Spina bifida is a birth defect. It is the most common of neural tube defect. In babies with spina bifida, a portion of the neural tube fails to develop or close properly, causing defects in the spinal cord and in the bones of the spine.
Spina bifida can range from mild to severe, depending on the type of defect, size, location and complications.
Types of Spina Bifida
- Spina Bifida Occulta is the mildest form and usually goes unnoticed. Occulta means hidden, here the defect is covered by skin. The skin over the lower spine may have a patch of hair, a birthmark, or a dimple between the buttocks. Most babies born with spina bifida occulta do not have long-term health problems.
- Meningocele spinal fluid and meninges protrude through an abnormal vertebral opening creating a fluid-filled sac called a meningocele. This sac is visible on a baby's head, neck, or back. Some individuals with meningocele may have few or no symptoms while others may experience symptoms as complete paralysis with bladder and bowel dysfunction.
- Myelomeningocele: Also known as open spina bifida, myelomeningocele is the most severe form. The spinal canal is open along several vertebrae in the lower or middle back resulting in partial or complete paralysis of the parts of the body below the spinal opening. There may be a severe impairment that the affected individual is unable to walk and may have bladder and bowel dysfunction. It's also common for babies to have hydrocephalus.
- Folate deficiency: Folate (vitamin B-9) is important to the healthy development of a baby; its deficiency increases the risk of spina bifida and other neural tube defects.
- Family history of neural tube defects: Couples who've had one child with a neural tube defect have a slightly higher chance of having another baby with the same defect.
- Medications: Like anti-seizure medications seem to cause neural tube defects when taken during pregnancy.
- Diabetes: Women with diabetes who don't control their blood sugar well have a higher risk of having a baby with spina bifida.
- Obesity: It is associated with an increased risk of neural tube birth defects, including spina bifida.
- Increased body temperature: Increased body temperature in the early weeks of pregnancy may increase the risk of spina bifida
Signs and symptoms
Depending on the severity of the defect and its location on the spine, symptoms vary. Mild defects may cause few or no problems, while more severe defects can cause serious problems:
- An abnormal tuft or clump of hair or a small dimple or birthmark on the skin at the site of the spinal malformation.
- Fluid-filled sac—visible on the back—protruding from the spinal canal
- Leg weakness and paralysis
- Bladder and bowel control problems, including incontinence, urinary tract infections
- Many individuals with spina bifida have an associated abnormality of the cerebellum, called the Arnold Chiari II malformation.
- A curve in their spine, such as scoliosis.
Tests and Diagnosis
Prenatal diagnosis: Expectant parents may be able to find out if a baby has spina bifida by:
- Maternal Serum Alpha-Fetoprotein (MSAFP) test: The alpha-fetoprotein (AFP) test is a blood test done between the 16th and 18th weeks of pregnancy, a sample of the mother's blood is drawn and tested for alpha-fetoprotein (AFP), abnormally high levels of AFP suggest that the baby has a neural tube defect, such as spina bifida,
- Prenatal ultrasound: Many obstetricians rely on ultrasonography to screen for spina bifida.
- Amniocentesis: It can also help determine whether a baby has spina bifida. A needle is inserted through the mother's belly and into the uterus to collect fluid that is tested for AFP.There is a slight risk of loss of pregnancy with an amniocentesis.
Postnatal Diagnosis: After birth, Ultrasound, Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scan is done to get a clearer view of spinal cord and vertebrae.
Complications of Spina Bifida
The complications are determined by the size and location of the malformation, all nerves located below the malformation are affected to some degree. Therefore, the higher the malformation occurs on the back, the greater the amount of nerve damage and loss of muscle function and sensation.
- Walking problems: The nerves that control the leg muscles don't work properly below the area of the spina bifida defect, causing muscle weakness of the legs, sometimes involving paralysis.
- Orthopedic complications: It includes a curved spine (scoliosis), abnormal growth or dislocation of the hip and joint deformities and other orthopedic concerns.
- Bowel and bladder problems: Because the nerves that supply the bowel and bladder come from the lowest level of the spinal cord.
- Accumulation of fluid in the brain (hydrocephalus): Babies born with myelomeningocele commonly experience accumulation of fluid in the brain, a condition known as hydrocephalus.
- Shunt malfunction
- Chiari malformation type II: Chiari malformation type II is a common brain abnormality in children with the myelomeningocele form of spina bifida. The brainstem is elongated and positioned lower than usual. This can cause problems with breathing and swallowing.
- Meningitis: Some babies with myelomeningocele may develop meningitis
- Tethered Spinal Cord: Tethered spinal cord results when the spinal nerves become bound to the scar where the defect was closed surgically, making the spinal cordless able to grow as the child grows.
- Latex allergy: Children with spina bifida have a higher risk of latex allergy, an allergic reaction to natural rubber or latex products.
Treatment of Spina Bifida
Spina Bifida Occulta usually does not need to be treated:
- There is no known cure for nerve damage caused by spina bifida. Children with an exposed opening on the back will need surgery to close it.
- A child with Meningomyelocele usually is operated on within two to three days of birth. This prevents infections and helps save the spinal cord from more damage.
- Pediatric neurosurgeons operate to close the opening on the back. The spinal cord and its nerve roots are put back inside the spine and covered with meninges.
- In babies with myelomeningocele, irreparable nerve damage has likely already occurred and ongoing care is usually needed. They may need more surgery for a variety of complications.
- Treatment for complications typically begins soon after birth.
- A shunt may be surgically installed to provide a continuous drain for the excess cerebrospinal fluid produced in the brain, as happens with hydrocephalus.
- A tethered spinal cord may be surgically repaired.
- Devices to help with movements such as crutches or wheelchairs may be useful.
- Children with spina bifida need close follow-up care and observation