Journal of neurotrauma
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Journal of neurotrauma · Feb 2023
Cumulative blast exposure estimate model for Special Operations Forces combat Soldiers.
Special Operations Forces (SOF) Service members endure frequent exposures to blast and overpressure mechanisms given their high training tempo. The link between cumulative subconcussive blasts on short- and long-term neurological impairment is largely understudied. Neurodegenerative diseases such as brain dysfunction, cognitive decline, mild cognitive impairment, and dementia may develop with chronic exposures. ⋯ Estimating blast exposures during routine CQB training can be determined from empirical measures taken in CQB environments. Factoring in daily, weekly, training cycle, or even career length may reasonably estimate cumulative occupational training blast exposures for SOF Service members. Future work may permit more granular exposure estimates based on operational blast exposures and those experienced by other military occupational specialties.
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Journal of neurotrauma · Feb 2023
Multicenter StudySerum Acylcarnitine and Long-term Functional Prognosis after Traumatic Brain Injury with Intracranial Injury: A Multicenter Prospective Study.
Serum biomarkers have potential to help predict prognosis of traumatic brain injury (TBI). The objective of this study was to evaluate the association between serum acylcarnitine levels and functional outcomes at 1 month/6 months after injury for TBI patients with intracranial hemorrhage or diffuse axonal injury. This study is a multi-center prospective cohort study in which adult TBI patients with intracranial injury visiting the emergency departments (EDs) from December 2018 to June 2020 were enrolled. ⋯ The odds for 1-month poor functional outcome increased in the high-normal and the high groups [adjusted odds ratios, AORs (95% confidence intervals, CIs): 1.56 (1.09-2.23) and 2.47 (1.63-3.75)], compared with the low-normal group) and also as a continuous variable [1.05 (1.03-1.07) for each 1 μmol/L]. Regarding 6-month mortality, the high group had significantly higher odds when compared with the low-normal group [AOR (95% CI): 2.16 (1.37-3.40)]. Higher serum acylcarnitine levels are associated with poor functional outcomes at 1 month/6 months after injury for TBI patients with intracranial injury.
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Journal of neurotrauma · Feb 2023
Long-term Changes in Brain Connectivity Reflected in Quantitative Electrophysiology of Symptomatic Former NFL Players.
Exposure to repetitive head impacts (RHI) has been associated with long-term disturbances in cognition, mood, and neurobehavioral dysregulation, and reflected in neuroimaging. Distinct patterns of changes in quantitative features of the brain electrical activity (quantitative electroencephalogram [qEEG]) have been demonstrated to be sensitive to brain changes seen in neurodegenerative disorders and in traumatic brain injuries (TBI). While these qEEG biomarkers are highly sensitive at time of injury, the long-term effects of exposure to RHI on brain electrical activity are relatively unexplored. ⋯ Within the NFL population, the algorithm separating AFE <12 from AFE ≥12 resulted in a sensitivity = 76%, a specificity = 52%, and an AUC = 0.72. The presence of a profile of EEG abnormalities in the NFL retirees and in those with younger AFE includes features associated with neurodegeneration and the disruption of neuronal transmission between regions. These results support the long-term consequences of RHI and the potential of EEG as a biomarker of persistent changes in brain function.
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Journal of neurotrauma · Feb 2023
Feasibility and utility of a flexible outcome assessment battery for longitudinal traumatic brain injury research: A TRACK-TBI study.
The effects of traumatic brain injury (TBI) are difficult to measure in longitudinal cohort studies, because disparate pre-injury characteristics and injury mechanisms produce variable impairment profiles and recovery trajectories. In preparation for the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study, which followed patients with injuries ranging from uncomplicated mild TBI to coma, we designed a multi-dimensional Flexible outcome Assessment Battery (FAB). The FAB relies on a decision-making algorithm that assigns participants to a Comprehensive (CAB) or Abbreviated Assessment Battery (AAB) and guides test selection across all phases of recovery. ⋯ Among participants followed at 2w (n = 2094), 3m (n = 1871), 6m (n = 1736), and 12m (n = 1607) post-injury, 95-99% received valid completion scores on the FAB, in full or in part, either in person or by telephone. Level of function assessed by the FAB-enabled approach at 2w was associated with 6m and 12m GOSE scores (proportional odds p < 0.001). These findings suggest that the participant classification methodology afforded by the FAB may enable more effective data collection to improve detection of natural history changes and TBI treatment effects.
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Journal of neurotrauma · Feb 2023
White Matter Integrity Relates to Cognition in Service Members and Veterans Following Complicated Mild, Moderate, and Severe TBI, but not Uncomplicated Mild TBI.
The extant literature investigating the relationship between diffusion tensor imaging (DTI) and cognition following traumatic brain injury (TBI) is limited by small sample sizes and inappropriate control groups. The present study examined DTI metric differences between service members and veterans (SMVs) with bodily injury (Trauma Control; TC), uncomplicated mild TBI (mTBI), complicated mild TBI (compTBI), and severe-moderate TBI combined (smTBI), and how DTI metrics related to cognition within each group. Participants were 226 SMVs (56 TC, 112 mTBI, 29 compTBI, 29 smTBI) with valid neuropsychological testing and DTI at least 11 months post-injury. ⋯ In contrast, there were no significant relationships between DTI metrics and cognition/emotional functioning within the mTBI or TC groups. Overall, findings suggest a dose-response relationship between TBI severity and the strength of the relationship between white matter integrity and cognitive performance, with essentially no relationship in mTBI, some findings in compTBI, and several strongly significant relationships in smTBI. In contrast to previously reported findings, there were no differences in DTI metrics between controls, mTBI, and compTBI, and DTI metrics were unrelated to cognition in our relatively large mTBI group.