Journal of neurotrauma
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Journal of neurotrauma · Jun 2021
Concussion and Risk of Chronic Medical and Behavioral Health Comorbidities.
While chronic neurological effects from concussion have been studied widely, little is known about possible links between concussion and long-term medical and behavioral comorbidities. We performed a retrospective cohort study of 9205 adult patients with concussion, matched to non-concussion controls from a hospital-based electronic medical registry. Patients with comorbidities before the index visit were excluded. ⋯ The risks for post-concussion comorbidities were also higher in patients under 40 years old compared with controls. Patients with concussion demonstrated an increased risk of development of medical and behavioral health comorbidities. Prospective studies are warranted to better describe the burden of long-term comorbidities in patients with concussion.
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Journal of neurotrauma · Jun 2021
Mechanical properties of the Cranial Meninges; A Systematic Review.
The meninges are membranous tissues that are pivotal in maintaining homeostasis of the central nervous system. Despite the importance of the cranial meninges in nervous system physiology and in head injury mechanics, our knowledge of the tissues' mechanical behavior and structural composition is limited. This systematic review analyzes the existing literature on the mechanical properties of the meningeal tissues. ⋯ The review identifies no peer-reviewed mechanical data on the falx and tentorium tissues, both of which have been identified as key structures in influencing brain injury mechanics. A dearth of mechanical data for the pia-arachnoid complex also was identified (no experimental mechanics studies on the human pia-arachnoid complex were identified), which is desirable for biofidelic modeling of human head injuries. Finally, this review provides recommendations on how experiments can be conducted to allow for standardization of test methodologies, enabling simplified comparisons and conclusions on meningeal mechanics.
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Journal of neurotrauma · Jun 2021
Verbal Episodic Memory Alterations and Hippocampal Atrophy in Acute Mild Traumatic Brain Injury.
Episodic memory deficit is a symptom frequently observed after a mild traumatic brain injury (mTBI). However, few studies have investigated the impact of a single and acute mTBI on episodic memory and structural cerebral changes. To do so, we conducted two experiments. ⋯ In Experiment 2, patients with mTBI exhibited a generally reduced hippocampal volume; however, we did not observe any linear correlation between hippocampal volume and memory scores. These results suggest that one single mTBI is associated with both episodic memory alteration and reduced volume of the hippocampus in the acute phase. Future studies are needed to elucidate the link between both measures.
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Journal of neurotrauma · Jun 2021
Hippocampal-Dependent Cognitive Dysfunction Following Repeated Diffuse Rotational Brain Injury in Male and Female Mice.
Cognitive dysfunction is a common, often long-term complaint following acquired traumatic brain injury (TBI). Cognitive deficits suggest dysfunction in hippocampal circuits. The goal of the studies described here is to phenotype in both male and female mice the hippocampal-dependent learning and memory deficits resulting from TBI sustained by the Closed-Head Impact Model of Engineered Rotational Acceleration (CHIMERA) device-a model that delivers both a contact-concussion injury as well as unrestrained rotational head movement. ⋯ Pathologically, the injury was characterized by white matter damage as observed by silver staining and glial fibrillary acidic protein (astrogliosis) in the optic tracts, with milder damage seen in the corpus callosum, and fimbria and brainstem (cerebral peduncles) of some animals. No changes in the density of GABAergic parvalbumin-expressing cells in the hippocampus, amygdala, or parietal cortex were found. This experiment confirmed significant sexually dimorphic cognitive impairments following a repeated, diffuse brain injury.
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Journal of neurotrauma · Jun 2021
MiR-17-92 cluster-enriched exosomes derived from human bone marrow mesenchymal stromal cells improve tissue and functional recovery in rats after traumatic brain injury.
Exosomes play an important role in intercellular communication by delivering microribonucleic acids (miRNAs) to recipient cells. Previous studies have demonstrated that multi-potent mesenchymal stromal cell (MSC)-derived exosomes improve functional recovery after experimental traumatic brain injury (TBI). This study was performed to determine efficacy of miR-17-92 cluster-enriched exosomes (Exo-17-92) harvested from human bone marrow MSCs transfected with a miR-17-92 cluster plasmid in enhancing tissue and neurological recovery compared with exosomes derived from MSCs transfected with an empty plasmid vector (Exo-empty) for treatment of TBI. ⋯ Moreover, Exo-17-92 treatment exhibited a significantly more robust therapeutic effect on improvement in functional recovery by reducing neuroinflammation and cell loss, enhancing angiogenesis and neurogenesis than did Exo-empty treatment. Exosomes enriched with miR-17-92 cluster have a significantly better effect on improving functional recovery after TBI compared with Exo-empty, likely by reducing neuroinflammation and enhancing endogenous angiogenesis and neurogenesis. Engineering specific miRNA in exosomes may provide a novel therapeutic strategy for management of unilateral moderate cortical contusion TBI.