Kernicterus: Symptoms, Causes, Treatment

What are the symptoms of kernicterus?

Kernicterus is a serious condition caused by high levels of bilirubin in the blood, leading to its accumulation in the brain tissues. The symptoms of kernicterus typically manifest as neurological problems due to bilirubin toxicity affecting the brain. These symptoms include:

1. Yellow Skin (Jaundice): Initially, there may be yellowing of the skin and whites of the eyes (jaundice), which is a sign of elevated bilirubin levels in the blood.
2. High-Pitched Cry: Infants with kernicterus may have a high-pitched cry that is different from their usual cry patterns.
3. Poor Feeding: Babies may exhibit poor feeding or feeding difficulties.
4. Lethargy: There can be increased sleepiness or lethargy, with reduced responsiveness to stimuli.
5. Muscle Rigidity or Floppiness: Kernicterus can lead to abnormal muscle tone, resulting in either increased muscle rigidity or decreased muscle tone (hypotonia).
6. Arching of the Body (Opisthotonus): In severe cases, infants may arch their back due to muscle spasms or stiffness.
7. Fever: Sometimes, infants with kernicterus may have an unexplained fever.
8. Seizures: Seizures can occur as a result of the neurological damage caused by bilirubin toxicity.
9. Delayed Developmental Milestones: As the condition progresses, there may be delays in reaching developmental milestones, such as sitting up, crawling, or walking.

Kernicterus is a rare but serious condition that requires immediate medical attention. High levels of bilirubin can be toxic to the brain, leading to lifelong neurological deficits or even death if not treated promptly. Newborns are routinely screened for jaundice in hospitals to detect elevated bilirubin levels early and initiate appropriate treatment to prevent kernicterus. If you notice any of these symptoms in a newborn, it’s crucial to seek medical care urgently for evaluation and treatment.

What are the causes of kernicterus?

Kernicterus is primarily caused by severe hyperbilirubinemia, which is an excessive accumulation of bilirubin in the blood. Bilirubin is a yellow pigment that forms when red blood cells break down. Normally, bilirubin is processed by the liver and then excreted from the body through bile. However, in certain circumstances, bilirubin levels can become dangerously high, leading to kernicterus. Here are the main causes:

1. Immature Liver Function in Newborns: Newborn infants are particularly susceptible to kernicterus because their livers are not fully matured, which can impair the ability to process and eliminate bilirubin efficiently.
2. Increased Bilirubin Production: Conditions that increase the breakdown of red blood cells can lead to higher levels of bilirubin production, such as hemolytic diseases (e.g., Rh incompatibility, ABO incompatibility) or genetic conditions affecting red blood cells.
3. Decreased Bilirubin Elimination: Conditions that impair the liver’s ability to process and excrete bilirubin can also contribute to kernicterus. These may include liver diseases or conditions that affect bile flow.
4. Breastfeeding: Breastfeeding jaundice and breast milk jaundice are conditions where breastfed infants are at higher risk of developing hyperbilirubinemia due to factors in breast milk that can affect bilirubin metabolism.
5. Delayed Meconium Passage: Meconium is the first stool passed by a newborn, and its timely passage helps eliminate excess bilirubin from the body. Delayed passage of meconium can lead to higher bilirubin levels.
6. Genetic Factors: Some infants may have genetic predispositions that affect how their bodies process bilirubin, making them more susceptible to kernicterus.
7. Prematurity: Premature infants are at higher risk of kernicterus due to their underdeveloped liver function and higher rates of hemolysis.
8. Infections: Certain infections, such as sepsis or meningitis, can cause inflammation and affect bilirubin metabolism, increasing the risk of kernicterus.

Early detection and management of jaundice in newborns are crucial to prevent kernicterus. Newborns are routinely screened for jaundice in hospitals, and treatment may include phototherapy (light therapy) or, in severe cases, exchange transfusion to lower bilirubin levels and prevent neurological damage. Prompt medical attention is essential if jaundice is observed in a newborn, to determine the cause and initiate appropriate treatment to prevent complications like kernicterus.

How is the diagnosis of kernicterus made?

Diagnosis of kernicterus is primarily based on clinical evaluation and assessment of bilirubin levels in the blood, along with consideration of neurological symptoms. Here’s how the diagnosis is typically made:

1. Clinical Evaluation: Healthcare providers will conduct a thorough physical examination, focusing on observing signs of jaundice (yellowing of the skin and eyes) and assessing the baby’s behavior and neurological status.
2. Bilirubin Levels: Blood tests are performed to measure the level of bilirubin in the baby’s blood. High levels of bilirubin (hyperbilirubinemia) are a key indicator that can suggest the potential for kernicterus.
3. Neurological Assessment: Infants suspected of having kernicterus will undergo a neurological examination to assess for signs such as poor muscle tone (hypotonia), abnormal posturing (such as arching of the back), seizures, and abnormal reflexes. These neurological findings, along with high bilirubin levels, raise suspicion for kernicterus.
4. Imaging Studies: In some cases, imaging studies such as MRI (Magnetic Resonance Imaging) or CT (Computed Tomography) scans may be performed to evaluate the extent of any brain damage caused by bilirubin toxicity. These imaging studies can help visualize any structural abnormalities or changes in brain tissue associated with kernicterus.
5. Electroencephalogram (EEG): An EEG may be done to assess brain function and detect abnormal electrical activity, especially if seizures are present or suspected.
6. Medical History: Information about the baby’s birth history, feeding patterns, and any illnesses or treatments received are important in determining the cause and severity of jaundice and evaluating the risk of kernicterus.

Early diagnosis of kernicterus is crucial to prevent long-term neurological complications. Infants at risk for high bilirubin levels, such as those born prematurely or with conditions predisposing them to hemolysis, are closely monitored for jaundice in the first few days after birth. Treatment for jaundice, including phototherapy and, in severe cases, exchange transfusion, is initiated promptly to lower bilirubin levels and reduce the risk of kernicterus. If kernicterus is suspected based on clinical signs and laboratory findings, immediate medical intervention and specialized care are essential to minimize neurological damage and support the baby’s health.

What is the treatment for kernicterus?

Treatment for kernicterus focuses on managing the complications resulting from bilirubin toxicity and providing supportive care to minimize neurological damage. Here are the main approaches to treatment:

1. Monitoring and Supportive Care: Infants with kernicterus require close monitoring of vital signs, neurological status, and bilirubin levels. Supportive care includes maintaining adequate hydration, nutrition, and ensuring a stable environment.
2. Phototherapy: Phototherapy, using specialized lights that help break down bilirubin in the skin, is typically the first-line treatment for high bilirubin levels (hyperbilirubinemia). It is effective in reducing serum bilirubin levels and preventing further bilirubin accumulation in the brain.
3. Exchange Transfusion: In severe cases of hyperbilirubinemia or kernicterus, where phototherapy alone is insufficient, exchange transfusion may be necessary. This procedure involves replacing a portion of the baby’s blood with donor blood to rapidly lower bilirubin levels.
4. Management of Complications: Treatment may also involve managing complications associated with kernicterus, such as seizures, feeding difficulties, and neurological deficits. Medications to control seizures and physical therapy to support motor development may be recommended as part of comprehensive care.
5. Long-Term Rehabilitation and Support: Infants who survive kernicterus may require ongoing rehabilitation and support services to address developmental delays, motor impairments, hearing loss, and other neurological sequelae. This may involve physical therapy, occupational therapy, speech therapy, and educational interventions tailored to the child’s specific needs.
6. Prevention: Prevention of kernicterus includes early detection and management of jaundice in newborns through routine screening and prompt treatment of hyperbilirubinemia. Healthcare providers monitor bilirubin levels closely, especially in infants at higher risk, to prevent bilirubin levels from reaching toxic levels.

The treatment approach for kernicterus is multidisciplinary, involving neonatologists, pediatric neurologists, nurses, therapists, and other healthcare professionals. Early intervention and comprehensive care are crucial to minimize neurological damage and optimize long-term outcomes for infants affected by kernicterus.