Neural Tube Defect

If a neural tube defect is detected in an ultrasound examination during pregnancy, this means a great shock for the expectant parents. Depending on the severity of this malformation, the baby is either unable to survive or is born with severe disabilities. In Germany, the risk of giving birth to a child with a neural tube defect is around 1 in 1000. To prevent this from happening in the first place, every woman of childbearing age should take appropriate precautions and take enough folic acid in good time.

Neural Tube Defect

What is a neural tube defect?

A neural tube defect results from a developmental disorder between about 18 and 28 days after conception. During this time, the precursor to the nervous system, the neural plate, forms in the embryo. Initially, it is an elongated indentation in an area that later develops into the child’s back. As cell division progresses, this indentation closes by day 28 after the egg and sperm cell connect to form the neural tube, which gives rise to the spinal cord, spinal column, brain, and skull. See percomputer for Hypoalgesia Explanation.

In a neural tube defect, it does not close completely. This defect can occur in one or more places of the future spine and can vary in size. The result is a so-called “open spine”, spina bifida or anencephaly. Anencephaly means “without a brain”.

Babies born with this severe form of neural tube defect are missing large parts of the brain and skullcap. These children are not viable. They are either born dead or die shortly after birth.

Causes

A neural tube defect can have many causes. They can be genetic, based on chromosomal disorders or caused by metabolic influences and harmful substances. A viral infection, for example with rubella, high fever or exposure to radiation from X-rays or a CT scan in early pregnancy can also trigger a neural tube defect.

Also at risk are women taking antiseizure drugs and those with type 1 diabetes, especially if poorly controlled. Another possible cause is folic acid deficiency.

Symptoms, Ailments & Signs

Symptoms of spina bifida depend on where the spine is damaged and whether the spinal cord is bulging outwards through the gap created in the neural tube. In the case of the mild form of spina bifida occulta, those affected often do not know anything about their deformity unless a doctor detects it during an X-ray examination.

Such a neural tube defect causes non-specific symptoms such as back pain, skin changes in the area of ​​the spinal defect or a weakness of the bladder sphincter. However, if the spinal cord or the meninges are affected by the neural tube defect and the nerve tissue is damaged, the spectrum of symptoms ranges from minor movement disorders to paraplegia.

Other symptoms can include scoliosis (a curvature of the spine), muscle wasting and joint misalignment. Spina bifida rarely causes brain damage. However, some infants develop hydrocephalus (hydrocephalus) when the posterior end of the cerebellum protrudes into the spinal canal. This does not cause brain damage, but it can impair the circulation of cerebral fluid. However, most affected children have normal intelligence.

Diagnosis & course of disease

A neural tube defect is usually detected by ultrasound. Large defects in the neural tube are already visible at a gestational age of twelve weeks. Less pronounced vertebral deviations can be observed between sixteen and twenty weeks.

However, if the back of the fetus is difficult to assess or if there is a high risk, an amniocentesis may also be needed. The triple test (blood test) in the fourth month of pregnancy is less meaningful.

Complications

Complications from a neural tube defect depend on where the defect is located. A particularly extreme form of neural tube malformation, anencephaly, is not compatible with life because large parts of the brain do not develop in the first place. The newborn dies after a few weeks. The second type of neural tube defect, spina bifida, presents in different ways with different effects.

Thus, the defect can go completely unnoticed if the spinal cord is not involved. If the spinal cord is involved and there is an open defect with exposure of the nerve tissue, the neural tube must be surgically closed immediately after birth or even before. Otherwise there is a risk of a serious infection that can be fatal. Even after that, most patients require lifelong care. In severe cases, those affected are at risk of paraplegia. Some patients suffer from urinary and fecal incontinence.

Sometimes both the spinal cord and the brain are affected. Then the mental development of the child can be negatively affected. However, it is not possible to make precise statements about the forecast in this regard. In most cases, children develop normal intelligence. Often there is also a neurogenic bladder, which requires constant medical treatment, since otherwise the loss of kidney function could occur as a complication.

When should you go to the doctor?

Neural tube defects develop in the closely monitored first trimester of pregnancy. That is why it is very important so early on that the woman regularly attends the preventive medical check-ups that are planned. In this context, a neural tube defect in the fetus can be identified and treated. In this way, the later consequences after the birth can at best be contained to such an extent that the baby can lead a largely normal life.

If a neural tube defect is already so severe that the child would be born with disabilities, the woman can still decide to have a late abortion. Prevention during pregnancy is also important in order to identify any nutrient deficiencies and other risk factors for a neural tube defect and to be able to intervene in good time. If a baby is born with a neural tube defect, the pediatrician is required immediately after the birth to determine whether the ultrasound images match the actual state of health of the newborn.

Depending on the type and severity of the neural tube defect, many newborns need surgery immediately after birth, because the earlier the treatment takes place, the easier it is to treat a congenital neural tube defect. Any surgical scars heal well at such an early age and can become almost invisible later in life. In this way, the newborn can also have a normal life.

Treatment & Therapy

American scientists began closing a neural tube defect before birth 20 years ago. In order to reach the baby, the abdomen and uterus had to be opened through larger incisions. In the meantime, a minimally invasive surgical method has been developed with which spina bifida can be closed in the womb – German Center for Fetal Surgery and Minimally Invasive Therapy (DZFT).

This prenatal procedure has beneficial effects on the function of the lower extremities, as well as the bladder and rectum. The formation of a hydrocephalus can also be limited. The best conditions for this procedure are in the early 20s of pregnancy. When babies are born with an open back, germs can get in and cause further nerve damage.

Therefore, the exposed spinal cord structures must be surgically closed in the first one to two days after birth. If a hydrocephalus is also diagnosed, an artificial drain for the excess brain water is also created. Regular bladder and bowel emptying must also be ensured if there is paralysis here.

A high-fiber diet and adequate fluid intake are important for affected children in order to keep the stool consistency soft. The aim of subsequent therapy will be to enable the children to be as independent and mobile as possible. A pediatrician knows the different specialties that can help. He can coordinate and ensure the exchange of information.

Outlook & Forecast

The resulting disease is important for the prognosis of neural tube defects. If the defect appears in the form of spina bifida occulta, those affected usually do not notice the malformation and can lead a normal life.

The situation is different with the myelomeningocele. This is a serious disease that can cause significant problems in childhood and adolescence as well as in adult life. This disease often leads to infections, problems with the urinary tract and kidneys, signs of paralysis and hydrocephalus (water on the head). Those affected often also show clear difficulties on a social level, mental disabilities and psychiatric problems are not uncommon. Very severe cases also show more extensive damage, which extremely reduces the survivability of the affected children. But even with myelomeningocele, most people affected can lead a good life and integrate into both social and professional life.

A neural tube defect is always treated with surgery. Depending on the type and severity, this usually takes place immediately after birth. This is particularly important for the prognosis, because the earlier the treatment is carried out, the better the prospects for later life.

Prevention

The best precautionary measure against a neural tube defect is an adequate supply of folic acid at the latest at the beginning of a pregnancy, even better when the desire to have children manifests itself. A developing baby needs this vitamin for its cells, tissues and organs. It plays an important role in the development of the brain and spinal cord. Adequate folic acid supply reduces the risk of a neural tube defect by half.

You can do that yourself

When prospective parents learn that their child has a neural tube defect, it comes as a shock at first. This is especially true if the defect is serious and the child is unlikely to survive. Other forms of neural tube defects can sometimes be corrected surgically during pregnancy (prenatal) or a few days after birth.

Children with a neural tube defect usually need help throughout their lives. This makes it very difficult for the parents of the affected children. Depending on the individual diagnosis of the defect, psychotherapeutic support or various self-help groups can help here. On the one hand, the Anencephaly info page (www.anencephaly.info) offers help for self-help, which makes its information available in several languages. Another Internet address is that of the Working Group Spina Bifida and Hydrocephalus e. V., a self-help group that has existed since 1966 (www.asbh.de). In the worst of all cases, the Federal Association for Orphaned Parents and Grieving Siblings in Germany (www.veid.de) can help.

It is generally helpful for patients affected by a neural tube defect to drink plenty of fluids and eat a diet rich in fibre. Both should keep the stool soft and thus make bowel movements easier. Physiotherapy allows the patient to become and remain flexible and thus independent. The therapies prescribed by the doctor should therefore be used without fail.