Traumatic brain injury: classification, models, and markers

Hydrogel-exosome system in tissue engineering: A promising therapeutic strategy

Characterized by their pivotal roles in cell-to-cell communication, cell proliferation, and immune regulation during tissue repair, exosomes have emerged as a promising avenue for "cell-free therapy" in clinical applications. Hydrogels, possessing commendable biocompatibility, degradability, adjustability, and physical properties akin to biological tissues, have also found extensive utility in tissue engineering and regenerative repair. The synergistic combination of exosomes and hydrogels holds the potential not only to enhance the efficiency of exosomes but also to collaboratively advance the tissue repair process. This review has summarized the advancements made over the past decade in the research of hydrogel-exosome systems for regenerating various tissues including skin, bone, cartilage, nerves and tendons, with a focus on the methods for encapsulating and releasing exosomes within the hydrogels. It has also critically examined the gaps and limitations in current research, whilst proposed future directions and potential applications of this innovative approach.

Crocetin protects mouse brain from apoptosis in traumatic brain injury model through activation of autophagy

BACKGROUND

Autophagy is recognized as a promising therapeutic target for traumatic brain injury (TBI). Crocetin is an aglycone of crocin naturally occurring in saffron and has been found to alleviate brain injury diseases. However, whether crocetin affects autophagy after TBI remains unknown. Therefore, we explore crocetin roles in autophagy after TBI.

METHODS

We used a weight-dropped model to induce TBI in C57BL/6J mice. Neurological severity scoring (NSS) and grip tests were used to evaluate the neurological level of injury. Brain edema, neuronal apoptosis, neuroinflammation and autophagy were detected by measurements of brain water content, TUNEL staining, ELISA kits and western blotting.

RESULTS

Crocetin ameliorated neurological dysfunctions and brain edema after TBI. Crocetin reduced neuronal apoptosis and neuroinflammation and enhanced autophagy after TBI.

CONCLUSION

Crocetin alleviates TBI by inhibiting neuronal apoptosis and neuroinflammation and activating autophagy.

Mortality and discharge disposition among older adults with moderate to severe traumatic brain injury

PURPOSE

This study examined the research on older adults with a moderate to severe traumatic brain injury (TBI), with a focus on mortality and discharge disposition.

METHOD

Systematic searches were conducted in MEDLINE, CINAHL, EMBASE and PsycINFO for studies up to April 2022 in accordance with PRISMA guidelines.

RESULTS

64 studies, published from 1992 to 2022, met the inclusion criteria. Mortality was higher for older adults ≥60 years old than for their younger counterparts; with a dramatic increase for those ≥80 yr, with rates as high as 93 %. Similar findings were reported regarding mortality in intensive care, surgical mortality, and mortality post-hospital discharge; with an 80 % rate at 1-year post-discharge. Up to 68.4 % of older adults were discharged home; when compared to younger adults, those ≥65 years were less likely to be discharged home (50-51 %), compared to those <64 years (77 %). Older adults were also more likely to be discharged to long-term care (up to 31.6 %), skilled nursing facilities (up to 46.1 %), inpatient rehabilitation (up to 26.9 %), and palliative or hospice care (up to 58 %).

CONCLUSION

Given their vulnerability, optimizing outcomes for older adults with moderate-severe TBI across the healthcare continuum is critical.

Hsa_circ_0018401 and miR-127-5p Expressions Are Diagnostic and Prognostic Markers for Traumatic Brain Injury (TBI) in Trauma Patients

This study investigated the potentials of hsa_circ_0018401 and miR-127-5p in traumatic brain injury (TBI) diagnosis, stratification and outcome prediction. A retrospective analysis of clinical data and blood samples of n = 109 TBI patients was performed. Expression levels of hsa_circ_0018401 and miR-127-5p were measured using Real-time PCR. The diagnostic values, as well as the values in TBI stratification, of hsa_circ_0018401 and miR-127-5p were assessed by receiver operating characteristic analyses. The prognostic impacts were investigated for one-year endpoint events using multivariable Cox regression analyses and receiver operating characteristic analysis. The target genes for miR-127-5p were predicted. An upregulation of hsa_circ_0018401 and a downregulation of miR-127-5p expression was detected in patients with TBI, and the highest or lowest levels were found in moderate/severe TBI. A negative correlation between miR-423-3p level and Dual luciferase reporter assay verified the binding relationship between hsa_circ_0018401 and miR-127-5p. Hsa_circ_0018401 and miR-127-5p, used alone or combinedly, showed clinical values for TBI diagnosis and stratification, as well as outcome prediction. The proteins for target genes covered TBI-related functions and pathways. Therefore, hsa_circ_0018401 and miR-127-5p could represent promising new biomarkers to identify TBI from healthy, moderate/severe TBI from mild TBI, as well as to predict the TBI outcome.

The effect of dexmedetomidine on the postoperative recovery of patients with severe traumatic brain injury undergoing craniotomy treatment: a retrospective study

BACKGROUND

Traumatic brain injury (TBI) has been a worldwide problem for neurosurgeons. Patients with severe TBI may undergo craniotomy. These patients often require sedation after craniotomy. Dexmedetomidine (DEX) has been used in patients receiving anesthesia and in intensive care units. Not much is known about the postoperative effect of DEX in patients with severe TBIs undergoing craniotomy. The purpose of this study was to explore the effects of postoperative DEX administration on severe TBI patients who underwent craniotomy.

METHODS

Patients who underwent craniectomy for severe TBI at our hospital between January 2019 and February 2022 were included in this study. The patients were admitted to the intensive care unit (ICU) after surgery to receive sedative medication. The patients were then divided into DEX and control groups. We analyzed the sedation, hemodynamics, and other conditions of the patients (hypoxemia, duration of ventilation during endotracheal intubation, whether tracheotomy was performed, and the duration in the ICU) during their ICU stay. Other conditions, such as delirium after the patients were transferred to the general ward, were also analyzed.

RESULTS

A total of 122 patients were included in this study. Among them, 53 patients received DEX, and the remaining 69 did not. The incidence of delirium in the general ward in the DEX group was significantly lower than that in the control group (P < 0.05). The incidence of bradycardia in the control group was significantly lower than that in the DEX group (P < 0.05). Other data from the DEX group and the control group (hypotension, hypoxemia, etc.) were not significantly different (P > 0.05).

CONCLUSION

The use of DEX in the ICU can effectively reduce the incidence of delirium in patients who return to the general ward after craniotomy. DEX had no adverse effect on the prognosis of patients other than causing bradycardia.

Antibody-labeled gold nanoparticle based resonance Rayleigh scattering detection of S100B

Traumatic brain injury (TBI) is a sudden brain injury due to an external force that causes a large number of deaths and permanent disabilities every year. S100B has been recognized as a potential objective quantitative biomarker for screening the prognosis of TBI and severe head injury. In this article, an anti-S100B monoclonal antibody was immobilized on cysteamine (Cy) functionalized gold nanoparticles (AuNPs) by EDC-NHS chemistry, which enabled S100B resonance Rayleigh scattering (RRS) detection based on antibody-labeled gold nanoparticles. The prepared conjugates were characterized by ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Based on the specific binding of the antibody and antigen, the RRS intensities at 381 nm and 541 nm wavelengths were significantly enhanced, and thus a dual wavelength overlapping resonance Rayleigh scattering (DWO-RRS) method was established. The scattering intensity of the two overlapping peaks was proportional to the concentration of S100B in the range of 0.05-4.5 ng mL-1 with a detection limit of 0.002 ng mL-1. The proposed DWO-RRS method is time-saving, simple, sensitive, and can be used to determine the concentration of S100B in human serum with satisfactory results, which has a promising application in the early diagnosis of TBI.

An overview of preclinical models of traumatic brain injury (TBI): relevance to pathophysiological mechanisms

Background

Traumatic brain injury (TBI) is a major cause of morbidity and mortality, affecting millions annually worldwide. Although the majority of TBI patients return to premorbid baseline, a subset of patient can develop persistent and often debilitating neurocognitive and behavioral changes. The etiology of TBI within the clinical setting is inherently heterogenous, ranging from sport related injuries, fall related injuries and motor vehicle accidents in the civilian setting, to blast injuries in the military setting.

Objective

Animal models of TBI, offer the distinct advantage of controlling for injury modality, duration and severity. Furthermore, preclinical models of TBI have provided the necessary temporal opportunity to study the chronic neuropathological sequelae of TBI, including neurodegenerative sequelae such as tauopathy and neuroinflammation within the finite experimental timeline. Despite the high prevalence of TBI, there are currently no disease modifying regimen for TBI, and the current clinical treatments remain largely symptom based. The preclinical models have provided the necessary biological substrate to examine the disease modifying effect of various pharmacological agents and have imperative translational value.

Methods

The current review will include a comprehensive survey of well-established preclinical models, including classic preclinical models including weight drop, blast injury, fluid percussion injury, controlled cortical impact injury, as well as more novel injury models including closed-head impact model of engineered rotational acceleration (CHIMERA) models and closed-head projectile concussive impact model (PCI). In addition to rodent preclinical models, the review will include an overview of other species including large animal models and Drosophila.

Results

There are major neuropathological perturbations post TBI captured in various preclinical models, which include neuroinflammation, calcium dysregulation, tauopathy, mitochondrial dysfunction and oxidative stress, axonopathy, as well as glymphatic system disruption.

Conclusion

The preclinical models of TBI continue to offer valuable translational insight, as well as essential neurobiological basis to examine specific disease modifying therapeutic regimen.

Mortality Predictors for Adult Patients with Mild-to-Moderate Traumatic Brain Injury: A Literature Review

Traumatic brain injuries (TBIs) represent a significant public health concern, with mild-to-moderate cases comprising a substantial portion of incidents. Understanding the predictors of mortality among adult patients with mild-to-moderate TBIs is crucial for optimizing clinical management and improving outcomes. This literature review examines the existing research to identify and analyze the mortality predictors in this patient population. Through a comprehensive review of peer-reviewed articles and clinical studies, key prognostic factors, such as age, Glasgow Coma Scale (GCS) score, the presence of intracranial hemorrhage, pupillary reactivity, and coexisting medical conditions, are explored. Additionally, this review investigates the role of advanced imaging modalities, biomarkers, and scoring systems in predicting mortality following a mild-to-moderate TBI. By synthesizing the findings from diverse studies, this review aims to provide clinicians and researchers with valuable insights into the factors influencing mortality outcomes in adult patients with a mild-to-moderate TBI, thus facilitating more informed decision making and targeted interventions in clinical practice.

Increasing Risk of Dementia Among Patients with Subsequent Epilepsy Within 2 Years Post-Traumatic Brain Injury: A Population-Based Case-Control Study

Background

Although the association between neurodegenerative diseases, such as dementia, and traumatic brain injury (TBI) has long been known, the association between dementia and TBI with epilepsy has been controversial.

Aim

This data-driven population-based study is designed to investigate the association between dementia and epilepsy after TBI within a 2-year period.

Methods

This case-control cohort study was conducted using the Longitudinal Health Insurance Database 2000 (LHID2000). We included 784 individuals ambulatory or hospitalized for TBI with epilepsy from 2001 to 2011, compared with 2992 patients with TBI without epilepsy who were matched for characteristics including sex, age, and healthcare resource use index date. Every participant was followed up for 5 years to ascertain any dementia development. Data were stratified and analyzed using the Cox proportional hazards regression.

Results

Through the 5-year follow-up period, 39 patients (5.21%) with TBI with epilepsy and 55 (1.53%) with TBI without epilepsy developed dementia. TBI with epilepsy was independently associated with a >3.03 times risk of dementia after correcting for age, sex, and comorbidities.

Conclusion

These findings suggest an increased risk of dementia in patients with TBI with epilepsy. Our research recommends that individuals with TBI and epilepsy be monitored more intensively.

Exploring Heparan Sulfate Proteoglycans as Mediators of Human Mesenchymal Stem Cell Neurogenesis

Alzheimer's disease (AD) and traumatic brain injury (TBI) are major public health issues worldwide, with over 38 million people living with AD and approximately 48 million people (27-69 million) experiencing TBI annually. Neurodegenerative conditions are characterised by the accumulation of neurotoxic amyloid beta (Aβ) and microtubule-associated protein Tau (Tau) with current treatments focused on managing symptoms rather than addressing the underlying cause. Heparan sulfate proteoglycans (HSPGs) are a diverse family of macromolecules that interact with various proteins and ligands and promote neurogenesis, a process where new neural cells are formed from stem cells. The syndecan (SDC) and glypican (GPC) HSPGs have been implicated in AD pathogenesis, acting as drivers of disease, as well as potential therapeutic targets. Human mesenchymal stem cells (hMSCs) provide an attractive therapeutic option for studying and potentially treating neurodegenerative diseases due to their relative ease of isolation and subsequent extensive in vitro expansive potential. Understanding how HSPGs regulate protein aggregation, a key feature of neurodegenerative disorders, is essential to unravelling the underlying disease processes of AD and TBI, as well as any link between these two neurological disorders. Further research may validate HSPG, specifically SDCs or GPCs, use as neurodegenerative disease targets, either via driving hMSC stem cell therapy or direct targeting.

Abnormal levels of expression of microRNAs in peripheral blood of patients with traumatic brain injury are induced by microglial activation and correlated with severity of injury

BACKGROUND

Microglia play a crucial role in regulating the progression of traumatic brain injury (TBI). In specific, microglia can self-activate and secrete various substances that exacerbate or alleviate the neuroimmune response to TBI. In addition, microRNAs (miRNAs) are involved in the functional regulation of microglia. However, molecular markers that reflect the dynamics of TBI have not yet been found in peripheral tissues.

METHODS

Paired samples of peripheral blood were collected from patients with TBI before and after treatment. Next-generation sequencing and bioinformatics analysis were used to identify the main pathways and biological functions of TBI-related miRNAs in the samples. Moreover, lipopolysaccharide-treated human microglia were used to construct a cellular immune-activation model. This was combined with analysis of peripheral blood samples to screen for highly expressed miRNAs derived from activated microglia after TBI treatment. Quantitative reverse-transcriptase polymerase chain reaction was used to determine the expression levels of these miRNAs, allowing their relationship with the severity of TBI to be examined. Receiver operating characteristic (ROC) curves were constructed to analyse the clinical utility of these miRNAs for determining the extent of TBI.

RESULTS

Sequencing results showed that 37 miRNAs were differentially expressed in peripheral blood samples from patients with TBI before and after treatment, with 17 miRNAs being upregulated and 20 miRNAs being downregulated after treatment. The expression profiles of these miRNAs were verified in microglial inflammation models and in the abovementioned peripheral blood samples. The results showed that hsa-miR-122-5p and hsa-miR-193b-3p were highly expressed in the peripheral blood of patients with TBI after treatment and that the expression levels of these miRNAs were correlated with the patients' scores on the Glasgow Coma Scale. ROC curve analysis revealed that abnormally high levels of expression of hsa-miR-122-5p and hsa-miR-193b-3p in peripheral blood have some clinical utility for distinguishing different extents of TBI and thus could serve as biomarkers of TBI.

CONCLUSION

Abnormally high levels of expression of hsa-miR-122-5p and hsa-miR-193b-3p in the peripheral blood of patients with TBI were due to the activation of microglia and correlated with the severity of TBI. This discovery may help to increase understanding of the molecular pathology of TBI and guide the development of new strategies for TBI therapy based on microglial function.

Tetrahydrocurcumin Protects Against GSK3β/PTEN/PI3K/Akt-Mediated Neuroinflammatory Responses and Microglial Polarization Following Traumatic Brain Injury

Tetrahydrocurcumin (THC) and microglial polarization play crucial roles in neuroprotection during traumatic brain injury (TBI). However, whether THC regulates microglial polarization in TBI is unknown. Thus, we intended to analyze the functions and mechanism of THC in nerve injury after TBI via the regulation of microglial polarization. A TBI rat model was established, and modified neurological function score (mNSS), brain water content, Nissl staining, and Fluoro-Jade B (FJB) staining were used to evaluate neurological function. The expression of the M1-linked markers CD16 and CD86, as well as the M2-associated markers CD206 and YM-1, was analyzed via qRT-PCR, western blotting, and immunofluorescence. The levels of inflammatory cytokines were assessed via ELISA. Primary microglia were isolated from the brain and treated with lipopolysaccharide (LPS) to induce injury. TUNEL staining was used to measure primary microglial apoptosis. The expression of GSK3β, PTEN, and PI3K/Akt pathway proteins was detected via western blotting. TBI induced nerve injury, while THC improved neurological function recovery after TBI. Further analysis indicated that THC enhanced M2 microglial polarization and attenuated the inflammatory reaction mediated by microglia both in vitro and in vivo. Moreover, we found that THC promoted the M2 microglial phenotype through upregulating GSK3β expression. Additionally, we proved that GSK3β activated the PI3K/Akt pathway by phosphorylating PTEN. In conclusion, we demonstrated that THC protected against nerve injury after TBI via microglial polarization via the GSK3B/PTEN/PI3K/Akt signaling axis, suggesting the potential of THC for TBI treatment by promoting microglial M2 polarization.

Functional recovery following traumatic brain injury in rats is enhanced by oral supplementation with bovine thymus extract

Traumatic brain injury (TBI) is one of the leading causes of death worldwide. There are currently no effective treatments for TBI, and trauma survivors suffer from a variety of long-lasting health consequences. With nutritional support recently emerging as a vital step in improving TBI patients' outcomes, we sought to evaluate the potential therapeutic benefits of nutritional supplements derived from bovine thymus gland, which can deliver a variety of nutrients and bioactive molecules. In a rat model of controlled cortical impact (CCI), we determined that animals supplemented with a nuclear fraction of bovine thymus (TNF) display greatly improved performance on beam balance and spatial memory tests following CCI. Using RNA-Seq, we identified an array of signaling pathways that are modulated by TNF supplementation in rat hippocampus, including those involved in the process of autophagy. We further show that bovine thymus-derived extracts contain antigens found in neural tissues and that supplementation of rats with thymus extracts induces production of serum IgG antibodies against neuronal and glial antigens, which may explain the enhanced animal recovery following CCI through possible oral tolerance mechanism. Collectively, our data demonstrate, for the first time, the potency of a nutritional supplement containing nuclear fraction of bovine thymus in enhancing the functional recovery from TBI.

Therapeutic effects of anti-diabetic drugs on traumatic brain injury

AIMS

In this narrative review, we have analyzed and synthesized current studies relating to the effects of anti-diabetic drugs on traumatic brain injury (TBI) complications.

METHODS

Eligible studies were collected from Scopus, Google Scholar, PubMed, and Cochrane Library for clinical, in-vivo, and in-vitro studies published on the impact of anti-diabetic drugs on TBI.

RESULTS

Traumatic brain injury (TBI) is a serious brain disease that is caused by any type of trauma. The pathophysiology of TBI is not yet fully understood, though physical injury and inflammatory events have been implicated in TBI progression. Several signaling pathways are known to play pivotal roles in TBI injuries, including Nuclear factor erythroid 2-related factor 2 (Nrf2), High mobility group box 1 protein/Nuclear factor kappa B (HMGB1/NF-κB), Adiponectin, Mammalian Target of Rapamycin (mTOR), Toll-Like Receptor (TLR), Wnt/β-catenin, Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT), Nod-like receptor protein3 (NLRP3) inflammasome, Phosphoglycerate kinase 1/Kelch-like ECH-associated protein 1 (PGK1/KEAP1)/Nrf2, and Mitogen-activated protein kinase (MAPK) . Recent studies suggest that oral anti-diabetic drugs such as biguanides, thiazolidinediones (TZDs), sulfonylureas (SUs), sodium-glucose cotransporter-2 inhibitors (SGLT2is), dipeptidyl peptidase-4 inhibitors (DPPIs), meglitinides, and alpha-glucosidase inhibitors (AGIs) could have beneficial effects in the management of TBI complications. These drugs may downregulate the inflammatory pathways and induce antioxidant signaling pathways, thus alleviating complications of TBI.

CONCLUSION

Based on this comprehensive literature review, antidiabetic medications might be considered in the TBI treatment protocol. However, evidence from clinical trials in patients with TBI is still warranted.

Traumatic Brain Injury Induces Nociceptin/Orphanin FQ and Nociceptin Opioid Peptide Receptor Expression within 24 Hours

Traumatic brain injury (TBI) is a major cause of mortality and disability around the world, for which no treatment has been found. Nociceptin/Orphanin FQ (N/OFQ) and the nociceptin opioid peptide (NOP) receptor are rapidly increased in response to fluid percussion, stab injury, and controlled cortical impact (CCI) TBI. TBI-induced upregulation of N/OFQ contributes to cerebrovascular impairment, increased excitotoxicity, and neurobehavioral deficits. Our objective was to identify changes in N/OFQ and NOP receptor peptide, protein, and mRNA relative to the expression of injury markers and extracellular regulated kinase (ERK) 24 h following mild (mTBI) and moderate TBI (ModTBI) in wildtype (WT) and NOP receptor-knockout (KO) rats. N/OFQ was quantified by radioimmunoassay, mRNA expression was assessed using real-time PCR and protein levels were determined by immunoblot analysis. This study revealed increased N/OFQ mRNA and peptide levels in the CSF and ipsilateral tissue of WT, but not KO, rats 24 h post-TBI; NOP receptor mRNA increased after ModTBI. Cofilin-1 activation increased in the brain tissue of WT but not KO rats, ERK activation increased in all rats following ModTBI; no changes in injury marker levels were noted in brain tissue at this time. In conclusion, this study elucidates transcriptional and translational changes in the N/OFQ-NOP receptor system relative to TBI-induced neurological deficits and initiation of signaling cascades that support the investigation of the NOP receptor as a therapeutic target for TBI.

Severe traumatic brain injury and acute kidney injury patients: factors associated with in-hospital mortality and unfavorable outcomes

OBJECTIVE

The purpose of this study was to identify the occurrence of AKI, and factors associated with in-hospital mortality and unfavorable outcomes in patients with severe traumatic brain injury (TBI) and acute kidney injury (AKI) severity.

METHOD

A retrospective cohort study which analyzed data with severe TBI between 2013 and 2017. We examined demographic and clinical information, and outcome by in-hospital mortality, and the Glasgow Outcome Scale six months after TBI. We associated factors to in-hospital mortality and unfavorable outcome in severe TBI and AKI with an association test.

RESULTS

A total of 219 patients were selected, 39.3% had an AKI, and several factors associated with AKI occurrence after severe TBI. Stage 2 or 3 of AKI (OR 12.489; 95% CI = 4.45-37.94) were independent risk for both outcomes in multivariable models, severity injury by the New Trauma Injury Severity Score (OR 0.97; 95% CI = 0.96-0.99) for mortality, and the New Injury Severity Score (OR1.07; 95% CI = 1.04-1.10) and Trauma and Injury Severity Score (OR = 0.98; 95% CI = 0.965-0.997) for unfavorable outcome.

CONCLUSION

The findings of our study confirmed that AKI severity and severity of injury was also related to increased mortality and unfavorable outcome after severe TBI.

Use of Virtual Reality in Patients with Acquired Brain Injury: A Systematic Review

BACKGROUND AND OBJECTIVES

ABI is found in all societies as the most severe, disabling neurological disorder. A cognitive rehabilitation program is essential for the clinical recovery of these patients, improving functional outcomes and quality of life. Modern technologies such as virtual reality (VR) offer several advantages over traditional therapies, including the ability to engage people in simulated performance of functional tasks. This review will examine the studies in which virtual reality has been used as an aid, technique, or intervention in patients with acquired brain injury.

MATERIALS AND METHODS

Studies were identified from an online search of PubMed, Cochrane Library, and Web of Science databases.

RESULTS

We found that TBI patients responded positively to VR treatment depending on the damaged or impaired cognitive and motor functions they acquired. It is now a tool that is available in the rehabilitation of these patients and supports the recovery of various motor and cognitive functions.

CONCLUSIONS

This review has shown that VR is an intervention technique that increasingly exists in clinical rehabilitation practice for ABI patients. The device uses advanced technologies that can cause general changes in cognitive, motor, and psychological aspects and create a simulated environment that can partially restore these functions and behaviors, as well as the behaviors of everyday life.

Polypathologies and Animal Models of Traumatic Brain Injury

Traumatic brain injury (TBI) is an important health issue for the worldwide population, as it causes long-term pathological consequences for a diverse group of individuals. We are yet to fully elucidate the significance of TBI polypathologies, such as neuroinflammation and tau hyperphosphorylation, and their contribution to the development of chronic traumatic encephalopathy (CTE) and other neurological conditions. To advance our understanding of TBI, it is necessary to replicate TBI in preclinical models. Commonly used animal models include the weight drop model; these methods model human TBI in various ways and in different animal species. However, animal models have not demonstrated their clinical utility for identifying therapeutic interventions. Many interventions that were successful in improving outcomes for animal models did not translate into clinical benefit for patients. It is important to review current animal models and discuss their strengths and limitations within a TBI context. Modelling human TBI in animals encounters numerous challenges, yet despite these barriers, the TBI research community is working to overcome these difficulties. Developments include advances in biomarkers, standardising, and refining existing models. This progress will improve our ability to model TBI in animals and, therefore, enhance our understanding of TBI and, potentially, how to treat it.

Total recall: the role of PIDDosome components in neurodegeneration

The PIDDosome is a multiprotein complex that includes p53-induced protein with a death domain 1 (PIDD1), receptor-interacting protein-associated ICH-1/CED-3 homologous protein with a death domain (RAIDD), and caspase-2, the activation of which is driven by PIDDosome assembly. In addition to the key role of the PIDDosome in the regulation of cell differentiation, tissue homeostasis, and organogenesis and regeneration, caspase-2, RAIDD and PIDD1 engagement in neuronal development was shown. Here, we focus on the involvement of PIDDosome components in neurodegenerative disorders, including retinal neuropathies, different types of brain damage, and Alzheimer's disease (AD), Huntington's disease (HD), and Lewy body disease. We also discuss pathogenic variants of PIDD1, RAIDD, and caspase-2 that are associated with intellectual, behavioral, and psychological abnormalities, together with prospective PIDDosome inhibition strategies and their potential clinical application.

Intranasal Insulin Alleviates Traumatic Brain Injury by Inhibiting Autophagy and Endoplasmic Reticulum Stress-mediated Apoptosis Through the PI3K/Akt/mTOR Signaling Pathway

Intranasal insulin reduces lesion size and enhances memory capacity in traumatic brain injury (TBI) models, but the molecular mechanisms behind this neuroprotective action not yet understood. Here we used Feeney's free-falling method to construct TBI mouse models and administrated intranasal insulin, rapamycin, insulin and rapamycin, or normal saline to assess their effects on neurological functions, cerebral edema, and the expression of Iba1 in microglia through immunofluorescence assay. We also measured concentrations of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the brain using enzyme immunosorbent assay, investigated apoptosis with TUNEL staining and Western blotting, and evaluated autophagy, endoplasmic reticulum (ER) stress, and PI3K/Akt/mTOR signaling pathway with Western blotting. The autophagosome was assessed through transmission electron microscopy. Our findings demonstrated that intranasal insulin promoted neurological recovery, decreased brain swelling, and reduced injury lesions on days 1, 3, and 7 post TBI. Moreover, intranasal insulin reduced microglia activation and the concentration of IL-1β or TNF-α on the same days. Through Western blotting and transmission electron microscopy, we observed that intranasal insulin suppressed autophagy while activating the PI3K/AKT/mTOR signaling pathway on days 1 and 3 post TBI. TUNEL assay and Western blotting also indicated that intranasal insulin inhibited ER stress-mediated apoptosis. Interestingly, the mTOR inhibitor rapamycin partially blocked the pro-autophagy and anti-apoptosis effects of intranasal insulin both on days 1 and 3 post TBI. Our results suggest that intranasal insulin can ameliorate TBI by regulating autophagy and ER stress-mediated apoptosis through the PI3K/AKT/mTOR signaling pathway, providing a promising therapeutic strategy for TBI.

Clinical Theragnostic Signature of Extracellular Vesicles in Traumatic Brain Injury (TBI)

Traumatic brain injury (TBI) is a common cause of disability and fatality worldwide. Depending on the clinical presentation, it is a type of acquired brain damage that can be mild, moderate, or severe. The degree of patient's discomfort, prognosis, therapeutic approach, survival rates, and recurrence can all be strongly impacted by an accurate diagnosis made early on. The Glasgow Coma Scale (GCS), along with neuroimaging (MRI (Magnetic Resonance Imaging) and CT scan), is a neurological assessment tools used to evaluate and categorize the severity of TBI based on the patient's level of consciousness, eye opening, and motor response. Extracellular vesicles (EVs) are a growing domain, explaining neurological complications in a more detailed manner. EVs, in general, play a role in cellular communication. Its molecular signature such as DNA, RNA, protein, etc. contributes to the status (health or pathological stage) of the parental cell. Brain-derived EVs support more specific screening (diagnostic and prognostic) in TBI research. Therapeutic impact of EVs are more promising for aiding in TBI healing. It is nontoxic, biocompatible, and capable of crossing the blood-brain barrier (BBB) to transport therapeutic molecules. This review has highlighted the relationships between EVs and TBI theranostics, EVs and TBI-related clinical trials, and related research domain-associated challenges and solutions. This review motivates further exploration of associations between EVs and TBI and develops a better approach to TBI management.

Traumatic Brain Injury in Cameroon: A Prospective Observational Study in a Level I Trauma Centre

Background and Objective: About 14 million people will likely suffer a traumatic brain injury (TBI) per year by 2050 in sub-Saharan Africa. Studying TBI characteristics and their relation to outcomes can identify initiatives to improve TBI prevention and care. The objective of this study was to define the features and outcomes of TBI patients seen over a 1-year period in a level-I trauma centre in Cameroon. Materials and Methods: Data on demographics, causes, clinical aspects, and discharge status were collected over a period of 12 months. The Glasgow Outcome Scale-Extended (GOSE) and the Quality-of-Life Questionnaire after Brain Injury (QoLIBRI) were used to evaluate outcomes six months after TBI. Comparisons between two categorical variables were done using Pearson's chi-square test. Results: A total of 160 TBI patients participated in the study. The age group 15-45 years was most represented (78%). Males were more affected (90%). A low educational level was seen in 122 (76%) cases. Road traffic incidents (RTI) (85%), assaults (7.5%), and falls (2.5%) were the main causes of TBI, with professional bike riders being frequently involved (27%). Only 15 patients were transported to the hospital by ambulance, and 14 of these were from a referring hospital. CT-imaging was performed in 78% of cases, and intracranial traumatic abnormalities were identified in 64% of cases. Financial constraints (93%) was the main reason for not performing a CT scan. Forty-six (33%) patients were discharged against medical advice (DAMA) due to financial constraints. Mortality was 14% (22/160) and high in patients with severe TBI (46%). DAMA had poor outcomes with QoLIBRI. Only four patients received post-injury physical therapy services. Conclusions: TBI in Cameroon mainly results from RTIs and commonly affects young adult males. Lack of pre-hospital care, financial constraints limiting both CT scanning and medical care, and a lack of acute physiotherapy services likely influenced care and outcomes adversely.

Inflammation biomarkers IL‑6 and IL‑10 may improve the diagnostic and prognostic accuracy of currently authorized traumatic brain injury tools

Traumatic brain injury (TBI) is currently one of the leading causes of mortality and disability worldwide. At present, no reliable inflammatory or specific molecular neurobiomarker exists in any of the standard models proposed for TBI classification or prognostication. Therefore, the present study was designed to assess the value of a group of inflammatory mediators for evaluating acute TBI, in combination with clinical, laboratory and radiological indices and prognostic clinical scales. In the present single-centre, prospective observational study, 109 adult patients with TBI, 20 adult healthy controls and a pilot group of 17 paediatric patients with TBI from a Neurosurgical Department and two intensive care units of University General Hospital of Heraklion, Greece were recruited. Blood measurements using the ELISA method, of cytokines IL-6, IL-8 and IL-10, ubiquitin C-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein, were performed. Compared with those in healthy control individuals, elevated IL-6 and IL-10 but reduced levels of IL-8 were found on day 1 in adult patients with TBI. In terms of TBI severity classifications, higher levels of IL-6 (P=0.001) and IL-10 (P=0.009) on day 1 in the adult group were found to be associated with more severe TBI according to widely used clinical and functional scales. Moreover, elevated IL-6 and IL-10 in adults were found to be associated with more serious brain imaging findings (r_s<0.442; P<0.007). Subsequent multivariate logistic regression analysis in adults revealed that early-measured (day 1) IL-6 [odds ratio (OR)=0.987; P=0.025] and UCH-L1 (OR=0.993; P=0.032) are significant independent predictors of an unfavourable outcome. In conclusion, results from the present study suggest that inflammatory molecular biomarkers may prove to be valuable diagnostic and prognostic tools for TBI.

Prospects for Nerve Regeneration and Gene Therapy in the Treatment of Traumatic Brain Injury

Traumatic brain injury (TBI) is a prevalent neurological disorder and a leading cause of death and disability worldwide. The high mortality rates result in a tremendous burden on society and families in terms of public health and economic costs. Despite advances in biomedical research, treatment options for TBI still remain limited, and there is no effective therapy to restore the structure and function of the injured brain. Regrettably, due to the excessive heterogeneity of TBI and the lack of objective and reliable efficacy evaluation indicators, no proven therapeutic drugs or drugs with clear benefits on functional outcomes have been successfully developed to date. Therefore, it is urgent to explore new therapeutic approaches to protect or regenerate the injured brain from different perspectives. In this review, we first provide a brief overview of the causes and current status of TBI and then summarize the preclinical and clinical research status of cutting-edge treatment methods, including nerve regeneration therapy and gene therapy, with the aim of providing valuable references for effective therapeutic strategies for TBI.

Life After Mild Traumatic Brain Injury: Widespread Structural Brain Changes Associated With Psychological Distress Revealed With Multimodal Magnetic Resonance Imaging

Background

Traumatic brain injury (TBI) can alter brain structure and lead to onset of persistent neuropsychological symptoms. This study investigates the relationship between brain injury and psychological distress after mild TBI using multimodal magnetic resonance imaging.

Methods

A total of 89 patients with mild TBI from the TRACK-TBI (Transforming Research and Clinical Knowledge in Traumatic Brain Injury) pilot study were included. Subscales of the Brief Symptoms Inventory 18 for depression, anxiety, and somatization were used as outcome measures of psychological distress approximately 6 months after the traumatic event. Glasgow Coma Scale scores were used to evaluate recovery. Magnetic resonance imaging data were acquired within 2 weeks after injury. Perivascular spaces (PVSs) were segmented using an enhanced PVS segmentation method, and the volume fraction was calculated for the whole brain and white matter regions. Cortical thickness and gray matter structures volumes were calculated in FreeSurfer; diffusion imaging indices and multifiber tracts were extracted using the Quantitative Imaging Toolkit. The analysis was performed considering age, sex, intracranial volume, educational attainment, and improvement level upon discharge as covariates.

Results

PVS fractions in the posterior cingulate, fusiform, and postcentral areas were found to be associated with somatization symptoms. Depression, anxiety, and somatization symptoms were associated with the cortical thickness of the frontal-opercularis and occipital pole, putamen and amygdala volumes, and corticospinal tract and superior thalamic radiation. Analyses were also performed on the two hemispheres separately to explore lateralization.

Conclusions

This study shows how PVS, cortical, and microstructural changes can predict the onset of depression, anxiety, and somatization symptoms in patients with mild TBI.

Dietary (Poly)phenols in Traumatic Brain Injury

Traumatic brain injury (TBI) remains one of the leading causes of death and disability in young adults worldwide. Despite growing evidence and advances in our knowledge regarding the multifaceted pathophysiology of TBI, the underlying mechanisms, though, are still to be fully elucidated. Whereas initial brain insult involves acute and irreversible primary damage to the brain, the processes of subsequent secondary brain injury progress gradually over months to years, providing a window of opportunity for therapeutic interventions. To date, extensive research has been focused on the identification of druggable targets involved in these processes. Despite several decades of successful pre-clinical studies and very promising results, when transferred to clinics, these drugs showed, at best, modest beneficial effects, but more often, an absence of effects or even very harsh side effects in TBI patients. This reality has highlighted the need for novel approaches that will be able to respond to the complexity of the TBI and tackle TBI pathological processes on multiple levels. Recent evidence strongly indicates that nutritional interventions may provide a unique opportunity to enhance the repair processes after TBI. Dietary (poly)phenols, a big class of compounds abundantly found in fruits and vegetables, have emerged in the past few years as promising agents to be used in TBI settings due to their proven pleiotropic effects. Here, we give an overview of the pathophysiology of TBI and the underlying molecular mechanisms, followed by a state-of-the-art summary of the studies that have evaluated the efficacy of (poly)phenols administration to decrease TBI-associated damage in various animal TBI models and in a limited number of clinical trials. The current limitations on our knowledge concerning (poly)phenol effects in TBI in the pre-clinical studies are also discussed.

Assessment of the incremental prognostic value from the modified frailty index-5 in complete traumatic cervical spinal cord injury

Frailty, as measured by the modified frailty index-5 (mFI-5), and older age are associated with increased mortality in the setting of spinal cord injury (SCI). However, there is limited evidence demonstrating an incremental prognostic value derived from patient mFI-5. We conducted a retrospective cohort study to evaluate in-hospital mortality among adult complete cervical SCI patients at participating centers of the Trauma Quality Improvement Program from 2010 to 2018. Logistic regression was used to model in-hospital mortality, and the area under the receiver operating characteristic curve (AUROC) of regression models with age, mFI-5, or age with mFI-5 was used to compare the prognostic value of each model. 4733 patients were eligible. We found that both age (80 y versus 60 y: OR 3.59 95% CI [2.82 4.56], P < 0.001) and mFI-5 (score ≥ 2 versus < 2: OR 1.53 95% CI [1.19 1.97], P < 0.001) had statistically significant associations with in-hospital mortality. There was no significant difference in the AUROC of a model including age and mFI-5 when compared to a model including age without mFI-5 (95% CI Δ AUROC [- 8.72 × 10^-4 0.82], P = 0.199). Both models were superior to a model including mFI-5 without age (95% CI Δ AUROC [0.06 0.09], P < 0.001). Our findings suggest that mFI-5 provides minimal incremental prognostic value over age with respect to in-hospital mortality for patients complete cervical SCI.

Recent Advances in Nanomedicine Development for Traumatic Brain Injury

Traumatic brain injury (TBI) is one of the major causes of morbidity and mortality worldwide, and it is also a risk factor for neurodegeneration. However, there has not been perceptible progress in treating acute TBI over the last few years, mainly due to the inability of therapeutic drugs to cross the blood-brain barrier (BBB), failing to exert significant pharmacological effects on the brain parenchyma. Recently, nanomedicines are emerging as a powerful tool for the treatment of TBI where nanoscale materials (also called nanomaterials) are employed to deliver therapeutic agents. The advantages of using nanomaterials as a drug carrier include their high solubility and stability, high carrier capacity, site-specific, improved pharmacokinetics, and biodistribution. Keeping these points in consideration, this article reviews the pathophysiology, current treatment options, and emerging nanomedicine strategies for the treatment of TBI. The review will help readers to gain insight into the state-of-the-art of nanomedicine as a new tool for the treatment of TBI.

An Overview on the Use of miRNAs as Possible Forensic Biomarkers for the Diagnosis of Traumatic Brain Injury

Determining the cause of death is one of the main goals of forensic pathology. However, conditions can occur in which common approaches—external inspection, autopsy, histology, etc.—might not be conclusive. With the advancement of molecular biology, several investigative techniques have been developed over the years, and the application as approaches complementary to routine procedures has proved useful in these cases. In this context, microRNA (miRNA) profiling has attracted increasing interest due to these molecules’ ability to regulate physiological and pathological processes. The evidence of differential miRNA expression in both animal models and human samples of traumatic brain injury (TBI) has laid the basis for comprehension of the underlying pathophysiological mechanisms, thus allowing us to identify some of them as possible TBI diagnostic biomarkers. The present narrative review aims to explore the primary miRNAs involved in the mechanisms underlying TBI, which could be considered for future evaluation as possible markers in a post mortem setting.

The Role of Decompressive Craniectomy on Functional Outcome, Mortality and Seizure Onset after Traumatic Brain Injury

BACKGROUND

Decompressive craniectomy (DC) to treat increased intracranial pressure after a traumatic brain injury (TBI) is a common but controversial choice in clinical practice. This study aimed to determine the impact of DC on functional outcomes, mortality and the occurrence of seizures in a large cohort of patients with TBI.

METHODS

This retrospective study included patients with TBI consecutively admitted for a 6-month neurorehabilitation program between 1 January 2009 and 31 December 2018. The radiological characteristics of brain injury were determined with the Marshall computed tomographic classification. The neurological status and rehabilitation outcome were assessed using the Glasgow Coma Scale (GCS) and the Functional Independence Measure (FIM), which were both assessed at baseline and on discharge. Furthermore, the GCS was recorded on arrival at the emergency department. The DC procedure, prophylactic antiepileptic drug (AED) use, the occurrence of early or late seizures (US, unprovoked seizures) and death during hospitalization were also recorded.

RESULTS

In our cohort of 309 adults with mild-to-severe TBI, DC was performed in 98 (31.7%) patients. As expected, a craniectomy was more frequently performed in patients with severe TBI (p < 0.0001). However, after adjusting for the confounding variables including GCS scores, age and the radiological characteristics of brain injury, there was no association between DC and poor functional outcomes or mortality during the inpatient rehabilitation period. In our cohort, the independent predictors of an unfavorable outcome at discharge were the occurrence of US (β = -0.14, p = 0.020), older age (β = -0.13, p = 0.030) and the TBI severity on admission (β = -0.25, p = 0.002). Finally, DC (OR 3.431, 95% CI 1.233-9.542, p = 0.018) and early seizures (OR = 3.204, 95% CI 1.176-8.734, p = 0.023) emerged as the major risk factors for US, independently from the severity of the brain injury and the prescription of a primary prophylactic therapy with AEDs.

CONCLUSIONS

DC after TBI represents an independent risk factor for US, regardless of the prescription of prophylactic AEDs. Meanwhile, there is no significant association between DC and mortality, or a poor functional outcome during the inpatient rehabilitation period.

Immunization with Neural-Derived Peptides in Neurodegenerative Diseases: A Narrative Review

Neurodegenerative diseases (NDDs) are a major health problem worldwide. Statistics suggest that in America in 2030 there will be more than 12 million people suffering from a neurodegenerative pathology. Furthermore, the increase in life expectancy enhances the importance of finding new and better therapies for these pathologies. NDDs could be classified into chronic or acute, depending on the time required for the development of clinical symptoms and brain degeneration. Nevertheless, both chronic and acute stages share a common immune and inflammatory pathway in their pathophysiology. Immunization with neural-derived peptides (INDP) is a novel therapy that has been studied during the last decade. By inoculating neural-derived peptides obtained from the central nervous system (CNS), this therapy aims to boost protective autoimmunity, an autoreactive response that leads to a protective phenotype that produces a healing environment and neuroregeneration instead of causing damage. INDP has shown promising findings in studies performed either in vitro, in vivo or even in some pre-clinical trials of different NDDs, standing as a potentially beneficial therapy. In this review, we will describe some of the studies in which the effect of INDP strategies have been explored in different (chronic and acute) neurodegenerative diseases.

Review: Emerging Eye-Based Diagnostic Technologies for Traumatic Brain Injury

The study of ocular manifestations of neurodegenerative disorders, Oculomics, is a growing field of investigation for early diagnostics, enabling structural and chemical biomarkers to be monitored overtime to predict prognosis. Traumatic brain injury (TBI) triggers a cascade of events harmful to the brain, which can lead to neurodegeneration. TBI, termed the "silent epidemic" is becoming a leading cause of death and disability worldwide. There is currently no effective diagnostic tool for TBI, and yet, early-intervention is known to considerably shorten hospital stays, improve outcomes, fasten neurological recovery and lower mortality rates, highlighting the unmet need for techniques capable of rapid and accurate point-of-care diagnostics, implemented in the earliest stages. This review focuses on the latest advances in the main neuropathophysiological responses and the achievements and shortfalls of TBI diagnostic methods. Validated and emerging TBI-indicative biomarkers are outlined and linked to ocular neuro-disorders. Methods detecting structural and chemical ocular responses to TBI are categorised along with prospective chemical and physical sensing techniques. Particular attention is drawn to the potential of Raman spectroscopy as a non-invasive sensing of neurological molecular signatures in the ocular projections of the brain, laying the platform for the first tangible path towards alternative point-of-care diagnostic technologies for TBI.

miR-21, miR-93, miR-191, miR-let-7b, and miR-499 Expression Level in Plasma and Cerebrospinal Fluid in Patients with Prolonged Disorders of Consciousness

In recent decades, significant progress has been achieved in understanding the mechanisms of disturbance and restoration of consciousness in patients after severe brain damage resulting in prolonged disorders of consciousness (pDOC). MicroRNAs (miRs) may be potential candidates as possible biomarkers for the classification of disease subtypes, and prognosis in patients with pDOC. The aim of the study was to analyze miRs expression levels (hsa-miR-21-5p, hsa-miR-93-5p, hsa-miR-191-5p, mmu-miR-499-5p, hsa-let-7b-5p) by a real-time polymerase chain reaction in plasma and cerebrospinal fluid (CSF) from patients with pDOC and to identify a potential biomarker for dividing patients into groups according to disease severity. We analyzed the levels of investigated miRs in pDOC patients, divided by etiology, CRSI, and the total group compared with controls. Our results showed that dividing patients with pDOC into groups according to the etiology of the disease resulted in the most significant differences in the levels of miR-93, -21, and -191 in CSF and plasma samples between groups of patients. Among the analyzed miRs, we did not find a marker that would help to distinguish VS/UWS patient groups from MCS. Examining of miRs as possible prognostic markers in patients with pDOC, the starting point seems to be the cause that led to the development of the disease.

The efficacy of tranexamic acid treatment with different time and doses for traumatic brain injury: a systematic review and meta-analysis

OBJECTIVE

Tranexamic acid (TXA) plays a significant role in the treatment of traumatic diseases. However, its effectiveness in patients with traumatic brain injury (TBI) seems to be contradictory, according to the recent publication of several meta-analyses. We aimed to determine the efficacy of TXA treatment at different times and doses for TBI treatment.

METHODS

PubMed, MEDLINE, EMBASE, Cochrane Library, and Google Scholar were searched for randomized controlled trials that compared TXA and a placebo in adults and adolescents (≥ 15 years of age) with TBI up to January 31, 2022. Two authors independently abstracted the data and assessed the quality of evidence.

RESULTS

Of the identified 673 studies, 13 involving 18,675 patients met our inclusion criteria. TXA had no effect on mortality (risk ratio (RR) 0.99; 95% confidence interval (CI) 0.92-1.06), adverse events (RR 0.93, 95% Cl 0.76-1.14), severe TBI (Glasgow Coma Scale score from 3 to 8) (RR 0.99, 95% Cl 0.94-1.05), unfavorable Glasgow Outcome Scale (GOS < 4) (RR 0.96, 95% Cl 0.82-1.11), neurosurgical intervention (RR 1.11, 95% Cl 0.89-1.38), or rebleeding (RR 0.97, 95% Cl 0.82-1.16). TXA might reduce the mean hemorrhage volume on subsequent imaging (standardized mean difference, -0.35; 95% CI [-0.62, -0.08]).

CONCLUSION

TXA at different times and doses was associated with reduced mean bleeding but not with mortality, adverse events, neurosurgical intervention, and rebleeding. More research data is needed on different detection indexes and levels of TXA in patients with TBI, as compared to those not receiving TXA; although the prognostic outcome for all harm outcomes was not affected, the potential for harm was not ruled out.

TRIAL REGISTRATION

The review protocol was registered in the PROSPERO International Prospective Register of Systematic Reviews (CRD42022300484).

Design and optimization of metformin-loaded solid lipid nanoparticles for neuroprotective effects in a rat model of diffuse traumatic brain injury: A biochemical, behavioral, and histological study

BACKGROUND AND PURPOSE

Following traumatic brain injury, inflammation, mitochondrial dysfunction, oxidative stress, ischemia, and energy crisis can cause mortality or long-term morbidity. As an activator of AMP-activated protein kinase, metformin reduces the secondary injuries of traumatic brain injury by compensating for the lack of energy in damaged cells. But the blood-brain barrier prevents a hydrophilic drug such as metformin from penetrating the brain tissue. Solid lipid nanoparticles with their lipid nature can cross the blood-brain barrier and solve this challenge. so This study aimed to investigate the effect of metformin-loaded lipid nanoparticles (NanoMet) for drug delivery to the brain and reduce complications from traumatic brain injury.

METHOD

Different formulations of NanoMet were designed by Box-Behnken, and after formulation, particle size, zeta potential, and entrapment efficiency were investigated. For in vivo study, Male rats were divided into eight groups, and except for the intact and sham groups, the other groups underwent brain trauma by the Marmarou method. After the intervention, the Veterinary Coma Scale, Vestibular Motor function, blood-brain barrier integrity, cerebral edema, level of inflammatory cytokines, and histopathology of brain tissue were assessed.

RESULTS

The optimal formula had a size of 282.2 ± 9.05 nm, a zeta potential of -1.65 ± 0.33 mV, and entrapment efficiency of 60.61 ± 6.09% which released the drug in 1400 min. Concentrations of 5 and 10 mg/kg of this formula improved the consequences of trauma.

CONCLUSION

This study showed that nanoparticles could help target drug delivery to the brain and apply the desired result.

A New Approach in the Treatment of Traumatic Brain Injury: The Effects of Levosimendan on Necrosis, Apoptosis, and Oxidative Stress

OBJECTIVE

Traumatic brain injury (TBI) is an essential and common health problem worldwide. Levosimendan is an inotropic and vasodilator drug used to treat heart failure. Moreover, it exerts pleiotropic effects and, thus, protective effects on many organs. The present study aimed to investigate the effect of levosimendan on necrosis, apoptosis, and reactive oxygen species in rats with TBI.

METHODS

The study included 28 female Wistar-Albino rats weighing 200-250 g. The rats were divided into 4 groups with 7 rats each as follows: Group 1: No trauma group (Control), Group 2: Traumatized, untreated group (T), Group 3: Levosimendan was administered at a dose of 12 μg/kg intraperitoneally 1 hour after the trauma (L1), Group 4: Levosimendan was administered at a dose of 12 μg/kg intraperitoneally 2 hours after the concussion (L2). After the experiment, the rats were decapitated, and the brain tissue was removed. Necrosis was assessed with Cresyl violet staining, apoptosis was assessed with immunohistochemical analysis, superoxide dismutase and catalase levels were measured with the spectrophotometric method, and malondialdehyde (MDA) levels were assessed by High-Performance Liquid Chromatography.

RESULTS

The number of necrotic cells in the L1 and L2 groups was significantly lower than in the K and T groups (P = 0.015 and P = 0.03, respectively). Although the active caspase-3 level was signified considerably in the T, L1, and L2 groups compared to the K group, no significant difference was found among these 3 groups (P > 0.05). The results of superoxide dismutase levels were similar to those of active caspase-3. catalase level was significantly higher in the K group than in the T and L2 groups (P = 0.045). Malondialdehyde activity was considerably higher in the L1 and L2 groups compared to the K group (P = 0.023).

CONCLUSIONS

Our results indicated that levosimendan may exert a neuroprotective effect by reducing necrosis in TBI and that levosimendan does not affect apoptosis and antioxidant levels in TBI. Comprehensive studies are needed to elucidate the effect of levosimendan on TBI fully.

Acid Sphingomyelinase Inhibitor, Imipramine, Reduces Hippocampal Neuronal Death after Traumatic Brain Injury

Traumatic brain injury (TBI) broadly degrades the normal function of the brain after a bump, blow, or jolt to the head. TBI leads to the aggravation of pre-existing brain dysfunction and promotes neurotoxic cascades that involve processes such as oxidative stress, loss of dendritic arborization, and zinc accumulation. Acid sphingomyelinase (ASMase) is an enzyme that hydrolyzes sphingomyelin to ceramide in cells. Under normal conditions, ceramide plays an important role in various physiological functions, such as differentiation and apoptosis. However, under pathological conditions, excessive ceramide production is toxic and activates the neuronal-death pathway. Therefore, we hypothesized that the inhibition of ASMase activity by imipramine would reduce ceramide formation and thus prevent TBI-induced neuronal death. To test our hypothesis, an ASMase inhibitor, imipramine (10 mg/kg, i.p.), was administrated to rats immediately after TBI. Based on the results of this study, we confirmed that imipramine significantly reduced ceramide formation, dendritic loss, oxidative stress, and neuronal death in the TBI-imipramine group compared with the TBI-vehicle group. Additionally, we validated that imipramine prevented TBI-induced cognitive dysfunction and the modified neurological severity score. Consequently, we suggest that ASMase inhibition may be a promising therapeutic strategy to reduce hippocampal neuronal death after TBI.

Effect of drug therapy on nerve repair of moderate-severe traumatic brain injury: A network meta-analysis

Objective: This network meta-analysis aimed to explore the effect of different drugs on mortality and neurological improvement in patients with traumatic brain injury (TBI), and to clarify which drug might be used as a more promising intervention for treating such patients by ranking.

Methods: We conducted a comprehensive search from PubMed, Medline, Embase, and Cochrane Library databases from the establishment of the database to 31 January 2022. Data were extracted from the included studies, and the quality was assessed using the Cochrane risk-of-bias tool. The primary outcome measure was mortality in patients with TBI. The secondary outcome measures were the proportion of favorable outcomes and the occurrence of drug treatment–related side effects in patients with TBI in each drug treatment group. Statistical analyses were performed using Stata v16.0 and RevMan v5.3.0.

Results: We included 30 randomized controlled trials that included 13 interventions (TXA, EPO, progesterone, progesterone + vitamin D, atorvastatin, beta-blocker therapy, Bradycor, Enoxaparin, Tracoprodi, dexanabinol, selenium, simvastatin, and placebo). The analysis revealed that these drugs significantly reduced mortality in patients with TBI and increased the proportion of patients with favorable outcomes after TBI compared with placebo. In terms of mortality after drug treatment, the order from the lowest to the highest was progesterone + vitamin D, beta-blocker therapy, EPO, simvastatin, Enoxaparin, Bradycor, Tracoprodi, selenium, atorvastatin, TXA, progesterone, dexanabinol, and placebo. In terms of the proportion of patients with favorable outcomes after drug treatment, the order from the highest to the lowest was as follows: Enoxaparin, progesterone + vitamin D, atorvastatin, simvastatin, Bradycor, EPO, beta-blocker therapy, progesterone, Tracoprodi, TXA, selenium, dexanabinol, and placebo. In addition, based on the classification of Glasgow Outcome Scale (GOS) scores after each drug treatment, this study also analyzed the three aspects of good recovery, moderate disability, and severe disability. It involved 10 interventions and revealed that compared with placebo treatment, a higher proportion of patients had a good recovery and moderate disability after treatment with progesterone + vitamin D, Bradycor, EPO, and progesterone. Meanwhile, the proportion of patients with a severe disability after treatment with progesterone + vitamin D and Bradycor was also low.

Conclusion: The analysis of this study revealed that in patients with TBI, TXA, EPO, progesterone, progesterone + vitamin D, atorvastatin, beta-blocker therapy, Bradycor, Enoxaparin, Tracoprodi, dexanabinol, selenium, and simvastatin all reduced mortality and increased the proportion of patients with favorable outcomes in such patients compared with placebo. Among these, the progesterone + vitamin D had not only a higher proportion of patients with good recovery and moderate disability but also a lower proportion of patients with severe disability and mortality. However, whether this intervention can be used for clinical promotion still needs further exploration.

Formation of Three-Dimensional Spheres Enhances the Neurogenic Potential of Stem Cells from Apical Papilla

Cell-based neural regeneration is challenging due to the difficulty in obtaining sufficient neural stem cells with clinical applicability. Stem cells from apical papilla (SCAPs) originating from embryonic neural crests with high neurogenic potential could be a promising cell source for neural regeneration. This study aimed to investigate whether the formation of 3D spheres can promote SCAPs' neurogenic potential.

MATERIAL AND METHODS

Three-dimensional SCAP spheres were first generated in a 256-well agarose microtissue mold. The spheres and single cells were individually cultured on collagen I-coated μ-slides. Cell morphological changes, neural marker expression, and neurite outgrowth were evaluated by confocal microscope, ELISA, and RT-qPCR.

RESULTS

Pronounced morphological changes were noticed in a time-dependent manner. The migrating cells' morphology changed from fibroblast-like cells to neuron-like cells. Compared to the 2D culture, neurite length, number, and the expression of multiple progenitors, immature and mature neural markers were significantly higher in the 3D spheres. BDNF and NGF-β may play a significant role in the neural differentiation of SCAP spheres.

CONCLUSION

The formation of 3D spheres enhanced the neurogenic potential of SCAPs, suggesting the advantage of using the 3D spheres of SCAPs for treating neural diseases.

Effect of acupuncture for disorders of consciousness in patients with stroke: A systematic review and meta-analysis

Background

Disorder of consciousness (DOC) is frequent in patients with stroke, which is the second most common cause of death and a leading cause of disability. Acupuncture has been used as a curative method for DOC treatment in China. Nevertheless, no critical systematic review of acupuncture's effect on DOC has been published. This review aims to evaluate the present evidence regarding the efficacy of acupuncture for DOC after stroke.

Methods

Seven databases were searched from their inception to November 1, 2021, containing three English databases (PubMed, Embase, and Cochrane Central Register of Controlled Trials) and four Chinese databases (CNKI, CBM, VIP, and Wanfang Database). The primary outcomes comprise the Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) before and after treatment. Secondary outcomes involve resuscitation rate, resuscitation time, and adverse events. Data synthesis was calculated by RevMan (V.5.4.1) software. According to the Cochrane Handbook, methodological quality was assessed with the risk of bias tool 2.0 (RoB2).

Results

Seventeen studies containing 1,208 patients were eventually included in our review. Overall, most trials were rated as high or had some concerns regarding the risk of bias. GCS was reported in 16 trials, and a meta-analysis showed that GCS improvement in the acupuncture group was greater than in the non-acupuncture group (MD 1.45, 95% CI 0.94–1.97, P &lt; 0.0001). One trial reported that GOS improvement in the acupuncture plus medication group was greater than in the medication group (MD 0.58, 95% CI 0.11–1.05, P = 0.01). Another study reported that acupuncture plus medication was statistically more effective in shortening resuscitation time than medication alone (MD−0.89, 95% CI −1.53 to −0.25, P = 0.006). Four trials reported that the resuscitation rate in the acupuncture group was higher than without acupuncture intervention (RR 1.68, 95% CI 1.30–2.18, I2 0%, P = 0.39). Adverse events were reported in two studies, with one case in the acupuncture group suffering from subcutaneous hematoma.

Conclusion

Acupuncture may improve consciousness level, increase the resuscitation rate, and shorten resuscitation time for post-stroke patients with DOC. Adverse events from acupuncture were rare, tolerable, and recoverable. However, the results should be interpreted cautiously, and more rigorous RCTs with better methodology are warranted.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=289802, identifier 289802.

The effect of age on in-hospital mortality among elderly people who sustained fall-related traumatic brain injuries at home: A retrospective study of a multicenter emergency department-based injury surveillance database

BACKGROUND

People older than 65 years tend to have traumatic brain injuries (TBIs) more frequently and have a higher mortality rate after TBI than younger individuals. The aim of this study was to determine the effects of age on in-hospital mortality among patients who had fall-related TBIs at home, emphasizing the effect of specific locations in the house on the outcome.

METHODS

This cross-sectional study was conducted using the Emergency Department-based Injury In-Depth Surveillance (EDIIS) database in South Korea. Patients aged 65 years or older with a slip or fall injury, accidental injury at home, and no major diagnosis other than TBI were included. The primary outcome was in-hospital mortality. Subgroup analysis was conducted to determine the effect of locations on the relationship between age and in-hospital mortality.

RESULTS

Of the 2,571,442 patients in the EDIIS database, 9,747 were included in this study. The most common injury location was room or bedroom (29.1%), followed by living room or kitchen (23.0%), bathroom (20.2%), stairs (15.8%), and outdoor spaces of the house (11.9%). There was a significant association between increased in-hospital mortality and oldest old age. The stairs or outdoor spaces of the house was significantly associated with in-hospital mortality compared to rooms inside the house. The oldest age group showed a higher association with in-hospital mortality than the young-old group, especially in the bathroom, stairs, and outdoor spaces of the house.

CONCLUSIONS

Elderly individuals over the age of 85 are the most vulnerable to fall-related TBI mortality at home. A fall prevention strategy for the oldest-old is needed, especially for the bathroom, stairs, and the ancillary space outside the house.

Management and Treatment of Traumatic Brain Injuries

Traumatic brain injuries (TBI) are one of the main reasons for death in recent years worldwide or globally. They are the number one cause of death for both civilians and military members. It affects how the brain functions and is currently one of the crucial concerns of global public health issues. TBI is increasing worldwide because of the increasing dependency on motorized vehicles and machinery. One of the reasons for TBI is the expanding human population. It is the major cause of death and disability in the world. In young adults around the world, it is the main cause of mortality and morbidity. Its complicated etiology and pathogenesis include primarily primary and secondary injury types. Neuroinflammation is also focused on TBI to be cured. The neuroprotection of the injured brain has received tremendous attention during TBI treatment. In this review, we will first discuss the definition of traumatic brain injury, its causes, and the symptoms experienced by patients of various age groups. Finally, treatment methods and advances in treatment will be discussed. In this review, the aftereffects of traumatic brain damage are also covered. Ferroptosis and choline phospholipids are also emphasized as important components of the treatment of traumatic brain damage in this review.

The Role of Hydrogen Sulfide Targeting Autophagy in the Pathological Processes of the Nervous System

Autophagy is an important cellular process, involving the transportation of cytoplasmic contents in the double membrane vesicles to lysosomes for degradation. Autophagy disorder contributes to many diseases, such as immune dysfunction, cancers and nervous system diseases. Hydrogen sulfide (H₂S) is a volatile and toxic gas with a rotten egg odor. For a long time, it was considered as an environmental pollution gas. In recent years, H₂S is regarded as the third most important gas signal molecule after NO and CO. H₂S has a variety of biological functions and can play an important role in a variety of physiological and pathological processes. Increasingly more evidences show that H₂S can regulate autophagy to play a protective role in the nervous system, but the mechanism is not fully understood. In this review, we summarize the recent literatures on the role of H₂S in the pathological process of the nervous system by regulating autophagy, and analyze the mechanism in detail, hoping to provide the reference for future related research.

New insights into the interplay between autophagy and oxidative and endoplasmic reticulum stress in neuronal cell death and survival

Autophagy is a dynamic process that maintains the normal homeostasis of cells by digesting and degrading aging proteins and damaged organelles. The effect of autophagy on neural tissue is still a matter of debate. Some authors suggest that autophagy has a protective effect on nerve cells, whereas others suggest that autophagy also induces the death of nerve cells and aggravates nerve injury. In mammals, oxidative stress, autophagy and endoplasmic reticulum stress (ERS) constitute important defense mechanisms to help cells adapt to and survive the stress conditions caused by physiological and pathological stimuli. Under many pathophysiological conditions, oxidative stress, autophagy and ERS are integrated and amplified in cells to promote the progress of diseases. Over the past few decades, oxidative stress, autophagy and ERS and their interactions have been a hot topic in biomedical research. In this review, we summarize recent advances in understanding the interactions between oxidative stress, autophagy and ERS in neuronal cell death and survival.

Prognostic Models in Severe Traumatic Brain Injury: A Systematic Review and Meta-analysis

This review aimed to analyze the results of investigations that performed external validation or that compared prognostic models to identify the models and their variations that showed the best performance in predicting mortality, survival, and unfavorable outcome after severe traumatic brain injury. Pubmed, Embase, Scopus, Web of Science, Cumulative Index to Nursing and Allied Health Literature, Google Scholar, TROVE, and Open Grey databases were searched. A total of 1616 studies were identified and screened, and 15 studies were subsequently included for analysis after applying the selection criteria. The Corticosteroid Randomization After Significant Head Injury (CRASH) and International Mission for Prognosis and Analysis of Clinical Trials in Traumatic Brain Injury (IMPACT) models were the most externally validated among studies of severe traumatic brain injury. The results of the review showed that most publications encountered an area under the curve ≥ 0.70. The area under the curve meta-analysis showed similarity between the CRASH and IMPACT models and their variations for predicting mortality and unfavorable outcomes. Calibration results showed that the variations of CRASH and IMPACT models demonstrated adequate calibration in most studies for both outcomes, but without a clear indication of uncertainties in the evaluations of these models. Based on the results of this meta-analysis, the choice of prognostic models for clinical application may depend on the availability of predictors, characteristics of the population, and trauma care services.

Potential Progression Mechanism and Key Genes in Early Stage of mTBI

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease caused by repetitive mild traumatic brain injury (rmTBI), and the lack of sensitive diagnostic and prognostic biomarkers for rmTBI leads to long-term sequelae after injury. The purpose of this study is to identify key genes of rmTBI and find the potential progression mechanism in early stage of mTBI. We downloaded the gene expression profiles of GSE2871 from Gene Expression Omnibus (GEO) datasets. Differentially expressed genes (DEGs) were screened from the cerebral cortex of rats 24 hours after smTBI, and these DEGs were then subjected to GO enrichment analysis, KEGG pathway analysis, PPI analysis, and hub analysis. Key genes were identified as the most significantly expressed genes and had a higher degree of connectivity from hub genes. By using homemade metal pendulum impact equipment and a multiple regression discriminant equation to assess the severity of rats after injury, smTBI and rmTBI rat models were established in batches, and q-PCR analyses were performed to verify the key genes. The main KEGG pathways were cytokine-cytokine receptor interaction and neuroactive ligand-receptor interaction. SPP1 and C3 were the most significant DEGs, and their connectivity degree was the highest 24 hours after smTBI (logFC > 4; connectivity degree ＞15). The q-PCR analyses were performed 24 hours and 14 days after mTBI. The results showed that SPP1 and C3 were significantly upregulated in smTBI and in rmTBI at 24 hours after injury compared with their levels in sham-injured rats, and the phenomenon persisted 14 days after injury. Notably, 14 days after injury, both of these genes were significantly upregulated in the rmTBI group compared with the smTBI. These pathways and genes identified could help understanding the development in mTBI.

Oxidative stress and mitochondrial dysfunction following traumatic brain injury: From mechanistic view to targeted therapeutic opportunities

Traumatic brain injury (TBI) is one of the most prevalent causes of permanent physical and cognitive disabilities. TBI pathology results from primary insults and a multi-mechanistic biochemical process, termed as secondary brain injury. Currently, there are no pharmacological agents for definitive treatment of patients with TBI. This article is presented with the purpose of reviewing molecular mechanisms of TBI pathology, as well as potential strategies and agents against pathological pathways. In this review article, materials were obtained by searching PubMed, Scopus, Elsevier, Web of Science, and Google Scholar. This search was considered without time limitation. Evidence indicates that oxidative stress and mitochondrial dysfunction are two key mediators of the secondary injury cascade in TBI pathology. TBI-induced oxidative damage results in the structural and functional impairments of cellular and subcellular components, such as mitochondria. Impairments of mitochondrial electron transfer chain and mitochondrial membrane potential result in a vicious cycle of free radical formation and cell apoptosis. The results of some preclinical and clinical studies, evaluating mitochondria-targeted therapies, such as mitochondria-targeted antioxidants and compounds with pleiotropic effects after TBI, are promising. As a proposed strategy in recent years, mitochondria-targeted multipotential therapy is a new hope, waiting to be confirmed. Moreover, based on the available findings, biologics, such as stem cell-based therapy and transplantation of mitochondria are novel potential strategies for the treatment of TBI; however, more studies are needed to clearly confirm the safety and efficacy of these strategies.

Long Non-coding RNA HOTAIR in Central Nervous System Disorders: New Insights in Pathogenesis, Diagnosis, and Therapeutic Potential

Central nervous system (CNS) disorders, such as ischemic stroke, neurodegenerative diseases, multiple sclerosis, traumatic brain injury, and corresponding neuropathological changes, often lead to death or long-term disability. Long non-coding RNA (lncRNA) is a class of non-coding RNA with a transcription length over 200 nt and transcriptional regulation. lncRNA is extensively involved in physiological and pathological processes through epigenetic, transcription, and post-transcriptional regulation. Further, dysregulated lncRNA is closely related to the occurrence and development of human diseases, including CNS disorders. HOX Transcript antisense RNA (HOTAIR) is the first discovered lncRNA with trans-transcriptional regulation. Recent studies have shown that HOTAIR may participate in the regulation of the occurrence and development of CNS disorders. In addition, HOTAIR has the potential to become a new biomarker for the diagnosis and prognosis assessment of CNS disorders and even provide a new therapeutic target for CNS disorders. Here, we reviewed the research results of HOTAIR in CNS disorders to provide new insights into the pathogenesis, diagnostic value, and therapeutic target potential of HOTAIR in human CNS disorders.

Overview of Cochrane Systematic Reviews of Rehabilitation Interventions for Persons with Traumatic Brain Injury: A Mapping Synthesis

Background: The World Health Organization has identified an unmet global need for rehabilitation interventions concerning 20 non-communicable diseases, traumatic brain injury included. This overview compiles and synthesizes the quality and quantity of available evidence on the effectiveness of rehabilitation interventions for traumatic brain injury from Cochrane systematic reviews (CSRs). The results will be used to develop the Package of Interventions for Rehabilitation. Methods: All CSRs on TBI tagged in the Cochrane Rehabilitation database published between August 2009 and September 2021 were included. Evidence mapping was implemented to extract study characteristics and evidence from the CSRs. Results: Six CSRs (42 studies; n = 3983) examined the effectiveness of either non-pharmacological or pharmacological interventions after TBI. Among 19 comparisons, 3% were rated as high in quality of evidence, 9% moderate, 54% low, and 34% very low. Non-pharmacological interventions with moderate quality, hospital-based cognitive rehabilitation and cognitive didactic therapy, likely produced minimal to no changes in the return-to-work rate. Anti-epileptic drugs and neuroprotective agents resulted in a minimal difference to the frequency of late seizure episodes in post-traumatic epilepsy. Conclusions: No prominent advances in treatment options were reported in any of the CSRs. The high rate of low and very low quality of evidence makes it difficult to ascertain the effectiveness of several recommended non-pharmacological interventions.