Spina Bifida

Spina bifida is a common birth defect where the spine of a fetus doesn’t fully develop during the first month of pregnancy, leading to what’s called a “split spine.” This condition, spina bifida, is usually noticeable when the baby is born. It is a common birth defect in the United States

It’s crucial to understand that this defect happens very early in pregnancy, often before a woman even knows she’s pregnant. It falls under a category of conditions called neural tube defects.

While spina bifida can sound alarming, it’s essential to recognize that its severity varies greatly. Some cases are so mild that they show no symptoms and don’t require treatment

However, there are more serious types where infants are born with open lesions on their spine. This results in significant nerve and spinal cord damage. While surgery can close the opening, the nerve damage often leads to permanent disability. Spina bifida can affect any part of the backbone, but it’s most commonly found in the lower back.

Types

1. Spina bifida occulta:

Sppina bifida occulta or hidden spina bifida stands as the mildest and most prevalent form of this condition. Typically affecting only a small portion of the spine, it often manifests without any symptoms and doesn’t necessitate treatment. In newborns with spina bifida occulta, the skin conceals the spinal bone deformity.

The term “spina bifida occulta” literally translates to “hidden spot on the spine,” and for many individuals with this type, the spot indeed remains hidden. However, some may display subtle changes in the skin overlying the bony defects. Defects such as a dimple, red or purple coloring, or a tuft of hair. It’s estimated that around 10% to 20% of the U.S. population has spina bifida occulta, with most unaware of its presence.

Occasionally, spina bifida occulta may present problems during adolescence. By this stage, the spinal cord has become attached to the backbone. During the growth spurt of adolescence, the nerves of the spinal cord may stretch. This can lead to issues like leg weakness, numbness, bladder infections, and incontinence. The severity of symptoms increases with the degree of spinal cord stretching. Surgery to alleviate these symptoms by reducing spinal cord tension is often straightforward and successful.

2. Meningocele

Meningocele, a less common form of spina bifida, involves the protrusion of the meninges, the membrane surrounding the spinal cord, through an opening in the spine, resulting in a visible lump or sac on the back. While more severe than spina bifida occulta, surgery can correct meningocele with minimal or no nerve damage. This corrective surgery is usually performed during infancy. Unlike other forms, in meningocele, the spinal cord develops normally without damage, and the child doesn’t experience neurological issues.

3. Myelomeningocele

Myelomeningocele represents the most severe form of this defect, occurring in nearly one out of every 1,000 live births. In infants born with myelomeningocele, the spinal cord fails to form correctly. Thus leading to a portion of the underdeveloped cord protruding through the back. This protrusion is surrounded by a sac containing cerebrospinal fluid and blood vessels, often left exposed as it lacks skin coverage.

Between 70% and 90% of infants with myelomeningocele also develop hydrocephalus, a condition characterized by an excess buildup of spinal fluid in the brain due to a defect at the base of the skull known as Chiari malformation. If untreated, hydrocephalus can lead to brain damage, seizures, or blindness. To prevent complications, doctors surgically implant plastic shunts beneath the skin to drain excess fluid into the abdominal cavity.

Infants with myelomeningocele commonly experience paralysis or weakness below the level of the spinal lesion. This affects the lower limbs, as well as issues with bladder and bowel function. In severe cases, it also affects the trunk and upper extremities.

Causes of Spina Bifida

The exact cause of spina bifida remains uncertain. Researchers believe it could be influenced by both environmental factors and genetic predisposition, possibly exacerbated by insufficient levels of folic acid, a type of vitamin B, in the mother’s system.

Certain patterns have been observed:

1. Demographic Trends: Spina bifida is more prevalent among white and Hispanic infants and is slightly more common in girls.
2. Maternal Health Factors: Women with poorly managed diabetes or who are obese have a higher risk of giving birth to a child with spina bifida.

While the precise mechanisms linking these factors to spina bifida are still being studied, these correlations provide valuable insight into potential risk factors.

Spina Bifida in adults

As individuals with this defect transition into adulthood, they encounter distinct challenges compared to children, including:

1. Normal Aging Effects: The typical aging process, which involves a decline in muscle strength, flexibility, and physical stamina, tends to progress more rapidly or severely for adults with the defect. Additionally, sensory abilities may decline faster.
2. Spinal Cord Tethering: This condition occurs when the spinal cord becomes attached to surrounding tissue, leading to symptoms such as skin sores, rapidly progressing scoliosis, loss of sensation, pain (especially in the lower extremities or testicles), and urinary tract infections or leakage.
3. Changes in Bowel Patterns: Adults may experience alterations in bowel patterns, such as constipation or abdominal pain.
4. Orthopedic Issues: These may include osteoporosis, early-onset arthritis, and progressive back pain.
5. Loss of Skin Sensation and Circulation: Adults with this defect may experience reduced skin sensation, poor circulation, inability to sweat, bruising, and slow wound healing.
6. Latex Allergy: Due to frequent medical interventions, individuals with this defect are at an increased risk of developing a latex allergy.
7. High Blood Pressure: This is a common issue among adults with spina bifida.
8. Sleep Apnea: Both obstructive and central sleep apnea can occur, potentially leading to long-term damage to the heart.
9. Obesity: Adults with spina bifida often have high rates of obesity, which can exacerbate existing health issues.
10. Pregnancy Complexity for Women: While women with spina bifida can conceive, their condition can complicate pregnancy due to the unique challenges they face.

Symptoms

In spina bifida occulta, you might notice a patch of hair or a birthmark where the spine is affected. For meningocele and myelomeningocele, you can visibly see a sac protruding from the baby’s back. In meningocele, this sac might have a thin layer of skin covering it.

In myelomeningocele, the spinal cord tissue is exposed without any skin covering. Additional symptoms include:

1. Weak leg muscles, sometimes leading to immobility.
2. Abnormal foot shape, uneven hips, or a curved spine (scoliosis).
3. Hydrocephalus, characterized by a buildup of fluid in the brain cavities. In infants, this might cause a larger head size, a bulging soft spot on the head, and other related symptoms.
4. Seizures.
5. Bowel or bladder issues.
6. Difficulty breathing, swallowing, or moving the upper arms.
7. Potential overweight condition.

The specific symptoms vary based on the location of the spinal problem and which nerves are affected.

Diagnosis

There are three primary tests available to diagnose spina bifida and other birth defects while the baby is still in the womb:

1. Blood Test: This involves analyzing a sample of the mother’s blood to detect a specific protein called AFP (alpha-fetoprotein) that the baby produces. Elevated levels of AFP may indicate the presence of spina bifida or another neural tube defect.
2. Ultrasound: Using high-frequency sound waves, this procedure generates images of the baby inside the womb on a computer monitor. If the baby has spina bifida, the ultrasound may reveal an open spine or a sac protruding from the spine.
3. Amniocentesis: If the blood test indicates high AFP levels but the ultrasound appears normal, your doctor might recommend amniocentesis. During this procedure, a small amount of fluid is extracted from the amniotic sac surrounding the baby using a needle. Elevated AFP levels in this fluid suggest that the skin around the baby’s sac is absent, allowing AFP to leak into the amniotic sac.

In some cases, spina bifida may only be diagnosed after the baby is born. This happens if the mother did not receive prenatal care or if abnormalities were not detected during ultrasound examinations.

Following birth, the doctor may conduct X-rays of the baby’s body and perform a magnetic resonance imaging (MRI) scan. These tests utilize strong magnets and radio waves to obtain more detailed images for accurate diagnosis and treatment planning.

Treatments

Treatment options for spina bifida vary depending on the severity of the condition. Interventions can begin either shortly after birth or even during pregnancy.

1. Postnatal Surgery:
   • For meningocele, surgery is typically performed within 24 to 48 hours after birth. Surgeons reposition the membrane around the spinal cord and close the opening.
   • In the case of myelomeningocele, surgeons place the exposed tissue and spinal cord back into the baby’s body and cover it with skin. If hydrocephalus is present, a shunt—a hollow tube—is inserted into the baby’s brain within 24 to 48 hours after birth to redirect excess fluid to another part of the body for reabsorption.
2. Prenatal Surgery:
   • In some cases, surgery can be conducted while the baby is still in the womb. This can be done typically before the 26th week of pregnancy. Surgeons enter the mother’s womb and close the opening over the baby’s spinal cord. While this approach may reduce the risk of certain birth defects, it poses risks to both the mother and the baby, potentially resulting in premature birth.
3. Follow-Up Surgeries:
   • Additional surgeries may be necessary to address issues with feet, hips, or the spine, or to replace the shunt in the brain.
   • Progressive tethering, a condition where the spinal cord becomes attached to the spinal canal. This affects 20% to 50% of children with myelomeningocele. Surgery may be required to address this as the child grows, to prevent muscle loss and bladder or bowel problems caused by spinal cord stretching.
4. Ongoing Management:
   • Some individuals with spina bifida may require assistive devices such as crutches, braces, or wheelchairs for mobility, while others may need catheters to manage bladder issues.
   • Close collaboration with the child’s medical team is crucial to ensure comprehensive health management and support for individuals with this chronic medical condition.

Prevention

Preventing spina bifida and reducing the risk of other birth defects can be achieved through simple measures, primarily by ensuring adequate intake of folic acid:

1. Supplementation: Taking a daily multivitamin containing folic acid has been proven effective in preventing spina bifida and lowering the likelihood of other birth defects. It is recommended that any woman who is pregnant or planning to conceive should consume 400 micrograms of folic acid per day. However, for women with a history of spina bifida or who have had a child affected by the condition, the recommended dosage is higher—4,000 micrograms per day—beginning at least one month before conception and continuing through the first few months of pregnancy.
2. Dietary Sources: Folic acid naturally occurs in various foods, particularly dark green vegetables, egg yolks, and certain fortified foods such as bread, pasta, rice, and breakfast cereals. Including these foods in your diet can contribute to meeting your daily folic acid requirements.

By incorporating folic acid supplementation and consuming folic acid-rich foods, women can significantly reduce the risk of spina bifida and promote the healthy development of their babies during pregnancy.

Sources:

1. Centre for Disease Control (CDC): “Spina Bifida”.
2. Spina Bifida Association: “What is Spina Bifida?”
3. Mayo Clinic: “Spina Bifida.”
4. National Institute of Neurological Diseases and Stroke: “Spina Bifida Fact Sheet.”