Causes
Hyperbilirubinemia during the neonatal period describes the history of nearly all individuals who suffer from kernicterus. It is thought that the blood–brain barrier is not fully functional in neonates and therefore it is unable to clear excess bilirubin that accumulates in the central nervous system during a hyperbilirubinemic state.
Bilirubin is known to accumulate in the gray matter of neurological tissue where it exerts direct neurotoxic effects. It appears that its neuotoxicity is due to mass-destruction of neurons by apotosis and necrosis.
Read more about this topic: Kernicterus