During the third to sixth week of pregnancy, the spinal column and spinal cord form in the embryo. They emerge from the neural tube, an embryonic tissue structure. Spina bifida is therefore one of the so-called neural tube defects.
Normally, the two vertebral arches fuse with the vertebral body to form a ring. This ring limits the vertebral foramen to the rear. The spinal cord is located in the vertebral foramen and is surrounded by spinal meninges.
In the case of spina bifida, the vertebral arches do not close, resulting in a vertebral fissure. These closure disorders most frequently affect the lower part of the spine, i.e. the lumbar spine and the sacrum.
Spina bifida is the second most common congenital malformation. However, it only occurs in around one in a thousand children in Central Europe. Girls are affected slightly more frequently than boys.
In medicine, a distinction is made between two forms:
- Spina bifida occulta (Latin: occulta = hidden) and
- Spina bifida aperta (Latin: aperta = open, visible), also known as myelocele, myelomeningocele.
In the more common spina bifida occulta, only the vertebral arch is split without the spinal cord being affected. The malformation is therefore not visible from the outside and is often only discovered by accidental X-ray examinations.
Spina bifida occulta usually does not require treatment and rarely causes symptoms.
In spina bifida aperta, not only the vertebral arches but also the spinal cord and/or the spinal meninges are split. The spinal cord often protrudes beyond the spinal canal like a sac. The spinal cord may be covered with a thin skin, but may also be completely exposed.
In spina bifida, parts of the spinal cord may protrude outwards © Nattapon | AdobeStock
The symptoms and consequential damage in early childhood and adulthood can vary greatly. They depend on where the vertebral fissure occurs and whether the spinal cord is affected.
Spina bifida occulta often causes no symptoms at all, as the spinal cord is not affected by the cleft.
The situation is different with spina bifida aperta. Here too, however, there are major differences in the intensity of the symptoms.
There may only be slight impairments when walking. Typical sequelae are
- Paralysis of the muscles,
- leg weakness,
- sensory disturbances,
- curvatures and misalignments of the joints as well as
- impairment of the gastrointestinal system.
Bladder function is often impaired. Infections of the urethra and voiding problems (e.g. incontinence) are typical consequences. In the worst case, paraplegia can occur.
A phenomenon that often occurs together with spina bifida is hydrocephalus. The disturbed circulation of the cerebrospinal fluid causes cerebrospinal fluid to accumulate. Hydrocephalus can lead to impaired performance and epileptic seizures.
The cause of the neural tube defect is still unknown. Genetic factors probably play an important role. If a child has already been born with spina bifida, the risk for the second child increases by around 40 percent.
External influences also appear to promote spina bifida. A folic acid deficiency is considered a significant risk factor. Doctors recommend that women with a folic acid deficiency take folic acid supplements before the planned pregnancy.
Furthermore
- Medication for epilepsy,
- gestational diabetes and
- obesity of the mother
can contribute to a malformation. Women with epilepsy should discuss an alternative therapy with their doctor.
Spina bifida can be suspected before birth through an amniocentesis. However, this examination does not provide 100% certainty.
Ultrasound examinations from the 12th week of pregnancy are generally more reliable. They can detect spina bifida at an early stage. A blood test of the mother in the 16th week of pregnancy can also make a diagnosis possible.
After birth, severe spina bifida is visible to doctors with the naked eye. In this case, the newborn's back is severely curved.
The actual extent of the deformity is determined using various procedures such as X-ray examinations and computer tomography.
Doctors from many specialist areas work together to examine the child holistically. These include pediatric neurologists and pediatric orthopedists.
The treatment of spina bifida depends on the severity of the deformity.
Mild spina bifida often requires no treatment. Treatment of a more severe form is carried out on an interdisciplinary basis by
The child should achieve good mobility in order to be able to participate in everyday life almost without restriction. An open spine is surgically closed by the doctors shortly after birth to prevent germs from entering the spinal cord.
In the case of hydrocephalus, a catheter is inserted to allow the cerebrospinal fluid to drain away. A catheter can also be inserted in the event of bladder problems. Walking and standing can be made easier with various orthopaedic aids. Surgery can also correct certain deformities.
The treatment of severe spina bifida involves lifelong and multidisciplinary care for those affected.
Further information on spina bifida can be found on the website of the Bundesverband zur Begleitung von Familien vorgeburtlich erkrankter Kinder e.V. (Federal Association for the Support of Families with Prenatally Ill Children).