Hypothermie pour la neuroprotection cérébrale de l’encéphalopathie anoxo-ischémique: certitudes et incertitudes

Abstract

Cerebral hypothermia is one of the first neuroprotective strategies that can improve outcome of experimental and human perinatal cerebral hypoxia-ischemia. Now, international guidelines for hypoxic-ischemic encephalopathy in term neonates recommend hypothermia. At several places, hypothermia could block the cascade of neurochemical events that mediate brain damage insult in term infants. Extended cooling must be initiated 6 h after injury, after obtaining accurate data about perinatal asphyxia and the severity of hypoxic-ischemic encephalopathy. At 18 months of life, hypothermia reduces the risk of death or disability in infants with moderate or severe hypoxic-ischemic encephalopathy. However, longer-term data have not been available to assess whether the benefits of hypothermia persist after 2 years of age. Extensions of indication are debated for late preterm infants or newborns admitted in intensive care unit after 6 hours of life, and clinical studies are actually performed on these subjects. However, if prognosis at 18 months is improved, more than 40% of treated newborns will have an unfavorable evolution. Other neuroprotective strategies as erythropoietin, melatonin, and xenon or magnesium sulfate are actually evaluated. Results of these last studies would be interesting in the future, because these strategies could be associated with hypothermia.