Introduction

Spina bifida literally means “split spine”. Spina bifida happens when a baby is in the womb and the spinal column does not close all the way. Spina bifida, the most common neutral 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 maybe covered by skin and 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, children 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.

Types of Spina bifida:

1. 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. Ther is an opening in one or more of the vertebrae ( bones ) of the spinal column without apparent damage to the spinal cord.

2. Meningocele : The meninges, or protective covering around the spinalcord, have pushed out through the opening in the vertebrae in the sac called the “Meningocele”. However, the spinal cord remains intact. This form can be repaired with little or no damage to the spinal cord.

3. Myelomeningocele : This is the most severe form of the spina bifida in which a portion of the spinal cord itself protrudes through the back. In some cases, sacs are covered with skin; in others, tissue and nerves are exposed.

Types and Clinical Features:

Spina Bifida Occulta

This mildest form results in a small separation or gap in one or more of the bones (vertebrae) of the spine. Because the spinal nerves usually aren’t involved, most children with this form of spina bifida have no signs or symptoms and experience no neurological problems.

Visible indications of spina bifida occulta can sometimes be seen on the newborn's skin above the spinal defect, including:

• An abnormal tuft of hair

• A collection of fat

• A small dimple or a birthmark

• Skin discoloration

Many people who have spina bifida occulta don't even know it, unless the condition is discovered during an X-ray or other imaging test done for unrelated reasons.

Meningocele

In this rare form, the protective membranes around the spinal cord (meninges) push out through the opening in the vertebrae. Because the spinal cord develops normally, these membranes can be removed by surgery with little or no damage to nerve pathways.

Myelomeningocele

Also known as open spina bifida, myelomeningocele is the most severe form

-   and the form people usually mean when they use the term "spina bifida.'ln myelomeningocele, the baby's spinal canal remains open along several vertebrae in the lower or middle back. Because of this opening, both the membranes and the spinal cord protrude at birth, forming a sac on the baby's back. In some cases, skin covers the sac. Usually, however, tissues and nerves are exposed, making the baby prone to life-threatening infections.

Neurological impairment is common, including:

•           Muscle weakness, sometimes involving paralysis

•           Bowel and bladder problems

•           Seizures, especially if the child requires a shunt

•           Orthopedic problems - such as deformed feet, uneven hips and a curved spine

(scoliosis) Investigations Physical Examination

The most obvious finding on physical examination is some degree of motor and sensory loss. Neurologic impairment is classified by traditional neurosegmental levels based on the clinically determined strength of specific muscle groups. The functional motor level does not always correspond to the anatomic level of the lesion.

In addition, it is important to realize that the motor paresis may be asymmetrical, that it may not correspond to the sensory level, and that it may result from a combination of upper and lower motor neuron lesions. Serial measurements and accurate documentation of the functional level of the lesion allow for early detection of progressive neurologic deterioration related to a variety of associated CNS problems.

In most cases, spina bifida is diagnosed prenatally, or before birth. However, some mild cases may go unnoticed until after birth (postnatal).Very mild forms (spinal bifida occulta), in which there are no symptoms, may never be detected.

Prenatal Diagnosis

The most common screening methods used to look for spina bifida during pregnancy are second trimester (16-18 weeks of gestation) maternal serum alpha fetoprotein (MSAFP) screening and fetal ultrasound. The MSAFP screen measures the level of a protein called alphafetoprotein(AFP), which is made naturally by the fetus and placenta. During pregnancy, a small amount of AFP normally crosses the placenta and enters the mother's blood stream. If abnormally high levels of this protein appear in the mother's bloodstream, it may indicate that the fetus has an "open" (not skin-covered) neural tube defect. The MSAFP test, however, is not specific for spina bifida and requires correct gestational dates to be most accurate; it cannot definitively determine that there is a problem with the fetus. If a high level of AFP is detected, the additional testing, such as an ultrasound or amniocentesis to help determine the cause.

The second trimester MSAFP screen described above may be performed alone or as part of a larger, multiple-marker screen. Multiple-marker screens look not only for neural tube defects, but also for other birth defects, including Down syndrome and other chromosomal abnormalities. First trimester screens for chromosomal abnormalities also exist but signs of spina bifida are not evident until the second trimester when the MSAFP screening is performed.

Amniocentesis—may also be used to diagnose spina bifida. Although amniocentesis cannot reveal the severity of spina bifida, finding high levels of AFP and other proteins may indicate that the disorder is present.

Postnatal Diagnosis

Mild cases of spina bifida (occulta, closed) not diagnosed during prenatal testing may be detected postnatally by plain film X-ray examination. Individuals with the more severe forms of spina bifida often have muscle weakness in their feet, hips, and legs that result in deformities that may be present at birth. Magnetic resonance imaging (MRI) or a computed tomography (CT) scan is done to get a clearer view of the spinal cord and vertebrae. If hydrocephalus is suspected, a CT scan and/orX-ray of the skull to look for extra cerebrospinal fluid inside the brain.

Treatment:

Spinabifida Occulta may not need any surgery, but just a watch on the patient is requiredto be vigilant that he/she does not develop any neurological symptoms. Other formsneed immideate surgical intervention, that too preferably from a paediatric neurosurgeon.

Physiotherapy

Physiotherapy is one of the most important ways of helping your child manage their condition so they're as independent as possible. For spina bifida, the main aim of physiotherapy is to promote movement and independent mobility to prevent the leg muscles from weakening.

Occupational therapy

An occupational therapist can identify problem areas in everyday life, such as getting dressed, and will help work out practical solutions. This can be by encouraging certain movements or providing equipment, such as handrails, to make the activity easier.

Assistive technology

Assistive technology can help children with spina bifida gain more independence and control over their symptoms.

Children with muscle weakness of the lower limbs will require a wheelchair. Electric wheelchairs are available, but using a manual wheelchair can help maintain good upper body strength. Leg braces and other walking aids can be used by children who have weakness to the muscles of the lower legs.

Computers are a good tool for children with learning disabilities. Software is available to help children organise their activities and plan their school work. There are also many educational programmes that use text and sound to help improve a child's reading ability.