anencephaly

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anencephaly

 [an″en-sef´ah-le]
congenital absence of the cranial vault, with the cerebral hemispheres completely missing or reduced to small masses. adj., adj anencephal´ic.

mer·o·an·en·ceph·a·ly

(mer'ō-an'en-sef'ă-lē),
Congenital absence of the calvaria and most of the brain, usually the forebrain and midbrain.
[mero- + G. an- priv. + enkephalos, brain]

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

anencephaly

(ăn′ən-sĕf′ə-lē)
n. pl. anencepha·lies
Congenital absence of most of the brain and spinal cord.

an′en·ce·phal′ic (-sə-făl′ĭk) adj.

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

anencephaly

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. Most anencephalics die within the first week, and are of use as potential organ donors; ethical dilemmas inherent in such use of humans has made this a contentious issue.

Anencephaly develops in the first month of gestation and affects 0.14–0.7/1000 live births. The primary defect is failure of cranial neurulation, the embryologic process separating the forebrain precursors from the amniotic fluid; since neural tissue is exposed, cerebral tissue is haemorrhagic, fibrotic, and gliotic without functional cortex.

Aetiology
Usually idiopathic, possibly multifactorial or polygenic in origin. The risk of neural tube defects, including anencephaly, can be decreased by an adequate maternal ingestion of folic acid during pregnancy.

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 1st 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.

mer·o·en·ceph·aly

(mĕr'ō-en-sef'ă-lē)
Congenital defective development of the brain in which the brain and cranium are present in rudimentary form.
Synonym(s): anencephaly.
[meros + G. an-, priv. + enkephalos, brain]

anencephaly

Absence of the greater part of the brain and of the bones (ACRANIA) at the rear of the skull. Anencephaly is a defect of development arising from a severe NEURAL TUBE DEFECT early in the development of the embryo and is incompatible with life. Anencephalic babies are born dead or die soon after birth. The term derives from the Greek an , not and encephalon , a brain. See ACEPHALUS.

Anencephaly

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

anencephaly

underdevelopment of the brain and cranial vault; incompatible with normal life

anencephaly

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