Journal of neurotrauma
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Journal of neurotrauma · Jun 2023
Impact of Chronological Age and Biological Sex on Cerebrovascular Reactivity in Moderate/Severe Traumatic Brain Injury: A CAnadian High-Resolution TBI (CAHR-TBI) Study.
Impaired cerebrovascular reactivity has emerged as an important associate with poor long-term outcome after moderate/severe traumatic brain injury (TBI). However, our understanding of what drives or modulates the degree of impaired cerebrovascular function remains poor. Age and biological sex remain important modifiers of cerebrovascular function in health and disease, yet their impact on cerebrovascular reactivity after TBI remains unclear. ⋯ There was no clear difference in cerebrovascular reactivity profiles between biological sex categories. These findings suggest that AMP-based cerebrovascular reactivity indices may be better positioned to detect impairment in TBI patients with advancing age. Further investigation into the utility of PAx and RAC is required, as they may prove useful for certain subgroups of patients.
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Journal of neurotrauma · Jun 2023
Assessing Pediatric Mild Traumatic Brain Injury and its Recovery using Resting-State MEG Source Magnitude Imaging and Machine Learning.
The objectives of this machine-learning (ML) resting-state magnetoencephalography (rs-MEG) study involving children with mild traumatic brain injury (mTBI) and orthopedic injury (OI) controls were to define a neural injury signature of mTBI and to delineate the pattern(s) of neural injury that determine behavioral recovery. Children ages 8-15 years with mTBI (n = 59) and OI (n = 39) from consecutive admissions to an emergency department were studied prospectively for parent-rated post-concussion symptoms (PCS) at: 1) baseline (average of 3 weeks post-injury) to measure pre-injury symptoms and also concurrent symptoms; and 2) at 3-months post-injury. rs-MEG was conducted at the baseline assessment. The ML algorithm predicted cases of mTBI versus OI with sensitivity of 95.5 ± 1.6% and specificity of 90.2 ± 2.7% at 3-weeks post-injury for the combined delta-gamma frequencies. ⋯ The ML algorithm accounted for 84.5% of the variance in predicting recovery measured by PCS changes between 3 weeks and 3 months post-injury in the mTBI group, and this was significantly lower (p < 10-4) in the OI group (65.6%). Frontal lobe pole (higher) gamma activity was significantly (p < 0.001) associated with (worse) PCS recovery exclusively in the mTBI group. These findings demonstrate a neural injury signature of pediatric mTBI and patterns of mTBI-induced neural injury related to behavioral recovery.
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Journal of neurotrauma · Jun 2023
Evans blue and FITC-dextran double labeling reveals precise sequence of vascular leakage and glial responses after exposure to mild-level blast-associated shock waves.
Abstract Blast-induced shock waves (BSWs) are responsible for several aspects of psychiatric disorders that are collectively termed mild traumatic brain injury (mTBI). The pathophysiology of mTBI includes vascular leakage resulting from blood-brain barrier (BBB) disruption. In this study, the precise sequence of BBB breakdown was examined using an Evans blue and fluorescein isothiocyanate (FITC)-dextran double labeling technique. ⋯ These regions showed distinct responses to BSW; moreover, clusters of reactive astrocytes were closely associated with the sites of BBB breakdown. In severe cases, these reactive astrocytes recruited activated microglia. Our findings provide important insights into the pathogenesis underlying mTBI and indicate that even mild BSW exposure affects the whole brain.
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Journal of neurotrauma · Jun 2023
High fat diet exacerbates stress responsivity in juvenile traumatic brain injury.
Abstract Traumatic brain injury (TBI) is one of the leading causes of death for children in the United States. Juveniles are more likely to sustain TBIs than most other age groups, and TBI has been shown to result in increased anxiety and stress behaviors. In addition, the hypothalamic-pituitary-adrenal (HPA) axis has previously been shown to become dysregulated after a TBI. ⋯ In addition, RT-PCR showed significantly reduced expression of relevant HPA axis genes, NR3C1, NR3C2, and CRHR2, in the hypothalamus of TBI subjects compared with Sham subjects. Further, AVP and CRHR2 in the hypothalamus were significantly reduced in HFD TBI compared with Chow TBI. These results offer evidence that TBI paired with high-fat diet consumption can cause HPA axis dysfunction, resulting in more anxiety-like behaviors.