Recent advances in traumatic brain injury

Current state of high-fidelity multimodal monitoring in traumatic brain injury

INTRODUCTION

Multimodality monitoring of patients with severe traumatic brain injury (TBI) is primarily performed in neuro-critical care units to prevent secondary harmful brain insults and facilitate patient recovery. Several metrics are commonly monitored using both invasive and non-invasive techniques. The latest Brain Trauma Foundation guidelines from 2016 provide recommendations and thresholds for some of these. Still, high-level evidence for several metrics and thresholds is lacking.

METHODS

Regarding invasive brain monitoring, intracranial pressure (ICP) forms the cornerstone, and pressures above 22 mmHg should be avoided. From ICP, cerebral perfusion pressure (CPP) (mean arterial pressure (MAP)-ICP) and pressure reactivity index (PRx) (a correlation between slow waves MAP and ICP as a surrogate for cerebrovascular reactivity) may be derived. In terms of regional monitoring, partial brain tissue oxygen pressure (PbtO₂) is commonly used, and phase 3 studies are currently ongoing to determine its added effect to outcome together with ICP monitoring. Cerebral microdialysis (CMD) is another regional invasive modality to measure substances in the brain extracellular fluid. International consortiums have suggested thresholds and management strategies, in spite of lacking high-level evidence. Although invasive monitoring is generally safe, iatrogenic hemorrhages are reported in about 10% of cases, but these probably do not significantly affect long-term outcome. Non-invasive monitoring is relatively recent in the field of TBI care, and research is usually from single-center retrospective experiences. Near-infrared spectrometry (NIRS) measuring regional tissue saturation has been shown to be associated with outcome. Transcranial doppler (TCD) has several tentative utilities in TBI like measuring ICP and detecting vasospasm. Furthermore, serial sampling of biomarkers of brain injury in the blood can be used to detect secondary brain injury development.

CONCLUSIONS

In multimodal monitoring, the most important aspect is data interpretation, which requires knowledge of each metric's strengths and limitations. Combinations of several modalities might make it possible to discern specific pathologic states suitable for treatment. However, the cost-benefit should be considered as the incremental benefit of adding several metrics has a low level of evidence, thus warranting additional research.

A novel mechanism linking ferroptosis and endoplasmic reticulum stress via the circPtpn14/miR-351-5p/5-LOX signaling in melatonin-mediated treatment of traumatic brain injury

Traumatic brain injury (TBI) can lead to disability or devastating consequences with few established treatments. Although ferroptosis has been shown to be involved in TBI, the underlying mechanism was rarely known. Melatonin has been indicated to exhibit neuroprotective activities. However, the anti-ferroptotic effects of melatonin on TBI have not yet to be elucidated. We aimed to investigate whether ferroptosis was induced in humans after TBI and whether ferroptosis inhibition by melatonin could protect against blood-brain barrier (BBB) damage after TBI in vivo and in vitro. Circular RNAs (circRNAs) are highly expressed in the brain. For the first time, differentially expressed circRNA after melatonin treatment for TBI were detected by RNA sequencing. We found that lipid peroxidation was induced in humans after TBI, while melatonin significantly improved brain function of mice after TBI and alleviated ferroptosis and endoplasmic reticulum (ER) stress in vivo and in vitro. A total of 1826 differentially expressed circRNAs were found (fold change >2, Q < 0.01), including 921 down-regulated and 905 up-regulated circRNAs in the injured brain tissues of TBI mice receiving melatonin treatment. Mechanistically, melatonin administration reduced the level of circPtpn14 (mmu_circ_0000130), which functioned by acting as a miR-351-5p sponge to positively regulate the expression of the ferroptosis-related 5-lipoxygenase (5-LOX). Moreover, circPtpn14 overexpression partly abolished the inhibitory effects of melatonin on ferroptosis. Collectively, our findings provide the first evidence that melatonin could exert anti-ferroptotic and anti-ER stress effects in brain injury by alleviating lipid peroxidation via the circPtpn14/miR-351-5p/5-LOX signaling.

Focally administered succinate improves cerebral metabolism in traumatic brain injury patients with mitochondrial dysfunction

Following traumatic brain injury (TBI), raised cerebral lactate/pyruvate ratio (LPR) reflects impaired energy metabolism. Raised LPR correlates with poor outcome and mortality following TBI. We prospectively recruited patients with TBI requiring neurocritical care and multimodal monitoring, and utilised a tiered management protocol targeting LPR. We identified patients with persistent raised LPR despite adequate cerebral glucose and oxygen provision, which we clinically classified as cerebral 'mitochondrial dysfunction' (MD). In patients with TBI and MD, we administered disodium 2,3-¹³C₂ succinate (12 mmol/L) by retrodialysis into the monitored region of the brain. We recovered ¹³C-labelled metabolites by microdialysis and utilised nuclear magnetic resonance spectroscopy (NMR) for identification and quantification.Of 33 patients with complete monitoring, 73% had MD at some point during monitoring. In 5 patients with multimodality-defined MD, succinate administration resulted in reduced LPR(-12%) and raised brain glucose(+17%). NMR of microdialysates demonstrated that the exogenous ¹³C-labelled succinate was metabolised intracellularly via the tricarboxylic acid cycle. By targeting LPR using a tiered clinical algorithm incorporating intracranial pressure, brain tissue oxygenation and microdialysis parameters, we identified MD in TBI patients requiring neurointensive care. In these, focal succinate administration improved energy metabolism, evidenced by reduction in LPR. Succinate merits further investigation for TBI therapy.

Histological and immunohistochemical study of brain damage in traumatic brain injuries in children, depending on the survival period

Numerous studies showed that, at present, traumatic brain injury (TBI) is one of the main causes of death in young adults, but also a main cause of disabilities at all ages. For these reasons, TBI are continuously investigated. In our study, we evaluated the histopathological (HP) and immunohistochemical (IHC) changes that occurred in the brain in underage patients after a severe TBI depending on the survival period. We histopathologically and immunohistochemically analyzed a number of 22 cases of children, deceased in Dolj County, Romania, following some severe TBI, undergoing autopsy within the Institute of Forensic Medicine in Craiova between 2015-2020. Patients were divided into three groups depending on the survival period, namely: (i) patients who died during the first 24 hours of the accident; (ii) patients who died after seven days of survival; (iii) patients who died after 15 days of survival. Microscopic examinations of the brain fragments, collected during the necropsy examination, showed that the traumatic agent caused primary injuries in all brain structures (cerebral parenchyma, meninges, blood vessels). However, HP injuries ranged in size and intensity from one area to another of the brain. In patients with a longer survival period, there was observed the presence of smaller primary injuries and larger secondary injuries. There was also observed a growth in the number of meningo-cerebral microscopic injuries, depending on the increase of the survival period.

Elevated Serum Complement C1q Levels After Traumatic Brain Injury and Its Association with Poor Prognosis

OBJECTIVE

Complement C1q is implicated in neuroinflammation. We intended to discern the relationship between serum C1q levels and severity in addition to prognosis following traumatic brain injury (TBI).

METHODS

In this prospective, observational study, serum C1q levels were quantified in 188 TBI patients and 188 healthy controls. Glasgow coma scale (GCS) and Rotterdam computed tomography (CT) classification were used as clinical and radiological indicators of severity. Patients with extended Glasgow outcome scale (GOSE) score of 1-4 at 6 months after trauma were considered to have a poor outcome. Multiple logistic regression model was built to ascertain the independent association of serum C1q levels with 6-month poor outcome. Receiver operating characteristic (ROC) curve was configured for analysis of prognostic capability with respect to serum C1q levels.

RESULTS

TBI patients exhibited substantially higher serum C1q levels than controls (median, 223.9 mg/l versus 75.4 mg/l). Serum C1q levels of patients were tightly correlated with GCS score (r = -0.671), Rotterdam CT classification (r = 0.604) and GOSE score (r = -0.581). An area under the ROC curve was yielded of 0.793 (95% confidence interval = 0.728-0.849), and serum C1q levels above 345.5 mg/l discriminated the risk of 6-month poor outcome with 59.6% sensitivity and 92.6% specificity. Serum C1q levels above 345.5 mg/l retained as an independent predictor for 6-month poor outcome with odds ratio of 4.922 (95% confidence interval = 1.552-15.606; P = 0.017).

CONCLUSION

Elevated serum C1q levels are closely correlated with traumatic severity and independently predicted the risk of long-term poor prognosis after TBI.

Utility of Serum Growth Arrest-Specific Protein 6 as a Biomarker of Severity and Prognosis After Severe Traumatic Brain Injury: A Prospective Observational Study

OBJECTIVE

Growth arrest-specific protein 6 (Gas6) may harbor protective effects in acute brain injury. This study was designed to determine the relation of serum Gas6 levels to severity and prognosis after traumatic brain injury (TBI).

METHODS

In this prospective cohort study of 114 controls and 114 patients with severe TBI, multivariate analysis was used to assess relationships between serum Gas6 levels, Glasgow coma scale (GCS) score, Rotterdam computed tomography (CT) score, postinjury 180-day mortality, overall survival and poor prognosis (Extended Glasgow outcome scale score 1-4).

RESULTS

Significantly increased serum Gas6 levels of patients (median, 10.3 ng/mL versus 32.5 ng/mL; P < 0.001), as compared with controls, were independently correlated with Rotterdam CT score (t = 3.629, P < 0.001) and GCS score (t=-3.393, P = 0.001), and independently predicted 180-day mortality (odds ratio, 1.078; 95% confidence interval (CI), 1.007-1.154), overall survival (hazard ratio, 1.074; 95% CI, 1.012-1.139) and poor prognosis (odds ratio, 1.129; 95% CI, 1.059-1.205). Areas under receiver operating characteristic curve (AUCs) of serum Gas6 levels for discriminating risks of 180-day mortality and poor prognosis were 0.785 (95% CI, 0.699-0.857) and 0.793 (95% CI, 0.707-0.863), respectively; and serum Gas6 levels above 30.9 ng/mL and 28.3 ng/mL predicted 180-day mortality and poor prognosis with maximum Youden indices of 0.451 and 0.468, respectively. The predictive ability of serum Gas6 levels for mortality was similar to those of GCS score (AUC, 0.833; 95% CI, 0.751-0.896; P = 0.286) and Rotterdam CT score (AUC, 0.823; 95% CI, 0.740-0.888; P = 0.432). The discriminatory capability of serum Gas6 levels for the risk of poor prognosis was in the range of GCS score (AUC, 0.846; 95% CI, 0.766-0.906; P = 0.178) and Rotterdam CT score (AUC, 0.831; 95% CI, 0.750-0.895; P = 0.368).

CONCLUSION

Serum Gas6 may appear as a promising biochemical parameter for aiding in the assessment of trauma severity and prediction of prognosis among patients with severe TBI.

Chronic Administration of 7,8-DHF Lessens the Depression-like Behavior of Juvenile Mild Traumatic Brain Injury Treated Rats at Their Adult Age

Traumatic brain injury (TBI) is a leading cause of mortality and morbidity among the global youth and commonly results in long-lasting sequelae, including paralysis, epilepsy, and a host of mental disorders such as major depressive disorder. Previous studies were mainly focused on severe TBI as it occurs in adults. This study explored the long-term adverse effect of mild TBI in juvenile animals (mTBI-J). Male Sprague Dawley rats received mTBI-J or sham treatment at six weeks old, then underwent behavioral, biochemical, and histological experiments three weeks later (at nine weeks old). TTC staining, H&E staining, and brain edema measurement were applied to evaluate the mTBI-J induced cerebral damage. The forced swimming test (FST) and sucrose preference test (SPT) were applied for measuring depression-like behavior. The locomotor activity test (LAT) was performed to examine mTBI-J treatment effects on motor function. After the behavioral experiments, the dorsal hippocampus (dHip) and ventral hippocampus (vHip) were dissected out for western blotting to examine the expression of brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB). Finally, a TrkB agonist 7,8-DHF was injected intraperitoneally to evaluate its therapeutic effect on the mTBI-J induced behavioral abnormalities at the early adult age. Results showed that a mild brain edema occurred, but no significant neural damage was found in the mTBI-J treated animals. In addition, a significant increase of depression-like behaviors was observed in the mTBI-J treated animals; the FST revealed an increase in immobility, and a decrease in sucrose consumption was found in the mTBI-J treated animals. There were no differences observed in the total distance traveled of the LAT and the fall latency of the rotarod test. The hippocampal BDNF expression, but not the TrkB, were significantly reduced in mTBI-J, and the mTBI-J treatment-induced depression-like behavior was lessened after four weeks of 7,8-DHF administration. Collectively, these results indicate that even a mild juvenile TBI treatment that did not produce motor deficits or significant histological damage could have a long-term adverse effect that could be sustained to adulthood, which raises the depression-like behavior in the adult age. In addition, chronic administration of 7,8-DHF lessens the mTBI-J treatment-induced depression-like behaviors in adult rats. We suggest the potential usage of 7,8-DHF as a therapeutic agent for preventing the long-term adverse effect of mTBI-J.

Traumatic Brain Injury and Risk of Dementia and Alzheimer's Disease: A Systematic Review and Meta-Analysis

INTRODUCTION

Previous studies have investigated the potential role of traumatic brain injury (TBI) in subsequent development of dementia and Alzheimer's disease (AD) but reported inconsistent results. We aim to determine the association between TBI and subsequent occurrence of dementia and AD.

METHODS

We performed a systematic search in PubMed and Web of Science for studies that quantitatively investigated the association between TBI and risk of dementia and AD and were published on or before September 21, 2021. A random-effect model was used to combine the estimates.

RESULTS

Twenty-five eligible articles were included in this meta-analysis. The results suggested that TBI was associated with an increased risk of dementia (pooled odds ratio [OR] = 1.81, 95% confidence interval [CI] = 1.53 - 2.14). However, no association was observed between TBI and Alzheimer's disease (pooled OR = 1.02, 95% CI = 0.91 - 1.15). In the subgroup analysis, TBI with loss of consciousness was not associated with risk of dementia (pooled OR = 0.96, 95% CI = 0.84 - 1.09). Besides, Asian ethnicity, male gender, and mean age of the participants less than 65 were associated with a higher risk of dementia.

CONCLUSION

Our study suggests an increased risk of dementia among individuals with TBI, highlighting the need for more intensive medical monitoring and health education in individuals with TBI. Biological mechanisms linking TBI and the development of dementia are needed in future studies.

The Impact of Hyperoxia Treatment on Neurological Outcomes and Mortality in Moderate to Severe Traumatic Brain Injured Patients

Background

Traumatic brain injury is a leading cause of morbidity and mortality worldwide. The relationship between hyperoxia and outcomes in patients with TBI remains controversial. We assessed the effect of persistent hyperoxia on the neurological outcomes and survival of critically ill patients with moderate-severe TBI.

Method

This was a retrospective cohort study of all adults with moderate-severe TBI admitted to the ICU between 1st January 2016 and 31st December 2019 and who required invasive mechanical ventilation. Arterial blood gas data was recorded within the first 3 hours of intubation and then after 6-12 hours and 24-48 hours. The patients were divided into two categories: Group I had a PaO2 < 120mmHg on at least two ABGs undertaken in the first twelve hours post intubation and Group II had a PaO2 ≥ 120mmHg on at least two ABGs in the same period. Multivariable logistic regression was performed to assess predictors of hospital mortality and good neurologic outcome (Glasgow outcome score ≥ 4).

Results

The study included 309 patients: 54.7% (n=169) in Group I and 45.3% (n=140) in Group II. Hyperoxia was not associated with increased mortality in the ICU (20.1% vs. 17.9%, p=0.62) or hospital (20.7% vs. 17.9%, p=0.53), moreover, the hospital discharge mean (SD) Glasgow Coma Scale (11.0(5.1) vs. 11.2(4.9), p=0.70) and mean (SD) Glasgow Outcome Score (3.1(1.3) vs. 3.1(1.2), p=0.47) were similar. In multivariable logistic regression analysis, persistent hyperoxia was not associated with increased mortality (adjusted odds ratio [aOR] 0.71, 95% CI 0.34-1.35, p=0.29). PaO2 within the first 3 hours was also not associated with mortality: 121-200mmHg: aOR 0.58, 95% CI 0.23-1.49, p=0.26; 201-300mmHg: aOR 0.66, 95% CI 0.27-1.59, p=0.35; 301-400mmHg: aOR 0.85, 95% CI 0.31-2.35, p=0.75 and >400mmHg: aOR 0.51, 95% CI 0.18-1.44, p=0.20; reference: PaO2 60-120mmHg within 3 hours. However, hyperoxia >400mmHg was associated with being less likely to have good neurological (GOS ≥4) outcome on hospital discharge (aOR 0.36, 95% CI 0.13-0.98, p=0.046; reference: PaO2 60-120mmHg within 3 hours.

Conclusion

In intubated patients with moderate-severe TBI, hyperoxia in the first 48 hours was not independently associated with hospital mortality. However, PaO2 >400mmHg may be associated with a worse neurological outcome on hospital discharge.

rhFGF20 promotes angiogenesis and vascular repair following traumatic brain injury by regulating Wnt/β-catenin pathway

The pathology of cerebrovascular disorders takes an important role in traumatic brain injury (TBI) by increasing intracranial pressure. Fibroblast growth factor 20 (FGF20) is a brain-derived neurotrophic factor, that has been shown to play an important role in the survival of dopaminergic neurons and the treatment of Parkinson's disease (PD). However, little is known about the role of FGF20 in the treatment of TBI and its underlying mechanism. The purpose of this study was to evaluate the protective effect of recombinant human FGF20 (rhFGF20) on protecting cerebral blood vessels after TBI. In this study, we indicated that rhFGF20 could reduce brain edema, Evans blue penetration and upregulated the expression of blood-brain barrier (BBB)-related tight junction (TJ) proteins, exerting a protective effect on the BBB in vivo after TBI. In the TBI repair phase, rhFGF20 promoted angiogenesis, neurological and cognitive function recovery. In tumor necrosis factor-α (TNF-α)-induced human brain microvascular endothelial cells (hCMEC/D3), an in vitro BBB disruption model, rhFGF20 reversed the impairment in cell migration and tube formation induced by TNF-α. Moreover, in both the TBI mouse model and the in vitro model, rhFGF20 increased the expression of β-catenin and GSK3β, which are the two key regulators in the Wnt/β-catenin signaling pathway. In addition, the Wnt/β-catenin inhibitor IWR-1-endo significantly reversed the effects of rhFGF20. These results indicate that rhFGF20 may prevent vascular repair and angiogenesis through the Wnt/β-catenin pathway.

The neuroprotection of hyperbaric oxygen therapy against traumatic brain injury via NF-κB/MAPKs-CXCL1 signaling pathways

It is well known that hyperbaric oxygen (HBO) therapy achieves neuroprotective effects by modulating neuroinflammatory responses. However, its underlying therapeutic mechanisms are not yet fully elucidated. Based on our previous studies, we further investigated whether HBO therapy exerts neuroprotective effects in vivo by regulating the nuclear factor-kappa B (NF-κB)/ mitogen-activated protein kinases (MAPKs) chemokine (C-X-C motif) ligand (CXCL)1 inflammatory pathway. In our study, a rat model of traumatic brain injury (TBI) was established by controlled cortical impact (CCI) to verify that the expression of CXCL1 and chemokine (C-X-C motif) receptor (CXCR)2 increased after TBI, and CXCL1 was mainly expressed in astrocytes, while CXCR2 was mainly expressed in neurons. Increased apoptosis of cortical nerve cells in the injured cortex was also found after TBI. Reduced nerve cell apoptosis with improved neurological function was observed after application of a CXCR2 antagonist. The expression of phospho-extracellular signal-regulated kinase (p-ERK), phospho-c-Jun N-terminal kinase (p-JNK) and p-NF-κB increased after TBI, and application of ERK, JNK and NF-κB inhibitors decreased expression of CXCL1 and CXCR2 in rats. We further found that HBO therapy down-regulated the expression of p-ERK, p-JNK, p-NF-κB, CXCL1, and CXCR2, and reduced nerve cell apoptosis, improved the neurological function of TBI rats, and ultimately alleviated the secondary injury. In conclusion, HBO therapy may exert neuroprotective effect by regulating the NF-κB/MAPKs (JNK and ERK)-CXCL1 inflammatory pathways following TBI, which probably provide the theoretical and experimental basis for the clinical application of HBO therapy in the treatment of TBI.

Electrochemical Immunosensing of Interleukin-6 in Human Cerebrospinal Fluid and Human Serum as an Early Biomarker for Traumatic Brain Injury

In this work, we develop a label-free electrochemical immunosensor for the detection of interleukin-6 (IL-6) in human cerebrospinal fluid (CSF) and serum for diagnostic and therapeutic monitoring. The IL-6 immunosensor is fabricated from gold interdigitated electrode arrays (IDEAs) that are modified with IL-6 antibodies for direct antigen recognition and capture. A rigorous surface analysis of the sensor architecture was conducted to ensure high structural fidelity and performance. Electrochemical characterization was conducted by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and sensing was performed using differential pulse voltammetry (DPV). The DPV peak current was used to quantify IL-6 in buffer, CSF, and serum in the range 1 pg mL^-1 < [IL-6] < 1 μg mL^-1. The IL-6 IDEA sensor achieved a limit of detection (LOD) of 1.63 pg mL^-1 in PBS, 2.34 pg mL^-1 in human CSF, and 11.83 pg mL^-1 in human serum. The sensor response is linear in the concentration range 10 pg mL^-1 < [IL-6] < 10 ng mL^-1, and the sensor is selective for IL-6 over other common cytokines, including IL-10 and TNF-α. EIS measurements showed that the resistance to charge transfer, R _CT, decreases upon IL-6 binding, an observation attributed to a structural change upon Ab-Ag binding that opens up the architecture so that the redox probe can more easily access the electrode surface. The IL-6 IDEA sensor can be used as a point-of-care diagnostic tool to deliver rapid results (∼3 min) in clinical settings for traumatic brain injury, and potentially address the unmet need for effective diagnostic and prognostic tools for other cytokine-related illnesses, such as sepsis and COVID-19 induced cytokine storms. Given the interdigitated electrode form factor, it is likely that the performance of the sensor can be further improved through redox cycling.

Downregulation of phosphoglycerate mutase 5 improves microglial inflammasome activation after traumatic brain injury

Traumatic brain injury (TBI) is considered as the most common cause of disability and death, and therefore an effective intervention of cascade pathology of secondary brain injury promptly can be a potential therapeutic direction for TBI prognosis. Further study of the physiological mechanism of TBI is urgent and important. Phosphoglycerate mutase 5 (Pgam5), a mitochondrial protein, mediate mitochondrial homeostasis, cellular senescence, and necroptosis. This study evaluated the effects of Pgam5 on neurological deficits and neuroinflammation of controlled cortical impact-induced TBI mouse model in vivo and LPS + ATP-induced microglia model in vitro. Pgam5 was overexpressed post-TBI. Pgam5 depletion reduced pyroptosis-related molecules and improved microglia activation, neuron damage, tissue lesion, and neurological dysfunctions in TBI mice. RNA-seq analysis and molecular biology experiments demonstrated that Pgam5 might regulate inflammatory responses by affecting the post-translational modification and protein expression of related genes, including Nlrp3, caspase1, Gsdmd, and Il-1β. In microglia, Pgam5-sh abrogated LPS + ATP-induced Il-1β secretion through Asc oligomerization-mediated caspase-1 activation, which was independent of Rip3. The data demonstrate the critical role Pgam5 plays in nerve injury in the progression of TBI, which regulates Asc polymerization and subsequently caspase1 activation, and thus reveals a fundamental mechanism linking microglial inflammasome activation to Asc/caspase1-generated Il-1β-mediated neuroinflammation. Thus, our data indicate Pgam5 worsens physiological and neurological outcomes post-TBI, which may be a potential therapeutic target to improve neuroinflammation after TBI.

Evaluation of Prognosis of Coma Patients With Acute Brain Injury by Electroencephalogram Bispectral Index Monitoring

BACKGROUND

The high mortality rate of comatose patients with traumatic brain injury is a prominent public health issue that negatively impacts patients and their families. Objective, reliable tools are needed to guide treatment decisions and prioritize resources.

OBJECTIVE

This study aimed to evaluate the prognostic value of the bispectral index (BIS) in comatose patients with severe brain injury.

METHODS

This was a retrospective cohort study of 84 patients with severe brain injury and Glasgow Coma Scale (GCS) scores of 8 and less treated from January 2015 to June 2017. Sedatives were withheld at least 24 hr before BIS scoring. The BIS value, GCS scores, and Full Outline of UnResponsiveness (FOUR) were monitored hourly for 48 hr. Based on the Glasgow Outcome Scale (GOS) score, the patients were divided into poor (GOS score: 1-2) and good prognosis groups (GOS score: 3-5). The correlation between BIS and prognosis was analyzed by logistic regression, and the receiver operating characteristic curves were plotted.

RESULTS

The mean (SD) of the BIS value: 54.63 (11.76), p = .000; and GCS score: 5.76 (1.87), p = .000, were higher in the good prognosis group than in the poor prognosis group. Lower BIS values and GCS scores were correlated with poorer prognosis. Based on the area under the curve of receiver operating characteristic curves, the optimal diagnostic cutoff value of the BIS was 43.6, and the associated sensitivity and specificity were 85.4% and 74.4%, respectively.

CONCLUSION

Taken together, our study indicates that BIS had good predictive value on prognosis. These findings suggested that BIS could be used to evaluate the severity and prognosis of severe brain injury.

CircLphn3 protects the blood-brain barrier in traumatic brain injury

Circular RNAs (circRNAs) are a new and large group of non-coding RNA molecules that are abundantly expressed in the central nervous system. However, very little is known about their roles in traumatic brain injury. In this study, we firstly screened differentially expressed circRNAs in normal and injured brain tissues of mice after traumatic brain injury. We found that the expression of circLphn3 was substantially decreased in mouse models of traumatic brain injury and in hemin-treated bEnd.3 (mouse brain cell line) cells. After overexpressing circLphn3 in bEnd.3 cells, the expression of the tight junction proteins, ZO-1, ZO-2, and occludin, was upregulated, and the expression of miR-185-5p was decreased. In bEnd.3 cells transfected with miR-185-5p mimics, the expression of ZO-1 was decreased. Dual-luciferase reporter assays showed that circLphn3 bound to miR-185-5p, and that miR-185-5p bound to ZO-1. Additionally, circLphn3 overexpression attenuated the hemin-induced high permeability of the in vitro bEnd.3 cell model of the blood-brain barrier, while miR-185-5p transfection increased the permeability. These findings suggest that circLphn3, as a molecular sponge of miR-185-5p, regulates tight junction proteins' expression after traumatic brain injury, and it thereby improves the permeability of the blood-brain barrier. This study was approved by the Animal Care and Use Committee of Chongqing Medical University of China (approval No. 2021-177) on March 22, 2021.

Serum hypoxia-inducible factor 1alpha emerges as a prognostic factor for severe traumatic brain injury

BACKGROUND

Hypoxia-inducible factor 1alpha (HIF-1α) is implicated in the cell's response to hypoxia. We investigated whether serum HIF-1α concentrations are correlated with the severity and clinical outcome of severe traumatic brain injury (sTBI).

METHODS

Serum HIF-1α concentrations were quantified in 104 sTBI patients and 80 healthy controls. Trauma severity was assessed using Glasgow coma scale (GCS). Glasgow outcome scale (GOS) score of 1-3 at post-trauma 90 days was defined as a poor outcome. Multivariate analyses were performed to discern the relationship between serum HIF-1α concentrations and outcome.

RESULTS

Patients displayed significantly higher serum HIF-1α concentrations than controls (median, 294.9 versus 102.7 pg/ml). HIF-1α concentrations were intimately related to GCS scores (r = -0.62) and GOS scores (r = -0.64). 48 patients (46.2%) experienced a poor outcome. Serum HIF-1α concentrations > 280.2 pg/ml significantly distinguished patients with the development of poor outcome with 77.1% sensitivity and 69.6% specificity (AUC, 0.750; 95% CI: 0.655-0.829). Serum HIF-1α concentrations > 280.2 pg/ml emerged as an independent predictor for poor outcome (OR: 4.179; 95% CI: 1.024-17.052).

CONCLUSIONS

Serum HIF-1α concentrations are tightly associated with trauma severity and poor 90-day outcome, substantializing serum HIF-1α as a promising prognostic biomarker for sTBI.

Dual-enzymatically cross-linked gelatin hydrogel promotes neural differentiation and neurotrophin secretion of bone marrow-derived mesenchymal stem cells for treatment of moderate traumatic brain injury

Traumatic brain injury (TBI) is one of the most devastating nervous injuries. Neural tissue engineering based on stem cells and bioactive scaffold is a promising but challenging approach for neural repair. A cutting-edge system with capability to control the fate of encapsulated stem cells is attractive to enhance neural regeneration after TBI. Herein, an injectable gelatin hydrogel dual-enzymatically cross-linked by horse radish peroxidase (HRP) and choline oxidase (ChOx) was performed as the neural scaffold to load murine bone marrow-derived mesenchymal stem cells (BMSC) for TBI treatment. The results of in vitro cellular experiments showed that low cross-linked gelatin hydrogel could obviously promote cellular viability, neural differentiation, and neurotrophins secretion of the loaded BMSC. In vivo tests on a TBI model of C57BL/6 mouse demonstrated that BMSC-laden gelatin hydrogel implants could significantly reduce the damaged area, ameliorate inflammation, attenuate neuronal apoptosis, facilitate survival and proliferation of endogenous neural cells, and promote the neurological function recovery of TBI mice. All data suggest that establishment of this three-dimensional (3D) gelatin hydrogel stem cell-loaded system is a promising therapeutic strategy for TBI or other neurological rehabilitation.

Therapeutic targets and molecular mechanism of calycosin for the treatment of cerebral ischemia/reperfusion injury

This study was designed to understand the pivotal anti-cerebral ischemia/reperfusion injury (CIRI) targets and pathways of calycosin through network pharmacology and molecular docking analyses. In this study, bioinformatics tools were employed to characterize and identify the pharmacological functions and mechanisms of calycosin for CIRI management. The network pharmacology data identified potential, merged CIRI-associated targets of calycosin including tumor protein p53 (TP53), protein kinase B (AKT1), vascular endothelial growth factor A (VEGFA), interleukin 6, tumor necrosis factor (TNF), and mitogen-activated protein kinase 1 (MAPK1). Molecular docking analysis indicated the binding efficacy of calycosin with three of the targets, namely TP53, AKT1, and VEGFA. The biological processes of calycosin for the treatment of CIRI are mainly involved in the improvement of endothelial cell proliferation and growth, inflammatory development, and cellular metabolism. In addition, the anti-CIRI actions of calycosin were primarily through suppression of the toll-like receptor, PI3K-AKT, TNF, MAPK, and VEGF signaling pathways. Taken together, the current bioinformatic findings revealed pivotal targets, biological functions, and pharmacological mechanisms of calycosin for the treatment of CIRI. In conclusion, calycosin, a functional phytoestrogen, can be potentially used for the treatment of CIRI in future clinical trials.

Development and Application of Medicine-Engineering Integration in the Rehabilitation of Traumatic Brain Injury

The rapid progress of the combination of medicine and engineering provides better chances for the clinical treatment and healthcare engineering. Traumatic brain injury (TBI) and its related symptoms have become a major global health problem. At present, these techniques has been widely used in the rehabilitation of TBI. In this review article, we summarizes the progress of the combination of medicine and industry in the rehabilitation of traumatic brain injury in recent years, mainly from the following aspects: artificial intelligence (AI), brain-computer interfaces (BCI), noninvasive brain stimulation (NIBS), and wearable-assisted devices. We believe the summary of this article can improve insight into the combination of medicine and industry in the rehabilitation of traumatic brain injury.

Omega-3 Fatty Acids and Vitamin D Decrease Plasma T-Tau, GFAP, and UCH-L1 in Experimental Traumatic Brain Injury

Traumatic brain injury (TBI) results in neuronal, axonal and glial damage. Interventions targeting neuroinflammation to enhance recovery from TBI are needed. Exercise is known to improve cognitive function in TBI patients. Omega-3 fatty acids and vitamin D reportedly reduce inflammation, and in combination, might improve TBI outcomes. This study examined how an anti-inflammatory diet affected plasma TBI biomarkers, voluntary exercise and behaviors following exposure to mild TBI (mTBI). Adult, male rats were individually housed in cages fitted with running wheels and daily running distance was recorded throughout the study. A modified weight drop method induced mTBI, and during 30 days post-injury, rats were fed diets supplemented with omega-3 fatty acids and vitamin D₃ (AIDM diet), or non-supplemented AIN-76A diets (CON diet). Behavioral tests were periodically conducted to assess functional deficits. Plasma levels of Total tau (T-tau), glial fibrillary acidic protein (GFAP), ubiquitin c-terminal hydrolase L1 (UCH-L1) and neurofilament light chain (NF-L) were measured at 48 h, 14 days, and 30 days post-injury. Fatty acid composition of food, plasma, and brain tissues was determined. In rats exposed to mTBI, NF-L levels were significantly elevated at 48 h post-injury (P < 0.005), and decreased to levels seen in uninjured rats by 14 days post-injury. T-tau, GFAP, and UCH-L1 plasma levels did not change at 48 h or 14 days post-injury. However, at 30 days post-injury, T-tau, GFAP and UCH-L1 all significantly increased in rats exposed to mTBI and fed CON diets (P < 0.005), but not in rats fed AIDM diets. Behavioral tests conducted post-injury showed that exercise counteracted cognitive deficits associated with mTBI. The AIDM diets significantly increased docosahexaenoic acid levels in plasma and brain tissue (P < 0.05), and in serum levels of vitamin D (P < 0.05). The temporal response of the four injury biomarkers examined is consistent with studies by others demonstrating acute and chronic neural tissue damage following exposure to TBI. The anti-inflammatory diet significantly altered the temporal profiles of plasma T-tau, GFAP, and UCH-L1 following mTBI. Voluntary exercise protected against mTBI-induced cognitive deficits, but had no impact on plasma levels of neurotrauma biomarkers. Thus, the prophylactic effect of exercise, when combined with an anti-inflammatory diet, may facilitate recovery in patients with mTBI.

Intelligent body behavior feature extraction based on convolution neural network in patients with craniocerebral injury

Patients with craniocerebral injury are in serious condition and inconvenient to take care of. This paper proposes a method of extracting the patient's body behavior feature based on convolution neural network, in order to reduce nursing workload and save hospital costs. The algorithm adopts double network model design, including the patient detection network model and the patient's body behavior feature extraction model. The algorithm is applied to the patient's body behavior detection system, so as to realize the recognition and monitoring of patients and improve the level of intelligent medical care for craniocerebral injury. Finally, the open source framework platform is used to test the patient behavior detection system. The experimental results show that the larger the test data set is, the higher the accuracy of patient body behavior feature extraction is. The average recognition rate of patient body behavior category is 97.8%, which verifies the effectiveness and correctness of the system. The application of convolution neural network connects image recognition with intelligent medical nursing, which provides reference and experience for intelligent medical nursing of patients with craniocerebral injury.

Role of Citicoline in the Management of Traumatic Brain Injury

Head injury is among the most devastating types of injury, specifically called Traumatic Brain Injury (TBI). There is a need to diminish the morbidity related with TBI and to improve the outcome of patients suffering TBI. Among the improvements in the treatment of TBI, neuroprotection is one of the upcoming improvements. Citicoline has been used in the management of brain ischemia related disorders, such as TBI. Citicoline has biochemical, pharmacological, and pharmacokinetic characteristics that make it a potentially useful neuroprotective drug for the management of TBI. A short review of these characteristics is included in this paper. Moreover, a narrative review of almost all the published or communicated studies performed with this drug in the management of patients with head injury is included. Based on the results obtained in these clinical studies, it is possible to conclude that citicoline is able to accelerate the recovery of consciousness and to improve the outcome of this kind of patient, with an excellent safety profile. Thus, citicoline could have a potential role in the management of TBI.

Traumatic Brain Injury Update

Traumatic brain injury is a devastating, life-changing event in most cases. After the primary brain insult, it is helpful to use evidence-based monitoring techniques to guide implementation of essential interventions to minimize secondary injury and thereby improve patient outcomes. An update on multimodal neuromonitoring is provided in this narrative review, with discussion of tools and techniques currently used in the treatment of patients with brain injury. Neuroprotective treatments, from the well-studied targeted temperature management to new potential therapeutics under investigation, such as glyburide, also are presented.

Niche Cells Crosstalk In Neuroinflammation After Traumatic Brain Injury

Traumatic brain injury (TBI) is recognized as the disease with high morbidity and disability around world in spite of the work ongoing in neural protection. Due to heterogeneity among the patients, it's still hard to acquire satisfying achievements in clinic. Neuroinflammation, which exists since primary injury occurs, with elusive duality, appear to be of significance from recovery of injury to neurogenesis. In recent years, studied have revealed that communication in neurogenic niche is more than “cell to cell” communication, and study on NSCs represent it as central role in the progress of neural regeneration. Hence, the neuroinflammation-affecting crosstalk after TBI, and clarifying definitive role of NSCs in the course of regeneration is a promising subject for researchers, for its great potential in overcoming the frustrating status quo in clinic, promoting welfare of TBI patient.

Bypassing TBI: Metabolic Surgery and the Link between Obesity and Traumatic Brain Injury-a Review

Obesity is a common outcome of traumatic brain injury (TBI) that exacerbates principal TBI symptom domains identified as common areas of post-TBI long-term dysfunction. Obesity is also associated with increased risk of later-life dementia and Alzheimer's disease. Patients with obesity and chronic TBI may be more vulnerable to long-term mental abnormalities. This review explores the question of whether weight loss induced by bariatric surgery could delay or perhaps even reverse the progression of mental deterioration. Bariatric surgery, with its induction of weight loss, remission of type 2 diabetes, and other expressions of the metabolic syndrome, improves metabolic efficiency, leads to reversal of brain lesions seen on imaging studies, and improves function. These observations suggest that metabolic/bariatric surgery may be a most effective therapy for TBI.

Correlations Between the Glasgow Score and the Survival Period in Patients with Severe Traumatic Brain Injury

Traumatic brain injury (TBI) contributes by 30% to the mortality induced by traumatic injuries, also being one of the major causes of invalidity worldwide. The clinical classification of the severity of mild, moderate or severe TBI is made according to the Glasgow scale, according to the patient's conscious state, motric changes, speech changes and eye opening. In our study, we evaluated the correlation between the Glasgow score at admission and the survival period of patients suffering from TBI, using the data recorded in the Forensic Medicine Institute of Craiova between 2011-2017 on 1005 cases with the diagnosis of death by TBI. We observed that TBI affects persons of all ages, starting from babies up to the elderly aged over 90 years old. Regarding the generation mechanism, most deaths were caused by fallings (438 cases, 43.58%), followed by car accidents (333 cases, representing 33.13%). The number of patients who presented a post-traumatic survival period was 802 (79.80%), of which 779 adults (77.51%) and 23 children (2.29%). Among these, 785 (78.11%-764 adults and 21 children) were hospitalized, while in 64.58% of the TBI patients there was recorded the Glasgow score at admission. 75% of the TBI patients in whom there was recorded the Glasgow score presented a 1st-4th coma degree, with a Glasgow score from 3 to 8 and only 25% had a slightly altered or preserved conscious state, with a Glasgow score=9-15. The survival period varied from less than 24 hours to over 15 days. In the hospitalized patients, there were performed emergency surgeries in 269 (26.76%) cases, the surgical intervention being temporized in 108 (10.74%) patients.

Acute Traumatic Brain Injury-Induced Neuroinflammatory Response and Neurovascular Disorders in the Brain

Acute traumatic brain injury (TBI) leads to neuroinflammation, neurodegeneration, cognitive decline, psychological disorders, increased blood-brain barrier (BBB) permeability, and microvascular damage in the brain. Inflammatory mediators secreted from activated glial cells, neurons, and mast cells are implicated in the pathogenesis of TBI through secondary brain damage. Abnormalities or damage to the neurovascular unit is the indication of secondary injuries in the brain after TBI. However, the precise mechanisms of molecular and ultrastructural neurovascular alterations involved in the pathogenesis of acute TBI are not yet clearly understood. Moreover, currently, there are no precision-targeted effective treatment options to prevent the sequelae of TBI. In this study, mice were subjected to closed head weight-drop-induced acute TBI and evaluated neuroinflammatory and neurovascular alterations in the brain by immunofluorescence staining or quantitation by enzyme-linked immunosorbent assay (ELISA) procedure. Mast cell stabilizer drug cromolyn was administered to inhibit the neuroinflammatory response of TBI. Results indicate decreased level of pericyte marker platelet-derived growth factor receptor-beta (PDGFR-β) and BBB-associated tight junction proteins junctional adhesion molecule-A (JAM-A) and zonula occludens-1 (ZO-1) in the brains 7 days after weight-drop-induced acute TBI as compared with the brains from sham control mice indicating acute TBI-associated BBB/tight junction protein disruption. Further, the administration of cromolyn drug significantly inhibited acute TBI-associated decrease of PDGFR-β, JAM-A, and ZO-1 in the brain. These findings suggest that acute TBI causes BBB/tight junction damage and that cromolyn administration could protect this acute TBI-induced brain damage as well as its long-time consequences.

Mast Cell Activation, Neuroinflammation, and Tight Junction Protein Derangement in Acute Traumatic Brain Injury

Traumatic brain injury (TBI) is one of the major health problems worldwide that causes death or permanent disability through primary and secondary damages in the brain. TBI causes primary brain damage and activates glial cells and immune and inflammatory cells, including mast cells in the brain associated with neuroinflammatory responses that cause secondary brain damage. Though the survival rate and the neurological deficiencies have shown significant improvement in many TBI patients with newer therapeutic options, the underlying pathophysiology of TBI-mediated neuroinflammation, neurodegeneration, and cognitive dysfunctions is understudied. In this study, we analyzed mast cells and neuroinflammation in weight drop-induced TBI. We analyzed mast cell activation by toluidine blue staining, serum chemokine C-C motif ligand 2 (CCL2) level by enzyme-linked immunosorbent assay (ELISA), and proteinase-activated receptor-2 (PAR-2), a mast cell and inflammation-associated protein, vascular endothelial growth factor receptor 2 (VEGFR2), and blood-brain barrier tight junction-associated claudin 5 and Zonula occludens-1 (ZO-1) protein expression in the brains of TBI mice. Mast cell activation and its numbers increased in the brains of 24 h and 72 h TBI when compared with sham control brains without TBI. Mouse brains after TBI show increased CCL2, PAR-2, and VEGFR2 expression and derangement of claudin 5 and ZO-1 expression as compared with sham control brains. TBI can cause mast cell activation, neuroinflammation, and derangement of tight junction proteins associated with increased BBB permeability. We suggest that inhibition of mast cell activation can suppress neuroimmune responses and glial cell activation-associated neuroinflammation and neurodegeneration in TBI.

Brain Tissue Oxygen and Cerebrovascular Reactivity in Traumatic Brain Injury: A Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury Exploratory Analysis of Insult Burden

Pressure reactivity index (PRx) and brain tissue oxygen (PbtO₂) are associated with outcome in traumatic brain injury (TBI). This study explores the relationship between PRx and PbtO₂ in adult moderate/severe TBI. Using the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) high resolution intensive care unit (ICU) sub-study cohort, we evaluated those patients with archived high-frequency digital intraparenchymal intracranial pressure (ICP) and PbtO₂ monitoring data of, a minimum of 6 h in duration, and the presence of a 6 month Glasgow Outcome Scale -Extended (GOSE) score. Digital physiological signals were processed for ICP, PbtO₂, and PRx, with the % time above/below defined thresholds determined. The duration of ICP, PbtO₂, and PRx derangements was characterized. Associations with dichotomized 6-month GOSE (alive/dead, and favorable/unfavorable outcome; ≤ 4 = unfavorable), were assessed. A total of 43 patients were included. Severely impaired cerebrovascular reactivity was seen during elevated ICP and low PbtO₂ episodes. However, most of the acute ICU physiological derangements were impaired cerebrovascular reactivity, not ICP elevations or low PbtO₂ episodes. Low PbtO₂ without PRx impairment was rarely seen. % time spent above PRx threshold was associated with mortality at 6 months for thresholds of 0 (area under the curve [AUC] 0.734, p = 0.003), > +0.25 (AUC 0.747, p = 0.002) and > +0.35 (AUC 0.745, p = 0.002). Similar relationships were not seen for % time with ICP >20 mm Hg, and PbtO₂ < 20 mm Hg in this cohort. Extreme impairment in cerebrovascular reactivity is seen during concurrent episodes of elevated ICP and low PbtO₂. However, the majority of the deranged cerebral physiology seen during the acute ICU phase is impairment in cerebrovascular reactivity, with most impairment occurring in the presence of normal PbtO₂ levels. Measures of cerebrovascular reactivity appear to display the most consistent associations with global outcome in TBI, compared with ICP and PbtO₂.

Severe traumatic brain injury (TBI) - a seven-year comparative study in a Department of Forensic Medicine

Deaths caused by traumatic brain injury (TBI) increase in incidence every year worldwidely, mainly in developing countries. Thus, World Health Organization (WHO) estimates that in 2020, TBI will become the third main cause of death. In our study, we evaluated the deaths caused by TBI recorded within the Institute of Forensic Medicine of Craiova, Romania, between 2011 and 2017. Therefore, according to age, the cases were divided into two groups: people aged 0-18 years old (including 18 years old) and people aged over 18 years old (a total of 1005 cases, of which 971 were adults and 34 included in the age group 0-18 years old). In both groups, most patients were males from the rural area. In adults, falling was the main legal entity of the cases, followed by car accidents (which were the most common in children). In both groups, in car accidents, most of them were pedestrians and car occupants. Various aggressions (human, animal, self-injury) were found in 94 (9.68%) of the adult cases and in four (11.76%) cases of children. Another parameter under study was the blood alcohol concentration, being observed that most of the subjects with positive blood alcohol content died from car accidents. By evaluating the Glasgow Coma Scale (GCS) score as a prognostic factor, most of the subjects presented third and fourth degree coma at admission; still, 5.14% of the adult patients who deceased had GCS score 15 at admission, death occurring probably by developing some intracranial hematomas in time. Regarding the morphology of the lesions, most patients presented various forms of cranial fractures, 185 (19.05%) adults in association with extradural hemorrhages∕hematomas, but also there were four cases with extradural hematomas without any cranial fractures. In children, there was highlighted a single case of extradural hemorrhage under the fracture line. Seventy-eight percent of the adults and 44.12% of children presented subdural hematomas associated with other meningo-cerebral lesions. Also, 83.63% of the adults and 97% of children presented brain contusions. In both groups, brain laceration was observed in approximately 50% of the cases.