Spina bifida
Overview
Spina
bifida is a birth defect that occurs when the spine and spinal cord don't form
properly. It's a type of neural tube defect. The neural tube is the structure
in a developing embryo that eventually becomes the baby's brain, spinal cord
and the tissues that enclose them.
Normally,
the neural tube forms early in pregnancy and it closes by the 28th day after
conception. In babies with spina bifida, a portion of the neural tube doesn't
close or develop 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. When necessary, early treatment for spina bifida
involves surgery — although such treatment doesn't always completely resolve
the problem.
Types
Spina
bifida can occur in different types: spina bifida occulta, myelomeningocele
(my-uh-lo-muh-NING-go-seel) or the very rare type meningocele
(muh-NING-go-seel).
Spina bifida occulta
"Occulta"
means hidden. It's the mildest and most common type. Spina bifida occulta
results in a small separation or gap in one or more of the bones of the spine
(vertebrae). Many people who have spina bifida occulta don't even know it,
unless the condition is discovered during an imaging test done for unrelated
reasons.
Myelomeningocele
Also
known as open spina bifida, myelomeningocele is the most severe type. The
spinal canal is open along several vertebrae in the lower or middle back. The
membranes and spinal nerves push through this opening at birth, forming a sac
on the baby's back, typically exposing tissues and nerves. This makes the baby
prone to life-threatening infections and may also cause paralysis and bladder
and bowel dysfunction.
Symptoms
Signs
and symptoms of spina bifida vary by type and severity, and also between
individuals.
·
Spina bifida occulta. Typically there aren't any signs or
symptoms because the spinal nerves aren't involved. But you can sometimes see
signs on the newborn's skin above the spinal defect, including an abnormal tuft
of hair, or a small dimple or birthmark. Sometimes, the skin marks can be signs
of an underlying spinal cord issue that can be discovered with MRI or
spinal ultrasound in a newborn.
·
Myelomeningocele. In this severe type of spina bifida:
o
The spinal canal remains open along several vertebrae in the lower
or middle back
o
Both the membranes and the spinal cord or nerves protrude at birth,
forming a sac
o
Tissues and nerves usually are exposed, though sometimes skin covers
the sac
When to see a doctor
Typically,
myelomeningocele is diagnosed before or right after birth, when medical care is
available. These children should be followed by a specialized team of doctors
throughout their lives, and families should be educated on the different
complications to watch for.
Children
with spina bifida occulta typically don't have any symptoms or complications,
so usually only routine pediatric care is needed.
Causes
Doctors
aren't certain what causes spina bifida. It's thought to result from a
combination of genetic, nutritional and environmental risk factors, such as a
family history of neural tube defects and folate (vitamin B-9) deficiency.
Risk
factors
Spina
bifida is more common among whites and Hispanics, and females are affected more
often than males. Although doctors and researchers don't know for sure why
spina bifida occurs, they have identified some risk factors:
·
Folate deficiency. Folate, the natural form of vitamin B-9,
is important to the development of a healthy baby. The synthetic form, found in
supplements and fortified foods, is called folic acid. A folate 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. That risk increases if two previous children have
been affected by the condition. In addition, a woman who was born with a neural
tube defect has a greater chance of giving birth to a child with spina bifida.
However, most babies with spina bifida are born to parents with no known family
history of the condition.
·
Some medications. For example, anti-seizure medications,
such as valproic acid (Depakene), seem to cause neural tube defects when taken
during pregnancy. This might happen because they interfere with the body's ability
to use folate and folic acid.
·
Diabetes. Women with diabetes who don't have well-controlled blood sugar
have a higher risk of having a baby with spina bifida.
·
Obesity. Pre-pregnancy obesity is associated with an increased risk of
neural tube birth defects, including spina bifida.
·
Increased body temperature. Some evidence suggests that increased
body temperature (hyperthermia) in the early weeks of pregnancy may increase
the risk of spina bifida. Elevating your core body temperature, due to fever or
using a sauna or hot tub, has been associated with a possible slightly
increased risk of spina bifida.
If
you have known risk factors for spina bifida, talk with your doctor to
determine if you need a larger dose or prescription dose of folic acid, even
before a pregnancy begins.
If
you take medications, tell your doctor. If you plan ahead, some medications can
be adjusted to diminish the potential risk of spina bifida.
Complications
Spina
bifida may cause minimal symptoms or minor physical disabilities. But severe
spina bifida can lead to more significant physical disabilities. Severity is
affected by:
·
The size and location of the neural tube defect
·
Whether skin covers the affected area
·
Which spinal nerves come out of the affected area of the spinal cord
This
list of possible complications may seem overwhelming, but not all children with
spina bifida get all of these complications. And these conditions can be
treated.
·
Walking and mobility problems. The nerves that
control the leg muscles don't work properly below the area of the spina bifida
defect. This can cause muscle weakness of the legs and sometimes paralysis.
Whether a child can walk typically depends on where the defect is, its size,
and the care received before and after birth.
·
Orthopedic complications. Children with myelomeningocele can have
a variety of problems in the legs and spine because of weak muscles in the legs
and back. The types of problems depend on the location of the defect. Possible
problems include orthopedic issues such as:
o
Curved spine (scoliosis)
o
Abnormal growth
o
Dislocation of the hip
o
Bone and joint deformities
o
Muscle contractures
·
Bowel and bladder problems. Nerves that supply the bladder and
bowels usually don't work properly when children have myelomeningocele. This is
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. Shunts placed in the brain to treat
hydrocephalus can stop working or become infected. Warning signs may vary. Some
of the warning signs of a shunt that isn't working include:
o
Headaches
o
Vomiting
o
Sleepiness
o
Irritability
o
Swelling or redness along the shunt
o
Confusion
o
Changes in the eyes (fixed downward gaze)
o
Trouble feeding
o
Seizures
·
Chiari malformation type II. Chiari malformation
(kee-AH-ree mal-for-MAY-shun) type II is a common brain abnormality in children
with the myelomeningocele type of spina bifida. The brainstem, or lowest part
of the brain above the spinal cord, is elongated and positioned lower than
usual. This can cause problems with breathing and swallowing. Rarely,
compression on this area of the brain occurs and surgery is needed to relieve
the pressure.
·
Infection in the tissues surrounding the brain (meningitis). Some babies with
myelomeningocele may develop meningitis, an infection in the tissues
surrounding the brain. This potentially life-threatening infection may cause
brain injury.
·
Tethered spinal cord. Tethered spinal cord results when the
spinal nerves bind to the scar where the defect was closed surgically. The
spinal cord is less able to grow as the child grows. This progressive tethering
can cause loss of muscle function to the legs, bowel or bladder. Surgery can
limit the degree of disability.
·
Sleep-disordered breathing. Both children and adults with spina
bifida, particularly myelomeningocele, may have sleep apnea or other sleep
disorders. Assessment for a sleep disorder in those with myelomeningocele helps
detect sleep-disordered breathing, such as sleep apnea, which warrants
treatment to improve health and quality of life.
·
Skin problems. Children with spina bifida may get wounds
on their feet, legs, buttocks or back. They can't feel when they get a blister
or sore. Sores or blisters can turn into deep wounds or foot infections that
are hard to treat. Children with myelomeningocele have a higher risk of wound
problems in casts.
·
Latex allergy. Children with spina bifida have a higher
risk of latex allergy, an allergic reaction to natural rubber or latex
products. Latex allergy may cause rash, sneezing, itching, watery eyes and a
runny nose. It can also cause anaphylaxis, a potentially life-threatening
condition in which swelling of the face and airways can make breathing
difficult. So it's best to use latex-free gloves and equipment at delivery time
and when caring for a child with spina bifida.
·
Other complications. More problems may arise as children with
spina bifida get older, such as urinary tract infections, gastrointestinal (GI)
disorders and depression. Children with myelomeningocele may develop learning
disabilities, such as problems paying attention, and difficulty learning
reading and math.
Prevention
Folic
acid, taken in supplement form starting at least one month before conception
and continuing through the first trimester of pregnancy, greatly reduces the risk
of spina bifida and other neural tube defects.
Get
folic acid first
Having
enough folic acid in your system by the early weeks of pregnancy is critical to
prevent spina bifida. Because many women don't discover that they're pregnant
until this time, experts recommend that all adult women of childbearing age
take a daily supplement of 400 to 1,000 micrograms (mcg) of folic acid.
Several
foods are fortified with 400 mcg of folic acid per serving,
including:
·
Enriched bread
·
Pasta
·
Rice
·
Some breakfast cereals
Folic
acid may be listed on food packages as folate, which is the natural form of
folic acid found in foods.
Planning
pregnancy
Adult
women who are planning pregnancy or who could become pregnant should be advised
to get 400 to 800 mcg of folic acid a day.
Your
body doesn't absorb folate as easily as it absorbs synthetic folic acid, and
most people don't get the recommended amount of folate through diet alone, so
vitamin supplements are necessary to prevent spina bifida. And it's possible
that folic acid will also help reduce the risk of other birth defects,
including cleft lip, cleft palate and some congenital heart defects.
It's
also a good idea to eat a healthy diet, including foods rich in folate or
enriched with folic acid. This vitamin is present naturally in many foods,
including:
·
Beans and peas
·
Citrus fruits and juices
·
Egg yolks
·
Milk
·
Avocados
·
Dark green vegetables, such as broccoli and spinach
When higher doses are needed
If you have spina bifida or
if you've previously given birth to a child with spina bifida, you'll need
extra folic acid before you become pregnant. If you're taking anti-seizure
medications or you have diabetes, you may also benefit from a higher dose of
this B vitamin. Check with your doctor before taking additional folic acid
supplements.
Jan Ricks Jennings, MHA,
LFACHE
Senior Management Consultant
Senior Management Resources,
LLC
Jan.Jennings@EagleTalons.net
JanJenningsBlog.Blogspot.com
412.913.0636 Cell
724.733.0509 Office
December 17, 2021