MR Brain is the best test to predict outcomes in infants with hypoxic-ischemic encephalopathy (HIE), and adding MR Spectroscopy is known to increase sensitivity of predictive models for neurodevelopmental outcomes. However, prior studies have not evaluated infants with HIE who have normal brain parenchyma after therapeutic hypothermia (TH) but with isolated abnormal MR spectroscopy. 

Neonatal HIE remains a major cause of neonatal mortality and later neurodevelopmental disability. In neonates, elevated lactate peak and quantitative lactate on MR spectroscopy can be one of the earliest imaging predictors of adverse outcomes in neonatal HIE.  

A retrospective cohort study of term babies born after 2010 who received TH at Parkland was performed. Infants were included if they were treated with TH and had a brain MRI with no parenchymal infarct or injury noted. Seventy-four infants met inclusion criteria of which 50 had normal MRS (absent lactate peak) and 24 had abnormal MRS (presence of lactate peak). Chi square tests were used to compare categorical variables. Student’s t-tests were used for normally distributed variables. 

Infants with abnormal MRS (presence of lactate peak) had lower Bayley language scale scores (p = 0.009), lower Bayley motor scale scores (p = 0.03), and a higher instance of cerebral palsy diagnoses (p = 0.04). 

Infants with abnormal MRS and presence of lactate in the setting of MRI brain with no parenchymal injury had significantly lower language and motor scale scores at 2 years and a higher instance of cerebral palsy diagnoses as compared to those infants with normal MRI and absent lactate peak. Abnormal MRS may provide insight into targeting therapies for infants with HIE. With wide ranging neurodevelopmental outcomes in infants with HIE, novel strategies for risk-stratification and targeted intervention will be crucial.  Future directions include assessing quantitative lactate  and ADC measurements to better clarify the relationship.