Spina bifida

 Definition (Spina bifida): Spina bifida is a serious birth abnormality in which the spinal cord is malformed and lacks its usual protective skeletal and soft tissue coverings.

Or,

Spina bifida is a congenital development defect in the vertebral column resulting in a lack of fusion of the vertebral arches so the vertebral canal is not closed.

Or,

Spina bifida is associated with failure of fusion of vertebral arches with or without protuison or dysplasia of the spinal cord and its membranes.

Causes:

1.      Unknown.

2.      Genetic factor.

3.      Congenital rubella syndrome.

4.      Foliate deficiency.

Risk factors:

1.      Low maternal blood level of folic acid at the time of conception.

2.      Family history of spina bifida.

3.      A mother who had a previous pregnancy with a neural tube defect.

4.      Certain medications given during pregnancy.

Types: There are three kinds of spina bifida:

1.      Occulta:This is least sever form and can have-

·         No symptoms.

·         Small defect in one or more vertebrae.

·         Spinal cord and nerves are normal.

·         Usually no complications.

2.      Meningocela: In this case the membrane poke through an open part of the spine. This forms a cyst. Spinal fluid can leak out. This type can be treated.

3.      Myelomeningocela: This is most severe form of spina bifida. In this case, the cyst contains membrane never roots and sometimes the spinal cord. This type can result in severe problems such as:

·         Paralysis and incontinence of bowel and bladder may occur frequently not cured by surgery.

·         Hydrocephalus a build up fluids in the brain that increase pressure on the brain.

4.      Myeloschisis: Spina bifida with myeloschisis is the most severe form of myelomeningocele. In this type, the involved area is represented by a flattened, plate-like mass of nervous tissue with no overlying membrane. The exposure of these nerves and tissues make the baby more prone to life-threatening infections such as meningitis. The protruding portion of the spinal cord and the nerves that originate at that level of the cord are damaged or not properly developed. As a result, there is usually some degree of paralysis and loss of sensation below the level of the spinal cord defect. Thus, the more cranial the level of the defect, the more severe the associated nerve dysfunction and resultant paralysis may be. People may have ambulatory problems, loss of sensation, deformities of the hips, knees or feet, and loss of muscle tone.

Mechanism:

Lack of fusion spinal column

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A soft unprotective area may be present

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May be covered by skin or open wound

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Sometime sac is covered by skin and also hidden from sight

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Sometime sac is filled with CSF

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Some sac is filled with CSF and also spinal cord

Clinical features:

The most immediate symptom of meningocele and myelomeningocele:

·         Sac filled with fluid leading out from the baby’s spine.

·         Spinal cord and tissue may also protrude through the back.

Infants and children with spina bifida may experience the following long term symptoms:

·         Bowel and bladder problems.

·         Frequent urinary tarct and other infections.

·         Learning disabilities.

·         Accumulation of fluid in the brain (hydrocephalus).

·         Scoliosis.

·         Latex allergy (from frequent surgeries early in life)

·         Inability to walk:

-Muscle weakness and paralysis of the lower extremities.

-Hip dislocation.

-Foot and ankle deformities.

·         Many children with myelomeningocele are wheelchair bound.

Complication:

1.      Urinary infection.

2.      Abnormal spinal curvature.

3.      Pressure sore.

4.      Problem in posture.

5.      Foot injuries.

6.      Contractures.

7.      Blindness.

Prevention:

1.      Supplement the diet with at least 400 micrograms of folic acid every day if someone plans to conceive .Supplementation must begin before the baby is conceived and should continue throughout the pregnancy.While a formalvitamin supplement containing folate may be the most reliable method of supplementation,foods with significant quantities of folate include:

-Leafy green vegetables.

-Orange juice.

-Beans.

-White flour products and cereals fortified with folate.

2.      Planning pregnancies. It is important to talk to the physician if someone has any of the risk factors listed above.

Prognosis: More than 80% of infants born with spina bifida survive with surgical and medical management. Although complications from paralysis, hydrocephaly, chiari II malformation and urinary tract deterioration threaten the well being of the survivors, the outlook for normal intellectual function is good.

Medical management:

1.      Occulta spina bifida requires no treatment.

2.      Meningocele spina bifida is treated with surgery to remove the cyst.