Anencephaly
Reprinted from:
National Institute of Neurological Disorders and Stroke
What is Anencephaly?
Anencephaly is a neural tube
defect (a disorder involving incomplete development of the brain, spinal cord,
and/or their protective coverings). The neural tube is a narrow sheath that
folds and closes between the 3rd and 4th weeks of pregnancy to form the brain
and spinal cord of the embryo. Anencephaly occurs when the "cephalic"
or head end of the neural tube fails to close, resulting in the absence of a
major portion of the brain, skull, and scalp. Infants with this disorder are
born without both a forebrain (the front part of the brain) and a cerebrum (the
thinking and coordinating area of the brain). The remaining brain tissue is
often exposed--not covered by bone or skin. The infant is usually blind, deaf,
unconscious, and unable to feel pain. Although some individuals with
anencephaly may be born with a rudimentary brain stem, the lack of a
functioning cerebrum permanently rules out the possibility of ever gaining
consciousness. Reflex actions such as respiration (breathing) and responses to
sound or touch may occur. The cause of anencephaly is unknown. Although it is
believed that the mother's diet and vitamin intake may play a role, scientists
believe that many other factors are also involved.
Is there any treatment?
There is no cure or standard treatment for anencephaly. Treatment is
supportive.
What is the prognosis?
The prognosis for individuals with anencephaly is extremely poor. If the
infant is not stillborn, then he or she will usually die within a few hours or
days after birth.
What research is being done?
The NINDS conducts and supports a wide range of
studies that explore the complex mechanisms of normal brain development. The
knowledge gained from these fundamental studies provides the foundation for
understanding how this process can go awry and, thus, offers hope for new means
to treat and prevent congenital brain disorders including neural tube defects
such as anencephaly.