Anencephaly

Anencephaly is a cephalic disorder that results from a neural tube defect that occurs when the cephalic (head) end of the neural tube fails to close, usually between the 23rd and 26th day of pregnancy, resulting in the absence of a major portion of the brain, skull, and scalp. Strictly speaking, the translation of the Greek term to English is "no brain" (that is, totally lacking), but it is accepted that children with this disorder are born without a forebrain, the largest part of the brain consisting mainly of the cerebral hemispheres, including the neocortex, which is responsible for higher-level cognition. The remaining brain tissue is often exposed, i.e. not covered by bone or skin. With very few exceptions, most babies with this disorder do not survive.