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Holoprosencephaly

Holoprosencephaly is a type of Cephalic disorder. This is a disorder characterized by the failure of the prosencephalon (the forebrain of the embryo) to develop. During normal development the forebrain is formed and the face begins to develop in the fifth and sixth weeks of human pregnancy, though the condition also occurs in other species (as with Cy, the Cyclops Kitty). Holoprosencephaly is caused by a failure of the embryo's forebrain to divide to form bilateral cerebral hemispheres (the left and right halves of the brain), causing defects in the development of the face and in brain structure and function. more...

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There are three classifications of holoprosencephaly. Alobar holoprosencephaly, the most serious form in which the brain fails to separate, is usually associated with severe facial anomalies. Semilobar holoprosencephaly, in which the brain's hemispheres have a slight tendency to separate, is an intermediate form of the disease. Lobar holoprosencephaly, in which there is considerable evidence of separate brain hemispheres, is the least severe form. In some cases of lobar holoprosencephaly, the patient's brain may be nearly normal.

Holoprosencephaly, once called arhinencephaly, consists of a spectrum of defects or malformations of the brain and face. At the most severe end of this spectrum are cases involving serious malformations of the brain, malformations so severe that they are incompatible with life and often cause spontaneous intrauterine death. At the other end of the spectrum are individuals with facial defects - which may affect the eyes, nose, and upper lip - and normal or near-normal brain development. Seizures and mental retardation may occur.

The most severe of the facial defects (or anomalies) is cyclopia, an abnormality characterized by the development of a single eye, located in the area normally occupied by the root of the nose, and a missing nose or a nose in the form of a proboscis (a tubular appendage) located above the eye. The condition is also referred to as cyclocephaly or synophthalmia.

In his book Mutants: On the Form, Varieties and Errors of the Human Body , Armand Marie Leroi describes the cause of cyclopia as a genetic malfunctioning during the process by which the embryonic brain is divided into two. Only later does the visual cortex take recognisable form, and at this point an individual with a single forebrain region will be likely to have a single, possibly rather large, eye (at such a time, individuals with separate cerebral hemispheres would form two eyes).

Leroi goes on to state that:

is, in all its manifestations, the most common brain deformity in humans, afflicting 1 in 16,000 live-born children and 1 in 200 miscarried foetuses.

The regular appearance in Western society of such deformed human babies seems to have ceased or been withheld from the public view, probably in part due to the contemporary Western practice of hospitalisation at birth.

On 11 January 2006, Associated Press and other news organisations published photographs of a kitten that was born in Oregon, United States with cyclopia. The kitten's owner expressed surprise at having witnessed such a thing, with some bloggers on the internet expressing disbelief over the authenticity of the photographs published.

Read more at Wikipedia.org


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Conflicting Ultrasound Standards Raise Legal Issues
From OB/GYN News, 5/1/01 by Bruce Jancin

VAIL, COLO. -- The "limited" ultrasound examination as defined by the American College of Obstetricians and Gynecologists presents a legal minefield for obstetricians at a time when litigation involving ultrasound is increasingly common, Dr. Richard L. Berkowitz said during a conference on obstetrics and gynecology sponsored by the University of Colorado.

"ACOG is our union, our club. ACOG is out there trying to help us, trying to help people who take care of pregnant women from getting creamed in court. But I think this document, which was designed to help us, is in fact incredibly counterproductive," said Dr. Berkowitz, who is professor and chairman of ob.gyn. at Mount Sinai School of Medicine, New York.

That's because performing a limited ultrasound exam as described in ACOG Technical Bulletin No. 187 can place a physician at odds with the 1990 American Institute of Ultrasound in Medicine--American College of Radiology guidelines for performance of the antepartum obstetrical ultrasound examination. And it is clearly this AIUM-ACR document, not the bulletin, that is viewed by the courts as the standard of care, he said.

"When you go to court, the plaintiff's lawyer is going to be holding up that AIUM-ACR document and saying it's the standard of care for a radiologist who does an ultrasound exam. He'll ask, 'Do you as an obstetrician really believe that you can use the same equipment on the same type of patient and have a completely different standard?'

"And the answer is no," Dr. Berkowitz said.

ACOG distinguishes between the limited ultrasound exam and the basic exam, which provides information about placental location, amniotic fluid volume, gestational age, a survey of fetal anatomy and maternal pelvic organs, and other features.

A limited examination is "appropriate and desirable," according to ACOG, in the assessment of amniotic fluid volume, fetal biophysical profile testing, ultrasound-guided amniocentesis, external cephalic version, confirmation of fetal presentation, location of the placenta in antepartum hemorrhage, and confirmation of fetal life or death.

In contrast, the AIUM-ACR guidelines state that a limited exam is acceptable only in clinical emergencies or as a follow-up to a complete basic ultrasound exam.

So a stand-alone limited exam would be perfectly appropriate under AIUM-ACR guidelines to confirm fetal life or death when an obstetrician is considering doing a crash Cesarean section or to localize the placenta in a case of antepartum hemorrhage, because these are emergencies.

But under the AIUM-ACR guidelines, a physician scanning a patient for any reason in a nonemergent situation--to assess amniotic fluid volume, for example, or to perform fetal biophysical profiling--needs to obtain and properly document all the information that's part of the basic ultrasound exam, unless that's been done previously.

That's how to stay out of medicolegal trouble with ultrasound, he stated at the meeting.

"There's a guy at our hospital who did an amniocentesis at his office in which he used ultrasound only to see where to put the needle. He got back a normal karyotype and later delivered a baby that had holoprosencephaly [absence of a midline structure in the brain that's evident starting in the first trimester]. I think the settlement was $2.5 million," Dr. Berkowitz recalled.

Misconceptions abound regarding the AIUM-ACR guidelines' call for a fetal anatomic survey as part of a basic exam in the second or third trimester.

Here, physicians aren't being asked to diagnose any particular anatomic defect. They're just being asked to look at the various organs and see whether they look all right.

"If you do that, you will pick up lots and lots of cases where things aren't right. And you then can refer that patient for a targeted or a level 2 exam," the ob.gyn. explained.

Adequate documentation of the basic exam includes a written report of the findings to be included in the medical record, regardless of whether the scan was done in the office, on the delivery floor, or in the ER.

It should include key biometric measurements and anatomic findings, along with pictures of any abnormalities detected during the exam, according to Dr. Berkowitz.

COPYRIGHT 2001 International Medical News Group
COPYRIGHT 2001 Gale Group

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