Neeraj Awasthy, Karam chand
Consultant Pediatrician

Address for Correspondence: Dr Neeraj Awasthy, 123, Anandkunj, Vikaspuri, New Delhi 110018. Email: n_awasthy@yahoo.com

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 arises from an embryonic defect occurring prior to day 26 which prevents the closure of the anterior neuropore. 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. Recurrence rate is 4% and increases to 10% if a couple have had 2 previous anencephalic infants. Whites are more affected than blacks (6:1). Females are more commonly affected than male. Organ donation is controversial and needs to be investigated.

Last updated: 1-09-2005 Vol 2 Issue 9 Art # 43

Awasthy N, Karam chand. Anencephaly. Pediatric Oncall [serial online] 2005 [cited 2005 September 1];2. Art # 43. Available from:
http://www.pediatriconcall.com/fordoctor/viewersChoice/Anencephaly.asp