Postasphyxial encephalopathy in term infants. Sonographic demonstration of increased echogenicity of the thalamus and basal ganglia.

Sonographic abnormalities secondary to postasphyxial encephalopathy in neonates are reviewed. This report emphasizes an additional finding, increased echogenicity of the thalamus and basal ganglia, demonstrated in four term infants. This abnormal finding is generally noted in the second week following asphyxia. In some cases, the increased thalamic echogenicity may be a temporary finding. A representative case is described and possible pathologic correlates are discussed.