Journal of neurotrauma
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This Introduction to a Special Issue on Mild Traumatic Brain Injury (mTBI) highlights the methodological challenges in outcome studies and clinical trials involving patients who sustain mTBI. Recent advances in brain imaging and portable, computerized cognitive tasks have contributed to protocols that are sensitive to the effects of mTBI and efficient in time for completion. Investigation of civilian mTBI has been extended to single and repeated injuries in athletes and blast-related mTBI in service members and veterans. ⋯ Recent use of closed head and blast injury animal models may more closely approximate clinical mTBI. Translation of interventions that are developed in animal models to patients with mTBI is a priority for the research agenda. This Special Issue on mTBI integrates basic neuroscience studies using animal models with studies of human mTBI, including the cognitive sequelae, persisting symptoms, brain imaging, and host factors that facilitate recovery.
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Journal of neurotrauma · Apr 2013
Updating memory after mild traumatic brain injury and orthopedic injuries.
Few studies have examined the trajectory of recovery of executive function (EF) after mild TBI (mTBI). Therefore, consensus has not been reached on the incidence and extent of EF impairment after mTBI. The present study investigated trajectory of change in executive memory over 3 months after mTBI on 59 right-handed participants with mTBI, as defined by Centers for Disease Control criteria, ages 14-30 years, recruited within 96 hours post-injury and tested <1 week (baseline), 1 month, and 3 months after injury. ⋯ Mixed model analyses revealed the trajectory of change in mTBI patients (high and low RPQ), OI patients, and TD subjects were similar over time (although the TD group differed from other groups at baseline), suggesting no recovery from mTBI up to 90 days. For categories maintained, differences in trajectory of recovery were discovered, with the OI comparison group surprisingly performing similar to those in the mTBI group with high RPQ symptoms, and different from low RPQ and the TD groups, bringing up questions about utility of OIs as a comparison group for mTBI. Patients with frontal lesions (on MRI) were also found to perform worse than those without lesions, a pattern that became more pronounced with time.
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Journal of neurotrauma · Apr 2013
Human mild traumatic brain injury decreases circulating branched-chain amino acids and their metabolite levels.
The pathophysiology of traumatic brain injury (TBI) is complex and not well understood. Because pathophysiology has ramifications for injury progression and outcome, we sought to identify metabolic cascades that are altered after acute human mild and severe TBI. Because catabolism of branched-chain amino acids (BCAAs; i.e., valine, isoleucine, and leucine) leads to glucose and energy metabolism, and neurotransmitter synthesis and availability, we investigated BCAA metabolites in plasma samples collected within 24 h of injury from mild TBI (Glasgow Coma Scale [GCS] score >12), severe TBI (GCS ≤8), orthopedic injury, and healthy volunteers. ⋯ Notably, logistic regression combination of three BCAA metabolites whose levels were changed by 24 h post-injury provided prognostic value (area under the curve=0.92) in identifying patients with severe TBI in whom elevated intracranial pressure (≥25 mm Hg) developed. These changes suggest alteration of BCAA metabolism after TBI may contribute to decreased energy production and neurotransmitter synthesis and may contribute to TBI pathophysiology. Supplementation of BCAAs and/or their metabolites may reduce TBI pathology and improve outcome.
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Journal of neurotrauma · Apr 2013
Rapid EEG activity during sleep dominates in mild traumatic brain injury patients with acute pain.
Chronic pain is a highly prevalent post-concussion symptom occurring in a majority of patients with mild traumatic brain injury (mTBI). About half of patients with mTBI report sleep-wake disturbances. It is known that pain can alter sleep quality in this population, but the interaction between pain and sleep is not fully understood. ⋯ Global qEEG showed lower delta (deep sleep) and higher beta and gamma power (arousal) at certain EEG derivations in patients with mTBI compared with controls (p<0.04). Patients with mTBI with pain, however, showed greater increase in rapid EEG frequency bands, mostly during REM sleep, and beta bands in non-REM sleep compared with patients with mTBI without pain and controls (p<0.001). Pain in patients with mTBI was associated with more rapid qEEG activity, mostly during REM sleep, suggesting that pain is associated with poor sleep and is a critical factor in managing post-concussion symptoms.
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Journal of neurotrauma · Apr 2013
Preinjury resilience and mood as predictors of early outcome following mild traumatic brain injury.
There is significant heterogeneity in outcomes following mild traumatic brain injury (mTBI). While several host factors (age, gender, and preinjury psychiatric history) have been investigated, the influence of preinjury psychological resilience and mood status in conjunction with mild TBI remains relatively unexplored. Euthymic mood and high resilience are potentially protective against anxiety and postconcussion symptoms, but their relative contributions are currently unknown. ⋯ Injury group and preinjury mood status were significant predictors for all three dependent variables at each study occasion (all p<0.007). Preinjury resilience showed a positive trend only for acute stress severity at baseline, but demonstrated significant prediction of all three dependent measures at one week and one month postinjury. These results suggest that preinjury depressed mood and resilience are significant contributors to the severity of postinjury anxiety and postconcussion symptoms, even after accounting for effects of other specific host factors.