Spina bifida: Causes and prognosis (Is it serious?)

Article reviewed and approved by Dr. Ibtissama Boukas, physician specializing in family medicine 

Some adults are diagnosed with spina bifida during a routine checkup. Or again, we observe it at the level of the spine (often, the lower back) in some babies at birth.

 

What is spina bifida, and what causes it? When should you worry when you are an expectant mother? Can it be prevented, or treated once it is diagnosed?

 

This article explains everything you need to know about spina bifida in adults and children, emphasizing simple and concrete notions aimed at improving the management of this disease.

Definition and anatomy

 

Before discussing spina bifida, it is appropriate to review certain notions of anatomical and embryogenesis aimed at better understanding this condition.

 

During fetal development, the brain and spinal cord form a furrow which will fold back on itself between the 21^e and the 28^e day to form what is called the neural tube.

 

If the neural tube does not close properly, we will have spina bifida. This congenital malformation affects 1.3 births out of 1000 in France.

 

 

Spina bifida can range from mild to severe, depending on several factors. More specifically, the severity of the condition is affected by:

 

• The size and location of spina bifida in the spine
• Whether the affected area is covered by skin or not
• The section of spinal cord affected by spina bifida, and the spinal nerves emerging from it

 

 

 

Types of spina bifida

 

Here are the common types of spina bifida:

 

 

Spina bifida occulta

 

This is the most common type. Fortunately, this condition is most often mild. the spina bifida occulta results in an incomplete closure of the neural tube, but which does not result in a sac outside the spine. Nerves, spinal cord and other tissues are therefore preserved inside the spinal canal.

 

The majority of people with this condition only discover it after a routine examination, such as magnetic resonance imaging (MRI) following an episode of back pain. In some rare cases, the complex forms of spina bifida occulta can lead to motor and sensory disorders, and damage to the colon. They are often associated with other malformations.

 

The number of cases of spina bifida in adults in France is estimated at 25.

 

Myelomeningocele

 

Myelomeningocele is the most serious type of spina bifida. the Spinal canal is open along several vertebrae dorsal or lumbar. This causes the spinal membranes and nerves to pass through this opening at birth.

 

There is therefore a "bag" of fluid in the back of the baby, exposing and irritating the tissues, the spinal cord and the nerves. Unfortunately, this makes the baby prone to infections and other life-threatening complications.

 

Meningocele

 

Meningocele is less serious than myelomeningocele. In this type of spina bifida, a sac of fluid comes out through an opening in the baby's back (due to incomplete closure of the neural tube). But unlike myelomeningocele, the spinal cord is not in this sac, and therefore remains inside the spinal canal.

 

The consequences observed are therefore less serious. In some cases, there are no symptoms. Other people may have a more or less pronounced disability (such as urinary problems).

 

 

Causes and risk factors

 

The exact causes for spina bifida to appear are unknown. On the other hand, certain genetic and environmental risk factors have been associated with this condition. Here is a list of potential causes that may explain spina bifida:

 

Folate deficiency

 

Folate is a natural form of B vitamin essential for fetal development. Folic acid, a derivative of folate, is found in certain foods and dietary supplements.

 

Maternal folic acid deficiency has been associated with increased risk of spina bifida and other neural tube defects.

 

Family history of neural tube defects

 

If you have spina bifida (even asymptomatic), the chances of having a child with this same condition are increased. This risk increases if you have more than one affected child, or if both parents are affected.

 

Some drugs

 

Certain medications taken during pregnancy could cause neural tube defects.

 

For example, anticonvulsants (such as valproic acid or sodium valproate) used in the treatment of epilepsy and bipolar disorder could interfere with the body's ability to use folic acid.

 

Diabetes

 

Diabetic women are more likely to have a baby with spina bifida. This is all the more true if blood sugar is not well controlled.

 

obesity

 

Obesity during pregnancy is associated with an increased risk of birth defects of the neural tube, including spina bifida.

 

Increase in body temperature.

 

Any increase in body temperature during the first trimester of pregnancy can increase the risk of having a baby with spina bifida.

 

This includes infections that cause fevers, or excessive use of saunas, jacuzzis or hot baths.

 

 

Diagnosis of spina bifida

 

In adults, spina bifida is often seen during routine medical imaging. It is mainly about spina bifida occulta having no functional repercussions.

 

Prenatal diagnosis will be especially relevant in pregnant women to detect spina bifida (or other congenital malformations) in the fetus.

 

 

Here are some examples of prenatal tests that are often done:

 

Blood tests

 

The purpose of the blood test will be to measure the amount of AFP produced by the fetus, and transmitted to the mother through the bloodstream.

 

A high level of AFP may indicate spina bifida or other neural tube defect.

 

Ultrasound or Ultrasound

 

Ultrasound is a test ofmedical imaging sometimes allowing the observation of a spina bifida.

 

 

Amniocentesis

 

For this test, the doctor takes a small sample of amniotic fluid. As with the blood test, the amount of AFP will be analyzed to determine if there is a potential presence of spina bifida.

 

It is often prescribed when blood tests show a high level of AFP, but ultrasound or ultrasound cannot support the diagnosis.

 

Because spina bifida can be associated with several disabling neurological and functional consequences, 80% of parents make the difficult choice to medically terminate the pregnancy. The choice of abortion when the diagnosis is announced should be discussed with her attending physician.

 

At birth

 

If spina bifida was not detected during pregnancy, it sometimes happens that it is detected at birth (for example by observing a tuft of hair or a dimple in the back of the baby).

 

In this case, a medical imaging examination will often be carried out afterwards to clarify the diagnosis, and to determine if there is indeed the presence of spina bifida.

 

 

Symptoms and consequences

 

As mentioned, spina bifida symptoms will vary greatly depending on the type, size, location and individual.

 

In the presence of spina bifida occulta, there are typically no associated symptoms. This means that if you are an adult who consults for back pain and spina bifida is discovered, it is not the cause of your low back pain.

 

Sometimes there is a topical change in the lumbar region in those with spina bifida occulta. This may include increased hairiness, a mark or a birthmark.

 

In the presence of myelomeningocele, on the other hand, the symptoms are more important. Depending on the individual, we can observe:

 

 

• Weakness or paralysis of the upper and/or lower limbs causing difficulty in walking
• Musculoskeletal disorders (pain, low back pain, sciatica, cruralgia, neuropathies)
• Urinary or faecal incontinence (often qualified as the most difficult disability to live with)
• Loss of feeling
• Scoliosis
• overweight
• Epileptic seizures
• Sleep apnea and others
• Dermatological problems
• Infections
• Hydrocephalus
• Intellectual and cognitive disorders 
• Meningitis
• Arnold-Chiari malformation
• Digestive or urinary disorders

 

It should be noted that spina bifida of the myelomeningocele type does not necessarily come with all the symptoms mentioned above. The level(s) affected in the spine, as well as the other consequences caused by spina bifida, will dictate the onset of symptoms.

 

 

Prognosis and life expectancy

 

Thanks to advances in medicine, 90% of babies with spina bifida live to adulthood, and most of them are functional. Fortunately, the death rate is less than 10% before the age of 6, especially in children who have undergone surgery.

 

Although life expectancy can be close to normal, most people with spina bifida still benefit from multidisciplinary care during their lifetime. This includes neurosurgical, pediatric, orthopedic, urological and/or psychological support depending on the case.

 

Obviously, the prognosis must be discussed with the attending physician, and will depend on several factors related to the spina bifida present in the individual concerned.

 

 

Treatment and prevention

 

Nowadays, there are certain treatment modalities for spina bifida.

 

When a baby has myelomeningocele-like spina bifida, surgery is sometimes needed to close the neural tube. It is a complex intervention that can be done before birth, or as soon as the baby is born.

 

Brain shunt surgery to reduce the risk of hydrocephalus is also considered in the presence of myelomeningocele. This operation must be performed within 48 hours of birth.

 

If hydrocephalus is observed (accumulation of fluid inside the ventricles of the brain), the surgeon will place a small valve to reduce intracranial pressure. This operation must be performed within 48 hours of birth. The valve will be kept for the entire existence of the affected person, and will be changed during his life in some cases.

 

In addition to surgery, the objective will be to accommodate the baby with spina bifida throughout his life. This may include:

 

• a walking aid (or a wheelchair in some cases)
• a special school if there are learning disabilities
• a catheter for incontinence disorders
• corrective surgeries based on functional repercussions

 

 

In extreme cases, it will be necessary to discuss with the doctor the possibility of abortion. Indeed, some operations (especially those performed before birth) involve several risks, especially for the mother. This occurs when there is concern for the survival of the newborn.

 

Prevention of spina bifida

 

In terms of prevention, the most important element will be taking folic acid in the form of a supplement for women wanting a child. This would significantly reduce the risk of spina bifida (and other neural tube defects) in newborns.

 

 

Ideally, folic acid should be taken before conception (at least one month before becoming pregnant), although it is sometimes difficult to predict pregnancy if it is unplanned.

 

In this case, folic acid should be taken regularly during pregnancy. 400 micrograms per day of folic acid is recommended, although this dose can be increased if the mother is considered "at risk" (for example, if she already has a child with spina bifida, if she is epileptic, or if she has a history of neural tube defect herself).

 

Besides folic acid, we have seen previously that obesity and diabetes may have a role to play in spina bifida. Women with diabetes will therefore need to control their blood sugar levels during pregnancy. As for obese women, weight control will be essential during this period.

 

Finally, as the increase in body temperature can affect the formation of the neural tube in the newborn, it is preferable to avoid excessively hot baths and saunas during the first months of pregnancy.

 

Ideally, the onset of any infection that could cause fever should also be avoided. Prompt control with medication should be implemented in case of infection.

 

 

Conclusion

 

The diagnosis of spina bifida is not always fatal, and depends on several factors that will dictate the symptoms and future repercussions.

 

Some types (such as spina bifida occulta) are asymptomatic, while others cause life-threatening consequences (in the presence of myelomeningocele).

 

When diagnosed early, management can be optimized. A specialist will be able to guide you through this process if your child has spina bifida.

 

 

Resources

 

National Spina Bifida Association

 

inspirational quote

 

“While some people with spina bifida have significant disabilities, others are less severely affected. Many of them finish their studies, and build a career and a family. They become doctors, teachers, artists, athletes and parents. Spina bifida is part of their life, but not considered a condemnation. »

American Spina Bifida Organization