Spina Bifida

What is spina bifida?

Spina bifida is one of a group of disorders called neural tube defects — malformations of the brain, spinal cord, or their coverings. Spina bifida occurs when a fetus's developing spinal column does not close properly in the first 28 days following fertilization. The disorder can take one of three forms:

Spina bifida occulta: The spinal column is not completely closed. This may not cause any symptoms and often requires no treatment.
Meningocele: Part of covering of the spinal cord called the meninges may protrude through an opening in the back.
Myelomeningocele: A portion of the spinal cord itself protrudes through an opening in the back.

Meningoceles and myelomeningoceles may appear as saclike structures on an infant's back at birth. When most people refer to spina bifida, they are referring to the most severe form, myelomeningocele. The incidence of neural tube defects varies by country, ranging between one and 10 per 10,000 births. Higher rates are often reported among poorer populations.

Symptoms of spina bifida

The symptoms of spinal bifida can range from mild to severe depending on the severity of the condition itself. In myelomeningocele, the child may have muscle weakness or paralysis below the level of the incompletely closed spinal column, because nerves traveling to the rest of the body from the spinal cord do not function properly. Loss of sensation and an inability to control bladder or bowel function are common.

Additionally, cerebrospinal fluid may build up in the brain, leading to a condition called hydrocephalus, which is common in children with myelomeningocele. If left untreated, hydrocephalus can cause brain damage, blindness, or seizures.

In addition to physical problems, spina bifida can produce learning problems, including difficulty with the following:

paying attention and expressing or understanding spoken language
reading and mathematical concepts
organizing or sequencing information.

Additional birth defects often accompany spina bifida, including abnormal brain development (called Chiari II malformation), cleft lip or palate, heart malformations, and abnormal genitourinary tract development. Other conditions that may occur more often in those with spina bifida than in those without neural tube defects include latex allergy (perhaps related to the multiple surgeries required early in life), obesity, skin problems, depression, and gastrointestinal disorders. Spina bifida is also associated with scoliosis, perhaps as a complication of muscle paralysis or abnormalities within the spinal cord.

Diagnosing spina bifida

Spina bifida most often is diagnosed at birth when a sac on the baby's spine is seen. Spina bifida may be suspected during pregnancy because a screening test, the alpha-fetoprotein (AFP), is higher than normal. Because a number of factors can influence the results of an AFP test, a high level does not establish the diagnosis by itself. If the AFP level is elevated, the test is usually repeated, and if the level is still abnormal, further tests such as ultrasound and amniocentesis may be recommended.

Expected duration of spina bifida

Spina bifida is a lifelong condition. A baby born with spina bifida (and myelomeningocele) usually has surgery within the first few days of life to attempt to preserve as much spinal cord function as possible. Other surgeries and extensive medical care probably will be required throughout the person's lifetime.

Preventing spina bifida

Studies have shown that getting enough folic acid dramatically reduces a woman's chance of giving birth to a baby with spina bifida. Folic acid supplementation should begin before pregnancy takes place, because the spinal column forms so early after fertilization. In addition to its ability to prevent spina bifida, folic acid appears to reduce its severity as well.

As a result of these studies, in 1992 the U.S. Public Health Service began recommending that all women of childbearing age consume 0.4 milligrams of folic acid daily. Consuming this amount probably requires taking a vitamin supplement, although folic acid is found in dark green leafy vegetables, egg yolks, and some fruits and their juices. Since the recommendation was issued, many other foods, including breads and cereals, are now fortified with folic acid.

Prenatal counseling may include testing for neural tube defects, complications of the condition, and consideration of terminating the pregnancy. Fetal surgery is available in only a few medical centers, so deciding where to deliver is important when a significant neural tube defect is suspected.

Certain complications of spina bifida may be prevented with proper medical care. For example, the detection and treatment of bladder problems and urinary tract infections can prevent the development of kidney disease.

Treating spina bifida

While spina bifida occulta usually requires no treatment, the more severe types of spina bifida usually require surgery soon after delivery to close the opening in the back, to preserve spinal cord function, and to reduce the risk of infection. Fetal surgery may be an option and is most often performed during the second trimester.

Additional surgeries are often required. Shunting, a procedure that drains excess fluid from the brain into the abdomen, controls hydrocephalus and can prevent or reduce many of the consequences of this condition.

Children with spina bifida will need to learn how to use wheelchairs, crutches, or braces to improve their mobility. Other interventions can help them become more independent in managing bladder and bowel problems. Educational issues can be addressed with the appropriate professionals.

Other treatments depend on the severity of the abnormality and which complications develop. For example, constipation can be treated with laxatives, and physical therapy can improve strength and function.

When to call a professional

Doctors will be involved from birth onward in the care of a child with spina bifida. If you notice an abnormal appearance in your child's back or have concerns about whether his or her neurological function is normal, let your child's pediatrician know.

Prognosis

As a result of today's sophisticated medical techniques and interventions, a child with spina bifida often lives well into adulthood, though usually with significant imapirment of spinal cord function.