What is Spina Bifida?

In September it was announced by the Department of Health that folic acid will be added to non-wholemeal wheat flour across the UK to help prevent life-threatening spinal conditions in babies. The aim is to avoid hundreds of potentially life-threatening spinal conditions in babies every year. It is estimated that between five per cent and 10 per cent of the UK population may have closed spina bifida, often without realising it. The most serious form of the condition, open spina bifida, is rare. Open spina bifida is found in about 6 babies out of every 10,000 (0.06%) in the UK, about 700 babies a year.

The addition of folic acid to food in a number of countries worldwide such as Australia, New Zealand and Canada, has helped to reduce neural tube defects such as spina bifida. Neural tube defects are a rare developmental condition which occurs very early in pregnancy and affects around 1,000 pregnancies each year in the UK. This occurs when the brain, spine, or spinal cord does not develop properly in the womb and can cause life-threatening health issues.

Adding folic acid to flour across the UK builds on 80 years of fortification and follows consultation with industry, stakeholders and the public. Since the Second World War, flour has been fortified with calcium, iron, niacin and thiamine during milling to support the nation’s health. Adding folic acid to flour will mean foods made with flour, such as bread, will actively help avoid around 200 neural tube defects each year, around 20% of the annual UK total. Folic acid is already voluntarily added by food manufacturers to breakfast cereal, including some gluten-free products, meaning people can usually get all they need from eating a balanced diet, but a higher intake is required in the first 12 weeks of pregnancy.

Health and Social Care Secretary Sajid Javid MP said:

“We are committed to giving more children a healthy start in life. With the safe and taste-free folic acid baked into the national diet, hundreds more babies will be born healthy each year. Focusing on preventing life-threatening health issues such as spina bifida, will ensure fewer people will require hospital treatment, and more individuals and families are able to live healthier lives”.

What is spina bifida?

Spina bifida literally means ‘split spine’. Spina bifida is a fault in the spinal column in which one or more vertebrae, that is the bones which form the backbone, fail to form properly, leaving a gap or split, causing damage to the nervous system.

The spine is made up of 33 bones, or vertebrae. The vertebrae have two main functions. One is to provide anchorage for muscles so that we can move as messages from the brain are sent to those muscles. The other is to provide protection to the spinal cord. The central nervous system and spine develops between the 14th and 23rd day after conception.

Spina bifida occurs when the neural tube fails to close correctly. The vertebrae also fail to close in complete rings around the affected portion of the spinal cord. This leaves a gap at the back, involving one or more vertebrae. The fault may occur in one or more of the vertebrae but it is most common around waist level. Spina bifida is one of a range of conditions all included under the umbrella term of ‘Neural Tube Defects’.

What are the types of spina bifida?

There are a number of different types of spina bifida; essentially, they fall into two categories, open spina bifida and closed spina bifida.

Open spina bifida – the visible signs are a sac or cyst, rather like a large blister on the back.

There are two forms of open spina bifida:

Myelomeningocele

This is the most serious and more common of the two forms of cystic spina bifida. Here the cyst not only contains tissue and cerebrospinal fluid (CSF) but also nerves and part of the spinal cord. The exposed spinal cord is damaged by the fluid in the womb during pregnancy and may also not develop properly. As a result, there is nearly always some resulting paralysis and loss of sensation. Nerves to and from the spinal cord emerging below the damaged region may not pass messages to the brain. The extent of this can be patchy and difficult to predict. The lower on the spine, and smaller the lesion, the less severe the resulting impairments are likely to be. Bladder and bowel problems occur in most people with myelomeningocele, as the nerves come from the very bottom of the spinal cord, and are always below the lesion. It is also necessary to have intact nerve pathways to the brain for complete control and sensation.

Meningocele

In this form, the sac contains meninges – that is, tissues which cover the brain and spinal cord – and CSF, but no spinal tissue. Development of the spinal cord may be affected, but impairment is usually less severe than myelomeningocele. Meningocele is the least common form of spina bifida.

Closed spina bifida

Closed forms of spina bifida are covered by the skin at birth, unlike myelomeningocele or meningocele, which are exposed and cystic. For some people with closed spina bifida, the condition involves the nerves and spinal cord, not only the vertebrae. It may be associated with a fatty lump embedded in the spinal column (lipomyelomeningocele), or a piece of bone which divides the spinal cord (diastematomyelia).

The forms of closed spina bifida include:

Spina bifida occulta

This is where one or more of the vertebrae, the spinal bones, are not closed completely at the back. In spina bifida occulta, the spinal cord and its covering stay in their normal position inside the spinal canal. Spina bifida occulta (SBO) occurs very commonly, affecting an estimated 8–15% of adults. In the UK, this means between 5 million to10 million people may have one or more vertebrae incompletely closed. Most people will remain unaware of it, or it may be discovered as a chance finding during tests for unrelated conditions, or after accidents. SBO can occur anywhere on the spine but is most common where the spine joins the pelvis, at L5/S1. Some people with SBO may have other conditions of the spinal bones, which may, but not always, cause pain and, occasionally, nerve involvement, as the spine becomes less stable.

These include:

•  Pars Defect – a small hairline fracture of part of the vertebrae.
•  Spondylosis – arthritis of the spine.
•  Spondylolisthesis – where one of the vertebrae slips out of position.

Occult spinal dysraphism

Describes a skin-covered spina bifida, which can include: lipomyelomeningocele, tethered cord, diastematomyelia or similar.

Lipomyelomeningocele

Is a closed spinal lesion in which part of the spinal cord and nerves are tangled in a benign fatty tumour. Like other forms of spina bifida, it develops during early pregnancy.

Tethered cord

A tethered cord is a spinal cord that can’t move freely inside the spinal canal. Before birth, the spinal cord is long, compared with the size of the baby, and ends at the bottom of the spinal canal. As a typically developing child grows, the spinal cord doesn’t grow, so the bottom end ‘rides up’ inside the bones; by the time the child reaches their adult height, the cord should end at around the first lumbar vertebra (L1).

Diastematomyelia

This is a condition in which the spinal cord is divided into two (lengthways), usually in the lumbar area. The spinal cord may join up again, but if it doesn’t, it is referred to as diplomyelia. Around half of people with diastematomyelia have their spinal cord divided by an extra piece of bone or band of fibrous tissue in the spinal canal. The spinal cord can become tethered because of the extra bone or tissue.

What causes spina bifida?

Spina bifida is a fault in the development of the neural tube that occurs very early in pregnancy, usually before the woman even knows she is pregnant. No single cause has been identified, although it is known that taking folic acid supplements before conception helps reduce the risk. Research is also ongoing into possible genetic and environmental causes.

Scientists at the UCL GOS Institute of Child Health reveal that new genetic mutations which occur during embryonic development can cause the severe birth defect spina bifida. Dr Gabriel Galea, principal investigator and lead author of the study, explains, “We found that the requirement for cells to talk to each other makes them exquisitely vulnerable to mutations in the planar cell polarity pathway. We now need to understand whether this vulnerability extends to other genes which could cause spina bifida. Detecting these mosaic mutations in living people will require technological advances and careful analysis of tissues resected during surgery.”

All types of spina bifida happen in the first month of pregnancy. At first, a foetus’ spinal cord is flat. It then closes into a tube called a neural tube. If this tube does not fully close, the baby is born with spina bifida.

Diabetes is also associated with developmental problems in babies, such as heart defects, kidney defects and genital problems, as well as spina bifida and anencephaly. Some medicines, such as sodium valproate used to treat epilepsy and bipolar disorder, are associated with NTD and other birth problems.

What are the signs and symptoms of spina bifida?

Spina bifida is most often picked up during an anomaly scan, which is offered between 18 weeks and 20 weeks of pregnancy and is commonly called the 20-week scan. It is also sometimes referred to as the mid-pregnancy scan. Spina bifida can usually be seen clearly on a scan, and of those babies who have this condition, around 9 out of 10 (90%) will be detected.

Symptoms depend on what kind of spina bifida a baby has and where it is on the spine. Some babies with spina bifida have few or no problems. But sometimes the condition can cause serious problems, including weakness, loss of bladder control, or paralysis.

A baby who is born with spina bifida may have or develop:

•  Weakness or paralysis in the legs.
•  Urinary incontinence.
•  Bowel incontinence.
•  A lack of sensation in the skin.
•  A build-up of cerebrospinal fluid (CSF), leading to hydrocephalus, and possibly brain damage.

The nervous system will also be more prone to infections, some of which can be life-threatening.

Myelomeningocele is the most severe form of spina bifida. If hydrocephalus is present, it increases the chance of learning problems.

Symptoms that may occur include:

•  Cognitive symptoms – such as awareness, thinking, learning, judging and knowing are known as cognition. Problems in the neural tube can affect brain development. If the brain’s cortex, and especially the frontal part, does not develop properly, cognitive problems can arise.
•  Chiari malformation – this is an abnormal brain development involving a part of the brain known as the cerebellum. This may cause hydrocephalus. It can affect language processing and physical coordination.
•  Learning difficulties – many people with spina bifida have normal intelligence, but some have difficulty with:
  – Learning
  – Focusing
  – Solving problems
  – Reading
  – Understanding spoken language
  – Making plans
  – Grasping abstract concepts
•  Coordination – there may be problems with visual and physical coordination such as doing up buttons or shoelaces can be difficult.
•  Paralysis – most people with this condition have some degree of paralysis in their legs. Leg braces or a walking stick can help a person with partial paralysis to be mobile. However, a person with total paralysis will need a wheelchair. Without exercise, the lower limbs can become weak, leading to dislocated joints and misshapen bones.
•  Other problems – bowel and urinary incontinence are common problems. Skin problems, gastrointestinal problems, latex allergies, and depression may also develop. Skin damage can occur if the person lacks sensation in the legs. They may injure or burn themselves without realising. There is a higher risk of meningitis among people with spina bifida, which can be life-threatening.

How is spina bifida diagnosed?

At the antenatal mid-term 20-week ultrasound scan the appearance of the skull bones and cerebellum, part of the back of the brain, show distinct signs that lead the sonographer to look for tiny changes in the spine. For example, the bones to the sides of the head can look pinched, and the cerebellum looks long, thin and wrapped around the spinal cord, instead of being round.

Prospective parents who have had a baby with a neural tube defect, or who have a close relative with a neural tube defect, should be referred to a genetic counsellor for advice; this referral can be made through a GP. Some parents whose babies are diagnosed with spina bifida take the heart-breaking decision not to proceed with the pregnancy.

Closed spinal lesions such as lipomyelomeningocele are often not detected at the antenatal mid-term ultrasound scan. The brain and skull will usually look normal so the changes to the spine may not be detected. Often people only become aware that they have it after having a back x-ray for an unrelated problem.

How is spina bifida treated?

It may be possible, under certain circumstances, to operate on the baby’s lesion in the womb, before 26 weeks of pregnancy.

Most commonly the baby will be seen by a paediatric neurosurgeon shortly after birth. The surgeon will then decide whether the baby should have surgery to repair the defect in the back. A surgeon can do this within 2 days of birth. They replace the spinal cord and any exposed tissues or nerves back into the newborn baby’s body, then close the gap in the vertebrae and seal the spinal cord with muscle and skin. Sometimes, in large lesions or premature babies, there may not be enough skin available to close the lesion right away, and the Plastic Surgery Team may be involved.

Many children with lesions in the mid-lumbar area can walk during childhood, but choose to use a wheelchair for longer distances, sports, or as they get older. Splints often help support the feet and ankles. If bone development problems occur later, such as scoliosis or dislocated joints, further corrective surgery may be necessary. A back brace can help correct scoliosis. Some adults with low lesions report reducing mobility from their 30s; the tethered cord may be a factor, and can sometimes be surgically treated.

Adult patients with spina bifida may need as few as half the calories of an adult without spina bifida, and weight gain is common. Considerable ongoing support may be needed to reduce weight.

Can spina bifida be prevented?

The exact reasons why the neural tube develops incorrectly are not yet known but it is probably connected with both genetic and environmental factors. Taking folic acid supplements can reduce the risk of spina bifida in unborn babies. For families with no history of spina bifida the Department of Health recommends women take an over-the-counter dose of 400mcg daily. For families where there is a history of spina bifida, a prescription dose (5mg) of folic acid is needed.

Folic acid should be taken daily for at least 12 weeks prior to conception and through to the 12th week of pregnancy. Even with fortification of flour products with folic acid, a supplementary tablet is needed.

Vitamin B12 works closely with folate, and low levels in the bloodstream increase the chance of a baby having Neural Tube Defects. Many foods rich in B12 include eggs and red meat so vegetarians and vegans may need to take extra B12 in order to get enough. Women who have had weight-loss surgery to their stomach or intestine should take advice well in advance of trying to conceive. B12 is only absorbed from food a little at a time.

Living with spina bifida

Those living with spina bifida will generally be living with some physical and/or intellectual difficulties that range from mild to severe and depend on the size and location of the opening in the spine and whether part of the spinal cord and nerves are affected.

Every child with spina bifida is different. In most cases, except for learning a few special medical procedures, caring for a baby or child with spina bifida will be much like caring for any infant. However, a child whose spina bifida is severe may need medical care for life.

Mobility and physical challenges are generally present for those living with spina bifida. Whilst some children and adults are able to walk without any aids or assistance, some require braces, walkers, crutches or a wheelchair.

Children and adults living with spina bifida have limited feeling in some areas of their body, resulting in them not feeling when they have hurt themselves, and therefore may not tell the person caring for them, so vigilance is crucial in carers. Another issue experienced by those with spina bifida is pressure sores and skin wounds; these are common and the primary source of hospitalisation for those living with spina bifida.

Other challenges faced by those living with spina bifida might include:

•  Learning difficulties including attention deficit hyperactivity disorder (ADHD) or other learning problems such as memory, comprehension and organisation.
•  Vision issues including poor eye-hand coordination, which can make it hard to do things such as writing.
•  Incontinence – they are prone to developing urinary tract infections (UTIs).
•  Maintaining a healthy weight.
•  Depression.
•  Difficulties in relating to and engaging with others.

However, many people with spina bifida are able to live generally normal and independent lives, and many people learn to drive and continue driving for many years without any difficulty at all. Many people travel and explore new places, although these holidays might need a little more preparation.

Many women with spina bifida can have healthy children themselves and will have a safe and successful pregnancy, although they will probably need to plan more carefully than other women.

Education and employment need not be a barrier to those with spina bifida, though there may be some initial challenges to overcome. Schools and employers may need to modify the classroom or workplace environment to meet the needs of someone with spina bifida.

Final thoughts

For anyone who has a child with spina bifida, the diagnosis may at first appear daunting; however, there is advice and support available.

Great Ormand Street Children’s Hospital (GOSH) has published a case study of an eight-year-old boy born with spina bifida, detailing his and his family’s experience of living with the condition.

Shine is a registered charity that provides specialist support from before birth and throughout the life of anyone living with spina bifida.