Spina bifida is a neural tube defect and is a developmental anomaly which occurs very early in pregnancy. The neural tube develops to form the spinal cord, brain and spine. When Spina Bifida occurs, the tube is split and one or more vertebrae (small bones of the back) fail to form properly, thus leaving a gap.

There are three main types of spina bifida.

Spina bifida occulta where the only sign of the malformation is a dimple or hair at the site of the defect on the skin of the back. This condition is very mild and is usually symptomless although occasionally there may be continence problems and difficulties with mobility.

In Spina bifida cystica a sac or cyst is visible on the back covered by a thin layer of skin. There are two forms: a meningocele and a myelomeningocele. In a meningocele the sac contains tissues which cover the spinal cord and cerebro-spinal fluid. The nerves are not normally badly damaged and there is little or no malfunction. This is the least common form of spina bifida. Myelomeningocele is the most common and severest form and is characterised by the inclusion in the sac of nerves and part of the spinal cord as well as tissue and cerebral-spinal fluid. Some degree of paralysis and loss of sensation occur below the site of the defect. The extent of the disability is dependent upon the extent of nerve damage.

Cranium bifida is a failure of development of the bones of the skull. In this form the sac is called an encephalocele. In some cases part of the brain is also enclosed in the sac while in others it contains only tissue and cerebro-spinal fluid. Anencephaly (absent brain) and iniencephaly (badly malformed brain) may also occur and in such cases the child will not survive.

Hydrocephalus is caused by an imbalance between the production and absorption of cerebro-spinal fluid in the brain. About eighty per cent of people with Spina Bifida have Hydrocephalus.

Inheritance patterns
Spina bifida has some genetic predisposition. Where a couple have an affected child there is a 1 in 25 chance of an affected pregnancy. For an affected person the risk of an affected child is 1 in 25.

Prenatal diagnosis
A raised alpha-feto protein blood test at sixteen weeks can indicate the presence of a neural tube defect. Amniocentesis at sixteen to eighteen weeks and detailed ultrasound scanning (at over sixteen weeks) can also identify neural tube defects. Unfortunately diagnostic screening for spina bifida is not one hundred per cent accurate. It is now known that taking Folic Acid Supplement of 0.4mg daily prior to conception and for the first three months of pregnancy reduces the risk for all women of having a baby with spina bifida. Women considered to be at risk should take a higher dose (4mg) prescribed by their doctor.

Medical text written November 1991 by Contact a Family. Approved November 1991 by Professor M Patton, Professor of Medical Genetics, St Georges Hospital Medical School, London, UK and Dr J E Wraith, Consultant Paediatrician, Royal Manchester Children's Hospital, Manchester, UK. Last updated May 1997 by Dr C R Birch, Consultant Physician and Medical Director, Grantham and District Hospital, Grantham, UK. Last reviewed July 2007 by Mr I K Pople, Consultant Neurosurgeon, Frenchay Hospital, Bristol, 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.

ASBAH

Association for Spina Bifida and Hydrocephalus (ASBAH)
42 Park Road
Peterborough
PE1 2UQ
Tel: 0845 450 7755 Helpline
Tel: 01733 555988
Fax: 01733 555985
e-mail: helpline@asbah.org
Web: http://www.asbah.org

The Association is a National Registered Charity No. 249338, established in 1966. It offers advice and information to individuals with hydrocephalus and/or spina bifida and their families or carers. It has a network of area advisers covering most parts of the country backed up by a team of specialist advisers in medical aspects of the conditions and education matters. It works with around 50 local associations in England, Wales and Northern Ireland. ASBAH publishes 'LINK' Journal quarterly and has a wide range of information available, details on request. The Association has over 8,000 families and individuals on its database.

Group details last updated August 2007.

SCOTTISH SPINA BIFIDA ASSOCIATION

Scottish Spina Bifida Association
The Dan Young Building
6 Craighalbert Way
Dullatur
Glasgow G68 0LS
Tel: 08459 11 11 12 (Lo-call Helpline)
Tel: 01236 794516/01236 794500
Fax: 01236 736435
e-mail: familysupport@ssba.org.uk
Web: http://www.ssba.org.uk

The Association is a National Registered Charity No. SCO13328, established in 1965. It offers a family support service throughout Scotland from a purpose-built family centre, providing information, support and advice to all users and their families. Home visits can also be arranged. It publishes a magazine "talk:BACK" three times per year, which is provided free to all users. There is also a wide range of information leaflets, publication list available on request. The Association has over 3,000 users.

Group details last updated August 2007.