Kernicterus Health Article

Definition

Kernicterus is a rare neurological condition that occurs in some newborns with severe jaundice.

See also: Newborn jaundice

Alternative Names

Bilirubin encephalopathy

Causes, incidence, and risk factors

Kernicterus is caused by very high levels of bilirubin. Bilirubin is a yellow pigment that is created in the body during the normal recycling of old red blood cells. High levels of bilirubin in the body can cause the skin to look yellow (which is called jaundice).

In some cases when there are extremely high levels of bilirubin in the body or the baby is extremely ill, the substance will move out of the blood and collect in the brain tissue. This can lead to serious neurological complications, including brain damage.

Kernicterus usually develops in the first week of life, but may be seen up until the third week. Newborns with Rh hemolytic disease that leads to hydrops fetalis are at high risk for severe jaundice that leads to this condition. However, kernicterus has been seen in apparently healthy babies.

Symptoms

The symptoms depend on the stage of kernicterus.

Early stage:

• Extreme jaundice
• Absent startle reflex
• Poor breast-feeding or sucking
• Extreme sleepiness (lethargy)

Mid stage:

• High-pitched cry
• Arched back with neck hyperextended backwards
• Bulging fontanel (soft spot)
• Seizures

Late stage (full neurological syndrome):

• High-frequency hearing loss
• Mental retardation
• Muscle rigidity
• Speech difficulties
• Seizures
• Movement disorder

Signs and tests

A blood test will show a high bilirubin level (greater than 20-25 mg/dL).

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

Treatment

• Phototherapy
• Exchange transfusion (may require multiple exchanges)

Treatment depends on how old the baby is (in hours) and whether the baby has any risk factors (such as prematurity).

Expectations (prognosis)

Kernicterus represents an extreme condition caused by hemolysis. The outcome is guarded. Many infants with late stage neurological syndrome die.

Complications

• Permanent brain damage
• Death

Calling your health care provider

Seek immediate medical help if your baby has signs of this condition.