Anencephaly Information

What is Anencephaly?

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 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.

Is there any treatment?

There is no cure or standard treatment for anencephaly. Treatment is supportive.

What is the prognosis?

The prognosis for individuals with anencephaly is extremely poor. If the infant is not stillborn, then he or she will usually die within a few hours or days after birth. [Editor's Note: The unborn child may have been diagnosed as having anencephaly, but be born with a less severe form of the disease, allowing the infant to live for years or more]

What research is being done?

The The National Institute of Neurological Disorders and Stroke conducts and supports a wide range of studies that explore the complex mechanisms of normal brain development. The knowledge gained from these fundamental studies provides the foundation for understanding how this process can go awry and, thus, offers hope for new means to treat and prevent congenital brain disorders including neural tube defects such as anencephaly.

Selected references

Berkow, R (ed). The Merck Manual of Diagnosis and Therapy: Specialties. vol. II, 16th edition, Merck & Co., Inc., Rahway, NJ, p. 307 (1992).

Bradley, W, et al (eds). Neurology in Clinical Practice: The Neurological Disorders. vol. II, 2nd edition, Butterworth-Heinemann, Boston, p. 1473 (1996).

Lemire, R, and Siebert, J. Anencephaly: Its Spectrum and Relationship to Neural Tube Defects. Journal of Craniofacial Genetics and Developmental Biology, 10;163-174 (1990).

Medical Task Force on Anencephaly. The Infant with Anencephaly. New England Journal of Medicine, 322:10; 669-674 (March 8, 1990).

Oakley, G, et al. More Folic Acid for Everyone, Now. Journal of Nutrition, 126:3; 751S-755S (March 1996).

Thomas, J, et al. Anencephaly and Other Neural Tube Defects. Frontiers of Neuroendocrinology, 15:2; 197-201 (June 1994).

Yen, I, et al. The Changing Epidemiology of Neural Tube Defects. American Journal of Diseases of Children, 146:7; 857-861 (July 1992)

Organizations

Anencephaly Support Foundation
20311 Sienna Pines Court
Spring, TX 77379
asf@asfhelp.com
http://www.asfhelp.com/
Tel: 888-206-7526

Association of Birth Defects Children
930 Woodcock Road
Suite 225
Orlando, FL 32803
http://www.birthdefects.org/
Tel: 407-895-0802
800-313-ABDC (2232)
Fax: 407-895-0824

March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
resourcecenter@modimes.org
http://www.modimes.org/
Tel: 914-428-7100
888-MODIMES (663-4637)
Fax: 914-428-8203

National Organization for Rare Disorders (NORD)
P.O. Box 8923 (100 Route 37)
New Fairfield, CT 06812-8923
orphan@rarediseases.org
http://www.rarediseases.org/
Tel: 203-746-6518
800-999-NORD (6673)
Fax: 203-746-6481

This fact sheet is in the public domain. You may copy it.

Provided by:
The National Institute of Neurological Disorders and Stroke
National Institutes of Health
Bethesda, MD 20892