Neurologic Conditions
Open Neural Tube Defect (also known Spina Bifida)
The neural tube is a portion of the developing embryo that becomes
the brain and the spinal cord. If the neural tube fails to close
properly, the result may be Spina Bifida (technically known as a
myelomeningocele). Complications associated with an open neural tube
defect are variable, and it is known that they are associated with the
size and position of the opening. In general, the higher the defect, the
more severe the complications, which can vary from no major
complications, paralysis of the lower limbs and incontinence of the
bowel and bladder to an inability for a baby to survive. Many
individuals with an isolated open spinal defect (depending on the
location of the opening along the spine) have normal intelligence.
Careful monitoring throughout pregnancy will be important to assess the
baby’s development and well-being. An open neural tube defect will need
to be surgically repaired shortly after birth.
Hydrocephalus
Hydrocephalus is the result of the accumulation of cerebrospinal
fluid in the ventricles, or chambers, in the baby’s brain. If a blockage
occurs that blocks the normal flow of cerebrospinal fluid, the
ventricles above the blockage will become dilated or enlarged by the
fluid that cannot pass the obstruction. This can result is an increased
head size to accommodate the excess fluid called hydrocephalus. There
are many causes of hydrocephalus such as an underlying chromosome
abnormality, genetic syndrome, developmental defect of the fetal brain,
fetal infection or hemorrhage. Careful monitoring throughout pregnancy
will be important to assess the baby’s development and well-being.
Typically treatment for hydrocephalus includes a shunt placement after
delivery to relieve the pressure in the baby’s brain.
Holoprosencephaly
Holoprosencephaly is a variable abnormality of the baby’s brain,
which is characterized by failure of the two halves of the brain to
separate fully during development. There are three types of
holoprosencephaly depending on the level of severity. Other brain
abnormalities, seizures, and other health concerns can also be present
as well. Individuals with holoprosencephaly can also have facial
changes including hypotelorism (eyes that are closer together than
average), cleft lip and/or cleft palate, etc. Most individuals with
holoprosencephaly have some degree of learning problems, which often
correlates to the degree of fusion in their brain. Unfortunately, if
the brain is severely fused, survival may be unlikely. There are many
causes of holoprosencephaly such as an underlying chromosome
abnormality, genetic syndrome, developmental defect of the fetal brain,
or maternal conditions such as diabetes or drug exposures. Careful
monitoring throughout pregnancy will be important to assess the baby’s
development and well-being. There is no cure for holoprosencephaly, and
treatment relies on alleviating symptoms such as seizures, which may
develop.