Hypoxic-Ischemic Encephalopathy Diagnosis and Management
Pathophysiology and Presentation
- HIE results from reduced oxygen supply to the brain, often due to events like cardiac arrest or other causes of cerebral hypoperfusion, according to the American College of Critical Care 1
- The clinical presentation of HIE may include seizures, which account for approximately 10% of seizures in term neonates, as reported by the American Heart Association and the American Stroke Association 2
- Some children with perinatal stroke or HIE may appear normal in the neonatal period but later present with early handedness, developmental delay, or seizures after 2 months of age, as noted by the American Heart Association and the American Stroke Association 2
Diagnostic Considerations
- Assessment of HIE is multidimensional and includes cerebral imaging, such as MRI with diffusion-weighted imaging, which is most sensitive, as recommended by the American Academy of Neurology 1
- Electroencephalogram (EEG) should be performed in patients with suspected HIE to differentiate between treatable non-convulsive status epilepticus and other causes, according to the American Clinical Neurophysiology Society 1
- Laboratory determination of neuron-specific enolase is also part of the diagnostic workup, as suggested by the American College of Critical Care 1
Prognostic Factors
- The presence of seizures in the neonatal period may predict the development of disabilities in the first years of life, as reported by the American Heart Association and the American Stroke Association 3
- Abnormal EEG background has been associated with childhood hemiplegia, according to the American Heart Association and the American Stroke Association 4
- Lesions involving the cortex, basal ganglia, and internal capsule on MRI are more likely to cause hemiplegia than strokes involving only one of these regions, as noted by the American Heart Association and the American Stroke Association 4
Management Considerations
- Supportive care is the cornerstone of management for all types of perinatal stroke and HIE, as recommended by the American Heart Association and the American Stroke Association 4
- Rehabilitation and ongoing physical therapy are reasonable approaches to reduce neurological dysfunction, according to the American Heart Association and the American Stroke Association 3
Hypoxic-Ischemic Encephalopathy Risk Stratification
Time-Sensitive Risk Factors
- The duration and severity of hypoxia are the single most important determinants of outcome, with prolonged hypoxia worsening prognosis 5, 6
- The timing of insult is crucial, with the time of onset defined as the last time the patient was observed to be normal 7