New concepts in perinatal hypoxia ischemia encephalopathy.

This article summarizes recent insights into perinatal hypoxic-ischemic brain injury in the neonate. Before effective treatments can be offered, diagnosis, timing, and an understanding of the pathogenesis are imperative. The analysis of appropriate animal models is also summarized in this review. These models have provided interesting evidence that after hypoxia ischemia, progenitor cells in the postnatal brain are stimulated to generate new neurons and oligodendrocytes. The role of these newly generated cells is unclear, and mechanisms of migration and survival are currently being elucidated. A discussion of more recent imaging techniques, such as diffusion tensor imaging, is provided. This allows for improved understanding of the microstructural organization of white matter and how this is altered by hypoxic-ischemic injury. Neuroprotection with hypothermia is now occurring in full-term neonates that meet clinical criteria; however, specific therapies such as inhibition of non-N-methyl-D-aspartate receptors may offer improved outcomes by targeting specific pathways and populations of cells.