The role of oxidative stress in perinatal hypoxic-ischemic brain injury.

INTRODUCTION The pathogenesis of perinatal hypoxic-ischemic brain damage is highly complex. OBJECTIVE The aim of this study was to assess the role of oxidative stress in hypoxic-ischemic brain injury and subsequent abnormal neurological outcome in infants with perinatal hypoxic-ischemic encephalopathy (HIE). We estimated perinatal oxidative brain damage measuring activity of glutathione peroxidase (GPX) in cerebrospinal fluid (CSF) as an indirect biomarker of free radical production during cerebral hypoxia-ischemia in correlation with the level of intracellular enzyme neuron specific enolase (NSE) in CSF as a biomarker of extend of brain injury. METHODS Ninety neonates (>32 GA) with perinatal HIE were enrolled prospectively. HIE was categorized into three stages according Sarnat and Sarnat clinical scoring system and changes seen on amplitude integrated EEG. CSF for GPX analysis and NSE analysis was taken in the first 72 hours of life. Neurodevelopment outcome was assessed at 12 months of corrected gestational age. RESULTS GPX activity in CSF was in good relation with clinical stage of HIE (p < 0.0001) and GA (p < 0.0001) and significantly corresponded with subsequent neurodevelopment outcome (p < 0.001). GPX activity in CSF showed a strong correlation with NSE levels in CSF (p < 0.001) as the biomarker of extent of brain injury. CONCLUSION Our results suggest that oxidative stress might be important contributing factor in perinatal hypoxic-ischemic brain damage, particularly in preterm neonates.