Journal of neurotrauma
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Journal of neurotrauma · Mar 2019
Extent of Spinal Cord Decompression in Motor Complete (American Spinal Injury Association Impairment Scale Grades A and B) Traumatic Spinal Cord Injury Patients: Post-Operative Magnetic Resonance Imaging Analysis of Standard Operative Approaches.
Although decompressive surgery following traumatic spinal cord injury (TSCI) is recommended, adequate surgical decompression is rarely verified via imaging. We utilized magnetic resonance imaging (MRI) to analyze the rate of spinal cord decompression after surgery. Pre-operative (within 8 h of injury) and post-operative (within 48 h of injury) MRI images of 184 motor complete patients (American Spinal Injury Association Impairment Scale [AIS] grade A = 119, AIS grade B = 65) were reviewed to verify spinal cord decompression. ⋯ The rates of decompression among patients who underwent laminectomy at one, two, three, four, or five levels were 58.3%, 68%, 78%, 80%, and 100%, respectively (p < 0.001). In multi-variate logistic regression analysis, only laminectomy was significantly associated with successful decompression (odds ratio 4.85; 95% confidence interval 2.2-10.6; p < 0.001). In motor complete TSCI patients, performing a laminectomy significantly increased the rate of successful spinal cord decompression, independent of whether anterior surgery was performed.
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Journal of neurotrauma · Mar 2019
Activating Adiponectin Signaling with Exogenous AdipoRon Reduces Myelin Lipid Accumulation and Suppresses Macrophage Recruitment after Spinal Cord Injury.
Myelin-laden macrophages (mye-MΦ), resulting primarily from internalization of myelin debris by infiltrating bone marrow-derived macrophages in spinal cord injury (SCI), trigger inflammatory responses that largely contribute to secondary injury. Adiponectin, which is secreted from adipose tissue, is an important hormone that modulates macrophage inflammation. In the present study, we examined the role of adiponectin on macrophage-mediated neuroinflammation after SCI. ⋯ In vivo data further confirmed that intravenous administration of AdipoRon after SCI dampened recruitment of macrophages and reduced myelin lipid accumulation. Accordingly, AdipoRon treatment ameliorated post-SCI tissue damage and astrogliosis, resulting in improved motor function. Although there was no significant pathological exacerbation in adiponectin-null mice subjected to SCI, our work reveals a functional link between adiponectin and hematogenous macrophages in the context of SCI, suggesting that activation of adiponectin signaling is a promising therapeutic approach to mitigate mye-MΦ-mediated neuroinflammation in neurological disorders involving demyelination.
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Journal of neurotrauma · Mar 2019
Submaximal Marker for Investigating Peak Muscle Torque Using Neuromuscular Electrical Stimulation after Paralysis.
Spinal cord injury (SCI) results in deleterious skeletal muscle adaptations, such as relevant atrophy and loss of force. In particular, the relevant loss of lower-limb force-generating capacity may limit functional mobility even if neuronal control was sufficient. Currently, methods of assessing maximal force-generating capacity using neuromuscular electrical stimulation (NMES) are limited in individuals who cannot tolerate higher stimulation amplitudes, such as those with residual sensation and those at risk of fracture. ⋯ NMES was delivered starting with an amplitude of 5 mA, and increasing by 5 mA for every subsequent stimulation until either the participant requested to stop the stimulation or the maximum stimulation amplitude (140 mA) was reached. Significant correlations between peak slope of the recruitment curve and peak torque for all muscle groups were found (knee extensors, r = 0.75; p < 0.0001; knee flexors, r = 0.68; p < 0.0001; ankle plantarflexors, r = 0.91; p < 0.0001), indicating that muscles that show greater peak slope of the recruitment curve tend to generate a greater peak torque. This suggests that peak slope, which was achieved at an average stimulation intensity (55.0 mA) that was 43% smaller than that corresponding to peak torque (97.4 mA), may be used as a submaximal marker for characterizing maximal torque output in individuals with SCI.
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Journal of neurotrauma · Mar 2019
Repetitive Concussive and Subconcussive Injury in a Human Tau Mouse Model Results in Chronic Cognitive Dysfunction and Disruption of White Matter Tracts, But Not Tau Pathology.
Due to the unmet need for a means to study chronic traumatic encephalopathy (CTE) in vivo, there have been numerous efforts to develop an animal model of this progressive tauopathy. However, there is currently no consensus in the field on an injury model that consistently reproduces the neuropathological and behavioral features of CTE. We have implemented a repetitive Closed-Head Impact Model of Engineered Rotational Acceleration (CHIMERA) injury paradigm in human transgenic (hTau) mice. ⋯ Severity of white matter disruption in the corpus callosum was moderately correlated with swimming speed, while white matter disruption in the fimbria showed weak but significant correlation with worse performance during probe trial. There was no evidence of tau pathology or astrogliosis in sham or injured animals. In summary, we show that repetitive brain injury produces persistent behavioral abnormalities as late as 1 year post-injury that may be related to chronic white matter disruption, although the relationship with CTE remains to be determined.
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Journal of neurotrauma · Mar 2019
Randomized Controlled TrialImpact of Low-Level Blast Exposure on Brain Function after a One-Day Tactile Training and the Ameliorating Effect of a Jugular Vein Compression Neck Collar Device.
Special Weapons and Tactics (SWAT) personnel who conduct breacher exercises are at risk for blast-related head trauma. We aimed to investigate the potential impact of low-level blast exposure during breacher training on the neural functioning of working memory and auditory network connectivity. We also aimed to evaluate the effects of a jugular vein compression collar, designed to internally mitigate slosh energy absorption, preserving neural functioning and connectivity, following blast exposure. ⋯ The elevation in fMRI activation in the non-collar group was found to correlate significantly (n = 7, r = 0.943, p = 0.001) with average peak impulse amplitude experienced during the training. In the resting-state fMRI analysis, significant pre- to post-training increase in connectivity between the auditory network and two discrete regions (left middle frontal gyrus and left superior lateral occipital/angular gyri) was found in the non-collar group, while no change was observed in the collar group. These data provided initial evidence of the impact of low-level blast on working memory and auditory network connectivity as well as the protective effect of collar on brain function following blast exposure, and is congruent with previous collar findings in sport-related traumatic brain injury.