II. Epidemiology: Incidence
- Acute Bilirubin Encephalopathy: 1 infant in 10,000
- Progresses to Kernicterus in 5% of infants
- Chronic Bilirubin Encephalopathy (Kernicterus): 1 infant in 100,000
III. Risk Factors
- See Nonphysiologic Neonatal Jaundice
- Severe Hyperbilirubinemia (>20 mg/dl)
- Hyperbilirubinemia alone does not predict Bilirubin Encephalopathy
- For healthy infants at term with Serum Bilirubin >30 mg/dl, only 5% develop Bilirubin Encephalopathy
- Gamaleldin (2011) Pediatrics 128(4): e925-31 [PubMed]
- Earlier Gestational age
- Hemolysis
- Sepsis
IV. Pathophysiology
- Unconjugated Bilirubin (indirect) elevation
- Total Bilirubin > 25 to 30 mg/dl
-
Bilirubin necroses Neurons
- Basal Ganglia
- Globus Pallidus
- Putamen
- Caudate nuclei
V. Symptoms and Signs
- Stage 1 : Acute Bilirubin Encephalopathy
- Moro Reflex diminished
- Tone diminished
- Lethargy
- Poor feeding
- Vomiting
- High pitched cry
- Stage 2 (High mortality in this stage)
- Opisthotonus
- Seizure
- Irritability
- Fever
- Rigidity
- Oculogyric Crisis
- Upward gaze paralyzed
- Stage 3
- Spasticity decreases at 1 week of age
- Stage 4: Kernicterus (Chronic Bilirubin Encephalopathy with Residual deficits)
- Spasticity
- Severe athetoid Cerebral Palsy
- High frequency Hearing Loss or Deafness
- Mild Mental Retardation
- Upward Gaze Paralysis
- Dental dysplasia
VI. Management
VII. Prognosis
- Significant mortality and morbidity
- Developmental follow-up is indicated for severe Hyperbilirubinemia