Journal of neurotrauma
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Journal of neurotrauma · Oct 2023
Fixed time point analysis reveals repetitive mild traumatic brain injury effects on resting state fMRI connectivity and neuro-spatial protein profiles.
Repetitive mild traumatic brain injuries (rmTBIs) are serious trauma events responsible for the development of numerous neurodegenerative disorders. A major challenge in developing diagnostics and treatments for the consequences of rmTBI is the fundamental knowledge gaps of the molecular mechanisms responsible for neurodegeneration. It is both critical and urgent to understand the neuropathological and functional consequences of rmTBI to develop effective therapeutic strategies. ⋯ Our analyses revealed aberrant connectivity changes in the thalamus, independent of microstructural damage or neuroinflammation. We also identified distinct changes in the levels of proteins linked to various neurodegenerative processes including total and phospho-tau species and cell proliferation markers. Together, our data show that rmTBI significantly alters brain functional connectivity and causes distinct protein changes in morphologically intact brain areas.
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Journal of neurotrauma · Oct 2023
Transcranial, noninvasive evaluation of the potential misery perfusion during hyperventilation therapy of traumatic brain injury patients.
Hyperventilation (HV) therapy uses vasoconstriction to reduce intracranial pressure (ICP) by reducing cerebral blood volume. However, as HV also lowers cerebral blood flow (CBF), it may provoke misery perfusion (MP), in which the decrease in CBF is coupled with increased oxygen extraction fraction (OEF). MP may rapidly lead to the exhaustion of brain energy metabolites, making the brain vulnerable to ischemia. ⋯ We have characterized each statistically significant event in detail and its possible relationship to clinical and radiological status (decompressive craniectomy and presence of a cerebral lesion), without detecting any statistically significant difference (p > 0.05). However, MP detection stresses the need for personalized, real-time assessment in future clinical trials with HV, in order to provide an optimal evaluation of the risk-benefit balance of HV. Our study provides pilot data demonstrating that bedside transcranial hybrid near-infrared spectroscopies could be utilized to assess potential MP.
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Journal of neurotrauma · Oct 2023
A morphologically individualized deep learning brain injury model.
The brain injury modeling community has recommended improving model subject specificity and simulation efficiency. Here, we extend an instantaneous (< 1 sec) convolutional neural network (CNN) brain model based on the anisotropic Worcester Head Injury Model (WHIM) V1.0 to account for strain differences due to individual morphological variations. Linear scaling factors relative to the generic WHIM along the three anatomical axes are used as additional CNN inputs. ⋯ This tool could be especially useful for youths and females due to their anticipated greater morphological differences relative to the generic model, even without the need for individual neuroimages. It has potential for a wide range of applications for injury mitigation purposes and the design of head protective gears. The voxelized strains also allow for convenient data sharing and promote collaboration among research groups.
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Journal of neurotrauma · Oct 2023
Observational StudyCushing Index based on Cushing signs to predict in-hospital mortality and early intervention for minor head injury.
A considerable number of patients with mild traumatic brain injury have been known to "talk and die." Serial neurological examinations, however, have been the only method of determining the necessity of repeat computed tomography (CT), and no validated method has been available to predict early deterioration of minor head injury. This study aimed to evaluate the association between hypertension and bradycardia, a classic sign of raised intracranial pressure (Cushing reflex) on hospital arrival and determine the clinical consequences of minor head injury after blunt trauma. We created a new Cushing Index (CI) by dividing the systolic blood pressure by the heart rate (equaling the inverse number of the Shock Index, a score for hemodynamic stability) and hypothesized that a high CI would predict surgical intervention for deterioration and in-hospital death among patients with minor head injury. ⋯ Patients with high index also had a higher incidence of emergency cranial surgery within 24h after arrival than those with an intermediate CI (746 [6.4%] vs. 879 [5.4%]; OR = 1.20 [1.08-1.33]; p < 0.001). In addition, patients with low CI (equal to high Shock Index, meaning hemodynamically unstable) showed higher in-hospital death compared with those with intermediate CI (360 [3.3%] vs. 373 [2.3%]; p < 0.001). In conclusion, a high CI (high systolic blood pressure and low heart rate) on hospital arrival would be helpful in identifying patients with minor head injury who might experience deterioration and need close observation.
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Journal of neurotrauma · Oct 2023
Mild Traumatic Brain Injury Affects Orexin/Hypocretin Physiology Differently in Male and Female Mice.
Traumatic brain injury (TBI) is known to affect the physiology of neural circuits in several brain regions, which can contribute to behavioral changes after injury. Disordered sleep is a behavior that is often seen after TBI, but there is little research into how injury affects the circuitry that contributes to disrupted sleep regulation. Orexin/hypocretin neurons (hereafter referred to as orexin neurons) located in the lateral hypothalamus normally stabilize wakefulness in healthy animals and have been suggested as a source of dysregulated sleep behavior. ⋯ Alterations in afferent excitatory activity occurred in different parameters in male and female animals. The increased afferent inhibitory activity after injury is more pronounced in recordings from female animals. Our results indicate that mTBI changes the physiology of orexin neuron circuitry and that these changes are not the same in male and female animals.