Neuropathology Associated with Hypoxic-Ischemic Injury in Sudden Unexpected Natural Death in Neonates and Infants

Abstract

Unexpected death in neonates and infants has no explanation in a larger percentage of cases than is true for adults. Sudden death in neonates/infants secondary to central nervous system (CNS) causes is relatively uncommon. Birth injury is typically but not always recognized. Even with a history of CNS injury, the death may still be unexpected. CNS pathology is fairly common at postmortem examination, but is often not causal. One of the most common critical neuropathologies is hypoxic-ischemic and may be hemorrhagic. In both the acute and chronic phases, the differentiation from nonaccidental trauma needs to be evaluated. Evaluation is best achieved in a well-fixed brain. Some pathology cannot be seen macroscopically and requires microscopic sections.