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Tuesday, May 3, 2005

What is Spina Bifida?

Yo!

Born a person with disabilities as a Spina Bifida. Thought i should post something about it. For learning purpose yeah? Wouldn't mind knowing parents of kids with SB. Do email me if you need other reasources to help. :)

Born to ride!! On a wheelchair...
Michael a.k.a WindyG

What is Spina Bifida?

Spina bifida is the most frequently occurring permanently disabling birth defect. It affects approximately one out of every 1,000 newborns in the United States. More children have spina bifida than have muscular dystrophy, multiple sclerosis, and cystic fibrosis combined.

Spina bifida, the most common neural tube defect (NTD), is one of the most devastating of all birth defects. It results from the failure of the spine to close properly during the first month of pregnancy. In severe cases, the spinal cord protrudes through the back and may be covered by skin or a thin membrane. Surgery to close a newborn's back is generally performed within 24 hours after birth to minimize the risk of infection and to preserve existing function in the spinal cord.

Because of the paralysis resulting from the damage to the spinal cord, people born with spina bifida may need surgeries and other extensive medical care. The condition can also cause bowel and bladder complications. A large percentage of children born with spina bifida also have hydrocephalus, the accumulation of fluid in the brain. Hydrocephalus is controlled by a surgical procedure called "shunting" which relieves the fluid build up in the brain by redirecting it into the abdominal area. Most children born with spina bifida live well into adulthood as a result of today's sophisticated medical techniques.

What about the physical limitations?

Children with spina bifida need to learn mobility skills, and often with the use of crutches, braces, or wheelchairs can achieve more independence. Also, with new techniques children can become independent in managing their bowel and bladder problems. Physical disabilities like spina bifida can have profound effects on the child's emotional and social development. It is important that health care professionals, teachers, and parents understand the child's physical capabilities and limitations. To promote personal growth, they should encourage children (within the limits of safety and health) to be independent, to participate in activities with their non-disabled peers and to assume responsibility for their own care.

Preventing Spina Bifida

Recent studies have shown that one factor that increases the risk of having an NTD baby is low folic acid status before conception and during the first few weeks of pregnancy. If all women of childbearing age were to consume 0.4 mg of folic acid prior to becoming pregnant and during the first trimester of pregnancy, the incidence of folic acid preventable spina bifida and anencephaly could be reduced by up to 75%!!

What is Folic Acid?

Folic acid, a common water-soluble B vitamin, is essential for the functioning of the human body. During periods of rapid growth, such as pregnancy and fetal development, the body's requirement for this vitamin increases. Folic acid can be found in multivitamins, fortified breakfast cereals, dark green leafy vegetables such as broccoli and spinach, egg yolks, and some fruits and fruit juices. However, the average American diet does not supply the recommended level of folic acid.

Types Of Spina Bifida

Spina Bifida Occulta

This is a mild form of spina bifida which is very common. Estimates vary but between 5% and 10% of people may have spina bifida occulta. It must be emphasised that, for the vast majority of those affected, having spina bifida occulta is of no consequence whatsoever. Often people only become aware that they have spina bifida occulta after having a back x-ray for an unrelated problem. However, for a few (about 1 in 1,000) there can be associated problems.

Why do some people have complications?

The term 'spina bifida occulta' is, in fact, not one but two separate conditions which have completely different consequences. This leads to confusion when such a diagnosis is used without qualification.

For the majority of people with spina bifida occulta it is a minor fault involving one vertebra in the lower back. The unfortunate use of this term for such a minor fault can lead to distress for the person concerned. However, it should be considered as insignificant, both for that person and his or her children.

For a small number of people with spina bifida occulta the fault is more extensive. Either the split in the spine is bigger, or may involve two or more vertebrae. There may be visible signs on the skin such as a mole or naevus (birthmark), a dimple or sinus (hole), or a patch of hair. This type of spina bifida occulta is significant.

There may be associated difficulties which may include the following: foot deformity, weakness and reduced sensation of the legs, change in hand function, bladder infections and incontinence and bowel problems.

These problems arise because the spinal cord becomes tethered to the backbone. Often a child who is previously symptomless may experience difficulties during the rapid growth of adolescence. This is because the nerves of the spinal cord are stretched and the symptoms may become progressively worse.

It is important to consult a GP, who, if appropriate, can refer to a neurosurgeon. Specialist scanning procedures such as MRI (magnetic resonance imaging) give a clear picture of the nerves and spinal column and the neurologist will be able to advise on the most appropriate treatment.

People with spina bifida occulta and progressive (worsening) symptoms of a stretched or tethered spinal cord need to have an operation on their lower spine to release the tension in the spinal cord. This is often a fairly simple and effective procedure, but occasionally the operation is very complicated and involves a (2% - 5%) risk of failure. It is often possible to improve symptoms in the legs with this operation, but it is rare for bladder function to return to normal. The main purpose of a "detethering operation" is to stop any further deterioration in leg or bladder function and it is important that a neurosurgical assessment is made as early as possible after the onset of symptoms. The operation is probably best done by those neurosurgeons who have a special interest in the condition.

What are the implications?

For the vast majority of people with the non-significant form of spina bifida occulta there are no known complications and there is no higher risk of having children with spina bifida than there is in the general population.

For those with the more complicated spina bifida occulta, there may be neurological problems which may or may not be present at birth and may be progressive. Those with significant spina bifida occulta have a higher risk, than the general population, of having children with spina bifida which could be cystica or occulta. This risk is between 2% and 4% and is the same risk that those with with spina bifida cystica have of passing on the disability.

However, the risk of having a baby with spina bifida can be dramatically reduced by taking folic acid (a B-group vitamin).

More information and advice

If someone suspects that they have occult spina bifida and is experiencing any of the problems described above, they should ask their GP for referral to a neurologist who can investigate and advise about treatment.

Women who know they have spina bifida occulta and are planning to have a baby can ask for a referral to a genetic who will consider both the family history and individual medical circumstances and advise on the risk of having a baby with spina bifida.

Spina Bifida Cystica (cyst-like)

The visible signs are a sac or cyst, rather like a large blister on the back, covered by a thin layer of skin.

There are two forms:
Meningocele

In this form, the sac contains tissues which cover the spinal cord (meninges) and cerebro-spinal fluid. This fluid bathes and protects the brain and spinal cord. The nerves are not usually badly damaged and are able to function, therefore there is often little disability present. This is the least common form.

Myelomeningocele (meningomyelocele)

This is the commoner of the two meningoceles and also the most serious. Here the sac or cyst not only contains tissue and cerebro-spinal fluid but also nerves and part of the spinal cord. The spinal cord is damaged or not properly developed. As a result, there is always some degree of paralysis and loss of sensation below the damaged vertebrae. The amount of disability depends very much on where the spina bifida is and the amount of nerve damage involved. Many children and adults with this condition experience problems with bowel and bladder control.

Cranium Bifida

Here the bones of the skull fail to develop properly. The sac which forms is known as encephalocele. It may contain tissue and cerebro-spinal fluid only. However, in some cases, part of the brain may also be present in the sac resulting in brain damage. The most severe forms of cranium bifida are iniencephaly and anencephaly. Here, the brain does not develop properly or is absent, and the baby is either stillborn or dies shortly after birth. Most babies born with spina bifida also have hydrocephalus (from the Greek hydro = water, cephalie = brain).

What is Hydrocephalus?

Hydrocephalus is commonly known as 'water on the brain', although this is not accurate. A watery fluid, known as cerebro-spinal fluid (or CSF, for short), is produced constantly inside each of the four spaces or ventricles inside the brain. The CSF normally flows through narrow pathways from one ventricle to the next, then out over the outside of the brain and down the spinal cord. The CSF is absorbed into the bloodstream and the amount and pressure are normally kept within a fairly narrow range. If the drainage pathways are obstructed at any point, the fluid accumulates in the ventricles inside the brain, causing them to swell - resulting in compression of surrounding tissue. In babies and infants, the head will enlarge. In older children and adults, the head size cannot increase as the bones which form the skull are completely joined together.

The majority of babies born with spina bifida have hydrocephalus. In addition to the lesion in the spinal cord, there are abnormalities in the physical structure of certain parts of the brain which develop before birth. This prevents proper drainage of the CSF. The increase in pressure due to this can also compress the abnormal parts of the brain even further.

How is Hydrocephalus Treated?

Some forms of hydrocephalus require no specific treatment. Other forms are temporary and do not require long-term treatment. However, most forms do require to be treated, and this is usually done surgically. Drugs have been used for many years but they may have unpleasant side effects and are not always successful.

The usual treatment is to insert a shunting device. It is important to note that this does not 'cure' the hydrocephalus and damage to the brain tissue remains. Shunting controls the pressure by draining excess CSF, so preventing the condition becoming worse. Symptoms caused by raised pressure usually improve but other problems of brain damage can remain. Increasingly an operation called Third Ventriculostomy is being performed in specialist units.

What is a Shunt?

A shunt is simply a drain which diverts the accumulated CSF from the obstructed pathways and returns it to the bloodstream. The device consists of a system of tubes with a valve to control the rate of drainage and prevent back-flow. It is inserted surgically so that the upper end is in a ventricle of the brain and the lower end leads either into the heart (ventriculo-atrial) or into the abdomen (ventriculo-peritoneal). The device is completely enclosed so that all of it is inside the body. The fluid which is drained into the abdomen passes from there into the bloodstream.

Other drainage sites such as the outer lining of the lungs (ventriculo-pleural shunt) can also be used. In most cases, the shunts are intended to stay in place for life, though alterations or revisions might become necessary from time to time.

Are there any complications?

Complications are usually caused either by blockage of the system or infection. They are only occasionally due to mechanical failure of the valve. The tube or catheter may become too short as the individual grows and an operation to lengthen it might be necessary.

Symptoms vary enormously between individuals and it is unwise to rely on a list which might not apply in any particular instance. Previous personal experience of a shunt problem is usually a reliable guide as to what to look for.

Shunt Blockage

Symptoms usually develop gradually. In some cases, it shows itself in a gradual deterioration in overall performance. Occasionally, symptoms are quite suddenly severe and may include headaches and vomiting. Various tests can be carried out to confirm the diagnosis. Medical advice should be sought urgently if a shunt blockage is suspected.

Shunt Infection

Symptoms vary with the route of drainage. In ventriculo-peritoneal shunts, the symptoms will often resemble those of a blockage. This is because the shunt becomes infected and the lower catheter is very often sealed off by tissue. There may be accompanying fever and abdominal pain or discomfort. In infection of ventriculo-atrial shunts, fever is present in most cases though often intermittently. Anaemia is frequently present, sometimes skin rashes along with joint pains.

In contrast to ventriculo-peritoneal shunts, such infections sometimes do not become apparent for months after the operation at which they were contracted.

Various tests can be carried out for shunt infection and medical advice should always be sought if an infection is suspected.

How are shunt problems treated?

Shunt blockages which are causing illness usually require an operation to replace or adjust the offending part of the shunt. Shunt infections are usually treated by removal of the whole shunt and a course of antibiotics before insertion of a new system. Modern approaches to antibiotic therapy mean that such treatment can be expected to succeed in most cases.

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