Cerebral Glucose Metabolism Measured by Positron Emission Tomography in Term Newborn Infants with Hypoxic Ischemic Encephalopathy

摘要

Total and regional cerebral glucose metabolism (CMRgl) was measured by positron emission tomography with 2-(18F) fluoro-2-deoxy-d-glucose (18FDG) in 20 term infants with hypoxic ischemic encephalopathy (HIE) after perinatal asphyxia. All infants had signs of perinatal distress, and 15 were severely acidotic at birth. Six infants developed mild HIE, twelve moderate HIE, and two severe HIE during their first days of life. The positron emission tomographic scans were performed at 4–24 d of age (median, 11 d). One hour before scanning, 2–3.7 MBq/kg (54–100 μCi/kg) 18FDG was injected i.v. No sedation was used. Quantification of CMRgl was based on a new method employing the glucose metabolism of the erythrocytes, requiring only one blood sample. In all infants, the most metabolically active brain areas were the deep subcortical parts, thalamus, basal ganglia, and sensorimotor cortex. Frontal, temporal, and parietal cortex were less metabolically active in all infants. Total CMRgl was inversely correlated with the severity of HIE (p -1·100 g-1, 11 with moderate HIE had 26.6 (13.0–65.1) μmol·min-1·100 g-1, and two with severe HIE had 10.4 and 15.0 μmol·min-1·100 g-1, respectively. Five of six infants who developed cerebral palsy had a mean (range) CMRgl of 18.1 (10.2–31.4) μmol·min-1·100 g-1 compared with 41.5 (13.0–100.8) μmol·min-1·100 g-1 in the infants with no neurologic sequela at 2 y. We conclude that CMRgl measured during the subacute period after perinatal asphyxia in term infants is highly correlated with the severity of HIE and short-term outcome.Abbreviations: Bglc, blood glucose concentration; CMRgl, cerebral metabolic rate of glucose; CP, cerebral palsy; FDG, fluoro-deoxyglucose; GA, gestational age; HIE, hypoxic ischemic encephalopathy; LC, lumped constant; LCMRgl, local cerebral metabolic rate of glucose; PET, positron emission tomography; ROI, region of interest; SUV, standardized uptake value