14 Spina BifidaThe human nervous system develops from a small, specialized plate of cells along the back of an embryo.Early in development, the edges of this plate begin to curl up toward each other, creating the neural tube—a narrow sheath that closes to form the brain and spinal cord of the embryo.the top of the tube becomes the brain and the remainder becomes the spinal cord.
15 This process is usually complete by the 28th day of pregnancy. But if problems occur during this process, the result can be brain disorders called neural tube defects, including spina bifida.
16 What is spina bifida?Spina bifida, which literally means “cleft spine,” is characterized by the incomplete development of the brain, spinal cord, and/or meninges.Spina bifida is one of the more common birth defects in the United States.It is among the most common severe birth defects in the United States, affecting 1,500 to 2,000 babies (one in every 2,000 live births) each year.
17 the different types of spina bifida Occulta: is the mildest and most common form in which one or more vertebrae are malformed.The name “occulta,” which means “hidden,” indicates that the malformation, or opening in the spine, is covered by a layer of skin. This form of spina bifida rarely causes disability or symptoms.
18 Closed neural tube defects make up the second type of spina bifida. This form consists of a diverse group of spinal defects in which the spinal cord is marked by a malformation of fat, bone, or membranes.In some patients there are few or no symptoms; in others the malformation causes incomplete paralysis with urinary and bowel dysfunction.
19 meningocele :the meninges protrude from the spinal opening, and the malformation may or may not be covered by a layer of skin.Some patients with meningocele may have few or no symptoms while others may experience symptoms similar to closed neural tube defects.
20 Myelomeningocele :is the most severe and occurs when the spinal cord is exposed through the opening in the spine, resulting in partial or complete paralysis of the parts of the body below the spinal opening. The paralysis may be so severe that the affected individual is unable to walk and may have urinary and bowel dysfunction.
21 What causes spina bifida? The exact cause of spina bifida remains a mystery. No one knows what disrupts complete closure of the neural tube, causing a malformation to develop.Scientists suspect genetic, nutritional, and environmental factors play a role. it appears to result from a combination of genetic and environmental risk factors, such as a family history of neural tube defects, folic acid deficiency and medical conditions such as diabetes and obesity.
22 Risk factorsRace. Spina bifida is more common among Hispanics and whites of European descent.Family history of neural tube defects. Couples who've had one child with a neural tube defect have a slightly higher chance of having another baby with the same defect. That risk increases if two previous children have been affected by the condition. In addition, a woman who was born with a neural tube defect, or who has a close relative with one, has a greater chance of giving birth to a child with spina bifida. However, most babies with spina bifida are born to parents with no known family history of the condition.
23 Folic acid deficiency. This vitamin is important to the healthy development of a fetus. Lack of folic acid (vitamin B-9) increases the risk of spina bifida and other neural tube defects.Some medications. Anti-seizure medications, such as valproic acid (Depakene), seem to cause neural tube defects when taken during pregnancy, perhaps because they interfere with the body's ability to use folic acid.
24 Diabetes. The risk of spina bifida increases with diabetes, especially when the mother's blood sugar is elevated early in her pregnancy. Much of this risk is preventable by careful blood sugar control and management.Obesity. There's a link between pre-pregnancy obesity and neural tube birth defects, including spina bifida. Obese women may have more babies with spina bifida possibly because of nutritional deficits from poor eating habits or because they may have diabetes.
25 Increased body temperature Increased body temperature. Some evidence suggests that increased body temperature (hyperthermia) in the early months of pregnancy may increase the risk of spina bifida.
26 ComplicationsFactors that affect the severity of complications include:The size and location of the neural tube defect .Whether skin covers the affected areaWhether spinal nerves come out of the affected area of the spinal cord.Children with myelomeningocele may experience physical and neurological problems, including lack of normal bowel and bladder control, and partial or complete paralysis of their legs.
27 Babies born with myelomeningocele also commonly experience accumulation of fluid in the brain, a condition known as hydrocephalus.Most babies with myelomeningocele will need a shunt .The majority of newborns with myelomeningocele survive.some may develop meningitis, an infection in the tissues surrounding the brain
28 Children with myelomeningocele may develop learning disabilities. Children with spina bifida may also suffer from latex allergies, skin problems, urinary tract infections, gastrointestinal disorders, seizure disorders, depression, and social and emotional problems.
29 Screening and diagnosis (1)Blood testssecond trimester maternal serum alpha fetoprotein (MSAFP)alpha-fetoprotein (AFP) is made naturally by the fetus and placenta. But if abnormally high levels of this protein appear in the mother’s bloodstream it may indicate that the fetus has a neural tube defect.The MSAFP test, however, is not specific for spina bifida.
30 Ultrasound: An advanced ultrasound can also detect signs of spina bifida. Amniocentesis An analysis indicates the level of AFP present in the amniotic fluid.A small amount of AFP is normally found in amniotic fluid.when an open neural tube defect is present, the amniotic fluid contains an elevated amount of AFP because the skin surrounding the baby's spine is gone and AFP leaks into the amniotic sac.MRI
31 Treatment There is no cure for spina bifida. The nerve tissue that is damaged or lost cannot be repaired or replaced.Treatment depends on the type and severity of the disorder.children with the mild form need no treatment .
32 The key priorities for treating myelomeningocele are to prevent infection from developing through the exposed nerves and tissue of the defect on the spine, and to protect the exposed nerves and structures from additional trauma.Doctors have recently begun performing fetal surgery for treatment of myelomeningocele.
33 Fetal surgery involves opening the mother’s abdomen and uterus and sewing shut the opening over the developing baby’s spinal cord. They believe the earlier the defect is corrected, the better the outcome is for the baby.Still, the benefits of fetal surgery are promising, and include less exposure of the vulnerable spinal nerve tissue and bones to the intrauterine environment, in particular the amniotic fluid, which is considered toxic.
34 Early surgery on the spinal cord may allow the child to regain a normal level of functioning and prevent further neurological deterioration.Some children will need subsequent surgeries to manage problems with the feet, hips, or spine.Individuals with hydrocephalus generally will require additional surgeries to replace the shuntSome individuals with spina bifida require assistive devices such as braces, crutches, or wheelchairs. The location of the malformation on the spine often indicates the type of assistive devices needed.
35 Treatment for paralysis and bladder and bowel problems typically begins soon after birth
36 PreventionFolic acid is an important vitamin in the development of a healthy fetus.Recent studies have shown that by adding folic acid to their diets, women of childbearing age significantly reduce the risk of having a child with a neural tube defect, such as spina bifida. Dosage:400 micrograms of folic acid dailyFoods high in folic acid include dark green vegetables, egg yolks, and some fruits.
37 prognosisPrognosis depends on the number and severity of abnormalities and associated complications.