Myelomeningocele

Myelomeningocele Spina Bifida – About Spina Bifida Cystica

There are three main types of spina bifida, but the one that most people think of when they hear the term “spina bifida” is myelomeningocele. To help learn more about the diagnosis and treatment of this disorder, it’s helpful to take a look at what symptoms and treatment options are currently available.

What is Myelomeningocele?

Also known as spina bifida cystica, myelomeningocele is the most severe form of spina bifida. It is thought to affect as many as 1 in 1000 live births, to varying degrees of severity. During prenatal development, if the neural tube surrounding the spine is unable to fuse closed, there will be an opening in the back in some cases. This allows portions of the sensitive nerves of the spinal cord and its surrounding tissues, or meninges, to protrude through the opening. They may bulge out of the back and be visible as well as susceptible to infection or nerve damage if left untreated. In most cases, surgery will be necessary to close this opening and protect the delicate spinal tissues and cord.

Causes of Myelomeningocele

Although there are a number of risk factors that have been associated with the onset of myelomeningocele in a fetus, there is no single known cause that can be given. Instead, attention must be paid to the various hereditary and environmental factors which can lead to its development. Some of these causes include the following:

  • Family history of neural tube defects – If a woman has given birth to a baby with spina bifida, there is a 1 in 20 chance that her next baby will also suffer from this birth defect.
  • Obesity – Women with a body mass index higher than 30 may be at risk.
  • Use of anti-seizure medications – Certain medications, including Carbamazepine, Lamotrigine and Valproate, have all been linked to spina bifida.
  • Folic acid deficiency – A B-vitamin found in foods such as broccoli and brown rice, a lack of folic acid may be linked to the development of spina bifida in infants. It’s recommended that all women of child-bearing age take 400 micrograms of this vitamin daily.
  • Diabetes – For unknown reasons, diabetes increases the risk of myelomeningocele.

In 90% of cases, however, there is no distinct cause for the development of myelomeningocele, making it hard to predict who will be born with it and who will not.

Signs and Symptoms of Myelomeningocele

Although mild forms of spina bifida will carry no symptoms at all, myelomeningocele will be quite distinctive and easy to diagnose. The most telltale sign right from birth is a sac protruding from the back, which will hold spinal cord tissue and membranes. Surrounding this, there may also be skin discoloration, skin dimpling, or birthmarks. Some other signs or symptoms of myelomeningocele could include the following:

  • Paralysis of lower half – Nerve damage can lead to partial or complete paralysis.
  • Incontinence – Because babies may lose feeling in the lower half of their bodies, this could cause difficulties with bladder control.
  • Bowel dysfunction – Along with bladder dysfunction, patients may also have difficulty with bowel movements.
  • Hydrocephalus – A side effect of myelomeningocele, the blockage of fluid that normally runs from the brain down the spinal cavity can lead to a buildup surrounding the brain. This is known as “fluid on the brain” and can be dangerous if left untreated.
  • Loss of sensation or numbness – There may not be full paralysis, but simply a feeling of numbness in certain parts of the body.

The degree to which these symptoms will be experienced can vary quite a bit depending on the severity of the disorder. The placement on the spine of the opening has been linked to the severity of the symptoms that are experienced.

Related Conditions

There are certain conditions, in addition to those described above such as hydrocephalus, that children who have myelomeningocele may be more prone to developing. This can be due to nerve damage, infection, and reasons that have yet to be discovered. Some of the related conditions include the following:

  • Learning disabilities
  • Depression
  • Allergy to latex
  • Obesity
  • Early onset of puberty
  • Tendonitis

As with the signs and symptoms of myelomeningocele, patients may experience all or none of these related conditions, depending on the severity of their condition.

Treatment Options for Myelomeningocele

It’s highly recommended to treat the symptoms of myelomeningocele as soon as possible to prevent extensive nerve damage. The longer that the spinal cord is left exposed, the higher the chance that there could be an infection or other complications. There are several different treatment options available, depending on the type of symptoms experienced, including the following:

  • Shunts – If the baby has developed hydrocephalus, as occurs in about 70-90% of myelomeningocele cases, then it’s necessary to place a shunt to drain the excessive cerebral fluid.
  • Catheter – A thin tube can be placed inside the bladder to help fight incontinence if bladder problems are present.
  • Medication – Antibiotics may be prescribed to help prevent or treat spinal infections, and incontinence medication can also be given to patients.
  • Surgery – In most cases, the baby will need to have surgery to replace the spinal cord inside the neural tube and close up any openings in the spine. This is usually carried out in the first days after birth, although in some cases it’s possible to undergo surgery while the baby is still in the womb. This depends on how early the myelomeningocele is diagnosed.

References:

1. http://www.spinabifidaassociation.org

2. http://emedicine.medscape.com/article/1266529-overview

3. http://www.bbc.co.uk/health/physical_health/conditions/spinabifida2.shtml

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