¹H MRS in acute traumatic brain injury

Abstract

The objective of this study was to demonstrate 1H MR spectroscopy (MRS) changes in cerebral metabolites after acute head trauma. Twenty-five patients (12 children, 13 adults) were examined with quantitative 1H MRS after closed head injury. Clinical grade (Glasgow Coma Scale [GCS]) and outcome (Rancho Los Amigos Medical Center Outcome Score [ROS]) were correlated with quantitative neurochemical findings. N-acetylaspartate (NAA), a neuronal and axonal marker, was reduced (P < .03-.001). In children, a reduced NAA/creatine plus phosphocreatine (Cr) level and the presence of detectable lipid/lactate predicted bad outcome (sensitivity, 89%; specificity, 89%). The first MRS examination of all patients correlated with ROS versus NAA (r = .65, P < .0001). Although most patients showed MRS abnormalities, striking heterogeneity of 1H MRS characterized the individual patients. 1H MRS identifies multiple patterns of diffuse brain injury after blunt head trauma. There was a strong correlation between MRS and outcome. Future prospective studies will be needed to determine the clinical usefulness of MRS in predicting outcome from closed head injury.

Mind the gaps—advancing research into short-term and long-term neuropsychological outcomes of youth sports-related concussions

“…191 Such findings suggest that even subconcussive head impacts can result in the activation of glutamate pathways, implying cellular injury or neuronal death, despite the absence of symptoms. Levels of creatinine and myoinositol (an organic osmolyte located in astrocytes 192,193 ) were also significantly altered in a subset of the participants in the aforementioned study.…”

N-Acetylaspartate in the CNS: From neurodiagnostics to neurobiology

“…In infants subject to "shaken baby syndrome" loss of NAA appears to follow a cascade of neurochemical events in which activated phospholipases are hypothesized to release lipids and macromolecules visible in the proton brain spectrum (Haseler et al, 1997). Childhood traumatic brain injury may result in a reversible loss of NAA which recovers approximately with the time-scale of recovery from the syndrome of inappropriate anti-diuretic hormone (SIADH) (Ross et al, 1998). Endocrine response to trauma, in the form of SIADH, is seen in 40 to 50% of children with head injury, and often results in reduced blood and brain osmolytes, or hyponatremia.…”

Emerging Imaging Tools for Use with Traumatic Brain Injury Research

“…At birth, NAA and Cr levels are low, whereas Cho and Ins are high. NAA and Cr increase rapidly with normal brain maturation in the first 18-24 months of life at the same time that Cho and Ins are decreasing rapidly, with all metabolites leveling off at near adult levels by 24 months (Kreis et al, 1993;Ross et al, 1998). However, NAA continues to rise slightly, peaking at *10-15 years, and then decreases slightly over time as the number of neurons and axons gradually declines with normal aging, whereas Cr continues to slightly increase after reaching adult levels (Kreis et al, 1993).…”