Kernicterus, a neurological syndrome caused by elevated levels of unconjugated bilirubin, poses risks such as jaundice in the first 24 hours of life and can be preventable with proper monitoring and follow-up care. Symptoms develop from lethargy and poor feeding to severe neurological impairment, with serious long-term outcomes for affected infants. Prevention involves universal screening for jaundice in newborns and timely monitoring to address elevated bilirubin levels and associated risks.

1. PEDIATRICS
RAAFI UL BASHEER ZARGAR

2. KERNICTERUS
• Kernicterus, or bilirubin
encephalopathy, is a neurologic
syndrome resulting from the
deposition of unconjugated
(indirect) bilirubin in the basal
ganglia and brainstem nuclei.

3. RISK
FACTORS
• Jaundice within first 24 hrs of birth
• A sibling who was jaundiced as neonate
• Unrecognised hemolysis (ABO- or Rh-
incompatibility)
• Non optimal sucking nursing
• Deficiency of G6PD
• Infection
• Cephalhematomas bruising
• East Asian or Mediterranean descent

4. PREVENTABLE CAUSES OF KERNICTERUS
• The American Academy of Pediatrics has identified potentially preventable causes of kernicterus, as follows:
(1) early discharge (<48 hr) with no early follow-up (within 48 hr of discharge); this problem is particularly
important in near-term infants (35-37 wk of gestation);
(2) failure to check the bilirubin level in an infant noted to be jaundiced in the 1st 24 hr;
(3) failure to recognize the presence of risk factors for hyperbilirubinemia;
(4) underestimation of the severity of jaundice by clinical (visual) assessment;
(5) lack of concern regarding the presence of jaundice;
(6) delay in measuring the serum bilirubin level despite marked jaundice or delay in initiating phototherapy in
the presence of elevated bilirubin levels; and
(7) failure to respond to parental concern regarding jaundice, poor feeding, or lethargy.

5. PATHOGENESIS • MULTIFACTORIAL
1. Unconjugated bilirubin levels,
2. Albumin binding and unbound bilirubin levels,
3. Passage across the blood-brain barrier, and
4. Neuronal susceptibility to injury.

6. ETIOPATHOGENESIS
• The precise blood level above which indirect-reacting
bilirubin or free bilirubin will be toxic for an individual infant
is unpredictable, but in a large series, kernicterus occurred
only in infants with a bilirubin >20 mg/dL.
• Ninety percent of the infants in whom kernicterus developed
were in previously healthy, predominantly breastfed term and
near-term infants.
• The duration of exposure to high bilirubin levels needed to
produce toxic effects are unknown.
• The more immature the infant is, the greater the susceptibility
to kernicterus.

7. CLINICAL
FEATURES
• INITIAL SIGNS
• LETHARGY
• POOR FEEDING
• LOSS OF MORO REFLEX
• LATER SIGNS
• INFANT APPEARS GRAVELY ILL
• PROSTRATIONS
• DIMINISHED TENDON REFLEXES
• RESPIRATORY DISTRESS
• OPISTHOTONOS WITH BULDGING FONTANELLE
• TWITCHING OF FACE OR LIMBS
• SHRILL HIGH PITCHED CRY

8. CLINICAL
FEATURES
• ADVANCED STAGE
• CONVULSIONS AND SPASM OCCUR
• AFFECTED INFANTS STIFFLY EXTENDING THEIR ARMS IN AN
INWARD ROTATION WITH THE FISTS CLENCHED.
• RIGIDITY IS RARE AT THIS LATE STAGE.

10. RECOVERY
• Many infants who progress to these severe neurologic signs
die; the survivors are usually seriously damaged but may
appear to recover and for 2-3 months show few abnormalities.
• Later in the 1st yr, opisthotonos, muscle rigidity, irregular
movements, and convulsions tend to recur.
• In the 2nd yr, the opisthotonos and seizures abate, but
irregular, involuntary movements, muscle rigidity, or, in some
infants, hypotonia increase steadily.
• By 3 yr of age, the complete neurologic syndrome is often
apparent; it consists of bilateral choreoathetosis with
involuntary muscle spasms, extrapyramidal signs, seizures,
mental deficiency, dysarthric speech, high-frequency hearing
loss, squinting, and defective upward eye movements.
• Pyramidal signs, hypotonia, and ataxia occur in a few infants.
In mildly affected infants, the syndrome may be characterized
only by mild to moderate neuromuscular incoordination,
partial deafness, or “minimal brain dysfunction,” occurring
singly or in combination; these problems may be unapparent
until the child enters school.

11. INCIDENCE AND PROGNOSIS
By pathologic criteria, kernicterus develops in 30% of infants (all gestational ages) with untreated hemolytic
disease and bilirubin levels >25-30 mg/dL.
The incidence at autopsy in hyperbilirubinemic preterm infants is 2-16%
Overt neurologic signs have a grave prognosis; more than 75% of infants die, and 80% of affected survivors
have bilateral choreoathetosis with involuntary muscle spasms.
Mental retardation, deafness, and spastic quadriplegia are common.

12. PREVENTION
• Universal screening for hyperbilirubinemia in the 1st 24-48 hr
after birth to detect infants at high risk for severe jaundice and
bilirubin induced neurologic dysfunction.
• Protocols
• Hour-specific bilirubin nomogram
• Physical examination, and
• Clinical risk factors

13. MANAGEMENT
• The following approach is further recommended:
(1) any infant who is jaundiced before 24 hr requires measurement of total and
direct serum bilirubin levels and, if it is elevated, evaluation for possible hemolytic
disease and
(2) follow-up should be provided within 2-3 days of discharge to all neonates
discharged earlier than 48 hr after birth.
• Early follow-up is particularly important for infants younger than 38 wk of
gestation.
• Parental communication with regard to concerns about infant’s skin color and
behavioral activities should be addressed early.
• Mothers should be advised to nurse their infants every 2-3 hr and to avoid
routine supplementation with water or glucose water in order to ensure
adequate hydration and caloric intake.

14. REFERENCES
I. NELSON TEXTBOOK OF
PEDIATRICS, 20TH EDITION

15. THANK YOU