Journal of neurotrauma
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Journal of neurotrauma · Mar 2019
Observational StudyA Preliminary High-Definition Fiber Tracking Study of the Executive Control Network in Blast-Induced Traumatic Brain Injury.
Blast-induced traumatic brain injury (bTBI) is common in veterans of the Iraq- and Afghanistan-era conflicts. However, the typical subtlety of neural alterations and absence of definitive biomarkers impede clinical detection on conventional imaging. This preliminary study examined the structure and functional correlates of executive control network (ECN) white matter in veterans to investigate the clinical utility of using high-definition fiber tracking (HDFT) to detect chronic bTBI. ⋯ Results support anomalous density and integrity of ECN connectivity, particularly of the right DLPFC-putamen pathway, in bTBI. Results also support exacerbated aging in veterans with bTBI. Similar ECN function despite anomalous microstructure could reflect functional compensation in bTBI, although alternate interpretations are explored.
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Journal of neurotrauma · Mar 2019
Hypocretin Mediates Sleep and Wake Disturbances in a Mouse Model of Traumatic Brain Injury.
Traumatic brain injury (TBI) is a major cause of disability worldwide. Post-TBI sleep and wake disturbances are extremely common and difficult for patients to manage. Sleep and wake disturbances contribute to poor functional and emotional outcomes from TBI, yet effective therapies remain elusive. ⋯ Post-TBI sleep-wake behavior was altered in a genotype-dependent manner: sleep of HCRT KO mice was not altered by TBI, whereas C57BL/6J mice had more non-rapid eye movement sleep, less wakefulness, and more short wake bouts and fewer long wake bouts. Numbers of hypocretin-positive cells were reduced in C57BL/6J mice by TBI. Collectively, these data indicate that the hypocretinergic system is involved in the alterations in sleep-wake behavior that develop after TBI in this model, and suggest potential therapeutic interventions.
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Journal of neurotrauma · Mar 2019
Development of a Model of Hemispheric Hypodensity ("Big Black Brain").
Subdural hematoma (SDH) is the most common finding after abusive head trauma (AHT). Hemispheric hypodensity (HH) is a radiological indicator of severe brain damage that encompasses multiple vascular territories, and may develop in the hemisphere(s) underlying the SDH. In some instances where the SDH is predominantly unilateral, the widespread damage is unilateral underlying the SDH. ⋯ Pathological examination revealed a hypoxic-ischemic injury-type pattern with vasogenic edema through much of the cortical ribbon with relative sparing of deep gray matter. The percentage of the hemisphere that was damaged was greater on the ipsilateral versus contralateral side and was positively correlated with SDH area and estimated seizure duration. Further studies are needed to parse out the pathophysiology of this injury and to determine if multiple injuries and insults act synergistically to induce a metabolic mismatch or if the mechanism of trauma induces severe seizures that drive this distinctive pattern of injury.
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Journal of neurotrauma · Mar 2019
Neuroimaging of Subacute Brain Inflammation and Microstructural Changes Predicts Long-Term Functional Outcome after Experimental Traumatic Brain Injury.
There is currently a lack of prognostic biomarkers to predict the different sequelae following traumatic brain injury (TBI). The present study investigated the hypothesis that subacute neuroinflammation and microstructural changes correlate with chronic TBI deficits. Rats were subjected to controlled cortical impact (CCI) injury, sham surgery, or skin incision (naïve). ⋯ Certain specific PET and DTI parameters had good sensitivity and specificity (area under the receiver operator characteristic [ROC] curve = 0.85-1.00) to distinguish between TBI animals with and without particular behavioral deficits. Depending on the investigated behavioral deficit, PET or DTI data alone, or the combination, could very well predict the variability in functional outcome data (adjusted R2 = 0.54-1.00). Taken together, both TSPO PET and DTI seem promising prognostic biomarkers to predict different chronic TBI sequelae.
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Journal of neurotrauma · Mar 2019
Cerebral Glucose Metabolism in Patients with Chronic Mental and Cognitive Sequelae after a Single Blunt Mild Traumatic Brain Injury without Visible Brain Lesions.
The aim of this study is to investigate glucose uptake on 18F-fluorodeoxyglucose positron emission tomography positron emission tomography (FDG-PET) in patients with chronic mental and cognitive symptoms following a single blunt mild traumatic brain injury (TBI) and without visible brain lesions on computed tomography (CT)/magnetic resonance imaging (MRI). Eighty-nine consecutive patients (mean age 43.8 ± 10.75 years) who had a single blunt mild TBI from a traffic accident and suffering from chronic mental and cognitive symptoms without visible brain lesions on CT/MRI were enrolled in the study. Patients underwent FDG-PET imaging, and the mean interval between the TBI and FDG-PET was 50.0 months. ⋯ Glucose uptake was significantly decreased in the bilateral prefrontal area and significantly increased around the limbic system in the patient group compared with normal controls. This topographical pattern of glucose uptake is different from that reported previously in patients with diffuse axonal injury (DAI), but may be similar to that seen in patients with major depression disorder. These results suggest that the pathological mechanism causing chronic mental and cognitive symptoms in patients with a single blunt mild TBI and without visible brain lesions might be different from that due to primary axonopathy in patients with DAI.