In vivo 31P and in vitro 1H nuclear magnetic resonance study of hypoglycemia during neonatal seizure.

To examine the hypothesis that hypoglycemia has an adverse effect on brain energy state during seizure, neonatal dogs were subjected to bicuculline-induced seizure while hyperglycemic, normoglycemic, or hypoglycemic. Cerebral blood flow increased and remained elevated in all animals subjected to seizure, regardless of blood or brain glucose concentration. In vivo 31P nuclear magnetic resonance spectroscopy disclosed a small (10-20%) decrease in adenosine triphosphate levels and a greater (20-40%) decline in phosphocreatine levels in animals experiencing seizure, irrespective of whether they were hyper-, normo-, or hypoglycemic. In vitro analysis of brain extracts with 1H nuclear magnetic resonance spectroscopy disclosed a significant elevation of lactate in all seizing animals. There were differences in brain alanine, glycine, and beta-hydroxybutyrate levels between the hyperglycemia-seizure and hypoglycemia-seizure groups. Alternate substrates such as lactate, fatty acids, or amino acids may be used when neonatal seizure is complicated by hypoglycemia, thereby preventing further deterioration of brain metabolic state.