Journal of neurotrauma
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Journal of neurotrauma · Oct 2016
Three months follow-up of rat mild traumatic brain injury: a combined [18F]FDG and [11C]PK11195 PET study.
Mild traumatic brain injury (mTBI) is the most common cause of head trauma. The time course of functional pathology is not well defined, however. The purpose of this study was to evaluate the consequences of mTBI in rats over a period of 3 months by determining the presence of neuroinflammation ([11C]PK11195) and changes in brain metabolism ([18F]FDG) with positron emission tomography (PET) imaging. ⋯ Alterations in glucose metabolism were detected over the 3 month period, with increased uptake in the medulla (p < 0.04, d ≥ 1.2), and decreased uptake in the globus pallidus, striatum, and thalamus (p < 0.04, d ≤ 1.2). Similar findings were observed in the voxel-based analysis (p < 0.05 at corrected cluster level). As a consequence of the mTBI, and in the absence of apparent behavioral alterations, relative brain glucose metabolism was found altered in several brain regions, which mostly correspond with those presenting neuroinflammation in the subacute stage.
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Journal of neurotrauma · Oct 2016
Circulating MicroRNAs as Potential Biomarkers for Traumatic Brain Injury-Induced Hypopituitarism.
Traumatic brain injury (TBI), a worldwide public health problem, has recently been recognized as a common cause of pituitary dysfunction. Circulating microRNAs (miRNAs) present in the sera are characteristically altered in many pathological conditions and have been used as diagnostic markers for specific diseases. It is with this goal that we planned to study miRNA expression in patients with TBI-induced hypopituitarism. ⋯ Statistical analyses showed that miRNA-126-3p (miR-126-3p) and miRNA-3610 (miR-3610) were detected in the sera of patients who developed hypopituitarism on the 1st, 7th, and 28th days, and in the 5th year following TBI. In addition, miRNA-3907 showed statistically significant and constant dynamic changes on the 1st, 7th, and 28th days, and in the 5th year in the patients with TBI. Our results indicated that altered expression of miR-126-3p and miR-3610 may play an important role in the development of TBI-induced hypopituitarism.
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Journal of neurotrauma · Oct 2016
Ultrastructure of diaschisis lesions following traumatic brain injury.
We used controlled cortical impact in mice to model human traumatic brain injury (TBI). Local injury was accompanied by distal diaschisis lesions that developed within brain regions anatomically connected to the injured cortex. At 7 days after injury, histochemistry documented broadly distributed lesions, particularly in the contralateral cortex and ipsilateral thalamus and striatum. ⋯ Cell bodies and processes that were silver positive at the light microscopy level showed hydropic disintegration consisting of: loss of nuclear heterochromatin; dilated somal and neuritic processes with a paucity of filaments, tubules, and mitochondria; and increased numbers of electron-dense membranous structures. Importantly the cell membrane itself was still intact 3 weeks after injury. Although the full biochemical nature of these lesions remains to be deciphered, the morphological preservation of damaged neurons and processes raises the question of whether this is a reversible process.
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Journal of neurotrauma · Oct 2016
Serum Neurofilament Light in American Football Athletes Over the Course of a Season.
Despite being underreported, American football boasts the highest incidence of concussion among all team sports, likely due to exposure to head impacts that vary in number and magnitude over the season. This study compared a biological marker of head trauma in American football athletes with non-contact sport athletes and examined changes over the course of a season. Baseline serum neurofilament light polypeptide (NFL) was measured after 9 weeks of no contact and compared with a non-contact sport. ⋯ Over the course of the season, an increase (effect size [ES] = 1.8; p < 0.001) was observed post-camp relative to baseline (1.52 ± 1.18 pg•mL-1), which remained elevated until conference play, when a second increase was observed (ES = 2.6; p = 0.008) over baseline (4.82 ± 2.64 pg•mL-1). A lack of change in non-starters resulted in substantial differences between starters and non-starters over the course of the season. These data suggest that a season of collegiate American football is associated with elevations in serum NFL, which is indicative of axonal injury, as a result of head impacts.
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Journal of neurotrauma · Oct 2016
Mechanisms of Head and Neck Injuries Sustained by Helmeted Motorcyclists in Fatal Real-World Crashes: Analysis of 47 In-Depth Cases.
Despite an improved understanding of traumatic head and neck injury mechanisms, the impact tests required by major motorcycle helmet standards have remained unchanged for decades. Development of new test methods must reflect the specific impact loads causing injury in real crashes as well as test criteria appropriate for the observed injury profiles. This study analysed a collection of in-depth crash investigations of fatally injured helmeted riders in the Adelaide metropolitan region between 1983 and 1994 inclusive to review the head and neck injury patterns that resulted from specific types of impact. ⋯ Motorcycle helmets are effective for preventing local skull fractures in impacts for which they are designed, whereas other serious injuries such as basilar skull fracture (BSF) and inertial brain injury persist despite helmet protection. Further impact test procedures should be developed for injurious impact types not currently assessed by major helmet standards, in particular facial impacts, and using test criteria based on commonly observed injuries. This study provides the necessary link, from impact load to injury, for guiding impact test development.