Journal of neurotrauma
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Journal of neurotrauma · Mar 2017
Acute cortical transhemispheric diaschisis after unilateral traumatic brain injury.
Focal neocortical brain injuries lead to functional alterations, which can spread beyond lesion-neighboring brain areas. The undamaged hemisphere and its associated disturbances after a unilateral lesion, so-called transhemispheric diaschisis, have been progressively disclosed over the last decades; they are strongly involved in the pathophysiology and, potentially, recovery of brain injuries. Understanding the temporal dynamics of these transhemispheric functional changes is crucial to decipher the role of the undamaged cortex in the processes of functional reorganization at different stages post-lesion. ⋯ This abnormal excitable state in the intact hemisphere was not accompanied by alterations in neuronal intrinsic properties, but it was associated with an impairment of the phasic gamma aminobutyric acid (GABA)ergic transmission and an increased expression of GABAA receptor subunits related to tonic inhibition exclusively in the contralateral hemisphere. These data unravel a series of early transhemispheric functional alterations after diffuse unilateral cortical injury, which may compensate and stabilize the disrupted brain functions. Therefore, our findings support the hypothesis that the undamaged hemisphere could play a significant role in early functional reorganization processes after a TBI.
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Journal of neurotrauma · Mar 2017
Randomized Controlled Trial Multicenter StudyAssociation between blood glucose levels the next day following targeted temperature initiation and outcome in traumatic brain injury: a post-hoc analysis of the B-HYPO study.
We investigated associations between blood glucose levels and clinical outcomes in participants of the multi-center randomized controlled Brain-Hypothermia (B-HYPO) study. Patients with severe traumatic brain injury (TBI, Glasgow Coma Scale 4-8) were assigned to therapeutic hypothermia (TH, 32-34°C, n = 98) or fever control (35.5-37.0°C, n = 50) groups. TH patients were cooled as soon as possible for ≥72 h and rewarmed at a rate of <1°C/d. ⋯ In the TH group, the initial stress hyperglycemia was sustained the next day after TH induction. Day 1 BG predicted outcome in TBI patients with TH and fever control. Our findings indicate the significance of BG control particularly during TH treatment.
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Journal of neurotrauma · Mar 2017
ReviewPumping the brakes: Neurotrophic factors for the prevention of dementia following traumatic brain injury.
Traumatic brain injury (TBI) is the leading cause of disability and death worldwide, affecting as many as 54,000,000-60,000,000 people annually. TBI is associated with significant impairments in brain function, impacting cognitive, emotional, behavioral, and physical functioning. Although much previous research has focused on the impairment immediately following injury, TBI may have much longer-lasting consequences, including neuropsychiatric disorders and cognitive impairment. ⋯ Unfortunately, however, no such treatment is currently available, making this a major area of unmet medical need. Increasing the level of neurotrophic factor expression in key brain areas may be one potential therapeutic strategy. Of the neurotrophic factors, granulocyte-colony stimulating factor (G-CSF) may be particularly effective for preventing the emergence of long-term complications of TBI, including dementia, because of its ability to reduce apoptosis, stimulate neurogenesis, and increase neuroplasticity.
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Journal of neurotrauma · Mar 2017
[18F]FDG-PET Combined with MRI Elucidates the Pathophysiology of Traumatic Brain Injury in Rats.
Non-invasive measurements of brain metabolism using 18F-fluorodeoxyglucose (FDG) with positron emission tomography (PET) may provide important information about injury severity following traumatic brain injury (TBI). There is growing interest in the potential of combining functional PET imaging with anatomical and functional magnetic resonance imaging (MRI). This study aimed to investigate the effectiveness of combining clinically available FDG-PET with T2 and diffusion MR imaging, with a particular focus on inflammation and the influence of glial alterations after injury. ⋯ Glial activation was not detected in the amygdala but neuronal damage was evident, as the amygdala was the only region to show a reduction in both FDG uptake and ADC at sub-acute time-points. Overall, FDG-PET detected glial activation but was confounded by the presence of cell damage, whereas MRI consistently detected cell damage but was confounded by glial activation. These results demonstrate that FDG-PET and MRI can be used together to improve our understanding of the complex alterations in the brain after TBI.
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Journal of neurotrauma · Mar 2017
Electrophysiological Correlates of Word Retrieval in Traumatic Brain Injury.
Persons who have had a traumatic brain injury (TBI) often have word retrieval deficits; however, the underlying neural mechanisms of such deficits are yet to be clarified. Previous studies in normal subjects have shown that during a word retrieval task, there is a 750 msec event-related potential (ERP) divergence detected at the left fronto-temporal region when subjects evaluate word pairs that facilitate retrieval compared with responses elicited by word pairs that do not facilitate retrieval. In this study, we investigated the neurophysiological correlates of word retrieval networks in 19 retired professional athletes with TBI and 19 healthy control (HC) subjects. ⋯ The EEG showed a significant group by condition interaction over the left fronto-temporal region. The HC group mean amplitudes were significantly different between conditions, but the TBI group data did not show this difference, suggesting neurophysiological effects of injury. These findings provide evidence that ERP amplitudes may be used as a marker of disrupted semantic retrieval circuits in persons with TBI even when those persons perform normally.