Spina bifida and other congenital brain and spinal disorders (in
conjunction with the Spina Bifida Clinic)
Spina Bifida is a rare birth disorder, affecting approximately 1
in 12-1400 live births, although fortunately its incidence appears to be
declining with each decade. It is the most serious birth disorder affecting the
nervous system compatible with life. Spina bifida occurs when a portion of the
fetal spinal cord, during the third and fourth weeks of pregnancy, fails to
properly close. As a result, the child is born with a part of the spinal cord
exposed on the back. There appear to be both genetic and environmental
influences that contribute to spina bifida. For example, once a couple has one
child with spina bifida, the risk of having a second child increases to 2-3%; if
the couple has two affected children, their risk of having a third child
increases to about 10%.
Recently, attention has been focused on nutrition, and in particular the role of
folate (a B vitamin) on reducing the incidence of spina bifida. Studies show
that a woman who takes folate supplementation before and during the early stages
of pregnancy has a lower chance of having a child with spina bifida. Any woman
who is contemplating getting pregnant should begin taking supplemental folate;
consult your physician for more information about this.
Can Spina Bifida be detected before birth?
Yes. There are three things that can be done prenatally to
detect spina bifida.
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Most women in the United States have blood drawn during the
16-18th weeks of pregnancy to check for blood levels of a protein,
alphafetoprotein, which is elevated in about 75-80% of women having fetuses
with spina bifida.
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Ultrasound (sonograms) of the fetus can detect signs of spina
bifida such as the open spine, the 'lemon sign', or the 'banana sign'
(particular features of the fetal head on ultrasound which indicate spina
bifida). Ultrasound has proven to be quite accurate in identifying spina
bifida and success rates approaching 100% have been reported recently.
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Maternal amniocentesis, in which a small sample of the
amnionic fluid is withdrawn through a thin needle, can detect alphafetoprotein
or another protein, acetylcholinesterase, in most pregnancies with spina
bifida.
Unfortunately, there are limitations on any test, and these
tests do not identify a child with spina bifida in every single case. Moreover,
these tests do not routinely identify other types of congenital spinal cord
malformations (such as spinal lipomas, split cord malformations, and other
disorders).
Treatment
The child born with spina bifida needs to have the exposed part of the spinal
cord repaired, to prevent further injury to the spinal cord and to prevent
infection. The malformation is usually closed during the first 24-48 hours after
birth. The 80-85% of children with spina bifida who develop hydrocephalus will
require a ventricular shunt to control the build-up of spinal fluid. Only about
25% of children have obvious hydrocephalus immediately after birth, and some
neurosurgeons place the shunt at the same time as the back closure. However,
about three-quarters of these patients don't have hydrocephalus at birth
(because the excess spinal fluid is leaking out of the open spinal cord on the
back) and hydrocephalus develops only after the back is closed. In these
children, the back is repaired, and the shunt is placed later only if the child
develops signs of hydrocephalus.
The child is usually also evaluated by a urologist and orthopedist to
evaluate the bladder, spine curvature, and leg deformities if present. The child
will usually be tested for bladder function and, if there are problems, a
catheterization schedule may be started and the parents taught how to do this -
a small catheter is inserted temporarily into the bladder through the urethra
(the opening through which we urinate) to drain the urine. The procedure isn't
difficult or painful to perform. The parents are usually given information about
spina bifida from either the physicians or a nurse coordinator for the spina
bifida program.
What later problems can develop?
Most children with hydrocephalus will require ongoing multidisciplinary care
from neurosurgeons, urologists and orthopedists. Because of the complexity of
their problems, these children should be cared for by people with some
experience in dealing with the problems these children face. This care is
usually best provided in a spina bifida center or clinic in which all of the
specialists are able to evaluate the child at the same time. Communication
between care givers is better, and little problems can be identified early,
before they become bigger problems. Studies have suggested that the care is not
only better in these multidisciplinary clinics, it also is more cost effective.
Children are usually followed 3 or 4 times a year for the first year, twice
yearly for the next few years, and annually thereafter, into adulthood. A
growing number of spina bifida centers also provide adult clinics for the 'grown
child'.
Unfortunately, many children with spina bifida require further operations and
other care for a variety of difficulties that may develop. Bracing is sometimes
necessary to improve function and walking. Bladder infection and kidney problems
can be addressed by the urologist. Progressive lower extremity or back curvature
can be treated with bracing or surgery to correct the problem.
From a neurosurgical perspective, ongoing shunt problems are the most
frequent problems many of these children face. Shunts may malfunction and may
need to be replaced or revised. About 15-25% of children develop problems from
the Chiari malformation (a brain malformation associated with the spina bifida
that can lead to problems with swallowing, voice, or arm strength, among other
problems) or the tethered spinal cord (a problem in which the spinal cord is
bound down in the scar of the closure and cannot grow with the child, producing
symptoms and signs in about a third of children with spina bifida - including
progressive weakness, worsening bowel or bladder control, back or leg pain, and
scoliosis or other orthopedic deformities. It should be stressed that both the
Chiari malformation and tethered spinal cord are present in the majority of
children with spina bifida, but only cause problems in a few; the mere presence
of an abnormality does NOT mean that the problem needs to be treated, unless the
child is having symptoms or signs.
Medical problems may also require treatment. Some children with spina bifida
(fortunately only a few) can have seizures that require medication to control.
Some children can have short stature and require growth hormone replacement to
help them grow. Children with spina bifida can also develop a unique form of
attention deficit disorder which can cause difficulties in school and which can
be treated with medications. Many of these problems can also be addressed and
followed in the clinic.
What is the long-term outlook for children with spina bifida?
Fortunately, with the proper medical care, children with spina bifida can
lead active and productive lives. These children are a testament to the human
spirit; most are successful in school and many are actively involved in modified
sports activities despite their physical challenges. Twenty year follow-up
studies of children with spina bifida show that they enter college in the same
proportion as the general population, and many are actively employed. With
recent improvements in care for these children, their outlook continues to
improve.
Questions and referrals can be directed to (717) 531-0857.
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