Kernicterus Underlying Cause
Kernicterus is caused by elevated levels of bilirubin in the bloodstream. High levels of bilirubin are toxic to the brain and spinal cord, which can result in damage to the cells in the brain and spinal cord.
The average life span for a normal red cell is 120 days. Red cells over 120 days old are broken down the liver and spleen. Bilirubin is produced from the breakdown of hemoglobin, which is the molecule that carries oxygen inside red blood cells. The liver processes the bilirubin and it is removed from the body in the stool. Elevated levels of bilirubin lead to yellow staining of the skin, called jaundice. More than half of all newborns appear slightly jaundiced on the second to third day of life.
Jaundice may occur under the following circumstances:
- Increased breakdown of red blood cells
- Poor processing of bilirubin by the liver
- Blockage of the flow of bilirubin from the liver to the intestine
Causes of severe jaundice and kernicterus include:
- Bhutani VK, Donn SM, Johnson LH. Risk management of severe neonatal hyperbilirubinemia to prevent kernicterus. Clin Perinatol. 2005 Mar;32(1):125-39, vii. 
- Gourley GR. Breast-feeding, neonatal jaundice and kernicterus. Semin Neonatol. 2002 Apr;7(2):135-41. 
- Rubaltelli FF. Current drug treatment options in neonatal hyperbilirubinaemia and the prevention of kernicterus. Drugs. 1998 Jul;56(1):23-30.