HYPOXIC-ISCHEMIC BRAIN INJURY IN THE NEONATAL PERIOD - CURRENT CONCEPTS, NOVEL DIAGNOSTIC APPROACHES AND NEUROPROTECTIVE STRATEGIES

In the presenting paper, we describe mechanisms of brain injury following a hypoxic-ischemic event in the neonatal period. Neuronal death occurs in two major phases, the primary neuronal cell loss at the time of the insult and the delayed neuronal cell loss, occurring about 6 hours - 4 days after the injury. We describe different cellular mechanisms responsible for the neuronal death. The main patterns of brain injury that can be readily recognized with the newer neuroimaging techniques are dependent on the gestational age of the newborn. In order to apply novel neuroprotective treatments to the newborns with hypoxic-ischemic encephalopathy ( HIE), the newborns at risk have to be identified as early as possible. Among the most useful diagnostic methods are amplitude-integrated EEG, new markers of brain lesions and different modalities of magnetic-resonance imaging. During resuscitation of neonates with HIE the importance of prevention of hyperoxia, and, during intensive care, of hypocapnia and hyperglycemia is stressed. In the treatment of newborns with HIE hypothermia, by means of both selective head cooling or whole body hypothermia, reduced the risk of death and disability according to three multicenter randomized controlled studies. It is therefore recommended for treatment of HIE in the newborn. One of the potentially beneficial effects of therapeutic hypothermia is also widening of the therapeutic window for intervention with other neuroprotective regimens. Among these, treatments with erythropoietin or minocycline seem to be clinically promising.