Overview of Cephalic Disorders
The term "cephalic disorders" refers to defects resulting from abnormal development of, or damage to, the brain and spinal cord. Cephalic disorders are present at or before birth. In most cases, the problem occurs early in the development of the fetal nervous system. In other cases, the problem occurs when the fibrous joints connecting the bones of the skull join prematurely.
Cephalic disorders may be caused by genetic conditions or by exposure of the mother and developing fetus to infections, toxic substances, medications, or radiation.
The severity of these disorders varies greatly. Some cause mild disabilities; others are profound, resulting in total lifelong disability, vastly reduced functional capacity, and sometimes death.
Anencephaly is one of the most serious cephalic disorders and afflicts roughly 1000 to 2000 babies born in the United States annually. Female infants are affected more often than males. Infants born with this disorder have no forebrain—the main portion of the cerebrum, responsible for thinking and coordination. Brain tissue that does develop often is not covered by bone or skin.
Causes of Anencephaly
The cause of anencephaly remains unknown. A developmental failure occurs between the 23rd and 26th days of pregnancy. The cephalic (or head) end of the neural tube fails to close, and major portions of the brain, skull, and scalp do not develop. Recent studies suggest the addition of folic acid to the diet of women in their child-bearing years may reduce the incidence of neural tube defects, suggesting that factors associated with diet and vitamins may play a role.
Signs and Symptoms of Anencephaly
Anencephalic infants typically are born blind, deaf, unconscious, and insensitive to pain. Some may have a rudimentary brainstem that permits reflex actions such as breathing and, in some cases, responsiveness to sound or touch.
Anencephaly often can be diagnosed before birth through an ultrasound examination.
Treatment for Anencephaly
The condition is untreatable and incurable.
Prognosis for Infants with Anencephaly
Without a functioning cerebrum, anencephalic infants cannot gain consciousness. Most anencephalic infants are stillborn or die within a few hours or days after birth.
In this disorder, there is abnormal enlargement of the occipital horns—the rear portion of the cavities or chambers of the brain. Colpocephaly results from underdevelopment or lack of thickening of the white matter in the posterior cerebrum.
Causes of Colpocephaly
The cause is unknown. Research suggests there may be a intrauterine disturbance between the 2nd and 6th months of pregnancy.
Signs and Symptoms of Colpocephaly
Infants with colpocephaly have abnormally small heads (microcephaly), profound mental retardation, motor abnormalities, muscle spasms, and seizures.
Diagnosis of Colpocephaly
Colpocephaly sometimes is discovered late in pregnancy but is often misdiagnosed as hydrocephalus—excessive cerebrospinal fluid in the brain. More often, colpocephaly is diagnosed after birth when symptoms appear.
Treatment for Colpocephaly
Treatment is symptomatic. Anti-convulsant drugs may prevent seizures and other medications may be prescribed to prevent muscle shrinkage or contractures.
Prognosis for Infants with Copocephaly
Prognosis depends on the severity of microcephaly and brain malformation. In some cases, children with colpocephaly are able to participate in special education.