Spina bifida

By - 2007-01-10 Find more articles like this in our SCI Sciatica and Back pain category.

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Spina bifida is a serious birth defect that occurs when the tissue surrounding the developing spinal cord of a fetus doesn't close properly.

It's part of a group of birth defects called neural tube defects, which affect the embryonic structure that eventually develops into the baby's brain, spinal cord and tissues that enclose them.

Under normal circumstances, the neural tube forms in the developing baby in the first few weeks of pregnancy and closes by the 28th day after conception.

Later, the top of this tube becomes the baby's brain, and the remainder of the tube becomes the baby's spinal cord. In babies with spina bifida, an area along the lower end of the neural tube fails to develop or close properly, causing defects in the spinal cord and in the bones that make up the backbone (vertebrae) . This can also occur in the middle or upper end of the spine, but it's less common.

Spina bifida malformations fall into three categories:

spina bifida occulta - In occulta there is no opening of the back, but the outer part of some of the vertebrae are not completely closed. 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. Many people with the mildest form of this type of spina bifida do not even know they have it.

spina bifida cystica (myelomeningocele) - In this, the most serious form, the unfused portion of the spinal column allows the spinal cord to protrude through an opening in the overlying vertebrae. The meningeal membranes that cover the spinal cord may or may not form a sac enclosing the spinal elements.

meningocele - In a posterior meningocele, the outer faces of some vertebrae are open and the meninges are damaged and pushed out through the opening, appearing as a sac or cyst which contains cerebrospinal fluid. The spinal cord and nerves are not involved and their function is normal.

Tethered Spinal Cord syndrome symptoms include lower body pain, leg weakness, incontinence, scoliosis, and numbness.

The most common location of the malformations is the lumbar and sacral areas of the spinal cord. The lumbar nerves control the muscles in the hip, leg, knee and foot, and help to keep the body erect. The sacral nerves control some of the muscles in the feet, bowel and urinary bladder, and the ability to have an erection.

Spina bifida is one of the more common birth defects in the United States. It occurs in approximately one out of every 1,000 to 2,000 births each year.

There is no single cause of spina bifida nor any known way to prevent it entirely. Dietary supplementation with folic acid has been shown to be helpful in preventing spina bifida. Sources of folic acid include, whole grains, fortified breakfast cereals, dried beans, leaf vegetables and fruits.

Treatment for spina bifida may involve surgery, but it depends on the severity of the condition.