Spina Bifida

	Spina Bifida and Anencephaly

Spina bifida and anencephaly are a group of conditions known medically as neural tube defects (NTDs). They occur when there is a failure in the development of the neural tube. This happens very early in pregnancy when the central nervous system and spine are developing, between 14 and 23 days after conception. This results in a gap or split in the spine or skull.

Anencephaly occurs when the fault is at the upper end of the neural tube, seriously affecting the brain and skull development. Unfortunately, babies with anencephaly do not survive long after their birth.

Spina bifida results when the split is along the spinal cord. In this case, one or more vertebrae fail to close properly around the spinal cord, leaving it unprotected. The result may be damage to the spine and nerves. Large lesions often result in paralysis and loss of sensation below the level of the fault. As with other forms of spinal cord impairment, bladder and bowel control may also be affected.

Smaller lesions may cause fewer problems, and occasionally have no adverse affects.

Spina bifida and anencephaly should be picked up via routine antenatal checks during pregnancy. Having had one child with spina bifida conveys an increased chance of around 1 in 35 of having another affected baby. However, taking folic acid supplements (5mg per day) both before conception and during pregnancy will reduce the chance of the developing baby being affected by spina bifida.

More than 85% of people with spina bifida also have hydrocephalus. Hydrocephalus can also occur by itself.

	Hydrocephalus

Hydrocephalus comes from the Greek words 'hydro' meaning water and 'cephalie' meaning head. It occurs when the drainage pathways of the cerebro-spinal fluid (CSF) become blocked. The CSF is a watery fluid that is produced constantly inside the four spaces ( ventricles) inside the brain. Normally, this fluid flows through narrow channels from one ventricle to the next, over the outside of the brain and down the spinal cord, and is absorbed back into the bloodstream. In hydrocephalus, the CSF accumulates in the ventricles of the brain, causing them to swell.

In babies, this causes the head to enlarge as the skull has not yet fused together. In older children and adults, the increased pressure causes headaches and vomiting, and would eventually become life threatening if left untreated. Hydrocephalus is usually treated with insertion of a 'shunt', a device which diverts the accumulated CSF fluid around the obstructed channels and returns it to the bloodstream. An operation is needed to insert the shunt, which is completely enclosed within the body.

Hydrocephalus can develop at any stage in the pregnancy, and may not always be discovered by routine tests. A condition which may look similar to hydrocephalus on an ultrasound scan, called mild ventriculomegaly, often settles down towards the end of pregnancy, and should not need treatment.

	Characteristic features of Spina Bifida

People with spina bifida alone have physical impairments but do not necessarily have learning difficulties. Most people with spina bifida also have hydrocephalus, which may affect balance and coordination, memory, and organisational skills. Many people with spina bifida use a wheelchair or other walking aid, either from childhood or later in life.

At birth, an operation may be required to repair the lesion on the back within the first couple of days of life. Insertion of a shunt to control hydrocephalus may require an operation within the first fortnight. Ongoing medical care may be necessary to manage bladder issues, to ensure that any shunt is operating effectively, and that there are no problems with kidney function. Orthopaedic operations or splints may be required to correct curvature of the spine, or to ensure that feet and ankles are well positioned.

People with spina bifida and hydrocephalus lead widely varying lives; many live independently, while others need more support. Aids and adaptations may be necessary to ensure that houses and vehicles are accessible. Assuming that there are no barriers to wheelchair users, children should be able to attend a mainstream school. Sometimes, extra support may be required to manage continence or mobility issues.

Many adults with spina bifida have had children of their own, although men may experience some fertility problems which require medical assistance.

Find out more about spina bifida from the Association for Spina Bifida and Hydrocephalus (ASBAH)