PURPOSE: To investigate the similarities and differences of cellular energy deficiencies due to asphyxia and to impaired oxidative phosphorylation caused by enzyme deficiencies using localized 1H-MR spectroscopy of the brain. MATERIAL AND METHODS: In 35 neonates and infants with a postconceptional age of 36.4-153 weeks, 1H-MR spectra were obtained from the basal ganglia. Of the 35 children, 14 served as a control group, 12 suffered from hypoxic-ischemic disease (HIE), and 9 had congenital enzymatic disorders. RESULTS: Eleven of the 12 children with HIE showed low N-acetyl aspartate (NAA) to trimethylamine (TMA) ratios, indicating neuronal damage. Lactate (Lac) to TMA ratios correlated with the HIE grade. Children with congenital disorders of energy metabolism had NAA/TMA ratios ranging from severely decreased to normal, but 7 of the 9 had high Lac signals, even in brains with normal NAA/TMA. CONCLUSION: High Lac/TMA even with normal NAA/TMA in children with enzyme deficiencies, in contrast to Lac/TMA that correlates with clinical grade and low NAA/TMA in asphyxic children, hints at different mechanisms of cell damage in the two disease groups.
PURPOSE: To investigate the similarities and differences of cellular energy deficiencies due to asphyxia and to impaired oxidative phosphorylation caused by enzyme deficiencies using localized 1H-MR spectroscopy of the brain. MATERIAL AND METHODS: In 35 neonates and infants with a postconceptional age of 36.4-153 weeks, 1H-MR spectra were obtained from the basal ganglia. Of the 35 children, 14 served as a control group, 12 suffered from hypoxic-ischemic disease (HIE), and 9 had congenital enzymatic disorders. RESULTS: Eleven of the 12 children with HIE showed low N-acetyl aspartate (NAA) to trimethylamine (TMA) ratios, indicating neuronal damage. Lactate (Lac) to TMA ratios correlated with the HIE grade. Children with congenital disorders of energy metabolism had NAA/TMA ratios ranging from severely decreased to normal, but 7 of the 9 had high Lac signals, even in brains with normal NAA/TMA. CONCLUSION: High Lac/TMA even with normal NAA/TMA in children with enzyme deficiencies, in contrast to Lac/TMA that correlates with clinical grade and low NAA/TMA in asphyxic children, hints at different mechanisms of cell damage in the two disease groups.