Paediatrics: Bilirubin encephalopathy (kernicterus)

Bilirubin encephalopathy (kernicterus)

A clinical syndrome resulting from the development of excessive neuro-toxic unconjugated bilirubin levels. Toxic levels lead to selective damage of the cerebellum, basal ganglia, and brainstem auditory pathways. It may occur in the healthy neonate if serum bilirubin is >360µmol/L, but usually only occurs at significantly higher serum levels (>430µmol/L after 48hr of life) unless:

• The infant is <24hr old.
• The infant is preterm.
• The infant is severely ill (any cause).
• The infant is acidotic.
• Caused by iso-immunization haemolytic disease.
• Reduced albumin binding caused by drugs or hypoalbuminaemia.

Presentation

• Lethargy progressing to hypertonia then hypotonia.
• Poor feeding.
• Fever.
• High-pitched cry.
• Opisthotonos.
• Seizures and coma.

The main differential diagnosis is meningoencephalitis/sepsis. Neonatal tetany may also present with opisthotonos.

Treatment

• Supportive (likely to require full intensive care).
• Urgent reduction of serum bilirubin by intensive phototherapy and exchange transfusion.
• Give IV immunoglobulin.
• Treat underlying cause.

Prognosis

The majority survives, but there is a high risk of athetoid cerebral palsy, deafness, and low IQ.