anencephaly

anencephaly /an·en·ceph·a·ly/ (an″en-sef´ah-le) congenital absence of the cranial vault, with the cerebral hemispheres completely missing or reduced to small masses.anencephal´ic

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an·en·ceph·a·ly (nn-sf-l)

n.

Congenital absence of most of the brain and spinal cord.

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anen·ce·phalic (-s-flk), anen·cepha·lous (-sf-ls) adj.

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Anencephaly

A hereditary defect resulting in the partial to complete absence of a brain and spinal cord. It is fatal.

Mentioned in: Amniocentesis, Polyhydramnios and Oligohydramnios

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anencephaly

[an′ensef′əlē]

Etymology: Gk, a + encephalos, without brain

a neural tube defect in which absence of major portions of the brain and malformation of the brainstem occur. The cranium does not close and the vertebral canal remains a groove. It is thought to be caused by a combination of genetic and environmental factors. Anencephaly is not compatible with life. It can be detected early in gestation by amniocentesis and analysis or by ultrasonography. Recent research has shown that a diet rich in folic acid may reduce the incidence of neural tube defects. See also neural tube defect. anencephalous, adj.

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anencephaly

congenital absence of the cranial vault, with the cerebral hemispheres completely missing or reduced to small masses.

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anencephaly

Neonatology A lethal malformation consisting of congenital partial or complete absence of the cranial vault accompanied by absence of overlying tissues, including the brain and cerebral hemispheres, skull and scalp; anencephaly develops in the 1^st month of gestation and affects 0.14-0.7/1000 live births; the 1º abnormality is failure of cranial neurulation, the embryologic process separating the forebrain precursors from the amniotic fluid; since neural tissue is exposed, cerebral tissue is hemorrhagic, fibrotic, gliotic without functional cortex Etiology Usually idiopathic, possibly multifactorial or polygenic in origin. See Uniform Determination of Death Act.