Spina bifida is a birth defect in which part of the spinal cord and spinal column, or backbone, fail to
develop normally. It is the most frequently occurring and permanently disabling of all birth defects.
Spina bifida occurs in about one of every 1000 live births in the U.S. - that's about 4000 children each year.
In Canada, it occurs in one out of every 750 births. More children are affected by spina bifida than muscular dystrophy, multiple sclerosis,
and cystic fibrosis combined. Spina bifida means 'spine in two parts' or 'open spine.'
Causes of Spina Bifida
The exact causes of spina bifida are not known. Scientists have determined that some possibilities are:
- a genetic or family tendency
- environmental factors
- deficient intake of folic acid
Once a family has a child with spina bifida, their risk of having another child with a central nervous system
disorder is higher than normal.
The spina bifida occurs during the first month of pregnancy when the central nervous system begins to form. We do not know why
parts of the spinal cord and the nerves branching out from it do not develop normally.
The bones -- or vertabrae or backbone -- that surround and protect the spinal cord also fail to form properly in this area. This leaves an
opening in the backbone underneath the skin. Part of the spinal cord and some of the nerves pass through this opening
into a fluid filled sac, or bulge, in the middle of the baby's back under the skin. This is called a lesion.
The lesion will often affect a baby's ability to move his or her legs, to feel some areas of the legs, buttocks and genitals, and to control bowel and
bladder functions. How much movement, feeling, and bowel and bladder control is affected depends on how much the child's nerves are damaged. It also depends
on where and at what level the lesion is on the child's back.
Types of Spina Bifida
- Myelomeningocele
- Meningocele
- Lipomyelomeningocele
- Occulta
Myelomeningocele (my-low-meh-NIN-go-seal) is the most common type of spina bifida as well as the most severe.
This picture is of a baby with a cele, or sac, filled with cerebrospinal fluid at the lesion level on his back.
It will be surgically closed before he will leave the hospital. A shunt will be put in place to reroute the excess
fluid that can build up in his brain to either his heart or his abdominal cavity.
Meningocele (me-nin-GO-seal) is a less severe form of spina bifida. Children who have spina bifida meningocele have a lesion and a sac
filled with cerebrospinal fluid, but the spinal cord is not pushed out into the sac. The damage to nerves is not as great.
Lipomyelomeningocele (ly-po-my-low-meh-nin-go-seal) involves abnomal fatty tissue being pushed through a vertebrae in the lower part of the spine.
There may or may not be nerve damage.
Occulta is the mildest form of spina bifida as well as the least common. Children who have spina bifida occulta may only have a small hole in the
lower part of the spinal cord where the vertebrae don't come together. Many people with this form of spina bifida don't even know they
have it because it is so mild.
Lesion Level
The spina bifida lesion may occur at any level of the spinal cord. Its most common location is the lower (lumbrosacral) part of the back. Below
the lesion, spinal cord nerves do not work properly. When nerves do not work, a loss of feeling, inability to use certain muscles or poor control of
bowel and bladder function may occur. The lesion's level indicates where the person will have no sensation or feeling. In general, the nerves in the
spinal cord branch out to cause feeling and movement in certain levels or parts of the body.
The following details will help you understand the most common nerve loss from lesions at different spinal cord levels.
Area of the Spinal Cord
Thoracic
Lesion level: T2-T12
Effect: Lack of feeling at chest and below
High-level Lumbar
Lesion Level: L1-L2
L1 Effect: Lack of feeling at waist and below
L2 Effect: Lack of feeling at upper and outer thighs and below
Will be able to bend forward at the waist but will not be able to move knees or ankles
Mid-level Lumbar
Lesion Level: L3-L5
L3 Effect: Lack of feeling at inner thighs, knees and below
L4 Effect: Lack of feeling at inner calves and below
L5 Effect: Lack of feeling at outer calves and below
Usually able to move both legs, knees and possibly ankles, but muscles in these areas may be weak
Sacral
Lesion Level: S1-S4
S1 Effect: Lack of feeling at heel. Will have some movement of ankles and feet.
S2-S4 Effect: Lack of feeling in genitals and buttocks. Will have almost normal movement and strength in legs,
feet and toes. May affect bowel and bladder function.
Parents may not be able to hold their baby right away because of the weakness of the lesion. The baby is
usually taken to the nursery or a specialized children's hospital right away. A neonatologist, a doctor who specializes in caring for
newborn babies, may examine your baby. Usually your child will be placed on his or her stomach or side to avoid pressure on the
fluid-filled sac on the back. The sac will be covered by a moist sterile gauze pad to protect it from infection. During the first
few days of life your baby will have many tests done.
Some of these tests include:
- an x-ray of the spine to show which vertebrae are involved
- an ultrasound exam of the head
- a special x-ray, called a CT or CAT scan (Computed Axial Tomography)
- blood tests
Afterward, the doctor will talk with you about the baby's treatment plan. This may include surgery while the baby
is still very little to repair the spinal cord lesion and treat the hydrocephalus. A neurosurgeon, a doctor
trained in surgery of the brain and spinal cord, will perform these surgeries.
Ask any questions you have about your baby and about hospital care. Repeat your questions to the nurses and doctors as many times
as you need to understand and feel comfortable about your baby's care. Some parents like to write down their questions before talking
with the doctor in order not to forget any of them. When you are away from the hospital, call as often as you want to check on your baby.
