Differential involvement of the brain in neonatal asphyxia: a pathogenic explanation.

Multiple cystic lesions in brain parenchyma supplied by the anterior cerebral circulation is a recognized pattern of cerebral injury associated with hypoxic-ischemic encephalopathy in the term infant. This report presents a series of seven infants (gestational age, 39.3 +/- 2.8 weeks; range, 36 to 44 weeks) who developed multicystic encephalomalacia in the distribution of the anterior cerebral circulation after severe neonatal asphyxia. Cerebral imaging and pathologic studies demonstrate relative preservation of the cerebellum, brain stem, and cerebral structures supplied by the vertebrobasilar circulation. Compared to the vertebrobasilar vasculature, the anterior cerebral vessels in the term infant have dense sympathetic innervation. Asphyxia, a potent sympathetic stimulator, may induce vasoconstriction in the anterior circulation and differentially accentuate the effects of hypoxia/ischemia on cerebral tissue.