Myelomeningocele: Symptoms, Causes, Treatment

What are the symptoms of myelomeningocele?

Myelomeningocele, a severe form of spina bifida, is a neural tube defect where the spinal canal and backbone do not close before birth, leading to a sac or cyst that protrudes from the baby’s back. This sac contains parts of the spinal cord, meninges, and nerves, which results in a wide range of symptoms, typically affecting movement, sensation, organ function, and cognitive abilities. Here’s a detailed look at the various symptoms and complications associated with myelomeningocele:

1. Neurological Symptoms

• Loss of Sensation: Due to nerve damage, affected individuals often have limited or no sensation below the site of the lesion, making it difficult to feel pain, temperature, or touch.
• Paralysis and Weakness: Many children experience partial or complete paralysis in the legs, impacting their ability to walk or bear weight. The severity depends on the location and extent of the defect on the spinal cord.
• Chiari II Malformation: This common condition in myelomeningocele patients occurs when brain tissue (usually the cerebellum) extends into the spinal canal, causing headaches, difficulty swallowing, balance issues, and respiratory problems.
• Hydrocephalus: About 80-90% of individuals with myelomeningocele develop hydrocephalus, a condition where cerebrospinal fluid builds up in the brain’s ventricles, potentially leading to increased intracranial pressure, headaches, and developmental delays if untreated.

2. Musculoskeletal Symptoms

• Spinal Deformities: Conditions like scoliosis (curvature of the spine) and kyphosis (hunching of the back) frequently develop due to weakened spinal structure and muscle imbalance.
• Contractures: Joint contractures, or tightened muscles and tendons, can cause the limbs to remain in a fixed position, particularly in the legs and feet.
• Clubfoot: Often present at birth, clubfoot is a deformity in which the foot is twisted, affecting balance and making walking difficult.

3. Urological Symptoms

• Neurogenic Bladder: Most patients experience neurogenic bladder, where they cannot control urination due to nerve impairment, leading to urinary incontinence, retention, or urinary tract infections. Regular catheterization or other interventions are often needed to manage these issues and prevent kidney damage.
• Renal Complications: Due to frequent urinary infections and retention, there is an elevated risk of kidney damage if the condition is not managed properly.

4. Gastrointestinal Symptoms

• Bowel Incontinence: Nerve damage affecting the bowels often leads to incontinence, making it difficult for the individual to control bowel movements. In some cases, patients experience constipation or require bowel management programs.

5. Cognitive and Developmental Symptoms

• Cognitive Impairment: While many individuals have normal intelligence, certain cognitive impairments related to attention, problem-solving, and memory are more common in those with hydrocephalus and Chiari II malformation.
• Learning Disabilities: Specific learning challenges, such as difficulties with math and problem-solving, are frequently noted, and some may require special educational support.
• Speech and Language Delay: Delays in language development or speech difficulties may occur, especially in those with associated brain malformations.

6. Skin and Orthopedic Complications

• Pressure Ulcers: Due to the lack of sensation, individuals are at risk for developing pressure ulcers, particularly in areas that experience prolonged pressure.
• Fractures: Reduced sensation and muscle control can lead to an increased risk of fractures, especially in the lower limbs.

7. Other Potential Symptoms

• Vision and Hearing Problems: Chiari II malformation and hydrocephalus can sometimes lead to issues with vision, such as strabismus (crossed eyes) or optic nerve damage, and in rare cases, hearing issues.
• Respiratory Issues: Respiratory challenges can arise from Chiari malformation or complications related to hydrocephalus, which may compress the brainstem.

What are the causes of myelomeningocele?

Myelomeningocele is a type of spina bifida, a congenital condition that occurs when the neural tube, which eventually forms the spine and surrounding structures, fails to close properly during early fetal development. The exact cause of myelomeningocele is multifactorial and involves a combination of genetic, environmental, and nutritional factors. Here are some of the key contributors:

1. Genetic Factors:

• Family History: A family history of neural tube defects (NTDs) can increase the risk of myelomeningocele. Genetic predisposition plays a role, meaning that certain genetic traits or mutations can be passed down among family members.
• Genetic Syndromes: Some genetic syndromes, such as trisomy 13 or trisomy 18, may be associated with a higher prevalence of myelomeningocele.

2. Nutritional Deficiencies:

• Folic Acid Deficiency: One of the most well-established risk factors for neural tube defects is a deficiency in folic acid (vitamin B9). Adequate folic acid intake before conception and during early pregnancy is crucial for neural tube development. Insufficient levels can lead to impaired neural tube closure.

3. Environmental Factors:

• Teratogens: Exposure to certain drugs or substances during pregnancy, known as teratogens, can increase the risk of myelomeningocele. This includes:
• Some anti-seizure medications (e.g., valproic acid).
• Certain medications or recreational drugs.
• Diabetes: Women with diabetes, particularly if poorly controlled during pregnancy, have an increased risk of having a child with spinal cord defects, including myelomeningocele.

4. Maternal Health Factors:

• Obesity: Some studies suggest that maternal obesity before and during pregnancy may be associated with an increased risk of neural tube defects.
• Maternal Age: Older maternal age is considered a risk factor for various congenital anomalies, including neural tube defects.

5. Geographic and Ethnic Factors:

• Geographic Variability: The incidence of myelomeningocele may vary based on geographical regions. In certain populations, such as those in North America and Europe, the occurrence has been noted to be higher.
• Ethnic Background: Some ethnic groups, particularly those of Hispanic descent, have been found to have higher rates of neural tube defects, including myelomeningocele.

Conclusion:

Myelomeningocele arises from a complex interplay of genetic predisposition, nutritional factors (notably folic acid deficiency), environmental exposures, maternal health, and demographic factors. Awareness of these risk factors can guide preventive measures, particularly the importance of folic acid supplementation before conception and during early pregnancy, which has been shown to significantly reduce the risk of neural tube defects. If there are concerns regarding myelomeningocele, it’s important to consult with healthcare providers for assessment and recommendation of appropriate prenatal care.

How is the diagnosis of myelomeningocele made?

The diagnosis of myelomeningocele, a form of spina bifida, typically involves a combination of prenatal screening, imaging studies, and physical examinations. Here’s an overview of the steps and methods used to diagnose myelomeningocele:

1. Prenatal Diagnosis:

• Ultrasound: Most cases of myelomeningocele are diagnosed prenatally through a routine ultrasound. At around 18-20 weeks of gestation, detailed imaging can reveal signs such as:
• A visible defect in the spine.
• Abnormalities in the fetal anatomy, including the presence of a sac containing the spinal cord and nerves.
• Associated findings like hydrocephalus (enlargement of the ventricles in the brain) and changes in the shape of the fetal spine.
• Maternal Serum Alpha-Fetoprotein (MSAFP) Testing: This blood test measures the level of alpha-fetoprotein (AFP) in the mother’s blood. Elevated levels of AFP may indicate an increased risk of neural tube defects, including myelomeningocele, leading to further evaluation with ultrasound.

2. Postnatal Diagnosis:

• Physical Examination: After birth, myelomeningocele is typically diagnosed through a physical examination. The healthcare provider will look for:
• A visible sac or protrusion on the baby’s back, usually located in the lumbar or sacral region.
• Neurological deficits, such as weakness or paralysis in the legs and changes in sensation.
• Imaging Studies: When myelomeningocele is diagnosed, additional imaging may be conducted to assess the extent of spinal cord involvement and any associated brain abnormalities:
• MRI (Magnetic Resonance Imaging): This non-invasive imaging technique provides detailed images of the spinal cord, brain, and surrounding structures. MRI can help identify any associated conditions, such as Chiari malformation (downward displacement of the cerebellum).

3. Multidisciplinary Evaluation:

• Depending on the findings, a multidisciplinary team may be involved in the diagnosis and management of myelomeningocele. This team typically includes:
• Pediatricians
• Neurologists
• Neurosurgeons
• Physical and occupational therapists

Conclusion:

The diagnosis of myelomeningocele is usually made through a combination of prenatal ultrasound and maternal serum alpha-fetoprotein testing, along with postnatal physical examination and imaging studies. Early diagnosis allows for better planning and management of care, both antenatally and postnatally. If myelomeningocele is suspected or diagnosed, early referral to a specialist or a multidisciplinary care team is essential for optimal management and intervention.

What is the treatment for myelomeningocele?

The treatment for myelomeningocele, a type of spina bifida, typically involves a combination of surgical and supportive interventions. The primary goal is to address the structural defect, prevent complications, and support the affected individual’s development and quality of life. Here’s an overview of the treatment options:

1. Surgical Treatment:

• Repair of the Defect:
• Prenatal Surgery: In some cases, if myelomeningocele is diagnosed before birth (usually around 19-25 weeks of gestation), prenatal repair of the defect via fetal surgery may be considered. This can potentially reduce the risk of certain complications, such as hydrocephalus and improve neurological outcomes.
• Postnatal Surgery: If prenatal surgery is not performed, surgical repair of the defect is typically done shortly after birth. The surgeon will close the opening in the spine, covering the exposed spinal cord and nerves with skin and/or lining tissue to help protect it from infection.

2. Management of Associated Conditions:

• Hydrocephalus Treatment: Many infants with myelomeningocele develop hydrocephalus, which may necessitate the placement of a shunt (a device used to drain excess cerebrospinal fluid) to prevent increased intracranial pressure.
• Orthopedic Management:
• Early evaluation and intervention for musculoskeletal issues may occur. This can involve physical therapy, bracing, or surgery to correct deformities (such as scoliosis or clubfeet) and improve mobility.

3. Ongoing Care and Rehabilitation:

• Multidisciplinary Care: A team approach involving various healthcare professionals is essential. This may include:
• Pediatricians
• Neurologists
• Neurosurgeons
• Physical and Occupational Therapists
• Urologists (for bladder and bowel management)
• Physical and Occupational Therapy: These therapies help with mobility, independence, and overall development. Strategies may include the use of assistive devices (such as wheelchairs or braces) to enhance mobility and functionality.

4. Bladder and Bowel Management:

• Children with myelomeningocele often experience urinary and bowel dysfunction. A comprehensive plan may include:
• Intermittent Catheterization: This technique helps manage urinary function and prevent urinary tract infections.
• Bowel Training: A regular bowel regimen may be established to facilitate bowel control.

5. Educational and Psychological Support:

• Ongoing psychological support and educational evaluations can be valuable in addressing specific learning needs or developmental delays. Various educational resources or special education services may be utilized to support learning.

6. Regular Monitoring:

• Regular follow-up visits are essential for monitoring growth and development, neurological function, and managing any emerging complications. This includes regular imaging studies to assess the status of the spinal cord and brain.

Conclusion:

The treatment for myelomeningocele is comprehensive and requires a coordinated, multidisciplinary approach. Early intervention, comprehensive management of associated conditions, and ongoing support can significantly improve the outcomes for affected individuals. If you or someone you know is facing myelomeningocele, working with a specialized medical team is crucial for effective treatment and support.