In this study it is hypothesized that magnesium sulphate in asphyxiated full-term neonates could lead to a gradual improvement in background pattern of the amplitude integrated EEG (aEEG), an early marker of hypoxic-ischaemic brain injury. In a double-blind, randomized, controlled pilot study of 22 asphyxiated full-term neonates 8 received magnesium sulphate, reaching serum Mg2+ levels of 2.5 mmol/L. Magnesium sulphate had no immediate effect on aEEG-patterns. At 12 h of age, aEEG was more depressed compared with aEEG at 3 h in 6 of the 8 magnesium-treated neonates, and in 3 of the 14 placebo-treated neonates (Mg2+ vs placebo: p < 0.05, Mann-Whitney). No further significant changes in aEEG were seen between 12 and 24 h. Outcome was unfavourable in 4 of the 8 magnesium-treated neonates, and in 8 of the 14 placebo-treated neonates.
Conclusion: Magnesium sulphate did not have a positive effect on aEEG patterns in this small group of asphyxiated term neonates.