Background: Perinatal asphyxia and resulting hypoxic-ischemic encephalopathy (HIE) remain a significant cause of neonatal morbidity and mortality. This review focuses on the utilization of bedside cranial ultrasound in HIE to guide appropriate therapy, monitor disease progress, provide prognostic information, and help identify relevant research areas.
Methods: A comprehensive literature search was conducted to review recognized patterns of HIE seen on ultrasound. Further efforts were focused on understanding the clinical relevance of these changes in the management of such infants and the prediction of long-term neurodevelopmental outcomes.
Results: We reviewed cranial sonographic changes in asphyxiated neonates. Dynamic changes are observed across various time frames; hyperechogenicity of the thalamus, basal ganglia, and the altered appearance of the posterior limb of the internal capsule (PLIC) are frequently seen in acute and subacute insults. Also, a resistive index of 0.55 or less in cerebral Doppler studies within the first 72 hours of life is associated with adverse short- and long-term outcomes and increased mortality.
Conclusion: Bedside cranial ultrasound is a useful screening tool for the diagnosis and monitoring of neonates with HIE. However, further studies are needed to improve our understanding of sonographic findings as predictors of adverse neurodevelopmental outcomes and mortality in affected neonates.