Normally, bilirubin bound to serum albumin stays in the intravascular space. However, bilirubin can cross the blood-brain barrier and cause kernicterus when serum bilirubin concentration is markedly elevated (hyperbilirubinemia Neonatal Hyperbilirubinemia Jaundice is a yellow discoloration of the skin and eyes caused by hyperbilirubinemia (elevated serum bilirubin concentration). The serum bilirubin level required to cause jaundice varies with... read more ), serum albumin concentration is markedly low (eg, in preterm infants Premature Infants An infant born before 37 weeks gestation is considered premature. Prematurity is defined by the gestational age at which infants are born. Previously, any infant weighing read more ), or bilirubin is displaced from albumin by competitive binders (eg, sulfisoxazole, ceftriaxone, and aspirin; free fatty acids and hydrogen ions in fasting, septic, or acidotic infants).
Symptoms and Signs of Kernicterus
In preterm infants, kernicterus may not cause recognizable clinical symptoms or signs. Early symptoms of kernicterus in term infants are lethargy, poor feeding, and vomiting. Opisthotonos, oculogyric crisis, seizures, and death may follow. Kernicterus may result in intellectual disability Intellectual Disability Intellectual disability is characterized by significantly subaverage intellectual functioning (often expressed as an intelligence quotient 70 to 75) combined with limitations of adaptive functioning... read more , choreoathetoid cerebral palsy Cerebral Palsy (CP) Syndromes Cerebral palsy refers to nonprogressive syndromes characterized by impaired voluntary movement or posture and resulting from prenatal developmental malformations or perinatal or postnatal central... read more , sensorineural hearing loss Hearing Impairment in Children Common causes of hearing loss are genetic defects in neonates and ear infections and cerumen in children. Many cases are detected by screening, but hearing loss should be suspected if children... read more 
, and paralysis of upward gaze later in childhood. It is unknown whether minor degrees of kernicterus can cause less severe neurologic impairment (eg, perceptual-motor problems, learning disorders).
Diagnosis of Kernicterus
Clinical evaluation
There is no reliable test to determine the presence of kernicterus, and the diagnosis is made presumptively. A definite diagnosis of kernicterus can be made only by autopsy.
Treatment of Kernicterus
Prevention of hyperbilirubinemia
There is no treatment once kernicterus develops; it must be prevented by treating hyperbilirubinemia Treatment Jaundice is a yellow discoloration of the skin and eyes caused by hyperbilirubinemia (elevated serum bilirubin concentration). The serum bilirubin level required to cause jaundice varies with... read more .
