SPINA BIFIDA

Introduction:

It is a neural tube defect, defective fusion of one or more posterior arches with resultant protrusion of the spinal canal. Spina bifida is a birth defect affecting the spinal column. It progresses from a cleft or split like opening in the back part of backbones. (The spinal vertebrae).In more severe form, it involves the spinal cord. Spina bifida is the most common group of birth defect known as neural tube defect which affects central nervous system (Brain and spinal cord). Spina bifida begins in the womb, when the tissues fold to form the neural tube, do not stay closed completely. This causes an opening in the vertebra which surrounds & protects the spinal cord. This occurs just a few weeks or 21 to 28 days after conception usually before the woman knows that she is pregnant.

Prevalence:

Incidence of Spina bifida, including Spina bifida occulta is about 0.1%.

General features:

People with Spina bifida occulta, are always completely a symptomatic.

• Various degrees of leg paralysis, spine curvature, hip, foot, and leg deformities & problems with bladder / bowel control.
• Abnormalities at the lower spine are always accompanied by upper spine abnormality (ARNOLD CHIARI MALFORMATION) causing subtle co-ordination, problems that usually can be improved by physical therapy.
• Spine, hip, foot, and leg deformities are often due to muscle imbalance.
• Most common bladder & bowel problems and inability to voluntarily relax the muscles that hold urine in the bladder and stool in the rectum.
• Hydrocephalous affecting about 90% people with Spina bifida.
• Tethered spinal cord -the cord is attached to surrounding tissues and can not move up and down freely as it normally does. This can cause foot / leg deformities, hip dislocation or scoliosis. The problems can worsen as the child grows and tethered cord is stretched.
• Obesity & urinary tract disorders (due to poor drainage).
• Pathologic bone fractures occur in as many as 25% of people with Spina bifida.
• Growth hormone deficiency resulting in short stature people which is common in Spina bifida.
• Although most people with Spina bifida have normal intelligence, may have learning disability.
• Intense exposure later, resulting in the early years of life because of frequent surgeries and other medical procedures. An allergic reaction to latex can be life threatening. (Latex is a natural rubber used in medical gloves, some types of elastic, balloons, and many other common items).
• Dimple, dark, small hairy patch on the skin overlying the base of spine, other may have a fatty growth called as epidural lipoma, that forms within the spinal cord. This is usually harmless but may result in tethering of spinal cord.

Types:

The defect varies in severity from a mere failure of the spinous process, to a bony defect with a major aberration in the development of the neural elements.

• Spina bifida.occulta.
• Spina bifida cystica.
• Meningocele
• Myelomeningocele
• Myelocele
• Syringocele

Spina bifida occulta:

• Occulta means hidden.
• Mildest and commonest form
• Failure of the vertebral arches to fuse results bifid spinous process of the vertebra.

Common features:

• Commonest site:-Lumbo-sacral spine.
• Externally the skin may be normal or there may be tell-tale signs in the form of a dimple in the skin. Lipomatous mass a dermal sinus or a tuft of hair.
• Neurological impairment: Muscle imbalance of the lower limb with selective wasting. This leads to foot deformities common ones being Equinovarus.
• Equinovarus: Estimates of prevalence from 5% to as high as 40% have been reported.

Spina bifida cystica:

There is developmental deficiency of lamina, spinous process, overlying muscles and skin. In severe cases, neural tube may be exposed. It usually involves neurological problems that can be very serious or even fatal. A section of spinal cord and the nerves that stem from the cord are exposed and visible on the outside of body or if there is a cyst. It encloses part of the cord and the nerves. This condition accounts for 94% of cases of true Spina bifida. This is the type of Spina bifida that causes vast majority of disability. Most infants with an open spine or myelomeningocele undergo surgery within the first 48 hours of life to close the defect. Antibiotics are given to prevent infection of the exposed spinal cord and nerves until structures can be protected by surgery. Before antibiotics were available most children born with myelomeningocele died soon after birth those who survive severely disabled. With modern treatment, almost all children survive and having some degree of leg paralysis and often difficulties with bladder and bowel function. Extent of paralysis depends on the part of spinal cord is involved. Higher the defect on the body, more severe the paralysis is. About 80% of myelomeningocele occurs in the lumbar and sacral regions of spine.

Meningocele:

In this variety, occasionally the spinal cord & its nerve roots are contact and the covering membrane projects as a dural sac. If this defect is closed by early surgery, paralysis can be avoidable and habilitation is easy.

Mylomeningocele:

Spinal cord is exposed to the surface as a plaque or nervous tissue. It is associated with muscles paralysis, sensory loss, bladder & bowel incontinence and deformities .It may be present from 4th thoracic to 1st sacral vertebra. This is associated with usual complications, paraplegia, bladder and kidneys infections, skin ulceration etc. Pathological fracture, meningitis, and hydrocephalous are also common.

Myelocele:

This type of Spina bifida results from an arrest in development at the time of closure of the neural groove. This is the commonest type of Spina bifida.

Syringocele:

Central canal of the cord is dilated and the cord lies with in the protruded meningeal sac together with the nerve arising from it.

Associated factors:

Most common birth defect historically occuring in 1 per 1000 live birth. The rates of Spina bifida are higher in Hispanics, and significantly among couples who have already had a child with spinal bifida.

Common Causes:

Genetic factors & Environmental factors, nutrition & exposure to harmful substance probably contribute to Spina bifida. Having a child with Spina bifida increases the chances that another child will also have Spina bifida by 8 times. People with Spina bifida appear to have abnormal metabolism of folic acid. This suggests that underlying problem in Spina bifida may be inborn error in folic acid metabolism rather than a simple deficiency in this nutrient.

Examinations and Tests:

• Prenatal test measures the level of maternal serum fetoprotein. This is usually high in women carrying a fetus with Spina bifida or other neural tube defects.
• Triple Screen: It includes AFP, Ultrasound, Testing of Amniotic fluid.
• CT- Scan and MRI. .

Treatments:

Treatment for Spina bifida depends on the severity of the condition.

• Most people with Spina bifida occulta require no treatment at all.
• Children with meningocele requires removal of the cyst, is survived with little of any disability.
• Children with myelomeningocele require complex and life long treatment & assistance.
• Special care is required for myelomeningocele child.
• Immediately transferred to a centre where newborn surgery can be performed.
• Treatment with antibiotics started as soon as possible for myelomeningocele. Because it prevents infection of the spinal cord which can be fatal.
• The operation involves closing the opening in the spinal cord & covering the cord with muscles and skin taken from either side of the back. Most common complications are tethered spinal cord & hydrocephalous, which can have very severe consequences.
• Care team includes pediatricians, neurologist, neurosurgeons, orthopedic surgeons, physical medicine specialist, endocrinologists, urologists, Therapists, psychiatrists, Orthoses specialists, nurses, dietician, social workers, other professionals.
• There is no cure for Spina bifida. The goal of treatment for Spina bifida is to allow the individual to achieve the highest possible level of functioning & independence. .

Medical Treatment:

After newborn surgery, children with severe Spina bifida undergo regular assessment to detect any deformities, developmental problems or other complication that may require intervention.

• Children should be watched for signs of hydrocephalous, tethered spinal cord, seizure activity, obesity, bowel and bladder control problem, frequents urinary tract infections, learning problems, emotional-psychosocial problems & other complications of Spina bifida.
• Care should be taken that early detection of these complications. .

THE FOCUS OF TREATMENT IS DEVELOPING STRENGTH, MOBILITY & INDEPENDENCE.:

Parents should work with a therapist to learn how to exercise the body and legs to maximize strength & movement. They should begin with these exercises as soon after the first surgery as possible. This not only readies the child for walking, but also prevents osteoporosis due to disuse.

• Children with Spina bifida should be provided with prolonged physical education or adaptive training. Many children can become mobile by wearing a brace / using crutches or an orthotics aid. These devices allow the child to function at the best possible level by helping with balance, posture & control.
• Despite, the assistance, some children of Spina bifida will never be able to walk independently. These children will use a wheel chair for the rest of their lives.
• Bowel and Bladder can cause not only physical problems but also social problems due to teasing, rejection, & isolation.
• Children can be taught techniques for emptying their bladder and bowel appropriately & independently, thus avoiding embarrassment.
• For example-use of a plastic tube to drain urine from the bladder on a regular schedule can help prevent overfilling which can injure the kidneys. This technique called as CLEAN INTERMITTENT CATHETERIZATION, is of proven benefit in people with Spina bifida. Prevention of obesity is an important aspect of medical care for person with Spina bifida. Education aspect & counseling physical activity & dietary choices can help maintain weight in a healthy level.
• Treatment for other complications of Spina bifida depends on the nature of the complication. Medications, Surgery, Physical therapy, or behavioral therapy may be appropriate.

Surgical Treatment:

Surgery is the most common treatment for Spina bifida & its complications. Most children with severe form need a series of operations.

• First, which is usually done in the first 48 hours of life, involves tucking the expose cord & nerve roots back into the surrounding membrane closing the defects in cord & membrane & covering the wound with muscle & skin flaps taken from either side of the back.
• Subsequent, surgeries involve correction of deformities. This might includes cutting tendons or ligaments to release contractures, and rebalancing muscles around the involved joints. When regular examinations indicate that the individual's functioning is declining while a physical deformity gets worse, surgery should be considered.

What are the general features of spina bifida?

• People with spina bifida occulta, are always completely a symptomatic.
• Various degree of leg paralysis, spine curvature, hip, foot, and leg deformities & problems with bladder / bowel control.
• Abnormalities at the lower spine are always accompanied by upper spine abnormality (ARNOLD CHIARI MALFORMATION) causing subtle co-ordination, problems that usually can be improved by physical therapy.
• Spine, hip, foot, and leg deformities are often due to muscle imbalance.
• Most common bladder & bowel problems and inability to voluntarily relax the muscles that hold urine in the bladder and stool in the rectum.
• Hydrocephalous affecting about 90%people with spina bifida.
• Tethered spinal cord -the cord is attached to surrounding tissues and can not move up and down freely as it normally does. This can cause foot / leg deformities, hip dislocation or scoliosis. The problems can worsen as the child grows and tethered cord is stretched.
• Obesity & urinary tract disorders (due to poor damage).
• Pathologic bone fractures occur in as many as 25% of people with spina bifida.
• Growth hormone deficiency resulting in short stature people which is common in spina bifida.
• Although most people with spina bifida have normal intelligence, may have learning disability.
• Intense exposure later, resulting in the early years of life because of frequent surgeries and other medical procedures. An allergic reaction to latex can be life threatening.(latex is a natural rubber used in medical gloves, some types of elastic, baloons, and many other common items).
• Dimple, dark, small hairy patch on the skin overlying the base of spine, other may have a fatty growth called as epidural lipoma, that forms within the spinal cord. This is usually harmless but may result in tethering of spinal cord.

Urologic surgery is often necessary because untreated contracture limits the ability of the bladder to hold enough urine to space out emptying and may obstruct flow from the kidneys, Untreated this can lead to kidney failure, which can cause premature death. In the 1990, pioneering surgeons developed a technique for repairing the spinal cord while the fetus is still in the womb. The reasoning behind this is that the longer the spinal cord is exposed to outside elements, even in the womb, the greater possibility for damage that has already occurred by the time the baby is born.

• Preliminary results have been good in that babies who underwent pre-natal surgery.
• Consequences are less likely than babies who underwent surgery at birth to require a shunt for drainage of hydrocephalous fluid.
• This surgery sharply increases the risk of premature birth which entails its own set of risks for the baby.

Hydrocephalous is treated by placement of shunt. A shunt is a special tube surgically placed in the head & under the skin down into the chest or abdomen. The shunt drains excess fluids from the brain into the abdomen where it can be eliminated without harm.

Therapy Management:

• Prevention and management of deformities
• Management of muscle paralysis.
• Care of skin and joints
• Management of bladder and bowel incontinence
• Education in ambulation and self care.

Prevention And Management Of Deformities:

Passive stretching and use of night splints to prevent deformities as far as possible.

Mild to moderate deformities:

Conservatively by passive stretching & adequate splinting.

Rigid deformities:

Manipulation under general anesthesia followed by plasters and splints.

Management of muscle paralysis:

Strengthening exercises for independent / crutch walking and transfer.

• Re-education of trunk muscles.
• Proper re-education of transplanted muscles.

Skin care and protection:

Protection of skin from pressures & ulceration is necessary. Careful examination of the skin at pressure points should be done regularly.

Management of bladder and bowel incontinence:

Frequent examination of the areas and necessary skin care should be a regular practice. Example: infection of urinary tract and failure of kidney function and bowel incontinence.

Educating in ambulance and self care:

• Strength the upper extremity shoulder girdle and trunk muscles.
• Prevent contractures by keeping the joint in correct position.
• Develop equilibrium reactions.
• Re-education in standing and gait training.

Other therapies:

A child's emotional & social development can be deeply affected by the physical disability. To keep this development on, as normal a track as possible, these children should be part of the mainstream, whenever possible.

• Most of these children can be educated in mainstream schools. They should be evaluated for learning, which can be addressed by the public school streams.
• Children should be in the least restrictive environmental possible. They should learn skills that help them be as independent as possible.
• They should be encouraged to participate with their peers in age appropriate activities such as clubs & teams to the best of their abilities.
• Children should take on responsibilities for their own care as much as possible.
• After childhood, group homes may be used to train patients with Spina bifida to live independently.
• The effectiveness of their therapy including their braces, orthotics, crutches, & wheelchair should be checked often & changes made if necessary.
• Development of hydrocephalous / worsening if deformities warrant the attention of the appropriate surgeon.
• Medical complications such as obesity or urinary tract infection require appropriate treatment. The goal is to prevent secondary chronic complications such as heart disease, diabetes & kidney problems.
• The individual's educational progress should be checked, learning disorders should be addressed with appropriate training.
• Their emotional & social development also needs to be checked & appropriate treatment / counseling offered if needed.

Prevention:

Mother having appropriate /adequate folic acid before and during early pregnancy can reduce the chance of having a child with Spina bifida. This does not work in all cases. But studies have shown that as many as 70% of cases of severe Spina bifida could be prevented by adequate folic acid intake.

FOLIC ACID IS ESSENTIAL FOR LIFE:

• Need for Folic acid increases during periods of rapid growth, such as development of a fetus in the womb.
• Many breakfast cereals & grain products in the world are now fortified with folic acid.
• Besides fortified foods, other good sources of folic acid include dark green leafy vegetables, Egg yolks, beans, whole grains, orange juice & citrus fruits.
• The average diet does not include the recommended levels of folic acid.

The critical need for folic acid is in the first 4 weeks of pregnancy. All women who are able to become pregnant should take a folic acid supplement, even if they are planning to become pregnant. The folic acid may be taken alone or as part of daily multivitamins. Women who do not plan to become pregnant in the near future should also take 400 micrograms per day.

Women who plan to become pregnant in the near future & have Spina bifida themselves, have had a child with Spina bifida or have had a previous pregnancy affected by Spina bifida or another neural tube defects should take 10 times of this dose (4000mcg) for 1-3 months before becoming pregnant. This higher dose is available only by prescription.