Traumatic brain injury

Computational modeling and uncertainty prediction of hyperelastic constitutive responses of damaged brain tissue under different temperature and strain rates

The effect of strain rate and temperature on the hyperelastic material stress-strain characteristics of the damaged porcine brain tissue is evaluated in this present work. The desired constitutive responses are obtained using the commercially available finite element (FE) tool ABAQUS, utilizing 8-noded brick elements. The model's accuracy has been verified by comparing the results from the previously published literature. Further, the stress-strain behavior of the brain tissue is evaluated by varying the damages at various strain rates and temperatures (13, 20, 27, and 37°C) under compression test. Additionally, the sensitivity analysis of the model is computed to check the effect of input parameters, that is, the temperature, strain rate, and damages on the material properties (shear modulus). The modeling and discussion sections enumerate the inclusive features and model capabilities.

Assessment of the Behaviors of an In Vitro Brain Model On-Chip under Shockwave Impacts

Herein we report the assessment of the effects of shockwave (SW) impacts on adult rat hippocampal progenitor cell (AHPC) neurospheres (NSs), which are used as in vitro brain models, for enhancing our understanding of the mechanisms of traumatic brain injury (TBI). The assessment has been achieved by using culture dishes and a new microchip. The microchip allows the chemicals released from the brain models cultured inside the cell culture chamber under SW impacts to diffuse to the nanosensors in adjacent sensor chambers through built-in diffusion barriers, which are used to prevent the cells from entering the sensor chambers, thereby mitigating the biofouling issues of the sensor surface. Experiments showed the negative impact of the SW on the viability, proliferation, and differentiation of the cells within the NSs. A qPCR gene expression analysis was performed and appeared to confirm some of the immunocytochemistry (ICC) results. Finally, we demonstrated that the microchip can be used to monitor lactate dehydrogenase (LDH) released from the AHPC-NSs subjected to SW impacts. As expected, LDH levels changed when AHPC-NSs were injured by SW impacts, verifying this chip can be used for assessing the degrees of injuries to AHPC-NSs by monitoring LDH levels. Taken together, these results suggest the feasibility of using the chip to better understand the interactions between SW impacts and in vitro brain models, paving the way for potentially establishing in vitro TBI models on a chip.

Neuroforensomics: metabolites as valuable biomarkers in cerebrospinal fluid of lethal traumatic brain injuries

Traumatic brain injury (TBI) is a ubiquitous, common sequela of accidents with an annual prevalence of several million cases worldwide. In forensic pathology, structural proteins of the cellular compartments of the CNS in serum and cerebrospinal fluid (CSF) have been predominantly used so far as markers of an acute trauma reaction for the biochemical assessment of neuropathological changes after TBI. The analysis of endogenous metabolites offers an innovative approach that has not yet been considered widely in the assessment of causes and circumstances of death, for example after TBI. The present study, therefore, addresses the question whether the detection of metabolites by liquid-chromatography-mass spectrometry (LC/MS) analysis in post mortem CSF is suitable to identify TBI and to distinguish it from acute cardiovascular control fatalities (CVF). Metabolite analysis of 60 CSF samples collected during autopsies was performed using high resolution (HR)-LC/MS. Subsequent statistical and graphical evaluation as well as the calculation of a TBI/CVF quotient yielded promising results: numerous metabolites were identified that showed significant concentration differences in the post mortem CSF for lethal acute TBI (survival times up to 90 min) compared to CVF. For the first time, this forensic study provides an evaluation of a new generation of biomarkers for diagnosing TBI in the differentiation to other causes of death, here CVF, as surrogate markers for the post mortem assessment of complex neuropathological processes in the CNS ("neuroforensomics").

The Frequency of Neuropsychiatric Sequelae After Traumatic Brain Injury in the Global South: A systematic review and meta-analysis

This study aimed to assess the prevalence of neuropsychiatric sequelae following traumatic brain injury (TBI) among the Western Asian, South Asian and African regions of the global south. All studies on psychiatric disturbances or cognitive impairment following TBI conducted (until August 2021) in the 83 countries that constitute the aforementioned regions were reviewed; 6 databases were selected for the literature search. After evaluating the articles using the Joanna Briggs Institute guidelines, the random effects model was used to estimate the prevalence of depression, anxiety, post-traumatic stress disorder (PTSD), TBI-related sleep disturbance (TBI-SD), obsessive-compulsive disorder (OCD) and cognitive impairment. Of 56 non-duplicated studies identified in the initial search, 27 were eligible for systematic review and 23 for meta-analysis. The pooled prevalence of depression in 1,882 samples was 35.35%, that of anxiety in 1,211 samples was 28.64%, that of PTSD in 426 samples was 19.94%, that of OCD in 313 samples was 19.48%, that of TBI-SD in 562 samples was 26.67% and that of cognitive impairment in 941 samples was 49.10%. To date, this is the first critical review to examine the spectrum of post-TBI neuropsychiatric sequelae in the specified regions. Although existing studies lack homogeneous data due to variability in the diagnostic tools and outcome measures utilised, the reported prevalence rates are significant and comparable to statistics from the global north.

Association of Central Nervous System-Affecting Medications With Occurrence and Short-Term Mortality of Traumatic Brain Injury

BACKGROUND AND OBJECTIVES

The use of medications commonly prescribed after traumatic brain injury (TBI) has been little studied before TBI. This study examined the association between the use of medications that affect the central nervous system (CNS) and the occurrence and short-term mortality of TBI.

METHODS

Mandatory Finnish registries were used to identify TBI admissions, fatal TBIs, and drug purchases during 2005-2018. Patients with TBI were 1:1 matched to nontrauma control patients to investigate the association between medications and the occurrence of TBI and 30-day mortality after TBI. Number needed to harm (NNH) was calculated for all medications.

RESULTS

The cohort included 59 606 patients with TBI and a similar number of control patients. CNS-affecting drugs were more common in patients with TBI than in controls [odds ratio = 2.07 (2.02-2.13), P < .001)]. Benzodiazepines were the most common type of medications in patients with TBI (17%) and in controls (11%). The lowest NNH for the occurrence of TBI was associated with benzodiazepines (15.4), selective serotonin uptake inhibitors (18.5), and second-generation antipsychotics (25.8). Eight percent of the patients with TBI died within 30 days. The highest hazard ratios (HR) and lowest NNHs associated with short-term mortality were observed with strong opioids [HR = 1.41 (1.26-1.59), NNH = 33.1], second-generation antipsychotics [HR = 1.36 (1.23-1.50), NNH = 37.1], and atypical antidepressants [HR = 1.17 (1.04-1.31), NNH = 77.7].

CONCLUSION

Thirty-seven percent of patients with TBI used at least 1 CNS-affecting drug. This proportion was significantly higher than in the control population (24%). The highest risk and lowest NNH for short-term mortality were observed with strong opioids, second-generation antipsychotics, and atypical antidepressants. The current risks underscore the importance of weighing the benefits and risks before prescribing CNS-affecting drugs in patients at risk of head injury.

Valued living after mild traumatic brain injury: Characteristics and relationship with outcomes

Psychological factors are strong predictors of mild traumatic brain injury (mTBI) recovery, consequently, psychological interventions can form part of an individual's rehabilitation. This may include enhancing valued living (VL), an approach that is effective in severe and mixed acquired brain injury samples. This study aimed to characterize VL in mTBI and explore its relationship with mTBI and mental health outcomes. 56 participants with a mTBI completed self-report measures before engaging in a psychological intervention. Pre-injury mental health and other demographic and injury-related variables, VL, post-concussion symptoms (PCS), functional disability, and stress, anxiety and depression were measured. A pre-injury mental health condition was significantly associated with VL. VL was uniquely associated with depression after mTBI (β = -0.08, p = .05), however, there was no relationship with PCS, functional disability, stress or anxiety (p > .05). Following mTBI individuals with a pre-injury mental health condition or who experience heightened depressive symptoms may benefit from a values-based intervention as part of their rehabilitation. Future research, however, is needed to examine the role of VL in mTBI recovery.

Is lifetime traumatic brain injury a risk factor for mild cognitive impairment in veterans compared to non-veterans?

Background: Traumatic brain injury (TBI) is prevalent in veterans and may occur at any stages of their life (before, during, or after military service). This is of particular concern, as previous evidence in the general population has identified TBI as a strong risk factor for mild cognitive impairment (MCI), a known precursor of dementia.Objectives: This study aimed to investigate whether exposure to at least one TBI across the lifetime was a risk factor for MCI in ageing UK veterans compared to non-veterans.Method: This cross-sectional study comprised of data from PROTECT, a cohort study comprising UK veterans and non-veterans aged ≥ 50 years at baseline. Veteran and TBI status were self-reported using the Military Service History Questionnaire (MSHQ) and the Brain Injury Screening Questionnaire (BISQ), respectively. MCI was the outcome of interest, and was defined as subjective cognitive impairment and objective cognitive impairment.Results: The sample population comprised of veterans (n = 701) and non-veterans (n = 12,389). TBI was a significant risk factor for MCI in the overall sample (OR = 1.21, 95% CI 1.11-1.31) compared to individuals without TBI. The prevalence of TBI was significantly higher in veterans compared to non-veterans (69.9% vs 59.5%, p < .001). There was no significant difference in the risk of MCI between veterans with TBI and non-veterans with TBI (OR = 1.19, 95% CI 0.98-1.45).Conclusion: TBI remains an important risk factor for MCI, irrespective of veteran status. The clinical implications indicate the need for early intervention for MCI prevention after TBI.

Long-term burden of war injuries among civilians in LMICs: case of the July 2006 war in Lebanon

Introduction

Lebanon, a country located on the eastern shore of the Mediterranean Sea, is one of the world's smaller sovereign states. In the past few decades, Lebanon endured a perpetual political turmoil and several armed conflicts. July 12, 2006, marked the start of a one-month war in Lebanon, which resulted in thousands of casualties. Little is known about the long-term consequences of war injuries inflicted on civilians during the July 2006 war.

Methods

The objectives of this paper were to identify and evaluate: 1- civilians' access to healthcare and medicine under conditions of war; 2- the long-term socioeconomic burden on injured civilians; and 3- their quality of life more than a decade post-war. We adopted a mixed-method research design with an emphasis on the qualitative component. We conducted interviews with patients, collected clinical and financial data from hospital medical records, and administered a self-rated health questionnaire, the EQ-5D-5L. Simple descriptive statistics were calculated using Excel. NVivo 12® was used for data management and thematic analysis.

Results

We conducted 25 interviews. Injured civilians were mostly males, average age of 27. The most common mechanism of injury was blast injury. Most patients underwent multiple surgeries as well as revision surgeries. The thematic analysis revealed three themes: 1- recall of the time of the incident, the thousand miles journey, and patients' access to services; 2- post-trauma sequelae and services; and 3- long-term impact. Patients described the long-term burden including chronic pain, poor mobility, anxiety or depression, and limited activities of daily living.

Discussion

Civilians injured during the July 2006 war described the traumatising events they endured during the war and the limited access to medical care during and post-war. Up until this study was conducted, affected civilians were still experiencing physical, psychological, and financial sequelae. Acknowledging the limitations of this study, which include a small sample size and recall bias, the findings underscore the necessity for the expansion of services catering to civilians injured during wartime.

Patterns of War-Related Traumatic Brain Injuries and Predictors of Mortality Among Civilians During the Syrian Armed Conflict

BACKGROUND AND OBJECTIVES

High-velocity weapons were used against unshielded civilians during the Syrian armed conflict, leading to a variety of combat-related traumatic brain injuries with high fatality and morbidity. Because of the lack of data in the literature about the management and outcomes of similar injuries, we aimed in this study to characterize shrapnel and gunshot injuries in this vulnerable group and to describe the association between the mechanisms, site, and type of injury and the outcomes.

METHODS

This was a single-center retrospective cohort study on new traumatic brain injuries in civilians who presented alive to the neurosurgery department at Damascus Hospital between 2014 and 2017. The analyzed data included the mechanism of injury and its type and site based on computed tomography scans. We also studied the neurological status at admission, the major interventions applied, and outcomes including mortality and neurological deficits at discharge.

RESULTS

Shrapnel and gunshot injuries more likely affected the frontal and parietal lobes, respectively. While shrapnel led to injuries in multiple body parts, gunshots led to localized but more severe injuries. Despite that, mortality rates were comparable between the two mechanisms. Injuries to the right parietal and right frontal lobes were more fatal with odds ratios of 2.61 (1.23-5.52) and 2.12 (1.00-4.50), respectively. Moreover, mortality was also linked to the radiological findings of loss of brain material with an odds ratio of 3.73 (1.42-9.81), intracerebral hemorrhage with an odds ratio of 3.60 (1.67-7.80), intraventricular hemorrhage with an odds ratio of 5.49 (1.68-17.95), and subdural hemorrhage with an odds ratio of 6.35 (2.29-17.66).

CONCLUSION

The unfortunate nature of the Syrian armed conflict, wherein civilians were targeted during their daily routine, seems to manifest a heightened propensity to affect the parietal lobes, potentially resulting in higher morbidity. Although shrapnel and gunshot injuries showed no significant difference in mortality rates, injuries involving loss of brain tissue and intracranial hemorrhage emerged as independent predictors of mortality.

The Protective Role and Mechanism of Mild Therapeutic Hypothermia Protection on Brain Cells

Background

Moderate therapeutic hypothermia is protective against several cellular stressors. However, the mechanisms behind this protection are not entirely known. In the current investigation, we investigated that therapeutic hypothermia at 33°C administered following peroxide-induced oxidative stress might protect human oligodendroglioma cells using an in vitro model.

Methods and Results

Tert-butyl peroxide treatment for one hour significantly increased cell apoptosis and suppressed cell viability. In the range of 50-1000 M tert-butyl peroxide, this cell death was dose-dependent. MTT assay and cell apoptosis assay were applied to analyze cell viability/death at 24 hours after peroxide-induced stress. Therapeutic hypothermia at 33°C delivered for two hours after peroxide exposure significantly increased cell viability and suppressed cell death. Even 15 minutes after peroxide washout when delayed hypothermia was used, this protection was still apparent. Three FDA-approved antioxidants (Tempol, EUK134, and Edaravone at 100 M) were added immediately after tert-butyl peroxide, followed by hypothermia treatment. These three antioxidants greatly increased cell viability and cell apoptosis. RT-qPCR was applied to determine the effects of hypothermia treatment on the expression of caspase-3 and -8 as well as tumor necrosis factor-alpha (TNF-α). Therapeutic hypothermia significantly downregulated these three factors.

Conclusion

Overall, these findings confirmed that hypothermia and antioxidants quenching reactive oxygen species may lower mitochondrial oxidative stress and/or apoptotic pathways. Further investigation are needed to investigate the role of hypothermia in other cell models.

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.

Recent Advances in Biomaterials-Based Therapies for Alleviation and Regeneration of Traumatic Brain Injury

Traumatic brain injury (TBI), a major public health problem accompanied with numerous complications, usually leads to serve disability and huge financial burden. The adverse and unfavorable pathological environment triggers a series of secondary injuries, resulting in serious loss of nerve function and huge obstacle of endogenous nerve regeneration. With the advances in adaptive tissue regeneration biomaterials, regulation of detrimental microenvironment to reduce the secondary injury and to promote the neurogenesis becomes possible. The adaptive biomaterials could respond and regulate biochemical, cellular, and physiological events in the secondary injury, including excitotoxicity, oxidative stress, and neuroinflammation, to rebuild circumstances suitable for regeneration. In this review, the development of pathology after TBI is discussed, followed by the introduction of adaptive biomaterials based on various pathological characteristics. The adaptive biomaterials carried with neurotrophic factors and stem cells for TBI treatment are then summarized. Finally, the current drawbacks and future perspective of biomaterials for TBI treatment are suggested.

Antioxidant-based neuroprotective effect of dimethylsulfoxide against induced traumatic brain injury in a rats model

Traumatic brain injury (TBI) has been the result of neurological deficit and oxidative stress. This study evaluated the antioxidative neuroprotective property and learning and memory-enhancing effects of dimethyl sulfoxide (DMSO) in a rat model after the induction of TBI. 21 albino rats with 7 rats per group were used in this study. Group I was induced with TBI and treated with DMSO at 67.5 mg/kg orally once daily which started 30 min after the induction of TBI and lasted 21 days. Group II was induced with TBI but not treated while Group III was neither induced with TBI nor treated. Assessment of behavioral function (Learning and memory, anxiety and motor function), the level of an antioxidant enzymes and their gene expression (superoxide dismutase, catalase, glutathione peroxidase), the biomarkers of oxidative stress (malondialdehyde) and S100B levels as well as brain tissues histological studies were conducted. Administration of DMSO to rats with induced TBI has improved learning and memory, locomotor function and decreased anxiety in Group I compared to Group II. Moreover, the level of S100B was significantly (p < 0.05) lower in Group I compared to Group II. Treatment with DMSO also decreased lipid peroxidation significantly (p < 0.05) compared to Group II. There exists a significant (p < 0.05) increase in CAT, SOD, and GPX activities in Group I compared to Group II. Therefore, DMSO has demonstrated a potential antioxidative neuroprotective effect through its ability to increase the level of antioxidant enzymes which they quench and inhibit the formation of ROS, thereby improving cognitive functions.

Systemic Elevation of n-3 Polyunsaturated Fatty Acids (n-3-PUFA) Is Associated with Protection against Visual, Motor, and Emotional Deficits in Mice following Closed-Head Mild Traumatic Brain Injury

Traumatic brain injury (TBI) causes neuroinflammation and neurodegeneration leading to various pathological complications such as motor and sensory (visual) deficits, cognitive impairment, and depression. N-3 polyunsaturated fatty acid (n-3 PUFA) containing lipids are known to be anti-inflammatory, whereas the sphingolipid, ceramide (Cer), is an inducer of neuroinflammation and degeneration. Using Fat1⁺-transgenic mice that contain elevated levels of systemic n-3 PUFA, we tested whether they are resistant to mild TBI-mediated sensory-motor and emotional deficits by subjecting Fat1-transgenic mice and their WT littermates to focal cranial air blast (50 psi) or sham blast (0 psi, control). We observed that visual function in WT mice was reduced significantly following TBI but not in Fat1⁺-blast animals. We also found Fat1⁺-blast mice were resistant to the decline in motor functions, depression, and fear-producing effects of blast, as well as the reduction in the area of oculomotor nucleus and increase in activated microglia in the optic tract in brain sections seen following blast in WT mice. Lipid and gene expression analyses confirmed an elevated level of the n-3 PUFA eicosapentaenoic acid (EPA) in the plasma and brain, blocking of TBI-mediated increase of Cer in the brain, and decrease in TBI-mediated induction of Cer biosynthetic and inflammatory gene expression in the brain of the Fat1⁺ mice. Our results demonstrate that suppression of ceramide biosynthesis and inflammatory factors in Fat1⁺-transgenic mice is associated with significant protection against the visual, motor, and emotional deficits caused by mild TBI. This study suggests that n-3 PUFA (especially, EPA) has a promising therapeutic role in preventing neurodegeneration after TBI.

Drug Repurposing: Promises of Edaravone Target Drug in Traumatic Brain Injury

Edaravone is a potent free-radical scavenger that has been in the market for more than 30 years. It was originally developed in Japan to treat strokes and has been used there since 2001. Aside from its anti-oxidative effects, edaravone demonstrated beneficial effects on proinflammatory responses, nitric oxide production, and apoptotic cell death. Interestingly, edaravone has shown neuroprotective effects in several animal models of diseases other than stroke. In particular, edaravone administration was found to be effective in halting amyotrophic lateral sclerosis (ALS) progression during the early stages. Accordingly, after its success in Phase III clinical studies, edaravone has been approved by the FDA as a treatment for ALS patients. Considering its promises in neurological disorders and its safety in patients, edaravone is a drug of interest that can be repurposed for traumatic brain injury (TBI) treatment. Drug repurposing is a novel approach in drug development that identifies drugs for purposes other than their original indication. This review presents the biochemical properties of edaravone along with its effects on several neurological disorders in the hope that it can be adopted for treating TBI patients.

Inhibition of microRNA-203 protects against traumatic brain injury induced neural damages via suppressing neuronal apoptosis and dementia-related molecues

BACKGROUND

Traumatic brain injury (TBI) can lead to cognitive dysfunction and motor dysfunction. TBI is a potential risk factor for subsequent dementia. Hyperphosphorylation of Tau and ApoE4 has been found in patients with TBI. A significant increase in miR-203 was also found in the peripheral blood of TBI mice. Thus, we hypothesize that miR-203 inhibitor protects against neuronal damage and behavioral deficits by inhibition of Tau phosphorylation, ApoE4 expression and apoptosis.

METHODS

TBI mice were induced and treated with miR-203 inhibitor. Tau phosphorylation and ApoE4, hippocampal long-term potentiation (LTP), learning and memory, and motor function were separately detected by Western blot analysis, electrophysiology recording and behavioral assessments including Morris water maze test, beam-balance test, beam-walk test and rotarod test. Caspase-3 activity and bcl-2 expression were detected by ELISA.

RESULTS

TBI induction led to increased phosphorylation of Tau and ApoE4 expression. Administration of miR-203 inhibitor suppressed TBI induced ApoE4 expression and Tau hyperphosphorylation, rescued TBI mediated hippocampal LTP deficits and hippocampus dependent learning and memory dysfunction. miR-203 inhibitor treatment also improved motor function. In addition, miR-203 inhibitor treatment inhibited neuronal apoptosis by inhibiting caspase-3 activity and increasing bcl-2 expression.

CONCLUSION

miR-203 inhibitor treatment can rescue TBI-induced neural damage by inhibiting neuronal apoptosis and dementia markers like ApoE4 expression and Tau phosphorylation.

Diabetes exacerbates brain pathology following a focal blast brain injury: New role of a multimodal drug cerebrolysin and nanomedicine

Blast brain injury (bBI) is a combination of several forces of pressure, rotation, penetration of sharp objects and chemical exposure causing laceration, perforation and tissue losses in the brain. The bBI is quite prevalent in military personnel during combat operations. However, no suitable therapeutic strategies are available so far to minimize bBI pathology. Combat stress induces profound cardiovascular and endocrine dysfunction leading to psychosomatic disorders including diabetes mellitus (DM). This is still unclear whether brain pathology in bBI could exacerbate in DM. In present review influence of DM on pathophysiology of bBI is discussed based on our own investigations. In addition, treatment with cerebrolysin (a multimodal drug comprising neurotrophic factors and active peptide fragments) or H-290/51 (a chain-breaking antioxidant) using nanowired delivery of for superior neuroprotection on brain pathology in bBI in DM is explored. Our observations are the first to show that pathophysiology of bBI is exacerbated in DM and TiO₂-nanowired delivery of cerebrolysin induces profound neuroprotection in bBI in DM, not reported earlier. The clinical significance of our findings with regard to military medicine is discussed.

A group memory rehabilitation programme for people with traumatic brain injuries: the ReMemBrIn RCT

BACKGROUND

People with traumatic brain injuries (TBIs) commonly report memory impairments. These are persistent, debilitating and reduce quality of life, but patients do not routinely receive memory rehabilitation after discharge from hospital.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of a group memory rehabilitation programme for people with TBI.

DESIGN

Multicentre, pragmatic, cluster randomised controlled trial. Qualitative and health economic evaluations were also undertaken.

SETTING

Community settings in nine sites in England.

PARTICIPANTS

Participants were aged 18-69 years, had undergone a TBI > 3 months prior to recruitment, reported memory problems, were able to travel to a site to attend group sessions, could communicate in English and gave informed consent.

RANDOMISATION AND BLINDING

Clusters of four to six participants were randomised to the memory rehabilitation arm or the usual-care arm on a 1 : 1 ratio. Randomisation was based on a computer-generated pseudo-random code using random permuted blocks of randomly varying size, stratified by study site. Participants and therapists were aware of the treatment allocation whereas outcome assessors were blinded.

INTERVENTIONS

In the memory rehabilitation arm 10 weekly sessions of a manualised memory rehabilitation programme were provided in addition to usual care. Participants were taught restitution strategies to retrain impaired memory functions and compensation strategies to enable them to cope with memory problems. The usual-care arm received usual care only.

MAIN OUTCOME MEASURES

Outcomes were assessed at 6 and 12 months after randomisation. Primary outcome: patient-completed Everyday Memory Questionnaire - patient version (EMQ-p) at 6 months' follow-up. Secondary outcomes: Rivermead Behavioural Memory Test - third edition (RBMT-3), General Health Questionnaire 30-item version, European Brain Injury Questionnaire, Everyday Memory Questionnaire - relative version and individual goal attainment. Costs (based on a UK NHS and Personal Social Services perspective) were collected using a service use questionnaire, with the EuroQol-5 Dimensions, five-level version, used to derive quality-adjusted life-years (QALYs). A Markov model was developed to explore cost-effectiveness at 5 and 10 years, with a 3.5% discount applied.

RESULTS

We randomised 328 participants (memory rehabilitation, n = 171; usual care, n = 157), with 129 in the memory rehabilitation arm and 122 in the usual-care arm included in the primary analysis. We found no clinically important difference on the EMQ-p between the two arms at 6 months' follow-up (adjusted difference in mean scores -2.1, 95% confidence interval -6.7 to 2.5; p = 0.37). For secondary outcomes, differences favouring the memory rehabilitation arm were observed at 6 months' follow-up for the RBMT-3 and goal attainment, but remained only for goal attainment at 12 months' follow-up. There were no differences between arms in mood or quality of life. The qualitative results suggested positive experiences of participating in the trial and of attending the groups. Participants reported that memory rehabilitation was not routinely accessible in usual care. The primary health economics outcome at 12 months found memory rehabilitation to be £26.89 cheaper than usual care but less effective, with an incremental QALY loss of 0.007. Differences in costs and effects were not statistically significant and non-parametric bootstrapping demonstrated considerable uncertainty in these findings. No safety concerns were raised and no deaths were reported.

LIMITATIONS

As a pragmatic trial, we had broad inclusion criteria and, therefore, there was considerable heterogeneity within the sample. The study was not powered to perform further subgroup analyses. Participants and therapists could not be blinded to treatment allocation.

CONCLUSIONS

The group memory rehabilitation delivered in this trial is very unlikely to lead to clinical benefits or to be a cost-effective treatment for people with TBI in the community. Future studies should examine the selection of participants who may benefit most from memory rehabilitation.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN65792154.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 16. See the NIHR Journals Library website for further project information.

Direct versus indirect transfer for traumatic brain injury to James Cook University Hospital: a retrospective study

INTRODUCTION

Patients with traumatic brain injury are referred to the neurosurgical unit at James Cook University Hospital, Middlesbrough, either from local accident and emergency departments (direct transfer from the scene) or from other hospitals (indirect transfer). This study looked at the outcome in both groups.

MATERIAL AND METHODS

This was a retrospective observational study using trauma audit research network data for patients treated for traumatic brain injury at the neurosurgery department at the neurosurgical unit at James Cook University Hospital.

RESULTS

A total of 356 patients with traumatic brain injury were admitted under the care of neurosurgeons; 143 (40%) of these patients had a neurosurgical procedure. Of the patients undergoing a neurological procedure, 111 patients were transferred directly while 32 were indirect transfers; 213 patients were managed conservatively. Of those managed conservatively, 165 were transferred directly while 48 were indirect transfers. We compared the length of hospital stay and Glasgow Outcome Scale score for the patients based on whether they were conservatively managed or required surgery in the direct and indirect transfer groups. The difference in the length of stay in the surgical and conservative groups following direct and indirect transfer was insignificant (p = 0.07). The time to the operation in direct and indirect transfer was also not statistically significant (p = 0.06).

CONCLUSION

Patients are as safe, if not safer, by reaching the nearest trauma unit with facilities for resuscitation and imaging.

Traumatic brain injury neuroelectrochemical monitoring: behind-the-ear micro-instrument and cloud application

Background

Traumatic Brain Injury (TBI) is a leading cause of fatality and disability worldwide, partly due to the occurrence of secondary injury and late interventions. Correct diagnosis and timely monitoring ensure effective medical intervention aimed at improving clinical outcome. However, due to the limitations in size and cost of current ambulatory bioinstruments, they cannot be used to monitor patients who may still be at risk of secondary injury outside the ICU.

Methods

We propose a complete system consisting of a wearable wireless bioinstrument and a cloud-based application for real-time TBI monitoring. The bioinstrument can simultaneously record up to ten channels including both ECoG biopotential and neurochemicals (e.g. potassium, glucose and lactate), and supports various electrochemical methods including potentiometry, amperometry and cyclic voltammetry. All channels support variable gain programming to automatically tune the input dynamic range and address biosensors’ falling sensitivity. The instrument is flexible and can be folded to occupy a small space behind the ear. A Bluetooth Low-Energy (BLE) receiver is used to wirelessly connect the instrument to a cloud application where the recorded data is stored, processed and visualised in real-time. Bench testing has been used to validate device performance.

Results

The instrument successfully monitored spreading depolarisations (SDs) - reproduced using a signal generator - with an SNR of 29.07 dB and NF of 0.26 dB. The potentiostat generates a wide voltage range from -1.65V to +1.65V with a resolution of 0.8mV and the sensitivity of the amperometric AFE was verified by recording 5 pA currents. Different potassium, glucose and lactate concentrations prepared in lab were accurately measured and their respective working curves were constructed. Finally,the instrument achieved a maximum sampling rate of 1.25 ksps/channel with a throughput of 105 kbps. All measurements were successfully received at the cloud.

Conclusion

The proposed instrument uniquely positions itself by presenting an aggressive optimisation of size and cost while maintaining high measurement accuracy. The system can effectively extend neuroelectrochemical monitoring to all TBI patients including those who are mobile and those who are outside the ICU. Finally, data recorded in the cloud application could be used to help diagnosis and guide rehabilitation.

Thiolated bone and tendon tissue particles covalently bound in hydrogels for in vivo calvarial bone regeneration

Bone regeneration of large cranial defects, potentially including traumatic brain injury (TBI) treatment, presents a major problem with non-crosslinking, clinically available products due to material migration outside the defect. Commercial products such as bone cements are permanent and thus not conducive to bone regeneration, and typical commercial bioactive materials for bone regeneration do not crosslink. Our previous work demonstrated that non-crosslinking materials may be prone to material migration following surgical placement, and the current study attempted to address these problems by introducing a new hydrogel system where tissue particles are themselves the crosslinker. Specifically, a pentenoate-modified hyaluronic acid (PHA) polymer was covalently linked to thiolated tissue particles of demineralized bone matrix (TDBM) or devitalized tendon (TDVT), thereby forming an interconnected hydrogel matrix for calvarial bone regeneration. All hydrogel precursor solutions exhibited sufficient yield stress for surgical placement and an adequate compressive modulus post-crosslinking. Critical-size calvarial defects were filled with a 4% PHA hydrogel containing 10 or 20% TDBM or TDVT, with the clinical product DBX^Ⓡ being employed as the standard of care control for the in vivo study. At 12 weeks, micro-computed tomography analysis demonstrated similar bone regeneration among the experimental groups, TDBM and TDVT, and the standard of care control DBX^Ⓡ. The group with 10% TDBM was therefore identified as an attractive material for potential calvarial defect repair, as it additionally exhibited a sufficient initial recovery after shearing (i.e., > 80% recovery). Future studies will focus on applying a hydrogel in a rat model for treatment of TBI. STATEMENT OF SIGNIFICANCE: Non-crosslinking materials may be prone to material migration from a calvarial bone defect following surgical placement, which is problematic for materials intended for bone regeneration. Unfortunately, typical crosslinking materials such as bone cements are permanent and thus not conducive to bone regeneration, and typical bioactive materials for bone regeneration such as tissue matrix are not crosslinked in commercial products. The current study addressed these problems by introducing a new biomaterial where tissue particles are themselves the crosslinker in a hydrogel system. The current study successfully demonstrated a new material based on pentenoate-modified hyaluronic acid with thiolated demineralized bone matrix that is capable of rapid crosslinking, with desirable paste-like rheology of the precursor material for surgical placement, and with bone regeneration comparable to a commercially available standard-of-care product. Such a material may hold promise for a single-surgery treatment of severe traumatic brain injury (TBI) following hemicraniectomy.

Characterization of Ionic and Lipid Gradients within Corpus Callosum White Matter after Diffuse Traumatic Brain Injury in the Rat

There is increased recognition of the effects of diffuse traumatic brain injury (dTBI), which can initiate yet unknown biochemical cascades, resulting in delayed secondary brain degeneration and long-term neurological sequela. There is limited availability of therapies that minimize the effect of secondary brain damage on the quality of life of people who have suffered TBI, many of which were otherwise healthy adults. Understanding the cascade of biochemical events initiated in specific brain regions in the acute phase of dTBI and how this spreads into adjacent brain structures may provide the necessary insight into drive development of improved therapies. In this study, we have used direct biochemical imaging techniques (Fourier transform infrared spectroscopic imaging) and elemental mapping (X-ray fluorescence microscopy) to characterize biochemical and elemental alterations that occur in corpus callosum white matter in the acute phase of dTBI. The results provide direct visualization of differential biochemical and ionic changes that occur in the highly vulnerable medial corpus callosum white matter relative to the less vulnerable lateral regions of the corpus callosum. Specifically, the results suggest that altered ionic gradients manifest within mechanically damaged medial corpus callosum, potentially spreading to and inducing lipid alterations to white matter structures in lateral brain regions.

Terson syndrome with persistent vitreous hemorrhage following traumatic brain injury

The objective of this study was to report clinical findings and surgical outcomes of 3 patients with persistent vitreous hemorrhage diagnosed as Terson syndrome (TS). Posterior segment changes, optical coherence tomography scans, fundus autofluorescence images, and fundus fluorescein angiography findings of patients were evaluated and pars plana vitrectomy (PPV) was performed on 3 eyes of three patients. All eyes operated after 6 months from the date of injury and final visual acuities were 20/200, 20/60 and 20/30. PPV is found as a safe and effective procedure for vitreous hemorrhage in TS. Delayed surgery in a young patient predicts a worse outcome.

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.

Traumatic Brain Injuries: Pathophysiology and Potential Therapeutic Targets

Traumatic brain injury (TBI) remains one of the leading causes of morbidity and mortality amongst civilians and military personnel globally. Despite advances in our knowledge of the complex pathophysiology of TBI, the underlying mechanisms are yet to be fully elucidated. While initial brain insult involves acute and irreversible primary damage to the parenchyma, the ensuing secondary brain injuries often progress slowly over months to years, hence providing a window for therapeutic interventions. To date, hallmark events during delayed secondary CNS damage include Wallerian degeneration of axons, mitochondrial dysfunction, excitotoxicity, oxidative stress and apoptotic cell death of neurons and glia. Extensive research has been directed to the identification of druggable targets associated with these processes. Furthermore, tremendous effort has been put forth to improve the bioavailability of therapeutics to CNS by devising strategies for efficient, specific and controlled delivery of bioactive agents to cellular targets. Here, we give an overview of the pathophysiology of TBI and the underlying molecular mechanisms, followed by an update on novel therapeutic targets and agents. Recent development of various approaches of drug delivery to the CNS is also discussed.

The Community Balance and Mobility Scale: Detecting Impairments in Military Service Members With Mild Traumatic Brain Injury

Introduction

The objective of this study was to determine the utility of the Community Balance and Mobility scale (CB&M) among service members presenting with mild traumatic brain injury (mTBI), to compare the results against well-established balance assessments, and to find a new military-specific CB&M cut score to help differentiate those with and without mTBI.

Materials and Methods

The setting was a 4-week, intensive-outpatient, interdisciplinary program for active duty service members with mTBI. This was a nonrandomized, cross-sectional design that compared multiple measures between two groups: active duty service members with (n = 45) and without (n = 45) mTBI. The assessments, including the Activities-Specific Balance Confidence Scale, gait speed (comfortable and fast), the Functional Gait Assessment, and the CB&M, were provided to both sample groups.

Results

The mTBI group performed significantly worse (P ≤ 0.01) across all measures. A higher cut score for the CB&M of 81.5 is suggested. The CB&M demonstrated the best sensitivity (78%) and specificity (91%) ratio, as well as the largest effect size and area under the curve(0.92).

Conclusion

All objective measures distinguish participants with mTBI from controls, ranging from fair to excellent. The recommended CB&M cut score of 81.5 allows for good variance, standard deviation, and reduced risk of ceiling or floor effects. Further examination of the recommended CB&M cut score is warranted for use in the mTBI civilian populations.

Inducing Mild Traumatic Brain Injury in C. elegans via Cavitation-Free Surface Acoustic Wave-Driven Ultrasonic Irradiation

Mild traumatic brain injury is an all-too-common outcome from modern warfare and sport, and lacks a reproducible model for assessment of potential treatments and protection against it. Here we consider the use of surface acoustic wave (SAW) irradiation of C. elegans worms—without cavitation—as a potential, ethically reasonable animal-on-a-chip model for inducing traumatic brain injury in an animal, producing significant effects on memory and learning that could prove useful in a model that progress from youth to old age in but a few weeks. We show a significant effect by SAW on the ability of worms to learn post-exposure through associative learning chemotaxis. At higher SAW intensity, we find immediate, thorough, but temporary paralysis of the worms. We further explore the importance of homogeneous exposure of the worms to the SAW-driven ultrasound, an aspect poorly controlled in past efforts, if at all, and demonstrate the absence of cavitation through a change in fluids from a standard media for the worms to the exceedingly viscous polyvinyl alcohol. Likewise, we demonstrate that acoustic streaming, when present, is not directly responsible for paralysis nor learning disabilities induced in the worm, but is beneficial at low amplitudes to ensuring homogeneous ultrasound exposure.

Acupuncture for hearing loss after traumatic brain injury: A protocol for systematic review of randomized controlled trial

BACKGROUND

This study aims to systematically assess the effectiveness and safety of acupuncture on hearing loss (HL) after traumatic brain injury (TBI).

METHODS

In this study, the following databases will be retrieved from inception up to the May 1, 2019: PUBMED, EMBASE, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, and Chinese Biomedical Literature Database. All databases will be retrieved without any language restrictions. Two reviewers will independently carry out article selection, data collection, and risk of bias evaluation. Any disagreements will be solved by a third reviewer through discussion.

RESULTS

This study will systematically investigate the effectiveness and safety of acupuncture for treating HL after TBI through evaluating HL assessment, hearing threshold, quality of life, and adverse events.

CONCLUSION

The expected findings of this study will provide latest evidence for assessing the effectiveness and safety of acupuncture for HL after TBI.

ETHICS AND DISSEMINATION

This study is supposed to be published in a peer-reviewed journal. No ethical approval is needed because this study will based on the literature analysis, but not the individual patient.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019133417.

Is traumatic brain injury a risk factor for neurodegeneration? A meta-analysis of population-based studies

Background

To determine the association of prior traumatic brain injury (TBI) with subsequent diagnosis of neurodegeneration disease.

Methods

All studies from 1980 to 2016 reporting TBI as a risk factor for diagnoses of interest were identified by searching PubMed, Embase, study references, and review articles. The data and study design were assessed by 2 investigators independently. A meta-analysis was performed by RevMan 5.3.

Results

There were 18 studies comprising 3,263,207 patients. Meta-analysis revealed a significant association of prior TBI with subsequent dementia. The pooled odds ratio (OR) for TBI on development of dementia, FTD and TDP-43 associated disease were 1.93 (95% CI 1.47–2.55, p < 0.001), 4.44 (95% CI 3.86–5.10, p < 0.001), and 2.97 (95% CI 1.35–6.53, p < 0.001). However, analyses of individual diagnoses found no evidence that the risk of Alzheimer’s disease, and Parkinson’s disease in individuals with previous TBI compared to those without TBI.

Conclusions

History of TBI is not associated with the development of subsequent neurodegeneration disease. Care must be taken in extrapolating from these results because no suitable criteria define post TBI neurodegenerative processes. Therefore, further research in this area is needed to confirm these questions and uncover the link between TBI and neurodegeneration disease.

Models used in the study of traumatic brain injury

Traumatic brain injury (TBI) is a contemporary health problem and a leading cause of mortality and morbidity worldwide. Survivors of TBI frequently experience disabling long-term changes in cognition, sensorimotor function, and personality. A crucial step in understanding TBI and providing better treatment has been the use of models to mimic the event under controlled conditions. Here, we describe the known head injury models, which can be classified as whole animal (in vivo), in vitro, and mathematical models. We will also review the ways in which these models have advanced the knowledge of TBI.

Shock waves increase pulmonary vascular leakage, inflammation, oxidative stress, and apoptosis in a mouse model

Severe lung damage is a major cause of death in blast victims, but the mechanisms of pulmonary blast injury are not well understood. Therefore, it is important to study the injury mechanism of pulmonary blast injury. A model of lung injury induced by blast exposure was established by using a simulation blast device. The effectiveness and reproducibility of the device were investigated. Eighty mice were randomly divided into eight groups: control group and 3 h, 6 h, 12 h, 24 h, 48 h, 7 days and 14 days post blast. The explosive device induced an explosion injury model of a single lung injury in mice. The success rate of the model was as high as 90%, and the degree of lung injury was basically the same under the same pressure. Under the same conditions, the thickness of the aluminum film can be from 0.8 mm to 1.6 mm, and the peak pressure could be from 95.85 ± 15.61 PSI to 423.32 ± 11.64 PSI. There is no statistical difference in intragroup comparison. A follow-up lung injury experiment using an aluminum film thickness of 1.4 mm showed a pressure of 337.46 ± 18.30 PSI induced a mortality rate of approximately 23.2%. Compared with the control group (372 ± 23 times/min, 85.9 ± 9.4 mmHg, 4.34 ± 0.09), blast exposed mice had decreased heart rate (283 ± 21 times/min) and blood pressure (73.6 ± 3.6 mmHg), and increased lung wet/dry weight ratio(2.67 ± 0.11), marked edematous lung tissue, ruptured blood vessels, infiltrating inflammatory cells, increased NF-κB (4.13 ± 0.01), TNF-α (4.13 ± 0.01), IL-1β (2.43 ± 0.01) and IL-6 (4.65 ± 0.01) mRNA and protein, decreased IL-10(0.18 ± 0.02) mRNA and protein ( P < 0.05). The formation of ROS and the expression of MDA5 (4.46 ± 0.01) and IREα (3.43 ± 0.00) mRNA and protein were increased and the expression of SOD-1 (0.28 ± 0.02) mRNA and protein was decreased ( P < 0.05). Increased expression of Bax (3.54 ± 0.00) and caspase 3 (4.18 ± 0.01) mRNA and protein inhibited the expression of Bcl-2 (0.39 ± 0.02) mRNA and protein. The changes of pulmonary edema, inflammatory cell infiltration, and cell damage factor expression increased gradually with time, and reached the peak at 12-24 h after the outbreak, and returned to normal at 7-14 days. Detonation injury can lead to edema of lung tissue, pulmonary hemorrhage, rupture of pulmonary vessels, induction of early inflammatory responses accompanied by increased oxidative stress in lung tissue cells and increased apoptosis in mice experiencing blast injury. The above results are consistent with those reported in other literatures. It is showed that the mouse lung blast injury model is successfully modeled, and the device can be used for the study of pulmonary blast injury. Impact statement The number of patients with explosive injury has increased year by year, but there is no better treatment. However, the research on detonation injury is difficult to carry out. One of the factors is the difficulty in making the model of blast injury. The laboratory successfully developed and produced a simulation device of explosive knocking through a large amount of literature data and preliminary experiments, and verified the preparation of the simulation device through various experimental techniques. The results showed that the device could simulate the shock wave-induced acute lung injury generated, which was similar to the actual knocking injury. The experimental process was controlled. Under the same condition, there was no statistical difference between the groups. It is possible to realize miniaturization and precision of an explosive knocking simulation device, which is a good experimental tool for further research on the mechanism of organ damage caused by detonation and the development of protective drugs.

Biofluid biomarkers of traumatic brain injury

PRIMARY OBJECTIVE

The purpose of this paper is to review the clinical and research utility and applications of blood, cerebrospinal fluid (CSF), and cerebral microdialysis biomarkers in traumatic brain injury (TBI).

RESEARCH DESIGN

Not applicable.

METHODS AND PROCEDURES

A selective review was performed on these biofluid biomarkers in TBI.

MAIN OUTCOME AND RESULTS

Neurofilament heavy chain protein (NF-H), glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase-L1 (UCHL1), neuron-specific enolase (NSE), myelin basic protein (MBP), tau, and s100β blood biomarkers are elevated during the acute phase of severe head trauma but have key limitations in their research and clinical applications to mild TBI (mTBI). CSF biomarkers currently provide the best reflection of the central nervous system (CNS) pathobiological processes in TBI. Both animal and human studies of TBI have demonstrated the importance of serial sampling of biofluids and suggest that CSF biomarkers may be better equipped to characterize both TBI severity and temporal profiles.

CONCLUSIONS

The identification of biofluid biomarkers could play a vital role in identifying, diagnosing, and treating the underlying individual pathobiological changes of TBI. CNS-derived exosomes analyzed by ultra-high sensitivity detection methods have the potential to identify blood biomarkers for the range of TBI severity and time course.

Implication of the Kallikrein-Kinin system in neurological disorders: Quest for potential biomarkers and mechanisms

Neurological disorders represent major health concerns in terms of comorbidity and mortality worldwide. Despite a tremendous increase in our understanding of the pathophysiological processes involved in disease progression and prevention, the accumulated knowledge so far resulted in relatively moderate translational benefits in terms of therapeutic interventions and enhanced clinical outcomes. Aiming at specific neural molecular pathways, different strategies have been geared to target the development and progression of such disorders. The kallikrein-kinin system (KKS) is among the most delineated candidate systems due to its ubiquitous roles mediating several of the pathophysiological features of these neurological disorders as well as being implicated in regulating various brain functions. Several experimental KKS models revealed that the inhibition or stimulation of the two receptors of the KKS system (B1R and B2R) can exhibit neuroprotective and/or adverse pathological outcomes. This updated review provides background details of the KKS components and their functions in different neurological disorders including temporal lobe epilepsy, traumatic brain injury, stroke, spinal cord injury, Alzheimer's disease, multiple sclerosis and glioma. Finally, this work will highlight the putative roles of the KKS components as potential neurotherapeutic targets and provide future perspectives on the possibility of translating these findings into potential clinical biomarkers in neurological disease.

Effects of tissue processing on bioactivity of cartilage matrix-based hydrogels encapsulating osteoconductive particles

In the treatment of severe traumatic brain injury (TBI), decompressive craniectomy is commonly used to remove a large portion of calvarial bone to allow unimpeded brain swelling. Hydrogels have the potential to revolutionize TBI treatment by permitting a single-surgical intervention, remaining pliable during brain swelling, and tuned to regenerate bone after swelling has subsided. With this motivation, our goal is to present a pliable material capable of regenerating calvarial bone across a critical size defect. We therefore proposed the use of a methacrylated solubilized decellularized cartilage (MeSDCC) hydrogel encapsulating synthetic osteogenic particles of hydroxyapatite nanofibers, bioglass microparticles, or added rat bone marrow-derived mesenchymal stem cells (rMSCs) for bone regeneration in critical-size rat calvarial defects. Fibrin hydrogels were employed as a control material for the study. MeSDCC hydrogels exhibited sufficient rheological performance for material placement before crosslinking ([Formula: see text] > 500 Pa), and sufficient compressive moduli post-crosslinking (E > 150 kPa). In vitro experiments suggested increased calcium deposition for cells seeded on the MeSDCC material; however, in vivo bone regeneration was minimal in both MeSDCC and fibrin groups, even with colloidal materials or added rMSCs. Minimal bone regeneration in the MeSDCC test groups may potentially be attributed to cartilage solubilization after decellularization, in which material signals may have degraded from enzymatic treatment. Looking to the future, an improvement in the bioactivity of the material will be crucial to the success of bone regeneration strategies for TBI treatment.

Combination Therapy for Multi-Target Manipulation of Secondary Brain Injury Mechanisms

Traumatic brain injury (TBI) is a major healthcare problem that affects millions of people worldwide. Despite advances in understanding and developing preventative and treatment strategies using preclinical animal models, clinical trials to date have failed, and a 'magic bullet' for effectively treating TBI-induced damage does not exist. Thus, novel pharmacological strategies to effectively manipulate the complex and heterogeneous pathophysiology of secondary injury mechanisms are needed. Given that goal, this paper discusses the relevance and advantages of combination therapies (COMTs) for 'multi-target manipulation' of the secondary injury cascade by administering multiple drugs to achieve an optimal therapeutic window of opportunity (e.g., temporally broad window) and compares these regimens to monotherapies that manipulate a single target with a single drug at a given time. Furthermore, we posit that integrated mechanistic multiscale models that combine primary injury biomechanics, secondary injury mechanobiology/neurobiology, physiology, pharmacology and mathematical programming techniques could account for vast differences in the biological space and time scales and help to accelerate drug development, to optimize pharmacological COMT protocols and to improve treatment outcomes.

Lack of mitochondrial ferritin aggravated neurological deficits via enhancing oxidative stress in a traumatic brain injury murine model

Oxidative stress has been strongly implicated in the pathogenesis of traumatic brain injury (TBI). Mitochondrial ferritin (Ftmt) is reported to be closely related to oxidative stress. However, whether Ftmt is involved in TBI-induced oxidative stress and neurological deficits remains unknown. In the present study, the controlled cortical impact model was established in wild-type and Ftmt knockout mice as a TBI model. The Ftmt expression, oxidative stress, neurological deficits, and brain injury were measured. We found that Ftmt expression was gradually decreased from 3 to 14 days post-TBI, while oxidative stress was gradually increased, as evidenced by reduced GSH and superoxide dismutase levels and elevated malondialdehyde and nitric oxide levels. Interestingly, the extent of reduced Ftmt expression in the brain was linearly correlated with oxidative stress. Knockout of Ftmt significantly exacerbated TBI-induced oxidative stress, intracerebral hemorrhage, brain infarction, edema, neurological severity score, memory impairment, and neurological deficits. However, all these effects in Ftmt knockout mice were markedly mitigated by pharmacological inhibition of oxidative stress using an antioxidant, N-acetylcysteine. Taken together, these results reveal an important correlation between Ftmt and oxidative stress after TBI. Ftmt deficiency aggravates TBI-induced brain injuries and neurological deficits, which at least partially through increasing oxidative stress levels. Our data suggest that Ftmt may be a promising molecular target for the treatment of TBI.

Monitoring changes of docosahexaenoic acid-containing lipids during the recovery process of traumatic brain injury in rat using mass spectrometry imaging

Brain lipid homoeostasis is critical during recovery process after traumatic brain injury (TBI). In this study, we integrated liquid extraction and electrosonic spray ionization technology to develop an ionization device coupled with a Fourier transform ion cyclotron resonance mass spectrometer for imaging of docosahexaenoic acid (DHA)-containing lipids on rat brain tissues. The ion images of the brain tissue sections from the normal rats and the rats after TBI at acute phase (0 and 1 day) and chronic phase (3, 5, and 7 days) were obtained. The imaging results indicate that the levels of DHA and lyso-phosphatidylethanolamine (22:6) in the injury area of TBI rats increased significantly at the acute phase and subsequently decreased at the chronic phase. But the levels of DHA-containing phospholipids including phosphatidylethanolamine (PE)(P-18:0/22:6), PE(18:0/22:6), and phosphatidylserine (18:0/22:6) decreased at the acute phase and gradually increased at the chronic phase in the injury area accompanied by the morphogenesis and wound healing. These findings indicate that the DHA may participate in the recovery process of brain injury. This is the first report to in situ detect the changes in the levels of DHA and DHA-containing lipids in the TBI model.

Considerations for Experimental Animal Models of Concussion, Traumatic Brain Injury, and Chronic Traumatic Encephalopathy-These Matters Matter

Animal models of concussion, traumatic brain injury (TBI), and chronic traumatic encephalopathy (CTE) are widely available and routinely deployed in laboratories around the world. Effective animal modeling requires careful consideration of four basic principles. First, animal model use must be guided by clarity of definitions regarding the human disease or condition being modeled. Concussion, TBI, and CTE represent distinct clinical entities that require clear differentiation: concussion is a neurological syndrome, TBI is a neurological event, and CTE is a neurological disease. While these conditions are all associated with head injury, the pathophysiology, clinical course, and medical management of each are distinct. Investigators who use animal models of these conditions must take into account these clinical distinctions to avoid misinterpretation of results and category mistakes. Second, model selection must be grounded by clarity of purpose with respect to experimental questions and frame of reference of the investigation. Distinguishing injury context ("inputs") from injury consequences ("outputs") may be helpful during animal model selection, experimental design and execution, and interpretation of results. Vigilance is required to rout out, or rigorously control for, model artifacts with potential to interfere with primary endpoints. The widespread use of anesthetics in many animal models illustrates the many ways that model artifacts can confound preclinical results. Third, concordance between key features of the animal model and the human disease or condition being modeled is required to confirm model biofidelity. Fourth, experimental results observed in animals must be confirmed in human subjects for model validation. Adherence to these principles serves as a bulwark against flawed interpretation of results, study replication failure, and confusion in the field. Implementing these principles will advance basic science discovery and accelerate clinical translation to benefit people affected by concussion, TBI, and CTE.

Neurobehavioral Management of Traumatic Brain Injury in the Critical Care Setting: An Update

Traumatic brain injury (TBI) is an alteration in brain function, or other evidence of brain pathology, caused by an external force. TBI is a major cause of disability and mortality worldwide. Post-traumatic amnesia, or the interval from injury until the patient is oriented and able to form and later recall new memories, is an important index of TBI severity and functional outcome. This article will discuss the updates in the epidemiology, definition and classification, pathophysiology, diagnosis, and management of common acute neuropsychiatric sequelae of traumatic brain injury that the critical care specialist may encounter.

Propofol Inhibits NLRP3 Inflammasome and Attenuates Blast-Induced Traumatic Brain Injury in Rats

Increasing evidence has demonstrated that inflammatory response plays a crucial role in the pathogenesis of secondary injury following blast-induced traumatic brain injury (bTBI). Propofol, a lipid-soluble intravenous anesthetic, has been shown to possess therapeutic benefit during neuroinflammation on various brain injury models. Recent findings have proved that the NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome involved in the process of the inflammatory response following brain trauma, may probably be a promising target in the treatment of bTBI. Rats were randomly divided into six groups (n = 8): normal group; bTBI-12 and 24 h group; bTBI-12 h and bTBI-24 h group treated with propofol; and bTBI treated with control dimethyl sulfoxide (DMSO) group. The effect of propofol on the expression and activation of NLRP3 inflammasome and the degree of oxidative stress and inflammatory cascades, as well as the brain trauma biomarkers were evaluated in rats suffering from bTBI. The enhanced expressions and activation of NLRP3 inflammasome in the cerebral cortex of bTBI rats were substantially suppressed by the administration of propofol, which was paralleled with the decreased oxidative stress, cytokines production, and the amelioration of cerebral cortex damage. Our results have, for the first time, revealed that over-activation of NLRP3 inflammasome in the cerebral cortex may be involved in the process of neuroinflammation during the secondary injury of bTBI in rats. Propofol might relieve the inflammatory response and attenuate brain injury by inhibiting ROS and reluctant depressing NLRP3 inflammasome activation and pro-inflammatory cytokines maturation.

Traumatic Brain Injury Incidence, Clinical Overview, and Policies in the US Military Health System Since 2000

Exposure to explosive armaments during Operation Iraqi Freedom and Operation Enduring Freedom contributed to approximately 14% of the 352 612 traumatic brain injury (TBI) diagnoses in the US military between 2000 and 2016. The US Department of Defense issued guidelines in 2009 to (1) standardize TBI diagnostic criteria; (2) classify TBI according to mechanism and severity; (3) categorize TBI symptoms as somatic, psychological, or cognitive; and (4) systematize types of care given during the acute and rehabilitation stages of TBI treatment. Polytrauma and associated psychological and neurologic conditions may create barriers to optimal rehabilitation from TBI. Given the completion of recent combat operations and the transition of TBI patients into long-term care within the US Department of Veterans Affairs system, a review of the literature concerning TBI is timely. Long-term follow-up care for patients who have sustained TBI will remain a critical issue for the US military.

Colloidal Gels with Extracellular Matrix Particles and Growth Factors for Bone Regeneration in Critical Size Rat Calvarial Defects

Colloidal gels encapsulating natural materials and exhibiting paste-like properties for placement are promising for filling complex geometries in craniofacial bone regeneration applications. Colloidal materials have demonstrated modest clinical outcomes as bone substitutes in orthopedic applications, but limited success in craniofacial applications. As such, development of a novel colloidal gel will fill a void in commercially available products for use in craniofacial reconstruction. One likely application for this technology is cranial reconstruction. Currently, traumatic brain injury (TBI) is often treated with a hemi-craniectomy, a procedure in which half the cranium is removed to allow the injured brain to swell and herniate beyond the enclosed cranial vault. The use of colloidal gels would allow for the design of a pliable material capable of expansion during brain swelling and facilitate cranial bone regeneration alleviating the need for a second surgery to replace the previously removed hemi-cranium. In the current study, colloidal nanoparticles of hydroxyapatite (HAp), demineralized bone matrix (DBM), and decellularized cartilage (DCC) were combined with hyaluronic acid (HA) to form colloidal gels with desirable rheological properties ([Formula: see text] ≥ 100 Pa). BMP-2 and VEGF growth factors were included to assess extracellular matrix (ECM) contribution of DBM and DCC. The HA-HAp (BMP-2) and HA-HAp-DCC group had 89 and 82% higher bone regeneration compared to the sham group, respectively (p < 0.01). Material retention issues observed may be alleviated by implementing chemical crosslinking. Overall, DCC may be a promising material for bone regeneration in general, and colloidal gels may hold significant potential in craniofacial applications.

A multi-body dynamics study on a weight-drop test of rat brain injury

Traumatic brain injury (TBI), induced by impact of an object with the head, is a major health problem worldwide. Rats are a well-established animal analogue for study of TBI and the weight-drop impact-acceleration (WDIA) method is a well-established model in rats for creating diffuse TBI, the most common form of TBI seen in humans. However, little is known of the biomechanics of the WDIA method and, to address this, we have developed a four-degrees-of-freedom multi-body mass-spring-damper model for the WDIA test in rats. An analytical expression of the maximum skull acceleration, one of the important head injury predictor, was derived and it shows that the maximum skull acceleration is proportional to the impact velocity but independent of the impactor mass. Furthermore, a dimensional analysis disclosed that the maximum force on the brain and maximum relative displacement between brain and skull are also linearly proportional to impact velocity. Additionally, the effects of the impactor mass were examined through a parametric study from the developed multi-body dynamics model. It was found that increasing impactor mass increased these two brain injury predictors.

Post-concussion symptoms and chronic pain after mild traumatic brain injury are modulated by multiple locus effect in the BDNF gene through the expression of antisense: A pilot prospective control study

Background: Mild traumatic brain injury (mTBI) often results in post-concussion symptoms, chronic pain, and sleepiness. Genetic factors are thought to play an important role in poor prognosis.

Aims: The aims of this study are to (1) document the prevalence of pain and post-concussion symptoms in mTBI patients in acute and chronic phases (2) determine whether candidate genes predispose to post-concussive symptoms and pain.

Methods: Posttraumatic symptoms, evaluated using the Rivermead Post-Concussion Symptoms Questionnaire, and pain were assessed in 94 mTBI patients in the acute phase as well as in 22 healthy controls. Assessment was repeated in 36 patients after one year who agreed to participate in the follow-up visit. Gene polymorphisms and expression were assessed in mTBI patients and healthy controls.

Results: In the acute phase, mTBI patients with pain (69%) presented more psychological symptoms and sleepiness and were less able to return to work than those without pain. At one year, 19% of mTBI patients had persistent pain and psychological distress. Two haplotypes (H2 and H3) in the brain-derived neurotrophic factor (BDNF) gene were shown to be respectively deleterious and protective against post-concussion symptoms and pain in both acute and chronic phases. Protective haplotype H3 was associated with a decreased expression of the anti-sense of BDNF (BDNF-AS). Deleterious haplotype H2 predicted the development of chronic pain at one year, whereas H3 was protective.

Conclusions: This pilot study suggests a protective mechanism of a multilocus effect in BDNF, through BDNF-AS, against post-concussion symptoms and pain in the acute phase and possibly chronic pain at one year post-mTBI. The role of antisense RNA should be validated in larger cohorts.