by Kimberly Allen, RN
Spina bifida is one of those “rare” conditions that most have never heard of or don’t know much about until it touches someone they know. Spina bifida is a birth defect that is part of a group pf birth defects known as neural tube defects. The neural tube is the part of the embryo that will evolve into the brain and spinal cord as well as the tissues that surrounds them of the baby. When a fetus develops normally the neural tube closes by the 28th day after conception. Spina bifida occurs when a segment of that neural tube doesn’t close properly. This then causes defects in not only the spinal cord but the vertebral bones that surrounds it.
Spina bifida is the most common of the neural tube defects. There are approximately 200,000 people in the US affected with spina bifida with approximately 240 new cases diagnosed every year. The incidence of spina bifida is higher on the East Coast than the West Coast as well as being higher in Caucasians and Hispanics than other races. Also, despite the fact that scientists have not been able to link a specific gene to spina bifida they do know that it tends to run in families. Scientists also know that folic acid plays a significant role in the development of your baby. If your folate levels are low the chances your baby may develop spina bifida as well as other neural tube defects increases. There are also certain medications, especially anti seizure medications, that if taken by the mother during pregnancy can cause neural tube defects including spina bifida. Women with uncontrolled diabetes as well as those that are obese before pregnancy also have an increased risk of their baby developing spina bifida. There has also been some research that indicates increasing your body temperature by using hot tubs or saunas, or if you have a high fever early in your pregnancy can increase the risk of your baby developing spina bifida.
There are 3 main types of spina bifida, spina bifida occulta, meningocele, and myelomeningocele. Of the 3 spina bifida occulta is the mildest. In this type you can not see the defect because it is covered with skin. For the most part children born with spina bifida occulta never even realize that they have the defect, unless they have a back x-ray for some other reason. In a baby born with a meningocele the membranes that cover and protect the brain and spinal cord called meninges push through the opening in the vertebrae. The opening is not covered by skin like in spina bifida occulta so the meninges push out through the baby’s back forming a small sac called a meningocele. This sac contains only fluid, the spinal cord is not in the sac. Typically there is very little to no nerve damage with this type of spina bifida, however it can cause some minor disabilities. Of the 3 types of spina bifida myelomeningocele is not only the most severe it also the rarest form. Though it is the rarest form this is the type most people are referring to when the say “spina bifida”. In this type nerves also push out through the vertebrae with fluid when the meningocele sac is formed. In this type the nerves are frequently damaged causing numerous problems. Babies born with this type of spina bifida usually have problems with walking and coordination as well as with bowel and bladder control.
Treatment of spina bifida depends on the type and severity of your baby’s condition. Typically babies born with spina bifida occult don’t require any treatment while on the other hand those born with meningocele or myelomengocele require surgery to replace the meninges as well as any nerves into the spinal column and close the opening. Surgery is usually done with in 24 to 48 hours after birth. If the birth defect is discovered during pregnancy some doctor’s prefer to perform pre-natal surgery. This involves repairing the spinal defect while you are still pregnant and the baby is still in utero.
Children born with myelomeningocele will need ongoing care even if surgery is performed in utero as nerve damage will have already occurred. They are likely to still have issues with paralysis as well as bowel and bladder problems requiring a multidisciplinary team of health care professionals to care for them.
Encephaloceles are the rarest type of the neural tube defects occurring in approximately 375 babies every year in the US. The neural tube begins as a tiny flat ribbon in the embryo. As the embryo develops the flat tube folds over forming a tube and closes. It is normally closed by the end of 4 weeks of pregnancy. If the tube doesn’t close completely a neural tube defect develops. They type of neural tube defect depends on the location of the opening. In spina bifida the opening is on the spine, while in encephaloceles the opening is in the skull. When the opening is in the skull the brain is directly affected. Encephaloceles most commonly develop at the base of the skull where it joins the neck, however, they can also develop in the middle of the upper portion of the skull as well as between the forehead and nose. Encephaloceles are similar to menigoceles in that they are small sacs protruding through an opening. The major difference is that instead of meninges and spinal nerves there is meninges and brain tissue in the protruding sac.
Children born with an encephalocele tend to have numerous other health issues. Most will also suffer from hydrocephalus, in other words a build up of excess cerebral spinal fluid around the brain. They usually experience numerous developmental delays as well as mental retardation. Many also have seizures along with difficulty moving their voluntary muscles in a coordinated manor making walking and reaching with their arms difficult. Most children with an encephalocele also have vision problems.
Although scientists do not know the exact cause of encephaloceles they believe there are several factors that contribute to their development. One is genetics. If there is a family history of neural tube defects, for example if another family member has spina bifida the chances of another being born with an encephalocele is higher. Women that have other medical conditions like obesity or uncontrolled diabetes have a greater chance of having a baby with a neural tube defect including encephalocele. There are also certain anti seizure medications that if taken during pregnancy can cause the development of encephaloceles as well as other neural tube defects. Scientists have also found that certain ethnic groups have a higher incidence of neural tube defects. For example in the US Hispanics have the highest incidence followed by Caucasians.
Fortunately with today’s technology neural tube defects including encephaloceles can be detected during pregnancy. This allows you and your doctor to plan for your baby’s birth and treatment. The only effective treatment currently available for encephalocele is surgery to reposition the brain tissue and meninges inside the skull and correct any deformities. Sometimes the surgeon will also place shunts to assist in draining excess cerebral spinal fluid from the brain. The surgery to repair encephaloceles is typically performed very soon after birth to prevent infection as well as drying out of the brain tissue. The surgery also relieves pressure that tends to delay normal brain development.
Though there is no known way to prevent encephaloceles recent studies indicate that increasing the folic acid in your diet before getting pregnant significantly reduces the number of babies born with neural tube defects including encephaloceles. Scientists have also found that women that eat healthy and exercise before as well as during pregnancy lower their risk of having a baby with a neural tube defect. It’s also important to not smoke or consume alcohol during pregnancy to reduce the risk of numerous complications including neural tube defects.
Kimberly Allen is a registered nurse with an AND in nursing. She has worked in ACF, LCF and psychiatric facilities, although she spent most of her career as a home health expert. She is now a regular contributor to HealthAndFitnessTalk.com, dispensing advice and knowledge about medical issues and questions. You can reach her with any comments or questions at firstname.lastname@example.org.