Journal of neurotrauma
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Journal of neurotrauma · Jun 2011
ReviewMechanisms of primary blast-induced traumatic brain injury: insights from shock-wave research.
Traumatic brain injury caused by explosive or blast events is traditionally divided into four phases: primary, secondary, tertiary, and quaternary blast injury. These phases of blast-induced traumatic brain injury (bTBI) are biomechanically distinct and can be modeled in both in vivo and in vitro systems. The primary bTBI injury phase represents the response of brain tissue to the initial blast wave. ⋯ These are well-described pathological findings within the SW literature. Acoustic impedance mismatch, penetration of tissue by shock/bubble interaction, geometry of the skull, shear stress, tensile stress, and subsequent cavitation formation, are all important factors in determining the extent of SW-induced tissue and cellular injury. Herein we describe the requirements for the adequate experimental set-up when investigating blast-induced tissue and cellular injury; review SW physics, research, and the importance of engineering validation (visualization/pressure measurement/numerical simulation); and, based upon our findings of SW-induced injury, discuss the potential underlying mechanisms of primary bTBI.
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Journal of neurotrauma · Jun 2011
Multicenter Study Clinical TrialBiokinetic analysis of ubiquitin C-terminal hydrolase-L1 (UCH-L1) in severe traumatic brain injury patient biofluids.
Ubiquitin C-terminal hydrolase-L1 (UCH-L1) is a neuron-specific enzyme that has been identified as a potential biomarker of traumatic brain injury (TBI). The study objectives were to determine UCH-L1 exposure and kinetic metrics, determine correlations between biofluids, and assess outcome correlations in severe TBI patients. Data were analyzed from a prospective, multicenter study of severe TBI (Glasgow Coma Scale [GCS] score ≤ 8). ⋯ Outcome analysis showed significant increases in median serum AUC (2016 versus 265 ng/mL*min, p=0.006), and Cmax (2 versus 0.4 ng/mL, p=0.003), and a shorter Tmax (8 versus 19 h, p=0.04) in those who died versus those who survived, respectively. In the first 24 h after injury, there was a statistically significant acute increase in CSF and serum median Cmax((0-24h)) in those who died. This study shows a significant correlation between UCH-L1 CSF and serum median concentrations and biokinetics in severe TBI patients, and relationships with clinical outcome were detected.
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Journal of neurotrauma · Jun 2011
Comparative StudyDetecting traumatic brain lesions in children: CT versus MRI versus susceptibility weighted imaging (SWI).
Cranial CT scans are at the center of decision making in brain injuries in children because of their speed and ability to detect surgically relevant lesions. However, alternative techniques, such as conventional MRI may have advantages in terms of radiation exposure and sensitivity to detect brain injury. Susceptibility-weighted imaging (SWI), a relatively novel MRI sequence, shows promise in terms of its sensitivity in detecting hemorrhagic lesions; however, its clinical potential remains uncertain. ⋯ Detection of any lesions occurred on CT scan in 68%, on MRI in 54%, and on SWI in 86% of cases, and SWI detected additional lesions 30% of the time compared to CT and MRI. SWI may be more sensitive in detecting traumatic lesions than CT or MRI. This may be important for the ongoing management of TBIs and their prognosis.
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Journal of neurotrauma · Jun 2011
Bimanual coordination and corpus callosum microstructure in young adults with traumatic brain injury: a diffusion tensor imaging study.
Bimanual actions are ubiquitous in daily life. Many coordinated movements of the upper extremities rely on precise timing, which requires efficient interhemispheric communication via the corpus callosum (CC). As the CC in particular is known to be vulnerable to traumatic brain injury (TBI), furthering our understanding of its structure-function association is highly valuable for TBI diagnostics and prognosis. ⋯ Finally, multiple regression analyses showed evidence of the high specificity of callosal subregions accounting for the variance associated with performance of the different bimanual coordination tasks. Whereas disruption in commissural pathways between occipital areas played a role in performance on the clinical tests of bimanual coordination, deficits in the switching task were related to disrupted interhemispheric communication in prefrontal, sensory, and parietal regions. This study provides evidence that structural alterations of several subregional callosal fibers in adults with TBI are associated with differential behavioral manifestations of bimanual motor functioning.
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Journal of neurotrauma · Jun 2011
Comparative StudyChanges in cerebral compartmental compliances during mild hypocapnia in patients with traumatic brain injury.
The benefit of induced hyperventilation for intracranial pressure (ICP) control after severe traumatic brain injury (TBI) is controversial. In this study, we investigated the impact of early and sustained hyperventilation on compliances of the cerebral arteries and of the cerebrospinal (CSF) compartment during mild hyperventilation in severe TBI patients. We included 27 severe TBI patients (mean 39.5 ± 3.4 years, 6 women) in whom an increase in ventilation (20% increase in respiratory minute volume) was performed during 50 min as part of a standard clinical CO(2) reactivity test. ⋯ During sustained hyperventilation, ICP increased (13.9 ± 6.2 vs. 15.3 ± 6.4 mmHg; p < 0.001), which correlated with a reduction in Ci (r(2) = 0.297; p = 0.003), but no significant changes in Ca were found during that period. The early reduction in Ca persisted irrespective of the duration of hyperventilation, which may contribute to the lack of clinical benefit of hyperventilation after TBI. Further studies are needed to determine whether monitoring of arterial and CSF compartment compliances may detect and prevent an adverse ischemic event during hyperventilation.