Neural tube defects are one type of birth defect. Neural tube defects affect the brain and spinal cord. Examples of neural tube defects include anencephaly, encephaloceles, iniencephaly, and spina bifida.
Anencephaly is a problem that occurs during fetal development in which the neural tube does not close. The result is that a large portion of the brain—including the frontal lobe and the cerebrum, along with the skull and scalp are missing. The child usually dies within a few hours of birth, if it is not stillborn. The precise cause of anencephaly is not known, but it is thought that increasing folic acid, also known as vitamin B9, with 4 mg supplements in the diets of women who are childbearing age may help decrease anencephaly, as well as other neural tube defects, by as much as 70 percent
Encephaloceles are neural tube defects that are rarer than anencephaly. In cases with encephaloceles, the neural tube does not close completely as the fetus is developing, with the result that the brain and its covering protrudes through openings in the skull. Other symptoms include microcephaly—a head of abnormally small size, hydrocephalus—an excess of cerebrospinal fluid in the brain, and craniofacial abnormalities, among others. A child with this condition may be of normal intelligence or suffer from issues of intelligence along with seizures, developmental delays, and vision problems.
Iniencephaly is another neural tube defect that is relatively rare and is caused by incomplete closure of the neural tube. It is related to spina bifida, but more severe, including such severe spine deformity that head is bent backward. It is often accompanied by anencephaly and or encaphalocele. Most infants with iniencephaly die within a few hours. Like the related disorders, it is believed that this neural tube defect can be widely prevented with folic acid.
Spina bifida is, along with anencephaly, one of the two most frequent neural tube defect and one of the most common birth defects that is disabling. In this case, the failure is that the fetal spinal column doesn’t complete its closure, which usually causes nerve damage that at least partially paralyzes the legs. At minimum, people with spina bifida may need devices to assist them in walking, such as braces or crutches, and in some cases, wheelchairs. Other issues that may occur along with spina bifida include learning disorders, hydrocephalus, and problems with bladder and bowel control. Like the other neural tube defects, it is thought that folic acid use will help prevent spina bifida.
