Proton Magnetic Resonance Spectroscopy Lactate/N-Acetylaspartate within 2 weeks of birth accurately predicts 2-year motor, cognitive and language outcomes in Neonatal Encephalopathy after Therapeutic Hypothermia

Abstract

OBJECTIVE: Brain proton (1H) magnetic resonance spectroscopy (MRS) lactate/N-Acetylaspartate (Lac/NAA) peak area ratio is used for prognostication in Neonatal Encephalopathy (NE). At 3-Tesla in NE babies, the objectives were to assess: (i) sensitivity and specificity of basal ganglia and thalamus (BGT) 1H MRS Lac/NAA for prediction of Bayley III outcomes at 2-years using optimized metabolite fitting (Tarquin) with threonine and total NAA; (ii) prediction of motor outcome with diffusion-weighted MRI; iii) BGT Lac/NAA correlation with the NICHD MRI score. MATERIALS AND METHODS: 55 (16 inborn, 39 outborn) NE infants at 39w+5d (35w+5d-42w+0d) admitted between February 2012 and August 2014 to UCH for therapeutic hypothermia underwent MRI and 1H MRS at 3T on day 2-14 (median day 5). MRIs were scored. Bayley III was assessed at 24 (22-26) months. RESULTS: Sixteen babies died (1 inborn, 15 outborn); 20, 19 and 21 babies had poor motor, cognitive and language outcomes. Using a threshold of 0.39, sensitivity and specificity of BGT Lac/NAA for 2-year motor outcome was 100% and 97%, cognition 90% and 97% and language 81% and 97% respectively. Sensitivity and specificity for motor outcome of mean diffusivity (MD; threshold 0.001 mm2 /s) up to day 9 was 72% and 39% and fractional anisotropy (FA; threshold 0.198) was 100%, and 94% respectively. Lac/NAA correlated with BGT injury on NICHD scores (2A, 2B, 3). CONCLUSIONS: BGT Lac/NAA on 1H MRS at 3T within 14 days accurately predicts 2-year motor, cognitive and language outcome and may be a marker directing decisions for therapies after cooling