The effect of whole-body cooling on brain metabolism following perinatal hypoxic-ischemic injury.

INTRODUCTION: Magnetic resonance imaging (MRI) and spectroscopy (MRS) have proven valuable in evaluating neonatal hypoxic-ischemic injury (HII). RESULTS: MRI scores in the basal ganglia of HII/HT(+) neonates were significantly lower than HII/HT(-) neonates, indicating less severe injury and were associated with lower discharge encephalopathy severity scores in the HII/HT(+) group (P = 0.01). Lactate (Lac) was detected in the occipital gray matter (OGM) and thalamus (TH) of significantly more HII/HT(-) neonates (31.6 and 35.3%) as compared to the HII/HT(+) group (10.5 and 15.8%). In contrast, the -N-acetylaspartate (NAA)-based ratios in the OGM and TH did not differ between the HII groups. DISCUSSION: Our data show that the HT was associated with a decrease in the number of HII neonates with detectable cortical and subcortical Lac as well as a decrease in the number of MRI-detectable subcortical lesions. METHODS: We retrospectively compared the medical and neuroimaging data of 19 HII neonates who received 72 h of whole-body cooling (HII/HT(+)) with those of 19 noncooled HII neonates (HII/HT(-)) to determine whether hypothermia was associated with improved recovery from the injury as measured by MRI and MRS within the first 14 days of life. MRI scores and metabolite ratios of HII/HT(+) and HII/HT(-) neonates were also compared with nine healthy, nonasphyxiated "control" neonates.