Anencephaly

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Classification according to ICD-10
Q00.0	Anencephaly
ICD-10 online (WHO version 2019)

As anencephaly or anencephaly (from Greek. Α privativum and ἐγκέφαλος enkephalos , "brain" → "without brain") is the most severe malformation form of a neural tube defect referred to (NRD). It occurs before the 26th day of pregnancy. In children with anencephalus, the top of the skull has not closed and parts of the bony roof , meninges , scalp, and brain are missing to varying degrees . The brain stem is only developed in a quarter of cases. Furthermore, the pituitary gland is underdeveloped. Life expectancy after birth is only a few hours.

frequency

Illustration of a newborn baby with anencephaly

About half of all malformations of the neural tube are caused by anencephaly. Before folic acid was introduced, anencephaly occurred in early pregnancy with an emphasis on the female sex ( gynecotropy 2: 1 to 4: 1). In Central Europe, an incidence of 1: 1000 is given. Live-born children with this malformation usually die within the first ten days after birth, usually after a few hours without intensive medical treatment.

history

In 1926 the first scientific publication on anencephaly was published by Eduard Gamper , so that Gamper's midbrain was also referred to as a result .

Further case studies were published with the express reference to an understanding of the performance of the subcortical brain structures - which showed that the extent of the different behavioral skills as well as the survival time were dependent on the level of individual organization and integration level of the developed nervous system. "The case of Monnier and Willi (1953) survived 57 days and would have lived longer if tube feeding had not been interrupted '".

Ethical questions have raised the demand by proponents of the partial brain death concept to allow the use of children with anencephaly for organ and tissue donation from a purely utility point of view. This has been prohibited in Germany since the Transplantation Act was passed in 1997.

Diagnosis

With the determination of the alpha-1-fetoprotein in the blood of the expectant mother as part of the prenatal diagnosis , the probability of a neural tube malformation can be calculated in the event of an increased concentration. The diagnosis is only confirmed by appropriate ultrasound or conventional imaging examinations ( fine or 3D ultrasound ).

Although anencephaly can be detected relatively early in the context of prenatal diagnosis , fewer mothers decide to terminate the pregnancy than with trisomy 21 (in comparison: 5642 terminations in 6141 prenatal diagnoses of trisomy 21 = 91.9%; 483 of 628 with anencephaly = 76 , 9%; 358 of 487 in spina bifida aperta  = 73.5%).

According to ICD-10, both suspected and confirmed malformations are classified with reference to the mother as O35.0 as “care for the mother in the event of (suspected) malformation of the central nervous system in the fetus” (anencephaly or spina bifida ); with reference to the child with Q00 (“anencephaly and similar malformations”).

The differential diagnosis is the Meckel-Gruber syndrome and other peculiarities with dysraphic developmental disorders in the area of ​​the head and spine.

Pregnancy and childbirth

Head of a fetus with anencephaly

The pregnant women themselves often need psychological support, otherwise they are not physically endangered by the malformation of their child. This may contribute to the fact that today more pregnant women or pairs of parents decide to carry the child to term and to accompany it for the few hours or days of its life, although the possibility of the termination of pregnancy for medical reasons exists.

As a rule, an unusually large amount of amniotic fluid accumulates during such a pregnancy ( hydramnios ), since children with anencephalus can not drink amniotic fluid due to the lack of the swallowing reflex . The amniotic fluid may need to be by means of a puncture ( amniotic fluid discharge puncture to be drained) since otherwise the risk of premature labor and premature fruit membrane rupture exists. This procedure is similar to that of amniocentesis and involves its risks.

A child with anencephaly can usually be born naturally ( vaginally ). The timing of the birth does not usually differ from that of the births of regular children. However, it is not uncommon for labor to be induced artificially, as the children's pituitary gland often does not work as usual and therefore often cannot give the appropriate signals for the natural triggering of labor at the end of the normal gestation period. Experience shows that artificially induced rupture of the amniotic sac significantly reduces the likelihood of a live birth.

The attending hospital staff should be informed about the diagnosis in order to be able to prepare emotionally and professionally for the birth of the child.

features

Anencephaly often occurs together with acrania as acephaly (cranioschisis totalis) and a spina bifida in the cervical area. Newborn children with anencephaly can be recognized by the following characteristics:

• Absence of the end brain and the roof of the skull
• Due to the obstruction of the neural tube (more precisely the neuropore cranialis anterior around the 25th day of development), instead of the brain, more or less degenerated tissue mass is free (dark red colored, soft)
• intact respiratory, circulatory and temperature regulation functions
• protruding eyes ; Eyelids appear puffy
• the skull is broad and flat
• Absence of the neck, the face and chest form a uniform surface
• the ears are small, dysplastic, and flapped forward
• often comes in addition a cleft palate before
• Live born children are sensitive to pain

A detailed case report (Monnier and Willi , 1953) about a boy with anencephaly who survived 57 days (until feeding was stopped by means of a tube ) contains the following description:

“His breathing was unstable but regular, he could suck and swallow, his body temperature fluctuated between 33 and 40 degrees Celsius, when he touched the lips, there was suction movements, a wake-up reaction with movements of the head, small twitches in arms with lifting to the head and a grasping reaction the legs on. When there was pain in the face, defensive movements of the whole body, a turn of the head and an opening of the mouth occurred. With the exception of certain regions, the rest of the body also responded to pain stimuli with head turns and stretching reactions. The face contracted on lemon juice, ammonia triggered a lightning-like reaction with pulling the head back, lively facial expressions and uttering a short scream. In addition, certain head, body and limb movements, spontaneous and in response to stimuli, were observed. In addition, various expression functions of facial expressions and phonation (whining, screaming) are described. "

Life expectancy

As a rule, the infants affected die (without intensive medical intervention) a few days after birth (2–4). As a rule, dehydration can be identified as the direct cause of death , as the lack of swallowing reflex prevents vital fluid intake.

Causes and likelihood of recurrence

In most cases, the causes are folic acid deficiency in the mother during pregnancy and exogenous factors. A more rare cause is a spontaneous malformation of the embryo. All these factors can only come into play if they are up to max. Beginning of the 5th week of development are present.

The exogenous factors include:

• Use or abuse of medication (including intake of non-prescribed vitamin preparations) by the mother
• Mother substance abuse
• Chemotherapy for cancer in pregnant women
• alcohol
• ionizing radiation (e.g. X-ray, CT)
• mercury
• various infectious diseases

Genetic factors are not known and can therefore almost be ruled out; for the same reason, the probability of recurrence in women who have already had a pregnancy with anencephalus malformation is no higher than in the rest of the population. But see Fowler Syndrome .

See also

• Aminopterin syndrome

literature

• S. Ashwal, JL Peabody, S. Schneider: Anencephaly: clinical determination of brain death an neuropathological studies. In: Pediatric Neurology. Volume 6, 1990, pp. 233-239.
• PA Bryne, JC Evers, RG Nilges: Anencephaly - organ transplantation? In: Issues in Law Medicine. Volume 9, 1993, pp. 23-33.
• Committee on Bioethics: Infants with anencephaly as organ sources: ethical considerations. In: Padiatrics. Vol. 89, 1992, pp. 1116-1119.
• Tess Gerritsen : Mortal Sin. 2006. (Novel featuring a baby with anencephaly)
• Susanne Gescher: Legal Problems of Abortion in Anencephaly. 1994.
• H. Goll: Children with anencephaly. Interdisciplinary state of research, ethical problems and support for parents and children. Unpublished manuscript . University of Erfurt, 2004.
• M. Jaquier, A. Klein, E. Boltshauser: Spontaneous pregnancy outcome after prenatal diagnosis of anencephaly. In: British Journal of Obstetrics and Gynaecology. Volume 113, 2006, pp. 951-953.
• O. Kurauchi, Y. Ohno, S. Mitzutani, Y. Comoda: Longitudinal monitoring of fetal behavior in twins when one is anencephalic. In: Obstetrics & Gynecology . Volume 86, 1995, pp. 672-674.
• Ronald J. Lemire: Anencephaly. Raven Press, 1978.
• W. Luyendijk, PD Treffers: The smile in ancephalic infants. In: Clinical Neurology and Neurosurgery. Volume 94, 1992, pp. 113-117.
• Inka Marold, Thorsten Marold: Immanuel - The story of the birth of an anencephalic child. Publishing house for culture and science, Bonn 1996, ISBN 3-926105-66-6 .
• K. Nakamura, M. Hanabusa, M. Okamoto: Classification of the anencephalic brain. In: Teratology . Volume 6, 1972, pp. 115-116.
• Stephen Clifford Rogers: Anencephalus, spina bifida and congenital hydrocephalus. Her Majesty's Stationery Office, 1976.
• Katrin Schmidt: Hold when nothing holds anymore. My story with our quietly born daughter . Neufeld Verlag , Schwarzenfeld 2016.
• DA Shewmonn: Anencephaly: selected medical aspects. In: Hastings Center Report. Volume 18, 1988, pp. 11-19.
• SE Sytsma: Reply to Loewy: Anencephalics and splippery slopes. In: Theoretical Medicine and Bioethics. Volume 20, 1995, pp. 455-460.
• Atussa Tschangizian: The medical liability with regard to removed body substances. Tort law problems of transplant medicine with special consideration of anencephalic infants. 2001.
• AM Vare, PC Bansal: Anencephaly. An anatomical study of 41 anencephalic infants. In: Indian Journal of Pediatry. Volume 38, 1971, pp. 301-305.
• J. Walters, S. Ashwal, Th. Masek: Anencephaly: Where do we stand? In: Seminars in Neurology. Volume 17, 1997, pp. 249-255.

Web links

Commons : Anencephaly  - collection of images, videos and audio files

• The difficulties with anencephalic infants and organ donation: The moral, ethical and legal stances by Jade-Evon Simard
• Anencephaly info

Individual evidence

1. ↑ Eduard Gamper: Reflex studies on a Anencephalus ; Journal for the whole of neurology and psychiatry, 104 (1926), pp. 47-73.
2. ↑ Andreas Zieger: How much brain do humans need? Notes on the anencephaly problem from a relational medical perspective . (PDF; 168 kB) 2004, p. 5 with reference to Marcel Monnier, Heinrich Willi : The integrative activity of the nervous system in the meso-rhombo-spinal anencephalus (midbrain creature). In: Monthly magazine for psychiatry and neurology . Volume 126, 1953, pp. 239-258; here p. 240.
3. ↑ Andreas Zieger: How much brain do humans need? Notes on the anencephaly problem from a relational medical perspective . (PDF; 168 kB) 2004, p. 1.
4. ↑ 2D ultrasound image of an ancephalic fetus ( Memento from January 5, 2006 in the Internet Archive ) Obgyn.net. Sunil Kabra: Ultrasound image of an ancephalic fetus. Sonoworld.com, 2005. Luiz Machado: 3D ultrasound image of an ancephalic fetus. anencephalie-info.org, 2001
5. ^ Wolfgang Lenhard: The influence of prenatal diagnosis and selective fetocide on the incidence of people with congenital disabilities. ( Memento of December 13, 2009 in the Internet Archive ) In: Curative Education Research. Volume 29, 2003, pp. 165-176.
6. ↑ Marcel Monnier, Heinrich Willi : The integrative activity of the nervous system in the meso-rhombo-spinal anencephalus (midbrain creature). In: Monthly magazine for psychiatry and neurology . Volume 126, 1953, pp. 239-258.
7. ^ Albert Stuart Reece, Gary Kenneth Hulse: Australihromothripsis, Epigenetics, Cannabis, Mutagenic Pathways and Transgenerational Effects .  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF) School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley 2016  

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