Diffuse axonal injury in children: Clinical correlation with hemorrhagic lesions

Abstract

An inception cohort of 40 children and adolescents with traumatic brain injury and suspected diffuse axonal injury were studied using a new high-resolution magnetic resonance imaging susceptibility-weighted technique that is very sensitive for hemorrhage. A blinded comparison was performed between the extent of parenchymal hemorrhage and initial clinical variables as well as outcomes measured at 6 to 12 months after injury. Children with lower Glasgow Coma Scale scores (< or =8, n = 30) or prolonged coma (>4 days, n = 20) had a greater average number (p = 0.007) and volume (p = 0.008) of hemorrhagic lesions. Children with normal outcomes or mild disability (n = 30) at 6 to 12 months had, on average, fewer hemorrhagic lesions (p = 0.003) and lower volume (p = 0.003) of lesions than those who were moderately or severely disabled or in a vegetative state. Significant differences also were observed when comparing regional injury to clinical variables. Because susceptibility-weighted imaging is much more sensitive than conventional T2*-weighted gradient-echo sequences in detecting hemorrhagic diffuse axonal injury, more accurate and objective assessment of injury can be obtained early after insult, and may provide better prognostic information regarding duration of coma as well as long-term outcome.

Emerging Imaging Tools for Use with Traumatic Brain Injury Research

“…SWI may be helpful in the detection of these ''microhemorrhages,'' especially in early acute and sub-acute phases of injury, and in detecting areas of hypoxia-ischemia induced secondary injury. SWI has demonstrated increased sensitivity to the number and volume of hemorrhagic traumatic axonal injury lesions as compared to conventional T2*-weighted two-dimensional (2D)-GRE imaging (Tong et al, 2003), and the extent of SWIidentified hemorrhage has been shown to correlate with initial severity of injury measured by Glasgow Coma Scale (GCS), duration of coma, long-term outcome measured at 6-12 months after injury (Tong et al, 2004), and specific neuropsychological deficits (Babikian et al, 2005). SWI is able to detect a larger number of lesions and to define smaller areas of damage than CT, T2-weighted imaging, and FLAIR imaging.…”

“…There are currently conflicting results on the relationship between outcome and the number of lesions on MRI, given the few comparison studies available. Some studies report that lesions on T2WI (Chastain et al, 2009;Gerber et al, 2004;Sigmund et al, 2007), FLAIR (Chastain et al, 2009;Sigmund et al, 2007), T2*-GRE (Gerber et al, 2004;Yanagawa et al, 2000), and SWI (Sigmund et al, 2007;Tong et al, 2004), can discriminate or correlate with outcomes. Other studies report that there is no correlation between outcomes and lesions on T2WI (Yanagawa et al, 2000), T2*-GRE (Scheid et al, 2003), and SWI (Chastain et al, 2009).…”

Metabolic Levels in the Corpus Callosum and Their Structural and Behavioral Correlates after Moderate to Severe Pediatric TBI

“…Histopathologically, DAI is characterized by widespread damage to the axons of the brainstem, parasagittal white matter of the cerebrum, corpus callosum (CC), and the graywhite junctions of the cerebral cortex (Meythaler et al, 2001), with greatest involvement in the frontal white matter, brainstem, diencephalon, and the CC (Tong et al, 2004). As the largest white matter tract in the brain, the CC is particularly vulnerable to DAI.…”

Microbleeds as a Prognostic Factor for Acute Subdural Hematoma

“…4,6,9,14) Microbleeds identified on T 2 *-weighted magnetic resonance (MR) images correlate with outcome in patients with diffuse axonal injury. 7,16,20) However, the relationship between microbleeds and prognosis in patients with acute SDH is not known. The present study investigated the relationship between microbleeds and outcome in patients with acute SDH.…”