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1994-01-17
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$Unique_ID{BRK03901}
$Pretitle{}
$Title{Kernicterus}
$Subject{Kernicterus Bilirubin Encephalopathy Posticteric Encephalopathy
Nuclear Jaundice }
$Volume{}
$Log{}
Copyright (C) 1986, 1990 National Organization for Rare Disorders, Inc.
233:
Kernicterus
** IMPORTANT **
It is possible the main title of the article (Kernicterus) is not the
name you expected. Please check the SYNONYMS listing to find the alternate
names and disorder subdivisions covered by this article.
Synonyms
Bilirubin Encephalopathy
Posticteric Encephalopathy
Nuclear Jaundice
General Discussion
** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only. It should not be used for diagnostic or treatment
purposes. If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.
Kernicterus is a condition characterized by an excess of bilirubin in the
blood in infancy. The bilirubin is deposited in the basal ganglia of the
brain and in the brainstem nuclei.
Symptoms
Early symptoms of Kernicterus in full term infants may include lethargy, poor
feeding and vomiting, a spasm with head and heels bent backward and the body
bowed forward (opisthotonus), upward deviation of the eyes, convulsions and
muscular rigidity. Later in childhood, survivors may manifest the typical
late triad of cerebral palsy marked by ceaseless jerky movements and slow
sinuous writhing movements (choreoathetosis), sensorineural hearing loss, and
loss of upward gaze. However, only minor problems characterized by
perceptual-motor handicaps and learning disorders in school may be present in
mild cases.
Causes
Historically, severe hemolytic jaundice of the newborn was the main cause of
Kernicterus. Erythroblastosis Fetalis, another cause of jaundice in infancy,
is a hemolytic anemia of the fetus or newborn. It is caused by transmission
through the placenta of maternal antibody, which is usually evoked by
maternal and fetal blood group incompatibility. Since new improved methods
of treating jaundice have evolved, the disorder tends to develop only in
premature or sick, very low birthweight infants with unconjugated
hyperbilirubinemia, particularly in the presence of certain predisposing
factors. These include:
1. low blood oxygen (hypoxemia)
2. acidosis (acidity of the blood)
3. infections
4. low albumin in the blood (hypoalbuminemia)
5. low body temperature (hypothermia).
Hyperbilirubinemia is an excess of bilirubin (the breakdown product of
hemoglobin and other blood pigments) in the blood. Excess bilirubin causes
jaundice which is characterized by a yellow color of the skin (which occurs
shortly after birth in this disorder).
Related Disorders
Jaundice, the yellow skin color which indicates an increased amount of
bilirubin in the blood, can have many causes including liver diseases and
hemolytic anemias. (For more information on these disorders, choose "liver"
and "hemolytic" as your search terms in the Rare Disease Database, and see
the related articles in the Prevalent Health Conditions/Concerns area of NORD
Services (rdb-4)).
Affected Population
Kernicterus can affect newborn infants of both sexes.
Therapies: Standard
Treatment of Kernicterus consists of early, frequent feedings of all newborns
to reduce the incidence and severity of too much bilirubin (a product of
blood-breakdown) in the blood. These feedings increase the mobility of the
bowels and frequency of stools, thereby minimizing the effects of the
circulation of bilirubin in the liver and intestines.
Phototherapy is used to treatment hyperbilirubinemia. Exposing newborns
with this disorder, particularly premature infants, to visible light in the
blue range, is most effective for photo-oxidizing bilirubin. Phototherapy
causes dermal photoisomerization of bilirubin, changing it to forms that the
liver can excrete more readily without glucuronidation.
A Plexiglass shield should be placed between the phototherapy lights and
the infant to screen out ultraviolet radiation that may be harmful, and the
infant should be blindfolded to prevent eye damage from the light. Care must
be taken to avoid nasal obstruction by the blindfold. The light should be
turned off and the blindfold removed during feedings. Since bilirubin in the
collection tubes may photo-oxidize rapidly, the light should also be off when
blood is taken for bilirubin determinations.
Although data regarding the effects of phototherapy on distribution of
bilirubin within the infant's body and long-term effects on mental
development of treated infants are not yet available, this form of therapy
has gained widespread use.
Phototherapy must never be started before the causes of the
hyperbilirubinemia have been fully evaluated.
Traditionally, dangerous levels of bilirubin are treated by exchange
blood transfusion via an umbilical vein catheter in order to prevent
Kernicterus. This procedure is safe when done by experienced personnel,
especially when it is done on otherwise healthy full-term newborns.
Therapies: Investigational
The Food and Drug Administration (FDA) has designated Zixoryn (flumecinol) as
an orphan drug which can be used for investigational therapy of
hyperbilirubinemia. Zixoryn can be used to treat newborn infants with
hyperbilirubinemia who are unresponsive to phototherapy.
This disease entry is based upon medical information available through
January 1990. Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.
Resources
For more information on Kernicterus, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
American Liver Foundation
998 Pompton Avenue
Cedar Grove, NJ 07201
(201) 857-2626
(800) 223-0179
The United Liver Foundation
11646 West Pico Blvd.
Los Angeles, CA 90064
(213) 445-4204 or 445-4200
Children's Liver Foundation
14245 Ventura Blvd.
Sherman Oaks, CA 91423
(818) 906-3021
NIH/National Institute of Child Health and Human Development
9000 Rockville Pike
Bethesda, MD 20892
(301) 496-5133
For information on genetics and genetic counseling referrals, please
contact:
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
(914) 428-7100
Alliance of Genetic Support Groups
35 Wisconsin Circle, Suite 440
Chevy Chase, MD 20815
(800) 336-GENE
(301) 652-5553
References
THE MERCK MANUAL 15th ed: R. Berkow, et al: eds; Merck, Sharp & Dohme
Research Laboratories, 1987. Pp. 1767, 1854, 1883.
CECIL TEXTBOOK OF MEDICINE, 18th ed.: James B. Wyngaarden, and Lloyd H.
Smith, Jr., Eds.: W.B. Saunders Co., 1988. Pp. 812, 1076.