spina bifida

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Definition

Spina bifida is a serious birth abnormality in which the spinal cord is malformed and lacks its usual protective skeletal and soft tissue coverings.

Description

Spina bifida may appear in the body midline anywhere from the neck to the buttocks. In its most severe form, termed spinal rachischisis, the entire spinal canal is open, exposing the spinal cord and nerves. More commonly, the abnormality appears as a localized mass on the back that is covered by skin or by the meninges, the three-layered membrane that envelopes the spina cord. Spina bifida is usually readily apparent at birth because of the malformation of the back and paralysis below the level of the abnormality.

Various forms of spina bifida are known as meningomyelocele, myelomeningocele, spina bifida aperta, open spina bifida, myelodysplasia, spinal dysraphism, spinal rachischisis, myelocele, and meningocele. The term meningocele is used when the spine malformation contains only the protective covering (meninges) of the spinal cord. The other terms indicate involvement of the spinal cord and nerves in the malformation. A related term, spina bifida occulta, indicates that one or more of the bony bodies in the spine are incompletely hardened, but that there is no abnormality of the spinal cord itself.

Spina bifida occurs worldwide, but there has been a steady downward trend in occurrence rates over the past 50 to 70 years, particularly in regions of high prevalence. The highest prevalence rates, about one in 200 pregnancies, have been reported from certain northern provinces in China. Intermediate prevalence rates, about one in 1,000 pregnancies, have been found in Central and South America. The lowest prevalence rates, less than one in 2,000 pregnancies, have been found in the European countries. The highest regional prevalence in the United States of about one in 500 pregnancies has occurred in the Southeast.

— Roger E. Stevenson

A congenital defect in which the spinal column is imperfectly closed so that part of the meninges or spinal cord protrudes, often resulting in hydrocephalus and other neurological disorders. Also called schistorrhachis.

[New Latin spīna bifida : Latin spīna, spine + Latin bifida, feminine of bifidus, split in two.]

Definition

Spina bifida belongs to a group of disorders known as neural tube defects (NTDs). These all involve problems in the development and closure of the neural tube, a structure in the human fetus that begins forming very early in a pregnancy. The neural tube eventually becomes the spinal column. When the neural tube does not close properly, it can lead to spina bifida, a disruption in the spinal column. Spina bifida occurs to varying degrees of severity, and in various forms.

Description

Spina bifida is also known by the name spinal dysraphism. It generally occurs in two major types. One types is spina bifida cystica or spina bifida aperta, which involves a sac filled with spinal contents along the spine. The other type is spina bifida occulta, in which the spinal cord stays inside the spinal canal and there is no sac.

Spina bifida ranges from having no or mild effects, to having severe effects and a significant impact upon a person's life. Physical symptoms can include weakness of limbs, paralysis, lack of bowel or bladder control, learning problems, hydrocephalus, seizures, central apnea, club-feet, impaired vision, and latex sensitivity.

Depending upon the involvement of the spinal problem, spina bifida can also have psychological and emotional impacts upon the affected person and his or her family.

Demographics

Spina bifida is fairly common; it is thought to occur in about one in 2,000 live births in the United States. NTDs in general occur in about one in 1,000 live births in the United States. Many areas have an even higher prevalence, for somewhat unknown reasons. A population with a higher prevalence for NTDs is the United Kingdom, with an estimated rate of 2.8 per 1,000 live births in the 1970s. A similar study in Ireland at that time estimated the rate to be about 7.1 per 1,000 live births. Through the advent of prenatal screening, prenatal diagnosis, pregnancy management options, and unknown factors the prevalence in the British Isles has fallen somewhat in recent years.

Higher rates of NTDs have been reported in the northwest British Isles, with lower rates in the southeast. In Canada, higher prevalence rates for NTDs have been reported in the eastern region of the country, as compared to the western region. A higher prevalence of NTDs has been seen in China in the provinces north of the Yangtze River, and these may be as much as six times higher than in the southern provinces. Pockets of higher prevalence have also been seen in India, but these do not fit any clear geographic areas or regions.

In the United States, people of Hispanic ancestry have a higher chance for NTDs than other ethnic groups. Conversely, African Americans and some Asians have a lower risk than other ethnic groups. When those with high NTD risks immigrate to other countries, they do not keep their high risk for NTDs. When those with low NTD risks migrate, they tend to maintain their low risk status, as a group.

Spina bifida has been reported in males and females roughly equally.

Causes and symptoms

Spina bifida occurs because the neural tube, around the area of the spine, fails to close during fetal development. A multifactorial cause for this has been assumed, because multiple factors seem to be involved. It may best be described as an interaction between multiple genes and the environment. Many aspects of this interaction are still not well understood. As well, an exact neurological cause for spina bifida has not been identified.

Spina bifida can run in families. Multiple genes may be involved because identical twins, those with the exact same genetics, have been studied at length. Spina bifida also occurs as part of genetic syndromes and chromosome disorders.

Numerous families with NTDs have been studied to help identify recurrence risks. Generally, the risk is 3–5% for a couple to have another child with an NTD if they already have one. If a parent has an NTD, they have a 3–5% chance to have a child with one. If two or more children already have NTDs, the risk is 6–9% for another one. If an NTD is in other more distant family members, the risk is somewhat higher than the average population, but probably not higher than 0.5%.

Environmental factors are also important in spina bifida. For example, taking the B vitamin folic acid before pregnancy conception has been shown to significantly reduce a woman's risk of having a child with the condition. Additionally, some medications can increase a woman's risk for spina bifida; these include some anti-seizures medications. As it turns out, many of these medications naturally reduce the levels of folic acid in one's body.

Neurological symptoms of spina bifida are varied. Many of them relate back to the early embryo's development, and how spina bifida occurs at this time. Three cell layers develop in the very early embryo; these are the ectoderm, mesoderm, and endoderm. The mesoderm normally sends signals to a region of the ectoderm to make it develop into neural tissue. Eventually, the neural ectoderm folds to form a tube, which runs for most of the length of the embryo. The top of the neural tube eventually forms the brain and top of the spinal column. The bottom of the neural tube eventually forms the lower back and bottom of the spinal column. This happens through very careful and controlled cell movements. The neural tube is usually completed forming by about 18 to 26 days after ovulation.

Failure of the neural tube to close causes spina bifida, and this disrupts the spinal column's structure and functioning. This disruption can be mild, as in spina bifida occulta. It may also be more severe with a large sac or cyst present, as in spina bifida cystica.

In about 80–90% of spina bifida cases, there is a cyst with parts of the spinal cord and spinal wall present. This is called a myelomeningocele (or meningomyelocele). This type of spina bifida can happen in a relatively high or low position on one's back. It often causes problems with bladder and bowel functioning, and sometimes paralysis or limb weaknesses. A neuropathic bladder can sometimes affect kidney functioning as well.

When a developing baby cannot move their limbs well in utero, this sometimes leads to feet and legs that turn inward, or clubfoot. As a result, some children with spina bifida are born with clubfoot.

Myelomeningoceles often cause spinal fluid to not flow properly through the system, and hydrocephalus may be a result. Head ultrasound scans may show hydrocephalus in about 90% of newborns with spina bifida. It is often associated with an Arnold-Chiari malformation, Type II. This occurs when the medulla pushes downward below the foramen magnum, and overlaps the spinal cord. This malformation is present in about 70% of people who have a meningomyelocele; it can cause distortion of the medulla and midbrain, as well as central apnea.

Hydrocephalus can eventually cause increased pressure to develop in the brain. This may ultimately lead to one's brain not being able to grow properly, and cause learning problems. Seizures may also be present. Learning problems are not a certainty with spina bifida, but when present they vary greatly. Their severity is impossible to predict. However, hydrocephalus and seizures put one at a higher risk for learning problems. Surveys on intellectual development have shown that children with hydrocephalus have lower IQs than their siblings without the condition.

In about 5% of spina bifida cases, there is no spinal tissue in the cyst wall; these are called meningoceles. Hydrocephalus is not usually present in this type of spina bifida, and a neurological examination may even be perfectly normal.

Optic atrophy and squinting may occur in people who have spina bifida, and a result of these may be poorer vision.

There is an association between spina bifida and latex sensitivity. Many have attributed this to the fact that people with the condition have a higher exposure to latex, since they may be in hospitals more often. Interestingly, a study in 2000 showed that 22% of children with spina bifida still had latex sensitivity, despite efforts to maintain latex-free environments for them.

Spina bifida occulta may cause mild symptoms, or none at all. Sometimes the only signs of it may in the lower spine area as a dimple, a small tuft of hair, or a small growth. If one has an imaging scan and a tethered spinal cord is noted, this can sometimes be a sign of spina bifida occulta as well.

Diagnosis

A early time to find spina bifida is during a detailed prenatal ultrasound scan, especially between 16 and 20 weeks gestation (from the last menstrual period). Ultrasounds cannot identify every structural problem in a developing baby, so some cases of spina bifida (especially mild forms) may be missed. However, it is a risk-free method to use that gives immediate results.

Prenatal blood screening is often offered to women between 15 and 21 weeks in a pregnancy. This screening measures the levels of various chemicals naturally found in a mother's blood, including alpha-fetoprotein (AFP). For this reason, the screening is often called AFP screening. AFP is a protein normally made by a developing fetus, so it is naturally present in maternal serum and called MSAFP. When a fetus has spina bifida, the levels of MS-AFP may be higher than usual because it leaks out of the hole in the spine. If a woman's AFP screen comes back abnormal with a high MS-AFP value, she often is at a higher risk for having a baby with spina bifida. This may prompt her physician to offer her a detailed ultrasound, as well as other medical options that might give her more information about the baby.

One option to find spina bifida is a procedure called amniocentesis. Amniocentesis involves removing a small amount of fluid from around the baby, using a fine needle. This fluid naturally contains AFP, which may also be elevated if the baby has spina bifida. There is a small risk of miscarriage, about one in 200, with this procedure. As such, every women usually receives proper counseling through their doctor or a genetic counselor before having the test done.

Sometimes, spina bifida can only be seen at birth. A physical examination usually identifies spina bifida cystica fairly easily, especially if the sac is large. Spina bifida occulta can be more difficult to find, but clues can be a dimple in the lower back, a tuft of hair, or a small growth.

Once spina bifida is seen outwardly, imaging scans like x rays, ultrasound, magnetic resonance imaging (MRI), or computed tomography (CT) can be helpful to see the extent of it. It is also a good way to identify whether someone has associated neurological complications like hydrocephalus.

Since spina bifida may occur as part of some genetic conditions, a medical geneticist should be involved to thoroughly examine a child with spina bifida. Identifying a particular syndrome in a child can help them receive more personalized medical care, and can help families identify a cause for why the spina bifida happened. It can also help to give families specific information about the chance of it happening again, for them or for other family members.

Some genetic testing, like chromosome studies, may identify a diagnosis or cause for the spina bifida. Abnormal genetic test results cannot be changed or reversed, but may provide answers about why the spina bifida occurred.

Treatment team

Treatment for people with spina bifida is highly dependent upon their symptoms. A multi-disciplinary team and approach is extremely helpful. Some hospitals offer day-long clinics devoted to people with spina bifida, which makes things much easier for families in terms of coordinating multiple appointments.

A treatment team for someone with spina bifida may include a neurologist, neurosurgeon, surgeon, neuropsychologist, medical geneticist, genetic counselor, orthopedic surgeon, physiatrist, physical therapist, occupational therapist, speech therapist, registered dietitian, social worker, nephrologist, ophthalmologist, audiologist, and a primary care provider. A neonatologist and pediatric specialists in those fields may be available to aid in the care for children. Those specializing in early childhood and development are particularly helpful, especially for issues related to attending school. Above all, good communication between the various specialists to coordinate care is essential.

Treatment

There is no known cure for spina bifida. Treatment primarily focuses on dealing with symptoms as they arise, since they vary so greatly from person to person.

Surgery to correct the spinal problem in spina bifida cystica is often done. This involves carefully tucking the spinal contents back into the spinal column, and closing the covering back up. This often happens shortly following birth to reduce the risk of developing an infection, and requires some time to heal afterward. Surgery has not been known to allow someone to regain functions they would not have had otherwise like movement, bowel, or bladder control.

A child with spina bifida is often carefully watched for signs of hydrocephalus. This may be done by measuring head circumference (which may enlarge) or with periodic head ultrasound or CT scans. If hydrocephalus is found, a procedure to put in a ventriculoperitoneal (VP) or ventriculoatrial (VA) shunt may be done. If a shunt is placed, it must be continually monitored and may need to be adjusted. Some people have their shunts removed later if the hydrocephalus never returns, and some people have a shunt for their entire lives.

Medications are widely available to treat those who develop seizures, and these may need periodic adjustments. Those who have problems with bowel or bladder control may require surgery, medications, or may never fully have these functions.

Babies and children with clubfoot often need to see an orthopedic surgeon and physiatrist, both of whom can recommend ways to correct them. Wearing braces on the legs can turn the feet back to their usual position, and this may be the only thing required. Sometimes surgery is necessary.

Surgery to correct the spinal problem during a pregnancy is experimental and not widely available. Since 1997, about 200 fetuses have had closure of myelomeningoceles during pregnancy. Since the surgery is so new, exact success rates, safety and long-term effects of the procedure are still not known as of early 2004.

Recovery and rehabilitation

Therapies and rehabilitation may be quite involved or relatively brief for people with spina bifida, depending on the severity of symptoms. Physical therapy is extremely important and can be ongoing. Speech and occupational therapies may be helpful if learning problems or delayed development are noted.

For those with wheelchairs, ramps and other assistive devices are helpful in their homes and places they frequent.

Clinical trials

As of early 2004, two clinical trials are under way in the United States to study spina bifida. National Institute of Child Health and Human Development (NICHD) sponsors both of these studies. One study is devoted to the genetics of spina bifida, recruiting many family members of an affected person to analyze and compare selected genes. The other study is attempting to identify the effectiveness and safety of spina bifida surgery during pregnancies. More information can be found at .

Prognosis

Prognosis in spina bifida is extremely varied and unpredictable. Years ago with far less intervention and fewer treatments available, someone with severe spina bifida had a high chance to die from complications. Mortality may still be high in complex cases even today. Conversely, those with a mild form of spina bifida may never even know they have it unless they have an internal imaging scan for an unrelated reason. As such, they may never have complications related to spina bifida and would have an average life span.

Today, there are far more options for helping those with spina bifida. Information can be learned during a pregnancy, allowing parents to make decisions and potentially prepare before birth. These treatments and therapies help maintain a better quality of life for those with spina bifida, and continue to offer hope.

Special concerns

Many couples who find their child has spina bifida during a pregnancy experience an array of emotional and psychological issues. They may be wondering how and why this happened, and may want some immediate answers. They also may be feeling guilt or wondering whether they could have caused it to happen. Issues related to these pregnancies, such as continuation or interrupting a pregnancy, can be complex and should be treated with sensitivity and care.

An important aspect of good prenatal care is regular folic acid supplementation, because this is known to reduce the risk for NTDs significantly. This can be gained through a prenatal vitamin, a separate supplement, or a healthy diet. Many breakfast cereals, breads, and other foods are now being supplemented with folic acid.

The current recommendation is for all women in their reproductive years to take 0.4 milligrams of folic acid daily, especially from about three to four months before conception. A woman with an affected child should take 4 milligrams of folic acid daily, beginning at least three to four months prior to conception. The reason for taking folic acid before conception is because the fetal spine forms very early, sometimes before a woman even knows she is pregnant.

Another tricky issue is managing the pregnancy of a woman with epilepsy or a seizure disorder. Many antiseizure medications, like Depakote, cause an increased risk for NTDs and spina bifida. However, the risk of a woman having a seizure during pregnancy is also significant. The art is to find a balance between these two risks, in a way that makes everyone feel the most comfortable.

Resources

BOOKS

Lutkenhoff, Marlene. Spinabilities: A Young Person's Guide to Spina Bifida. Woodbine House, 1997.

Lutkenhoff, Marlene. Children with Spina Bifida: A Parent's Guide, 1st ed. Woodbine House, 2003.

Sandler, Adrian. Living with Spina Bifida: A Guide for Families and Professionals. University of North Carolina Press, 2004.

PERIODICALS

Frey, Lauren, and W. Allen Hauser. "Epidemiology of Neural Tube Defects." Epilepsia 44, Suppl. 3 (2003): 4–13.

Zipitis, Christos S., and Constantinos Paschalides. "Caring for a child with spina bifida: understanding the child and carer." Journal of Child Health Care 7, no. 2 (2003): 101–112.

WEBSITES

Children with Spina Bifida: A Resource Page for Parents.www.waisman.wisc.edu/~rowley/sb-kids/index.html.

March of Dimes.www.modimes.org.

National Institute of Neurological Disorders and Stroke.www.ninds.nih.gov/index.htm.

ORGANIZATIONS

Association for Spina Bifida & Hydrocephalus (U.K.). ASBAH House, 42 Park Road, Peterborough, United Kingdom PE1 2UQ. (01733) 555988. (01733) 555985. info@asbah.org. http://www.asbah.org.

Spina Bifida and Hydrocephalus Association of Canada. 977-167 Lombard Avenue, Winnipeg, Manitoba, Canada R3B 0V3. 204-925-3650 or 800-565-9488; Fax: 204-925-3654. spinab@mts.net. http://www.sbhac.ca/index.php?page=main.

Spina Bifida Association of America. 4590 MacArthur Boulevard N.W., Suite 250, Washington, DC 20007-4226. 202-944-3285 or 800-621-3141; Fax: 202-944-3295. sbaa@sbaa.org. http://www.sbaa.org.

Deepti Babu, MS, CGC

Congenital neural tube defect due to developmental anomaly in early embryonic development. Supplements of folic acid (400 μg/day), begun before conception, reduce the risk.

Definition

Spina bifida is a birth abnormality in which the spine is malformed and lacks its usual protective skeletal and soft tissue coverings.

Description

Spina bifida may appear in the body midline anywhere from the neck to the buttocks. In its most severe form, termed spinal rachischisis, the entire spinal canal is open, exposing the spinal cord and nerves. More commonly, the abnormality appears as a localized mass on the back that is covered by skin or by the meninges, the three-layered membrane that envelops the spinal cord. Spina bifida is usually readily apparent at birth because of the malformation of the back and paralysis below the level of the abnormality.

Various forms of spina bifida are known as meningomyelocele, myelomeningocele, spina bifida aperta, open spina bifida, myelodysplasia, spinal dysraphism, spinal rachischisis, myelocele, and meningocele. The term meningocele is used when the spine malformation contains only the protective covering (meninges) of the spinal cord. The other terms indicate involvement of the spinal cord and nerves in the malformation. A related term, spina bifida occulta, indicates that one or more of the bony bodies in the spine are incompletely hardened, but that there is no abnormality of the spinal cord itself.

Demographics

Spina bifida occurs worldwide, but there has been a steady downward trend in occurrence rates since about 1940, particularly in regions of high prevalence. The highest prevalence rates, about one in 200 pregnancies, have been reported from certain northern provinces in China. Intermediate prevalence rates, about one in 1000 pregnancies, have been found in Central and South America. The lowest prevalence rates, less than one in 2,000 pregnancies, have been found in European countries. The highest regional prevalence in the United States of about one in 500 pregnancies has occurred in the Southeast.

Causes and Symptoms

Spina bifida may occur as an isolated abnormality or in the company of other malformations. As an isolated abnormality, spina bifida is caused by the combination of genetic factors and environmental influences that bring about malformation of the spine and spinal column. The specific genes and environmental influences that contribute to the many-factored causes of spina bifida were not as of 2004 completely known. An insufficiency of folic acid is known to be one influential nutritional factor. Changes (mutations) in genes involving the metabolism of folic acid are believed to be significant genetic risk factors. The recurrence risk after the birth of an infant with isolated spina bifida is 3 to 5 percent. Recurrence may be for spina bifida or another type of spinal abnormality.

Spina bifida may arise because of chromosome abnormalities, single gene mutations, or specific environmental insults such as maternal diabetes mellitus or prenatal exposure to certain anticonvulsant drugs. The recurrence risk varies with each of these specific causes.

In most cases, spina bifida is obvious at birth because of malformation of the spine. The spine may be completely open, exposing the spinal cord and nerves. More commonly, the spine abnormality appears as a mass on the back covered by membrane (meninges) or skin. Spina bifida may occur any where from the base of the skull to the buttocks. About 75 percent of abnormalities occur in the lower back (lumbar) region. In rare instances, the spinal cord malformation may occur internally, sometimes with a connection to the gastrointestinal tract.

In spina bifida, many complications arise, dependent in part on the level and severity of the spine malformation. As a rule, the nerves below the level of the abnormality develop in a faulty manner and fail to function, resulting in paralysis and loss of sensation below the level of the spine malformation. Since most abnormalities occur in the lumbar region, the lower limbs are paralyzed and lack sensation. Furthermore, the bowel and bladder have inadequate nerve connections, causing an inability to control bowel and bladder function. Most infants also develop hydrocephaly, an accumulation of excess fluid in the four cavities of the brain. At least one of every seven cases develops findings of Chiari II malformation, a condition in which the lower part of the brain is crowded and may be forced into the upper part of the spinal cavity.

There are a number of mild variant forms of spina bifida, including multiple vertebral abnormalities, skin dimples, tufts of hair, and localized areas of skin deficiency over the spine. Two variants, lipomeningocele and lipomyelomeningocele, typically occur in the lower back area (lumbar or sacral) of the spine. In these conditions, a tumor of fatty tissue becomes isolated among the nerves below the spinal cord, which may result in tethering of the spinal cord and complications similar to those with open spina bifida.

Diagnosis

Few disorders are to be confused with open spina bifida. The diagnosis is usually obvious based on the external findings at birth. Paralysis below the level of the abnormality and fluid on the brain (hydrocephaly) may contribute to the diagnosis. Other spine abnormalities such as congenital scoliosis and kyphosis, or soft tissue tumors overlying the spine, are not likely to have these accompanying findings. In cases in which there are no external findings, the diagnosis is more difficult and may not become evident until neurological abnormalities or hydrocephaly develop weeks, months, or years following birth.

Prenatal diagnosis may be made in most cases with ultrasound examination after 12 to 14 weeks of pregnancy. Many cases are also detected by the testing of the mother's blood for the level of alpha-fetoprotein at about 16 weeks of pregnancy. If the spine malformation is not skin covered, alpha-fetoprotein from the fetus's circulation may leak into the surrounding amniotic fluid, a small portion of which is absorbed into the mother's blood.

Treatment

Aggressive surgical and medical management have improved the survival and function of infants with spina bifida. Initial surgery may be carried out during the first days of life, in the hope of providing protection against injury and infection. Subsequent surgery is often necessary to protect against excessive curvature of the spine, and in the presence of hydrocephaly, to place an echanical shunt to decrease the pressure and amount of cerebrospinal fluid in the cavities of the brain. Because of weakness or paralysis below the level of the spine abnormality, most children require physical therapy, bracing, and other orthopedic assistance in order to be able to walk. A variety of approaches including periodic bladder catheterization, surgical diversion of urine, and antibiotics are used to protect urinary function.

Although most individuals with spina bifida have normal intellectual function, learning disabilities or mental retardation occur in a minority. This deficit may result, in part, from hydrocephaly and/or infections of the nervous system. Children so affected may benefit from early educational intervention, physical therapy, and occupational therapy. Counseling to improve self-image and lessen barriers to socialization becomes important in late childhood and adolescence.

Open fetal surgery has been performed for spina bifida during the last half of pregnancy. After direct closure of the spine malformation, the fetus is returned to the womb. By preventing chronic intrauterine exposure to mechanical and chemical trauma, prenatal surgery improves neurological function and leads to fewer complications after birth. Fetal surgery is considered experimental, and results have been mixed.

Prognosis

More than 80 percent of infants born with spina bifida survive with surgical and medical management. Although complications from paralysis, hydrocephaly, Chiari II malformation, and urinary tract deterioration threaten the well-being of the survivors, the outlook for normal intellectual function is good.

Prevention

Prevention of isolated spina bifida and other spinal abnormalities became possible in the 1980s and 1990s. The major prevention is through the use of folic acid, one of the B vitamins, for several months prior to and following conception. The Centers for Disease Control and Prevention (CDC) recommend the intake of 400 micrograms of synthetic folic acid every day for all women of childbearing years. For women who have had a previous child with spina bifida, the CDC recommends a daily intake of 4 milligrams of synthetic folic acid to help prevent a recurrence of spina bifida in future pregnancies.

Parental Concerns

Caring for a child with spina bifida can be a daunting endeavor. Initially, parents may be overwhelmed with the medical decisions to be made and with the grief experienced after the birth of a special needs child. Many parents benefit from early and continuing involvement of an experienced social worker. There will be a multitude of medical decisions to be made. Children with spina bifida require a multidisciplinary team of healthcare providers, including surgeons, physicians, and therapists. Parents may find it helpful to designate a physician, usually the primary pediatrician, or an experienced rehabilitation counselor to act as an advocate for their child and to aid them in coordinating their child's treatment program.

Parental concerns may be two-fold, medical and emotional. Medical concerns include monitoring their child's condition after surgery. Children with spina bifida may have many surgical procedures throughout their lives. Post surgical complications are common but may often be avoided. Parents will be given care instructions after each surgery. Children with spina bifida face a multitude of heath issues such as monitoring bladder and bowel function, maintaining proper nutrition, preventing broken bones, promoting healthy growth and development, and encouraging activity and mobility. Many children with spina bifida have non-surgical treatments as well, such as positional aides to help the child sit and stand, physical therapy, and bracing and splints usually of the lower extremities.

Parents of children with spina bifida experience an array of emotions, including grief, fear, anxiety, and stress. Spina bifida impacts not only the affected child but the entire family. Groups and networks of other families affected by spina bifida can provide valuable support. Parents may need to be active in ensuring that their child receives the early intervention and educational services available in their community. Each state has programs to encourage healthy development in children with special needs.

Finally, parents should remember that most children with spina bifida live productive and happy lives. For the most part, children with spina bifida have average or above-average intelligence. Many of these children can go on to higher education, have active careers, and live self-sufficiently. It is important for parents to encourage strong self esteem in their child and to foster independent living skills.

Resources

Books

Behrman, Richard E., Robert M. Kliegman, and Hal B. Jenson, eds. Nelson Textbook of Pediatrics, 16th ed. Philadelphia: W. B. Saunders, 2000.

Sutton, Amy L. Back and Neck Sourcebook: Basic ConsumerHealth Information. Detroit, MI: Omnigraphics, 2004.

Organizations

March of Dimes Birth Defects Foundation. 1275 Mamaroneck Ave., White Plains, NY 10605. Web site: www.modimes.org.

National Birth Defects Prevention Network. Web site: www.nbdpn.org.

Shriners Hospitals for Children. International Shrine Headquarters, 2900 Rocky Point Dr., Tampa, FL 33607–1460. Web site: www.shrinershq.org.

Spina Bifida Association of America. 4590 MacArthur Blvd. NW, Suite 250, Washington, DC 20007–4226. Web site: www.sbaa.org.

[Article by: Roger E. Stevenson Deborah L. Nurmi, MS]

A congenital condition that involves an imperfectly closed spinal column, often resulting in neurological disorders.

Spina bifida cystica
Classification and external resources
ICD-10	Q05., Q76.0
ICD-9	741, 756.17
OMIM	182940
DiseasesDB	12306
eMedicine	orthoped/557
MeSH	C10.500.680.800

Spina bifida (Latin: "split spine") is a developmental birth defect caused by the incomplete closure of the embryonic neural tube. Some vertebra overlying the spinal cord are not fully formed and remain unfused and open. If the opening is large enough, this allows a portion of the spinal cord to stick out through the opening in the bones. There may or may not be a fluid filled sac surrounding the spinal cord. Other neural tube defects include anencephaly, a condition in which the portion of the neural tube which will become the cerebrum does not close, and encephalocele, which results when other parts of the brain remain unfused.

Spina bifida malformations fall into four categories: spina bifida occulta, spina bifida cystica (myelomeningocele), meningocele and lipomeningocele. The most common location of the malformations is the lumbar and sacral areas . Myelomeningocele is the most significant form and it is this that leads to disability in most affected individuals. The terms spina bifida and myelomeningocele are usually used interchangeably.

Spina bifida can be surgically closed after birth, but this does not restore normal function to the affected part of the spinal cord. Intrauterine surgery for spina bifida has also been performed and the safety and efficacy of this procedure is currently being investigated. The incidence of spina bifida can be decreased by up to 75 percent when daily folic acid supplements are taken prior to conception.^[1]

Contents 1 Signs and symptoms 2 Diagnosis of the different types 2.1 Spina bifida occulta 2.2 Meningocele 2.3 Spina bifida cystica 3 Pathophysiology 4 Treatment 4.1 Fetal Surgery Clinical Trial 5 Epidemiology 6 Prevention 7 Pregnancy screening 8 Notable people 9 In media 10 See also 11 References 12 External links

Signs and symptoms

Children with spina bifida often have hydrocephalus, which consists of excessive accumulation of cerebrospinal fluid in the ventricles of the brain.^[2]

According to the Spina Bifida Association of America (SBAA), over 73 percent of people with spina bifida develop an allergy to latex, ranging from mild to life-threatening. The common use of latex in medical facilities makes this a particularly serious concern. The most common approach is to try to avoid development of the allergy by avoiding contact with latex-containing products such as examination gloves, catheters, and many of the products used by dentists.^[3]

Diagnosis of the different types

Spina bifida occulta

X-ray image of Spina bifida occulta in S-1

Occulta is Latin for "hidden". This is one of the mildest forms of spina bifida.^[4]

In occulta, the outer part of some of the vertebrae are not completely closed.^[3] The split in the vertebrae is so small that the spinal cord does not protrude. The skin at the site of the lesion may be normal, or it may have some hair growing from it; there may be a dimple in the skin, a lipoma, a dermal sinus or a birthmark.^[5]

Many people with the mildest form of this type of spina bifida do not even know they have it, as the disease is asymptomatic in most cases.^[5] A systematic review of radiographic research studies found no relationship between spina bifida occulta and back pain.^[6] More recent studies not included in the review support the negative findings.^[7][8][9]

However, other studies suggest spina bifida occulta is not always harmless. One study found that among patients with back pain, severity is worse if spina bifida occulta is present.^[10][11]

Meningocele

The least common form of spina bifida is a posterior meningocele (or meningeal cyst).

In a posterior meningocele, the outer faces of some vertebrae are open (unfused) and the meninges are damaged and pushed out through the opening, appearing as a sac or cyst which contains cerebrospinal fluid. Apart from spina bifida, causes of meningocele include teratoma and other tumors of the sacrococcyx and of the presacral space, and Currarino syndrome. Usually a meningocele has no negative long-term effects, although there are reports of tethered cord.

Spina bifida cystica

Spina bifida cystica is also known as meningomyelocele. In this, the most serious and common^[12] form, the unfused portion of the spinal column allows the spinal cord to protrude through an opening. The meningeal membranes that cover the spinal cord form a sac enclosing the spinal elements. Spina bifida with myeloschisis is the most severe form of spina bifida cystica. In this defect, the involved area represented by a flattened, plate-like mass of nervous tissue with no overlying membrane. The exposure of these nerves and tissues make the baby more prone to life-threatening infections.^[13]

The protruded portion of the spinal cord and the nerves which originate at that level of the cord are damaged or not properly developed. As a result, there is usually some degree of paralysis and loss of sensation below the level of the spinal cord defect. Thus, the higher the level of the defect the more severe the associated nerve dysfunction and resultant paralysis. People may have ambulatory problems, loss of sensation, deformities of the hips, knees or feet and loss of muscle tone. Depending on the location of the lesion, intense pain may occur originating in the lower back, and continuing down the leg to the back of the knee.

Many individuals with spina bifida will have an associated abnormality of the cerebellum, called the Arnold Chiari II malformation. In affected individuals the back portion of the brain is displaced from the back of the skull down into the upper neck. In approximately 90 percent of the people with myelomeningocele, hydrocephalus will also occur because the displaced cerebellum interferes with the normal flow of cerebrospinal fluid.

The myelomeningocele (or perhaps the scarring due to surgery) tethers the spinal cord. In some individuals this causes significant traction on the spinal cord and can lead to a worsening of the paralysis, scoliosis, back pain, or worsening bowel and/or bladder function.

Pathophysiology

Spina bifida is caused by the failure of the neural tube to close during the first month of embryonic development (often before the mother knows she is pregnant).

Normally the closure of the neural tube occurs around 28 days after fertilization.^[14] However, if something interferes and the tube fails to close properly, a neural tube defect will occur. Medications such as some anticonvulsants, diabetes, having a relative with spina bifida, obesity, and an increased body temperature from fever or external sources such as hot tubs and electric blankets can increase the chances a woman will conceive a baby with a spina bifida. However, most women who give birth to babies with spina bifida have none of these risk factors, and so in spite of much research, it is still unknown what causes the majority of cases.

The varying prevalence of spina bifida in different human populations and extensive evidence from mouse strains with spina bifida suggests a genetic basis for the condition. As with other human diseases such as cancer, hypertension and atherosclerosis (coronary artery disease), spina bifida likely results from the interaction of multiple genes and environmental factors.

Research has shown that lack of folic acid (folate) is a contributing factor in the pathogenesis of neural tube defects, including spina bifida. Supplementation of the mother's diet with folate can reduce the incidence of neural tube defects by about 70 percent, and can also decrease the severity of these defects when they occur.^[15][16][17] As of yet it is unknown how or why folic acid has this effect.

Spina bifida does not follow direct patterns of heredity like muscular dystrophy or haemophilia. Studies show that a woman who has had one child with a neural tube defects such as spina bifida, have about a three percent risk of having another child with a neural tube defect. This risk can be reduced to about one percent if the woman takes high doses (4 mg/day) of folic acid before and during pregnancy. For the general population, low-dose folic acid supplements are advised (0.4 mg/day).

Treatment

There is no known cure for nerve damage due to spina bifida. To prevent further damage of the nervous tissue and to prevent infection, pediatric neurosurgeons operate to close the opening on the back. During the operation for spina bifida cystica, the spinal cord and its nerve roots are put back inside the spine and covered with meninges. In addition, a shunt may be surgically installed to provide a continuous drain for the cerebrospinal fluid produced in the brain, as happens with hydrocephalus. Shunts most commonly drain into the abdomen. However, if spina bifida is detected during pregnancy, then open fetal surgery can be performed.

Most individuals with myelomeningocele will need periodic evaluations by specialists including orthopedists to check on their bones and muscles, neurosurgeons to evaluate the brain and spinal cord and urologists for the kidneys and bladder. Such care is best begun immediately after birth. Most affected individuals will require braces, crutches, walkers or wheelchairs to maximize their mobility. The higher the level of the spina bifida defect the more severe the paralysis. Thus, those with low levels may need only short leg braces while those with higher levels do best with a wheelchair. Many will need to manage their urinary system with a program of catheterization. Most will also require some sort of bowel management program.

Fetal Surgery Clinical Trial

Management of Myelomeningocele Study (MOMS)^[18] is a phase III clinical trial to evaluate the safety and efficacy of fetal surgery to close a myelomeningocele. This involves surgically opening the pregnant mother's abdomen and uterus to operate on the fetus. Fetal skin grafts are used to cover the exposed spinal cord, to protect it from further damage caused by prolonged exposure to amniotic fluid. The fetal surgery may decrease some of the damaging effects of the spina bifida, but at some risk to both the fetus and the pregnant woman.

Epidemiology

Spina bifida is one of the most common birth defects, with an average worldwide incidence of 1–2 cases per 1000 births, but certain populations have a significantly greater risk.

In the United States, the average incidence is 0.7 per 1000 live births. The incidence is higher on the East Coast than on the West Coast, and higher in whites (1 case per 1000 live births) than in blacks (0.1–0.4 case per 1000 live births). Immigrants from Ireland have a higher incidence of spina bifida than do nonimmigrants.^[19][20]

The highest incidence rates worldwide were found in Ireland and Wales, where 3–4 cases of myelomeningocele per 1000 population have been reported during the 1970s, along with more than six cases of anencephaly (both live births and stillbirths) per 1000 population. The reported overall incidence of myelomeningocele in the British Isles was 2–3.5 cases per 1000 births.^[19][20] Since then, the rate has fallen dramatically with 0.15 per 1000 live births reported in 1998.^[14]

Parents of children with spina bifida have an increased risk of having a second child with a neural tube defect.^[19][20]

This condition is more likely to appear in females; the cause for this is unknown.

Prevention

There is no single cause of spina bifida nor any known way to prevent it entirely. However, dietary supplementation with folic acid has been shown to be helpful in preventing spina bifida (see above). Sources of folic acid include whole grains, fortified breakfast cereals, dried beans, leaf vegetables and fruits.^[21]

Folate fortification of enriched grain products has been mandatory in the United States since 1998. The U.S. Food and Drug Administration, Public Health Agency of Canada^[22] and UK recommended amount of folic acid for women of childbearing age and women planning to become pregnant is at least 0.4 mg/day of folic acid from at least three months before conception, and continued for the first 12 weeks of pregnancy.^[23] Women who have already had a baby with spina bifida or other type of neural tube defect, or are taking anticonvulsant medication should take a higher dose of 4–5 mg/day.^[23]

Certain mutations in the gene VANGL1 are implicated as a risk factor for spina bifida: these mutations have been linked with spina bifida in some families with a history of spina bifida.^[24]

Pregnancy screening

Neural tube defects can usually be detected during pregnancy by testing the mother's blood (AFP screening) or a detailed fetal ultrasound. Spina bifida may be associated with other malformations as in dysmorphic syndromes, often resulting in spontaneous miscarriage. However, in the majority of cases spina bifida is an isolated malformation.

Genetic counseling and further genetic testing, such as amniocentesis, may be offered during the pregnancy as some neural tube defects are associated with genetic disorders such as trisomy 18. Ultrasound screening for spina bifida is partly responsible for the decline in new cases, because many pregnancies are terminated out of fear that a newborn might have a poor future quality of life. With modern medical care, the quality of life of patients has greatly improved.^[14]

Notable people

People of note born with spina bifida:

• Jade Calegory, actor, best known for his role as the disabled main character in Mac and Me.
• Lucy Coleman, from the children's TV show Signing Time!
• James Connelly, U.S. Paralympian, 2006 Bronze Medal Winner; Sledge Hockey
• Jean Driscoll,^[25] Olympian and eight-time Boston Marathon winner
• Aaron Fotheringham, U.S. wheelchair skateboarder
• Dame Tanni Grey-Thompson, Welsh Paralympian
• Lawrence Gwozdz, U.S. saxophonist
• Blaine Harrison,^[26] of the British band Mystery Jets
• Robert Hensel, Guinness world record holder
• Rene Kirby,^[27] U.S. actor in films such as Shallow Hal and Stuck on You
• John Mellencamp,^[28] U.S. rock and roll musician
• Dr. Karin Muraszko,^[29] chair of Department of Neurosurgery at University of Michigan, first female appointed to position in the country
• Reba Schappell, conjoined twin and country music musician
• Bobby Steele, U.S. punk rock guitarist and songwriter
• Jeffrey Tate, British conductor
• Dale Tryon, Baroness Tryon, Australian socialite and friend of Prince Charles
• Hank Williams, U.S. country music singer
• Lucinda Williams,^[30] U.S. country music singer/songwriter
• Miller Williams,^[30] U.S. poet
• Justin Yoder, U.S. soap box racer

In media

A young girl living with spina bifida was the subject of a Canadian short documentary I'll Find a Way, winner of the Academy Award for Best Live Action Short Film in 1977.^[31]

See also

• Hydrocephalus
• Valproic acid
• Neural tube defect
• Open fetal surgery
• MOMS Trial
• Pseudomeningocele
• Samuel Armas (an early recipient of open fetal surgery)
• Malone antegrade continence enema (MACE)
• Mitrofanoff appendicovesicostomy

References

1. ^ "Life saving Folic Acid Recommendation welcomed". ASBAH. http://www.asbah.org/folicacid/research/lifesavingfolicacidrecommendationwelcomed.htm. Retrieved on 2009-02-14. 
2. ^ National Institute of Neurological Disorders and Stroke
3. ^ ^{a b} Foster, Mark R. "Spina Bifida". http://www.emedicine.com/orthoped/TOPIC557.HTM. Retrieved on 2008-05-17. 
4. ^ "What Is Spina Bifida?". ASBAH. http://www.asbah.org/Spina+Bifida/informationsheets/whatisspinabifida.htm. Retrieved on 2009-02-14. 
5. ^ ^{a b} "Spina Bifida Occulta". ASBAH. http://www.asbah.org/Spina+Bifida/informationsheets/spinabifidaocculta.htm. Retrieved on 2009-02-14. 
6. ^ van Tulder MW, Assendelft WJ, Koes BW, Bouter LM (1997). "Spinal radiographic findings and nonspecific low back pain. A systematic review of observational studies". Spine 22 (4): 427–34. doi:10.1097/00007632-199702150-00015. PMID 9055372. 
7. ^ Iwamoto J, Abe H, Tsukimura Y, Wakano K (2005). "Relationship between radiographic abnormalities of lumbar spine and incidence of low back pain in high school rugby players: a prospective study". Scandinavian journal of medicine & science in sports 15 (3): 163–8. doi:10.1111/j.1600-0838.2004.00414.x. PMID 15885037. 
8. ^ Iwamoto J, Abe H, Tsukimura Y, Wakano K (2004). "Relationship between radiographic abnormalities of lumbar spine and incidence of low back pain in high school and college football players: a prospective study". The American journal of sports medicine 32 (3): 781–6. doi:10.1177/0363546503261721. PMID 15090397. 
9. ^ Steinberg EL, Luger E, Arbel R, Menachem A, Dekel S (2003). "A comparative roentgenographic analysis of the lumbar spine in male army recruits with and without lower back pain". Clinical radiology 58 (12): 985–9. doi:10.1016/S0009-9260(03)00296-4. PMID 14654032. 
10. ^ Taskaynatan MA, Izci Y, Ozgul A, Hazneci B, Dursun H, Kalyon TA (2005). "Clinical significance of congenital lumbosacral malformations in young male population with prolonged low back pain". Spine 30 (8): E210–3. doi:10.1097/01.brs.0000158950.84470.2a. PMID 15834319. 
11. ^ Avrahami E, Frishman E, Fridman Z, Azor M (1994). "Spina bifida occulta of S1 is not an innocent finding". Spine 19 (1): 12–5. doi:10.1097/00007632-199401000-00003. PMID 8153797. 
12. ^ "Myelomeningocele". NIH. http://www.nlm.nih.gov/medlineplus/ency/article/001558.htm. Retrieved on 2008-06-06. 
13. ^ Mayo Clinic
14. ^ ^{a b c} T. Lissauer, G. Clayden. Illustrated Textbook of Paediatrics (Second Edition). Mosby, 2003. ISBN 0-723-43178-7
15. ^ Holmes LB (1988). "Does taking vitamins at the time of conception prevent neural tube defects?". JAMA 260 (21): 3181. doi:10.1001/jama.260.21.3181. PMID 3184398. 
16. ^ Milunsky A, Jick H, Jick SS, et al. (1989). "Multivitamin/folic acid supplementation in early pregnancy reduces the prevalence of neural tube defects". JAMA 262 (20): 2847–52. doi:10.1001/jama.262.20.2847. PMID 2478730. 
17. ^ Mulinare J, Cordero JF, Erickson JD, Berry RJ (1988). "Periconceptional use of multivitamins and the occurrence of neural tube defects". JAMA 260 (21): 3141–5. doi:10.1001/jama.260.21.3141. PMID 3184392. 
18. ^ MOMS website and MOMS summary on ClinicalTrials.gov
19. ^ ^{a b c} Lemire RJ (1988). "Neural tube defects". JAMA 259 (4): 558–62. PMID 3275817.
20. ^ ^{a b c} Cotton P (1993). "Finding neural tube 'zippers' may let geneticists tailor prevention of defects". JAMA 270 (14): 1663–4. PMID 8411482.
21. ^ "Folic Acid Fortification". FDA. February 1996. http://vm.cfsan.fda.gov/~dms/wh-folic.html. 
22. ^ "Folic Acid - Public Health Agency of Canada". http://www.phac-aspc.gc.ca/fa-af/index.html. 
23. ^ ^{a b} "Why do I need folic acid?". NHS Direct. 2006-04-27. http://www.nhsdirect.nhs.uk/articles/article.aspx?articleId=913. Retrieved on 2006-08-19. 
24. ^ Kibar Z, Torban E, McDearmid JR, Reynolds A, Berghout J, Mathieu M, Kirillova I, De Marco P, Merello E, Hayes JM, Wallingford JB, Drapeau P, Capra V, Gros P (2007). "Mutations in VANGL1 associated with neural-tube defects" (^{[dead link]} – ^{Scholar search}). N. Engl. J. Med. 356 (14): 1432–7. doi:10.1056/NEJMoa060651. PMID 17409324. http://content.nejm.org/cgi/pmidlookup?view=short&pmid=17409324&promo=ONFLNS19. 
25. ^ Jean Driscoll, Olympian, Paralympian, Speaker, Corporate Spokesperson, Author, Professional Athlete
26. ^ Martin, Dan (2008-06-14). "Dan Martin meets Blaine from the Mystery Jets". guardian.co.uk. http://www.guardian.co.uk/music/2008/jun/14/features16.theguide. Retrieved on 2008-08-06. 
27. ^ Interview with actress Sascha Knopf from Shallow Hal
28. ^ John Mellencamp bio from Yahoo Music
29. ^ Gavin, Kara (2001). "U-M Neurosurgeon Urges Women to Protect their Children by Taking Folic Acid". Medicine at Michigan 3 (2). http://www.medicineatmichigan.org/magazine/2001/spring/huron/huron12.asp. Retrieved on 2008-07-03. 
30. ^ ^{a b} Lewine, Edward (March 1, 2009). "Domains: Country House". New York Times (The New York Times Company): pp. MM17. http://www.nytimes.com/2009/03/01/magazine/01wwln-domains-t.html. Retrieved on 2009-03-02. 
31. ^ Shaffer, Beverly (1977). "I'll Find a Way". National Film Board of Canada Web site. http://www.nfb.ca/film/Ill_find_a_way. Retrieved on 2009-05-27. 

External links

• CDC: Spina Bifida
• The International Federation for Spina Bifida and Hydrocephalus - umbrella organization of spina bifida and hydrocephalus organizations
• Association for Spina Bifida and Hydrocephalus
• National Spina Bifida Association
• Spina Bifida Support Forum
• The Management of Myelomeningocele Study (MOMS)
• UCSF Fetal Treatment Center: Myelomeningocele (Spina Bifida)
• National Institute of Neurological Disorders and Stroke: Spina Bifida Information Page
• Mayo Clinic: Spina bifida Symptoms

v • d • e Congenital malformations and deformations of nervous system (Q00-Q07, 740-742) Brain Neural tube defect Anencephaly (Acephaly, Acrania, Iniencephaly) · Encephalocele · Arnold-Chiari malformation Other Microcephaly · Congenital hydrocephalus (Dandy-Walker syndrome) other reduction deformities (Holoprosencephaly, Lissencephaly, Pachygyria, Hydranencephaly) Septo-optic dysplasia · Megalencephaly CNS cyst (Porencephaly, Schizencephaly) Polymicrogyria (Bilateral frontoparietal polymicrogyria) Spinal cord Neural tube defect Spina bifida · Rachischisis Other Currarino syndrome · Diastomatomyelia · Syringomyelia see also non-congenital CNS, tumors

v • d • e Congenital malformations and deformations of musculoskeletal system / musculoskeletal abnormality (Q65-Q76, 754-756) Limb/ dysmelia Upper clavicle/shoulder: Cleidocranial dysostosis · Sprengel's deformity · Wallis Zieff Goldblatt syndrome hand deformity: Madelung's deformity · Clinodactyly Lower hip: Dislocation of hip/Hip dysplasia · Upington disease · Coxa valga · Coxa vara knee: Genu valgum · Genu varum foot deformity: Club foot · Flat feet · Pes cavus · Rocker bottom foot Either/both dactyly/digit: Polydactyly/Syndactyly (Webbed toes) · Arachnodactyly · Cenani Lenz syndactylism · Ectrodactyly · Brachydactyly reduction deficits/limb: Acheiropodia · ectromelia (Phocomelia, Amelia, Hemimelia) multiple joints: Arthrogryposis · Larsen syndrome · Rapadilino syndrome Craniofacial Craniosynostosis: Scaphocephaly · Oxycephaly · Trigonocephaly Craniofacial dysostosis: Crouzon syndrome · Hypertelorism · Hallermann-Streiff syndrome · Treacher Collins syndrome other: Macrocephaly · Platybasia · Craniodiaphyseal dysplasia · Dolichocephaly · Greig cephalopolysyndactyly syndrome · Plagiocephaly · Saddle nose Other axial spine: spinal curvature (Scoliosis) · Klippel-Feil syndrome · Spondylolisthesis · Spina bifida occulta ribs: Cervical rib · Bifid rib sternum: Pectus excavatum · Pectus carinatum Abdominal wall Hernia: Congenital diaphragmatic hernia (Bochdalek hernia) Omphalocele · Gastroschisis · Prune belly syndrome see also non-congenital, neoplasia

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