The prognostic value of amplitude-integrated electroencephalography in neonates with hypoxic-ischemic encephalopathy

BACKGROUND/AIM

Diagnosis of perinatal hypoxic-ischemic encephalopathy (HIE) and early prediction neurological outcome is important and difficult. The aim of this study was to determine the prognostic value of amplitude-integrated electroencephalography (aEEG) for abnormal neurodevelopment outcome in a neonate with HIE.

METHODS

A total of 90 neonates > 32 gestational age (GA) with HIE were enrolled prospectively. All neonates with HIE were categorized into three grades according to the Sarnat and Sarnat clinical scoring system (mild HIE, moderate HIE and severe HIE). aEEG traces were recorded with a cerebral function monitor (CFM) during the first 72 h of life. The neurodevelopment outcome was assessed at 12 months of age of corrected gestational age.

RESULTS

The pattern of aEEG correlated with the severity of HIE (p < 0.0001) and subsequent neurodevelopment outcome (p < 0.001). We found that aEEG background patterns exhibited superior prediction of abnormal outcomes at 12 months of age (sensitivity of 91.7% and specificity of 94.3%, positive predictive value of 78.6% and negative predictive value of 98.1%) when compared to aEEG seizure (sensitivity of 94% and specificity of 48%, positive predictive value of 57% and a negative predictive value of 92%). Electroclinical dissociation seizure was detected in 28% of the neonates with HIE.

CONCLUSIONS

Our results confirm that aEEG is simple and accurate bedside diagnostic method for assessing extension of hypoxic-ischemic brain damage and early identification of neonates with perinatal HIE who are at high risk of neurodevelopmental impairment.

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.

Altered translational fidelity of a Salmonella typhimurium LT2 mutant resistant to the aminoglycoside antibiotic neamine

A neamine-resistant mutant of Salmonella typhimurium LT2 with altered translational fidelity was isolated. The phenomenon was expressed in severe restriction of amber suppressor activity in vivo as well as in decreased misreading of poly(U) RNA in vitro. The mutation conferring resistance to neamine was mapped at 72 min on the Salmonella genetic map, where some of the ribosomal genes have already been mapped. This location indicates that the neamine-resistant phenotype as well as an altered translational fidelity could be a consequence of an alteration of the ribosomal structure.