NationMaster - Encyclopedia: 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. Children with this disorder are born without a forebrain, the largest part of the brain consisting mainly of the cerebral hemispheres (which include the isocortex, which is responsible for higher level cognition, i.e., thinking). The remaining brain tissue is often exposed - not covered by bone or skin. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization (WHO). ... // Q00-Q99 - Congenital malformations, deformations and chromosomal abnormalities (Q00-Q07) Congenital malformations of the nervous system (Q00) Anencephaly and similar malformations (Q01) Encephalocele (Q02) Microcephaly (Q03) Congenital hydrocephalus (Q04) Other congenital malformations of brain (Q05) Spina bifida (Q06) Other congenital malformations of spinal cord (Q07) Other congenital malformations of nervous... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The Disease Bold textDatabase is a free website that provides information about the relationships between medical conditions, symptoms, and medications. ... eMedicine is an online clinical medical knowledge base that was founded in 1996. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Cephalic disorders are congenital conditions that stem from damage to, or abnormal development of, the budding nervous system. ... The neural tube is the embryonal structure that gives rise to the brain and spinal cord. ... This article is about human pregnancy in biological females. ... The scalp is the anatomical area bordered by the face anteriorly and the neck to the sides and posteriorly. ... A male Caucasian toddler child A child (plural: children) is a young human. ... In the anatomy of vertebrates, the prosencephalon is a part of encephalon, or brain. ... The telencephalon (te-len-seff-a-lon) is the technical name for a large region within the brain which is attributed many functions, which some groups would class as unique features which make humans stand out from other species. ... Isocortex is the part of the cerebral cortex with a six layer laminar structure. ... Look up Cognition in Wiktionary, the free dictionary. ...

Presentation

Infants born with anencephaly are usually blind, deaf, unconscious, and unable to feel pain. Although some individuals with anencephaly may be born with a rudimentary brainstem, which controls autonomic and regulatory function, the lack of a functioning cerebrum is usually thought of as ruling out the possibility of ever gaining consciousness, even though it has been disputed specifically.^[1] Reflex actions such as breathing and responses to sound or touch may occur. This article is about the visual condition. ... This article discusses the way the word deaf is used and how deafness is perceived by hearing and Deaf communities. ... Unconsciousness is the absence of consciousness. ... Look up Pain in Wiktionary, the free dictionary. ... The brain stem is the stalk of the brain below the cerebral hemispheres. ... This article is in need of attention from an expert on the subject. ... Consciousness is a quality of the mind generally regarded to comprise qualities such as subjectivity, self-awareness, sentience, sapience, and the ability to perceive the relationship between oneself and ones environment. ... For other uses, see Reflexive (disambiguation). ...

Diagnosis

Anencephaly can often be diagnosed before birth through an ultrasound examination. The maternal serum alpha-fetoprotein (AFP screening)^[2] and detailed fetal ultrasound^[3] can be useful for screening for neural tube defects such as spina bifida or anencephaly. For other uses, see Ultrasound (disambiguation). ... Alpha-fetoprotein (AFP) is a protein that is normally only produced in the foetus during its development. ... Alpha-fetoprotein screening, also called AFP screening, triple test, and expanded AFP screening, is a screening blood test usually offered between 15-20 weeks of pregnancy. ...

There are many false diagnoses for anencephaly, as it is not a common diagnosis, often confused with exencephaly or microcephaly. Also, sometimes a false prognosis stating that an anencephalic baby can live for years is given, but this cannot occur because the brain is open, meaning that infection sets in rapidly. The anencephalic brain is also usually very disorganised on a cellular level. Exencephaly is a type of cephalic disorder. ...

Prognosis

There is no cure or standard treatment for anencephaly and the prognosis for affected individuals is poor. Most anencephalic babies do not survive birth, accounting for 55% of non-aborted cases. If the infant is not stillborn, then he or she will usually die within a few hours or days after birth from cardiorespiratory arrest. Image File history File links Anencephaly_side. ... Image File history File links Anencephaly_side. ... The expected result of pregnancy is the birth of a living child. ...

In almost all cases anencephalic infants are not aggressively resuscitated since there is no chance of the infant ever achieving a conscious existence. Instead, the usual clinical practice is to offer hydration, nutrition and comfort measures and to "let nature take its course". Artificial ventilation, surgery (to fix any co-existing congenital defects), and drug therapy (such as antibiotics) are usually regarded as futile efforts. Clinicians and medical ethicists may view the provision of nutrition and hydration as medically futile. Occasionally some may even go one step further to argue that euthanasia is morally and clinically appropriate in such cases. For other meanings of CPR, see CPR (disambiguation). ... In chemistry, hydration is the condition of being combined with water. ... Food is any substance, usually composed primarily of carbohydrates, fats, water and/or proteins, that can be eaten or drunk by an animal for nutrition and/or pleasure. ... An antibiotic is a drug that kills or slows the growth of bacteria. ... For mercy killings not performed on humans, see Animal euthanasia. ... Morality (from the Latin manner, character, proper behavior) has three principal meanings. ...

Rate of occurrence

In the United States, approximately 1,000 to 2,000 babies are born with anencephaly each year. Female babies are more likely to be affected by the disorder.^{[citation needed]}

Causes

The cause of anencephaly is disputed. Neural tube defects do not follow direct patterns of heredity, though there is some indirect evidence of inheritance^[4], and recent animal models indicating a possible association with deficiencies of the transcription factor TEAD2.^[5] Studies show that a woman who has had one child with a neural tube defect such as anencephaly, has about a 3% risk to have another child with a neural tube defect.^{[citation needed]} The ancients had a variety of ideas about heredity: Theophrastus proposed that male flowers caused female flowers to ripen; Hippocrates speculated that seeds were produced by various body parts and transmitted to offspring at the time of conception, and Aristotle thought that male and female semen mixed at conception. ... In molecular biology, a transcription factor is a protein that binds DNA at a specific promoter or enhancer region or site, where it regulates transcription. ...

It is known that women taking certain medication for epilepsy and women with insulin dependent diabetes have a higher chance of having a child with a neural tube defect. Genetic counseling is usually offered to women at a higher risk of having a child with a neural tube defect to discuss available testing. Genetic counseling is the process by which patients or relatives, at risk of an inherited disorder, are advised of the consequences and nature of the disorder, the probability of developing or transmitting it, and the options open to them in management and family planning in order to prevent, avoid or...

Recent studies have shown that the addition of folic acid to the diet of women of child-bearing age may significantly reduce, although not eliminate, the incidence of neural tube defects. Therefore, it is recommended that all women of child-bearing age consume 0.4 mg of folic acid daily, especially those attempting to conceive or who may possibly conceive, as this can reduce the risk to 0.03%.^[6] It is not advisable to wait until pregnancy has begun, since by the time a woman knows she is pregnant, the critical time for the formation of a neural tube defect has usually already passed. A physician may prescribe even higher dosages of folic acid (4 mg/day) for women who have had a previous pregnancy with a neural tube defect. Folic acid and folate (the anion form) are forms of the water-soluble Vitamin B9. ... In nutrition, the diet is the sum of food consumed by a person or other organism. ...

Anencephaly, and other physical and mental deformities, can be blamed on a high exposure such toxins as lead, chromium, mercury, nickel and others. Evidence of this is seen in areas in Mexico surrounding the maquiladoras (factories in export processing zones, owned by trans-national corporations that are not held accountable to local, labor, or environmental laws).^[7]

References

A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... The National Institute of Neurological Disorders and Stroke is a part of the U.S. National Institutes of Health. ...

External links

A congenital disorder is a medical condition or defect that is present at or before birth (for example, congenital heart disease). ... The nervous system is a highly specialized network whose principal components are nerves called neurons. ... For other uses, see Brain (disambiguation). ... For acephaly as a poetic device, see Acephalous line. ... Acrania is a cephalic disorder of a human fetus characterised by a partial or complete absence of the cranium. ... Cephalic disorders are congenital conditions that stem from damage to, or abnormal development of, the budding nervous system. ... Dandy-Walker syndrome (DWS), or Dandy-Walker complex, is a congenital brain malformation involving the cerebellum and the fluid filled spaces around it. ... Cephalic disorders are congenital conditions that stem from damage to, or abnormal development of, the budding nervous system. ... Cephalic disorders are congenital conditions that stem from damage to, or abnormal development of, the budding nervous system. ... Pachygyria (from the Greek pachy meaning thick or fat gyri) is a congenital malformation of the cerebral hemisphere. ... Hydranencephaly is a type of cephalic disorder. ... Septo-optic dysplasia (SOD) is a congenital malformation syndrome manifested by hypoplasia (underdevelopment) of the optic nerve, hypopituitarism, and absence of the septum pellucidum (a midline part of the brain). ... Megalencephaly is a type of cephalic disorder. ... Cephalic disorders are congenital conditions that stem from damage to, or abnormal development of, the budding nervous system. ... Cephalic disorders are congenital conditions that stem from damage to, or abnormal development of, the budding nervous system. ... A brain tumor is any intracranial tumor created by abnormal and uncontrolled cell division, normally either in the brain itself (neurons, glial cells (astrocytes, oligodendrocytes, ependymal cells), lymphatic tissue, blood vessels), in the cranial nerves (myelin-producing Schwann cells), in the brain envelopes (meninges), skull, pituitary and pineal gland, or... The brain stem is the lower part of the brain, adjoining and structurally continuous with the spinal cord. ... Arnold-Chiari malformation, sometimes referred to as Chiari malformation or ACM, is a congenital malformation of the brain. ... The Spinal cord nested in the vertebral column. ... Currarino syndrome is a condition where the sacrum (the fused vertebrae forming the back of the pelvis) is not formed properly, there is a mass in the presacral space in front of sacrum, and there are malformations of the anus or rectum. ... Sacrococcygeal teratoma (SCT), a birth defect, is a tumor located at the base of the tailbone (coccyx). ... Diastematomyelia is a congenital condition in which a part of the spinal cord is split, usually at the level of the upper lumbar vertebra. ... An uncollapsed syrinx (before surgery). ... Image File history File links Question_book-3. ...

Contents

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