Brainstem lesions in the course of chronic fetal asphyxia.

We present a neuropathological study of brainstem involvement during the neonatal period, under the influence of prolonged fetal asphyxia. The investigation was performed on 20 brains of premature and mature newborns, who died in the course of chronic asphyxia. Ischemic cell change, neuronal loss and gliosis were present in the brainstem of all infants. Two topographic patterns of brainstem lesions in chronic anoxic encephalopathy were distinguishable in the newborns. The neurons of the cranial nerve nuclei were more severely damaged in the group of premature newborns. More severe lesions of the reticular formation were found in the group of mature newborns. The topography of brainstem damage seems to be dependent on the maturity of CNS structures at the time of injury.