Overview of Brain and Spinal Cord Birth Defects
Birth defects of the brain and spinal cord can occur in early or late fetal development.
Typical symptoms include intellectual disability, paralysis, incontinence, or loss of sensation in some parts of the body.
The diagnosis is based on computed tomography and magnetic resonance imaging.
Folate taken before pregnancy and during pregnancy can reduce the risk of certain types of defects.
Some defects can be repaired surgically, but brain or spinal cord damage is usually permanent.
Of the many possible defects in the brain and spinal cord, those known as neural tube defects develop within the first weeks of pregnancy. Other defects, including hydrocephalus and microcephaly, develop later in pregnancy.
There are many causes of birth defects of the brain and spinal cord, including many previously unknown genetic factors.
Many children with brain and spinal cord defects also have visible abnormalities in the head or back. Symptoms of brain or spinal cord damage may develop if the defect affects brain or spinal cord tissue. Brain damage can be fatal or result in mild or severe disabilities which may include intellectual disability, seizures, and paralysis. Spinal cord damage can result in paralysis, incontinence, and loss of sensation to areas of the body reached by nerves below the level of the defect (see Figure: Where Is the Spinal Cord Damaged?).
Before birth, amniocentesis (removing a sample of fluid from around the fetus), prenatal ultrasonography, or a newer technique called fetal MRI may enable doctors to identify many of these defects during pregnancy. When a defect is identified, parents need psychologic support and genetic counseling because the risk of having other children with such a defect is high.
Folate (a B vitamin, folic acid) taken before and during pregnancy can decrease the risk of some neural tube defects. For this reason, women of child-bearing age are encouraged to take folate if they think that they may become pregnant.
Some defects, such as those that cause visible openings or swellings, can be repaired surgically. Although brain or spinal cord damage from the defect is usually permanent, surgery can help prevent further complications and improve function. With prompt surgical intervention, some children have near-normal development.