but larger neuromas pressing on facial nerves can be removed but may result in some paralysis. Very large tumours compressing the brainstem can lead to hydrocephalus (build up of fluid in the brain), and a life threatening rise in intracranial pressure. In this case surgery aims to relieve the hydrocephalus and the increased intracranial pressure. Radiosurgery is also used in appropriate cases. In some very small tumours there are minimal or no symptoms; in these cases regular MRI scans may be the only checks that need to be made.

Inheritance patterns
There is a known association of acoustic neuroma with Neurofibromatosis type 2 (NF2),an autosomal dominantly inherited disorder with complete penetrance. In NF2 there is a defect in a tumour suppressor gene on chromosome 22.

Prenatal diagnosis
Not as yet.

Medical text written July 2002 by Contact a Family. Approved July 2002 by Dr R Davies, Consultant Audiological Physician, National Hospital for Neurology and Neurosurgery, London, UK.

Further Online Resources
Medical texts in The Contact a Family Directory are designed to give a short, clear description of specific conditions and rare disorders. More extensive information on this condition can be found on a range of reliable, validated web sites and links to them are included in the CD-ROM version of this Directory. Further information on these resources can be found in our Medical Information on the Internet article.

British Acoustic Neuroma Association (BANA)
Oak House
Ransom Wood Business Park
Southwell Road West
Mansfield
NG21 0HJ
Tel: 0800 652 3143
Tel: 01623 632143 
Fax: 01632 635313  
e-mail: admin@bana-uk.com
Web: http://www.bana-uk.com

The Association is a National Registered Charity No. 1024443, established in 1992. It works to support affected individuals and to promote and support research into the disorder. It also supports research into procedures assisting the rehabilitation of individuals and has a network of local groups. It publishes a quarterly magazine 'Headline News' and has information available, details on request. The Association has over 1100 members.

Group details last updated February 2008.