Proton magnetic resonance spectroscopy improves outcome prediction in perinatal CNS insults

Abstract

Objective: Prediction of neurologic outcome is difficult in neonates with acute nervous system injury. Previous studies using proton magnetic resonance spectroscopy (1H-MRS) have been used to predict short-term neurologic outcome in neonates with a variety of neurologic insults. We were interested in determining the effectiveness of combining clinical evaluation and spectroscopy obtained at the time of injury in predicting neurologic outcome at 24 months. Study Design: We studied 33 neonates with acute central nervous system injury, 5.8±3.7 days of injury, owing to hypoxic-ischemic encephalopathy. Neonates were assessed using clinical variables (initial arterial pH, initial blood glucose, Sarnat score, electroencephalography) and spectroscopy (NAA/Cho, NAA/Cre, Cho/Cre, and lactate). Neonates were divided into two outcome groups: good/moderate and poor. Differences between the groups were assessed using χ2 and t-test analyses. We analyzed the best predictors of outcome using discriminant analysis and calculated sensitivity, specificity, positive, and negative predictive values for each variable independently and in combination. Results: There were significant differences between the good/moderate and poor outcome for the Sarnat score, EEG, lactate, and NAA/Cho. Spectroscopy combined with clinical variables improved sensitivity, but not specificity for predicting outcome. The presence of lactate had the best individual predictive value. Combination of the clinical with the MRS variables had the highest predictive value. Conclusion: Proton magnetic resonance spectroscopy done early after injury improves the ability to predict neurologic outcome at 24 months of age.