In this, the least common form, the outer part of some of the vertebrae are split and the meninges are damaged and pushed out through the opening, appearing as a sac or cyst, which contains both the meninges and cerebrospinal fluid. The nerves are not usually badly damaged and are able to function, therefore there is often little disability present. There are usually no negative long-term effects, although problems have been known to arise.
Spina bifida is caused by the failure of the neural tube to close during embryonic development. Normally the closure of the neural tube occurs around the thirtieth day after fertilization. However, if something interferes and the tube fails to close properly, a neural tube defect will occur. Neural tube defects include the conditions of anencephaly, encephalocele, and spina bifida.
Spina bifida occurs in the first month of pregnancy, often before the woman knows that she is pregnant.The incidence of SB is reported to vary in different parts of the world depending on the geographic region, seasons at conception, gender of the affected infants, ethnicity, and socioeconomic status of the parents, maternal age and parity. Canadian, Australian, European, and American studies have reported changes in the birth prevalence of SB in their populations over the past decades.
The reason for this decrease seems to be from the effect of early diagnosis, selective termination of SB pregnancies, genetic counselling, and nutritional supplementation before and during pregnancy. Research has indicated that the appropriate intake of folic acid, a B vitamin, before and during early pregnancy has been shown to prevent 50-70% of neural-tube defects.
There is neither single cause of spina bifida nor any known way to prevent it entirely. However, to help reduce the chances of having babies with spina bifida, it is recommended for women of childbearing age and women planning to become pregnant to take at least 0.4 mg/day of folic acid from at least one month before conception, and continued for the first 12 weeks of pregnancy. 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. As yet it is unknown how or why folic acid helps to prevent spina bifida. Sources of folic acid include: whole grains, fortified breakfast cereals, dried beans, leaf vegetables, fruits.
Spina bifida results in varying degrees of paralysis, hydrocephalus, absence of skin sensation, incontinence, and spine and limb problems depending on the severity and location of the lesion damage on the spine. In very rare cases, cognitive problems also result.
Most babies born with the condition will need surgeries to correct spinal, foot or leg problems, shunt surgery to drain fluid from the brain, application of techniques to control bladder and bowel function (such as self-catherization or diapers), and braces or other equipment to assist in walking.
There is no cure for spina bifida. Treatment requires a multidisciplinary approach starting with surgical repair of the spine, and other supportive therapies. Taking folic acid (400mcg), at least three months before conception until at least the first three months of pregnancy, can greatly reduce the risk of Neural Tube Defects. Children with severe spina bifida require long-term, intensive therapy that is designed to encourage development and prevent deterioration in physical abilities and kidney function. Surgery may be needed to close the opening in the spinal column and to treat the associated hydrocephalus, bladder and kidney abnormalities and physical deformities.
In developing countries, late presentation is the norm. This is probably due to cultural and religious beliefs and inadequate man power which militates against early referral and appropriate management. In such environments, the need to pursue aggressively, strategies that will reduce the incidence of this disease condition cannot be overemphasized.