MR spectroscopy: Predicting long‐term neuropsychological outcome following pediatric TBI

Abstract

Purpose: To identify useful acute indicators of long-term neurocognitive outcome beyond clinical variables for children and adolescents treated for a traumatic brain injury (TBI). Materials and Methods:The efficacy of magnetic resonance spectroscopy (MRS) acquired 6 Ϯ 4 days after TBI in 20 children/adolescents in predicting intellectual and neuropsychological functioning one to four years post injury was assessed. Short echo-time single voxel MRS (SVS) from normal-appearing brain was compared to intermediate echo-time multivoxel MR spectroscopic imaging (MRSI) from normal-appearing and visibly-injured brain acquired through the level of the corpus callosum (CC).Results: N-acetyl aspartate (NAA) was moderate to strongly correlated with cognitive scores. Mean NAA/creatine (Cre) from MRSI alone explained over 40% of the variance in cognitive scores and 18% of the variance above and beyond demographic and clinical variables alone. Mild to moderate associations were noted between SVS metabolites (glutamate/glutamine [Glx] and myoinositol [mI]) and cognitive scores, with no such associations apparent for choline (Cho) or Cre. Exploratory analyses revealed trends for regional neuroimaging data and specific cognitive abilities. Conclusion:Acute MR spectroscopy of the pediatric brain injury patient improves prognostic ability and may provide valuable information for early treatment and intervention planning.

Imaging Evidence and Recommendations for Traumatic Brain Injury: Advanced Neuro- and Neurovascular Imaging Techniques

“…80 In pediatric patients with accidental and nonaccidental TBI, MR spectroscopy has shown potential for providing early prognostic information regarding clinical outcomes. 62, [87][88][89][90][91][92][93][94] Reduced NAA has been correlated with impaired long-term neuropsychological function in children. 89,90,92,94 Elevated total Cho has also been described and may be related to diffuse axonal injury and/or repair.…”

“…62, [87][88][89][90][91][92][93][94] Reduced NAA has been correlated with impaired long-term neuropsychological function in children. 89,90,92,94 Elevated total Cho has also been described and may be related to diffuse axonal injury and/or repair. 84,95 Studies have shown that elevated lactate levels are more common following nonaccidental TBI 62,87 and are strongly correlated with poor outcomes.…”

Emerging Imaging Tools for Use with Traumatic Brain Injury Research

“…MRS provides a sensitive assessment of post-injury neurometabolite alterations, particularly in tissue with no visible injury on conventional imaging, and has shown potential for providing early prognostic information regarding clinical outcome in pediatric patients with accidental and nonaccidental TBI (Aaen et al, 2010;Ashwal et al, 2000;Babikian et al, 2006;Brenner et al, 2003;Holshouser et al, 1997Holshouser et al, , 2005 Studies using proton MRS in children have found similar neurometabolite alterations after injury. Typically, N-acetyl aspartate (NAA), an amino acid synthesized in mitochondria, is a neuronal and axonal marker that is reduced as a result of neuronal loss or dysfunction after injury.…”

Late Proton Magnetic Resonance Spectroscopy following Traumatic Brain Injury during Early Childhood: Relationship with Neurobehavioral Outcomes

“…Most of the research by the same group focuses on the acute (approximately 1 week post-injury) metabolic changes following injury and the possibility that MRS offers early prognostic information regarding outcome (Ashwal et al, 2000;Babikian et al, 2006;Brenner et al, 2003;Holshouser et al, 2005). These investigators have found reductions of NAA/Cr or NAA/Cho and increases of Cho/Cr in normal appearing occipital gray matter and parietal white matter (Ashwal et al, 2000;Babikian et al, 2006;Brenner et al, 2003;Holshouser et al, 2005). Because Cr has been thought to remain constant, Cr has often been used in the denominator in computing metabolite ratios and not studied independently (Ashwal et al, 2006a,b).…”

“…Because Cr has been thought to remain constant, Cr has often been used in the denominator in computing metabolite ratios and not studied independently (Ashwal et al, 2006a,b). Researchers have shown correlations between reduced NAA/Cr and NAA/Cho and increased Cho/Cr and severity of injury as assessed by admission GCS score (Ashwal et al, 2000;Brenner et al, 2003), as well as by longer-term neurological (Ashwal et al, 2000;Brenner et al, 2003) and neuropsychological (Babikian et al, 2006;Brenner et al, 2003) outcomes.…”