Spina bifida is characterized by incomplete closure of certain bones of the spinal column (vertebrae), leaving a portion of the spinal cord exposed. Part of the contents of the spinal canal may protrude through this opening. In the most severe form, rachischisis, the opening is extensive. Spina bifida may cause difficulties with bladder control, walking and/or other functions, depending on the severity of associated symptoms.
Patients with spina bifida have a wide variety of symptoms and physical findings, depending on the extent of the defect in the spine. The mildest form of the condition, spina bifida occulta, causes few if any symptoms, and may go undetected. In this mild form, the lack of closure of the neural tube affects only a small area of the spine and is found on X-rays. The disorder may be suspected because of a dimple or tuft of hair on the back overlying the affected area. Impaired bladder control is a common finding, even with relatively mild forms of the condition.
In more severe forms of spina bifida, a sac (meningocele or myelomeningocele) may push its way out through the opening. A meningocele involves the meninges, the tough membrane that covers and protects the brain and cord. This sac may be small or it may be as large as a grapefruit. The meningocele may be covered with skin, or the nerve tissue may be exposed. Generally the sac contains cerebrospinal fluid (CSF). A myelomeningocele represents the most severe form of spina bifida and indicates that a portion of the spinal cord itself has pushed through the spinal (vertebral) opening into the sac in the back of the torso.
The malformation of the lower spinal cord causes abnormalities of the lower trunk and extremities of varying severity. If the condition is mild, the person may only experience some muscle weakness and impaired skin sensations. In patients with meningocele, accumulation of cerebrospinal fluid in the brain results in enlargement of the head (hydrocephalus) and possible brain damage.
Although spina bifida is usually present at birth, it occasionally is first seen during adolescence. The rapid growth during this time stretches the shortened nerves and may cause progressive weakness. Prenatal testing for spina bifida is available. However, this test is not absolutely reliable.
The exact cause of spina bifida is not known. A combination of hereditary and environmental factors may be involved. Studies have also indicated that a lack of folic acid in the mother’s diet during pregnancy heightens the risk of spina bifida and other neural tube defects.
In most cases, babies with spina bifida and other neural tube defects are born into families with no history of these disorders. However, if a child in a family has spina bifida, the likelihood of the parents having another child with this disorder in the future is increased.
Spina bifida is the most common neural tube defect in the United States. Between 1,500 and 2,000 babies out of about 4 million births are born with this disorder each year in the United States.
The U.S. Public Health Service (PHS) advises women of childbearing age to take 0.4 mg of folic acid daily, either through diet or low dose supplements. Women are urged not to take more than 1.0 mg of folic acid daily unless advised by a physician because high doses of folic acid can mask other vitamin deficiencies.
The mildest cases of spina bifida may not require treatment. The moderate cases require a decision as to whether or not surgery is advisable. Surgery may prevent the worsening of the condition in some instances, but cannot restore the lost function. In those extreme cases where the sac (meningocele) breaks or appears about to break, immediate surgery becomes essential.
The family doctor or the orthopedist may prescribe corrective shoes, braces, crutches, or other devices. These help the affected individual to make the most effective use of the weakened muscles, and to prevent the arms and legs from being maintained in an improper or awkward position. Range of motion exercises may also be helpful.
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government website.
For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
For information about clinical trials sponsored by private sources, contact:
Currently (2006), there are two clinical studies dealing with this condition listed on www.clinicaltrials.gov. One explores the condition’s genetics and the other examines coping skills of children with chronic health problems. Spina bifida is included in this study.
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FROM THE INTERNET
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