Chronic bilirubin encephalopathy (formerly known as kernicterus) is brain damage caused by unconjugated bilirubin deposition in basal ganglia and brain stem nuclei.
Normally, bilirubin bound to serum albumin stays in the intravascular space. However, bilirubin can cross the blood-brain barrier and cause chronic bilirubin encephalopathy (CBE) when one of the following occurs:
The serum bilirubin concentration is markedly elevated (hyperbilirubinemia).
The serum albumin concentration is markedly low (eg, in preterm infants).
Bilirubin is displaced from albumin by competitive binders (eg, sulfisoxazole, ceftriaxone, and aspirin; free fatty acids and hydrogen ions in infants who are septic or acidotic).
Symptoms and Signs of Chronic Bilirubin Encephalopathy
In preterm infants, CBE may not cause recognizable clinical symptoms or signs.
Early symptoms of CBE in term infants are lethargy, poor feeding, and vomiting. Opisthotonos, oculogyric crisis, seizures, and death may follow.
CBE may result in intellectual disability, choreoathetoid cerebral palsy, sensorineural hearing loss, and paralysis of upward gaze later in childhood. It is unknown whether minor degrees of CBE cause less severe neurologic impairment (eg, perceptual-motor problems, learning disorders).
Diagnosis of Chronic Bilirubin Encephalopathy
Clinical evaluation
There is no reliable test to determine the presence of CBE, and the diagnosis is made presumptively.
A definitive diagnosis of CBE can be made only by autopsy.
Treatment of Chronic Bilirubin Encephalopathy
Prevention of unsafe hyperbilirubinemia
There is no treatment once CBE develops; it must be prevented by treating hyperbilirubinemia.
