Randomized controlled trials in adult traumatic brain injury

ApoE Mimetic Peptides as Therapy for Traumatic Brain Injury

The lack of targeted therapies for traumatic brain injury (TBI) remains a compelling clinical unmet need. Although knowledge of the pathophysiologic cascades involved in TBI has expanded rapidly, the development of novel pharmacological therapies has remained largely stagnant. Difficulties in creating animal models that recapitulate the different facets of clinical TBI pathology and flaws in the design of clinical trials have contributed to the ongoing failures in neuroprotective drug development. Furthermore, multiple pathophysiological mechanisms initiated early after TBI that progress in the subacute and chronic setting may limit the potential of traditional approaches that target a specific cellular pathway for acute therapeutic intervention. We describe a reverse translational approach that focuses on translating endogenous mechanisms known to influence outcomes after TBI to develop druggable targets. In particular, numerous clinical observations have demonstrated an association between apolipoprotein E (apoE) polymorphism and functional recovery after brain injury. ApoE has been shown to mitigate the response to acute brain injury by exerting immunomodulatory properties that reduce secondary tissue injury as well as protecting neurons from excitotoxicity. CN-105 represents an apoE mimetic peptide that can effectively penetrate the CNS compartment and retains the neuroprotective properties of the intact protein.

Psychiatric sequelae of traumatic brain injury - future directions in research

Despite growing appreciation that traumatic brain injury (TBI) is an important public health burden, our understanding of the psychiatric and behavioural consequences of TBI remains limited. These changes are particularly detrimental to a person's sense of self, their relationships and their participation in the wider community, and they continue to have devastating individual and cumulative effects long after TBI. This Review relates specifically to TBIs that confer objective clinical or biomarker evidence of structural brain injury; symptomatic head injuries without such evidence are outside the scope of this article. Common psychiatric, affective and behavioural sequelae of TBI and their proposed underlying mechanisms are outlined, along with a brief overview of current treatments. Suggestions for how scientists and clinicians can work together in the future to address the chasms in clinical care and knowledge are discussed in depth.

Effects of early adjunctive pharmacotherapy on serum levels of brain injury biomarkers in patients with traumatic brain injury: a systematic review of randomized controlled studies

Objectives: Traumatic brain injury (TBI) is one of the top causes of morbidity and mortality worldwide. The review aimed to discuss and summarize the current evidence on the effectiveness of adjuvant neuroprotective treatments in terms of their effect on brain injury biomarkers in TBI patients. Methods: To identify relevant studies, four scholarly databases, including PubMed, Cochrane, Scopus, and Google Scholar, were systematically searched using predefined search terms. English-language randomized controlled clinical trials reporting changes in brain injury biomarkers, namely, neuron-specific enolase (NSE), glial fibrillary acid protein (GFAP), ubiquitin carboxyl-terminal esterase L1 (UCHL₁) and/or S100 beta (S100 ß), were included. The methodological quality of the included studies was assessed using the Cochrane risk-of-bias tool. Results: A total of eleven studies with eight different therapeutic options were investigated; of them, tetracyclines, metformin, and memantine were discovered to be promising choices that could improve neurological outcomes in TBI patients. The most utilized serum biomarkers were NSE and S100 ß followed by GFAP, while none of the included studies quantified UCHL₁. The heterogeneity in injury severity categories and measurement timing may affect the overall evaluation of the clinical efficacy of potential therapies. Therefore, unified measurement protocols are highly warranted to inform clinical decisions. Conclusion: Few therapeutic options showed promising results as an adjuvant to standard care in patients with TBI. Several considerations for future work must be directed towards standardizing monitoring biomarkers. Investigating the pharmacotherapy effectiveness using a multimodal biomarker panel is needed. Finally, employing stratified randomization in future clinical trials concerning potential confounders, including age, trauma severity levels, and type, is crucial to inform clinical decisions. Clinical Trial Registration: [https://www.crd.york.ac.uk/prospero/dis], identifier [CRD42022316327].

Mediators, Moderators, and Covariates: Matching Analysis Approach for Improved Precision in Cognitive-Communication Rehabilitation Research

PURPOSE

The dual goals of this tutorial are (a) to increase awareness and use of mediation and moderation models in cognitive-communication rehabilitation research by describing options, benefits, and attainable analytic approaches for researchers with limited resources and sample sizes and (b) to describe how these findings may be interpreted for clinicians consuming research to inform clinical care.

METHOD

We highlight key insights from the social sciences literature pointing to the risks of common approaches to linear modeling, which may slow progress in clinical-translational research and reduce the clinical utility of our work. We discuss the potential of mediation and moderation analyses to reduce the research-to-practice gap and describe how researchers may begin to implement these models, even in smaller sample sizes. We discuss how these preliminary analyses can help focus resources for larger trials to fully encapsulate the heterogeneity of individuals with cognitive-communication disorders.

RESULTS

In rehabilitation research, we study groups, but we use the findings from those studies to treat individuals. The most functional clinical research is about more than establishing only whether a given effect exists for an "average person" in the group of interest. It is critical to understand the active ingredients and mechanisms of action by which a given treatment works (mediation) and to know which circumstances, contexts, or individual characteristics might make that treatment most beneficial (moderation).

CONCLUSIONS

Increased adoption of mediation and moderation approaches, executed in appropriate steps, could accelerate progress in cognitive-communication rehabilitation research and lead to the development of targeted treatments that work for more clients. In a field that has made limited progress in developing successful interventions for the last several decades, it is critical that we harness new approaches to advance clinical-translational research results for complex, heterogeneous groups with cognitive-communication disorders.

Clinical Outcome of Patients Diagnosed Traumatic Intracranial Epidural Hematoma With Severe Brain Injury (Glasgow Coma Scale ≤8) Who Undergo Surgery: A Report From the Korean Neuro-Trauma Data Bank System

OBJECTIVE

To evaluate the clinical outcomes and prognostic factors in surgically treated patients with severe brain injury (Glasgow Coma Scale [GCS] score ≤8) diagnosed with traumatic epidural hematoma (EDH).

METHODS

From January 2018 to June 2021, 1,122 patients with an initial GCS score ≤8 were retrospectively enrolled in the Korean Neuro-Trauma Data Bank System. Clinical data of 79 surgically treated patients with EDH were compared between the unfavorable (scores of 1-4 on the Glasgow Outcome Scale-Extended [GOSE]) and favorable (score of 5-8 on the GOSE) outcome groups.

RESULTS

The overall mortality rate was 13.9%, and 60.8% of the patients had good outcomes at six months post-trauma. In the univariate analysis, increasing age (p=0.010), lower initial GCS score (p=0.001), higher Rotterdam computed tomography (CT) score (p=0.012), craniotomy rather than craniectomy (p=0.032), larger EDH volume (p=0.007), and loss of pupillary reactivity (unilateral unreactive pupil, p=0.026; bilateral unreactive pupils, p<0.001), were significantly correlated with unfavorable outcomes. Of these factors, increasing age (p=0.011) and bilateral unreactive pupils (p=0.002) were the most significant risk factors in the multivariate logistic regression analysis. The interval from admission to the brain CT scan was not correlated with the outcome; however, it was significantly longer in the unfavorable outcome group.

CONCLUSION

Despite severe brain injury, more than half of the patients with EDH had favorable outcomes after surgical treatment. Our findings suggest that prompt diagnosis and surgical treatment should be considered for such cases.

An overview of systematic reviews on the pharmacological randomized controlled trials for reducing intracranial pressure after traumatic brain injury

BACKGROUND

There is a need for an overview of systematic reviews (SRs) examining randomized clinical trials (RCTs) of pharmacological interventions in the treatment of intracranial pressure (ICP) post-TBI.

OBJECTIVES

To summarize pharmacological effectiveness in decreasing ICP in SRs with RCTs and evaluate study quality.

METHODS

Comprehensive literature searches were conducted in MEDLINE, PubMed, EMBASE, PsycINFO, and Cochrane Library databases for English SRs through October 2020. Inclusion criteria were SRs with RCTs that examined pharmacological interventions to treat ICP in patients post-TBI. Data extracted were participant characteristics, pharmacological interventions, and ICP outcomes. Study quality was assessed with AMSTAR-2.

RESULTS

Eleven SRs between 2003 and 2020 were included. AMSTAR-2 ratings revealed 3/11 SRs of high quality. Pharmacological interventions included hyperosmolars, neuroprotectives, anesthetics, sedatives, and analgesics. Study samples ranged from 7 to 1282 patients. Hyperosmolar agents and sedatives were beneficial in lowering elevated ICP. High bolus dose opioids had a more deleterious effect on ICP. Neuroprotective agents did not show any effects in ICP management. RCT sample sizes and findings in the SRs varied. A lack of detailed data syntheses was noted. AMSTAR-2 analysis revealed moderate-to-high quality in most SRs. Future SRs may focus on streamlined reporting of dosing and clearer clinical recommendations.

CONCLUSIONS

PROSPERO-Registration: CRD42015017355.

Sleep and Executive Functioning in Pediatric Traumatic Brain Injury Survivors after Critical Care

Over 50,000 children are hospitalized annually for traumatic brain injury (TBI) and face long-term cognitive morbidity. Over 50% develop sleep/wake disturbances (SWDs) that can affect brain development and healing. We hypothesized SWDs would portend worse executive function outcomes in children aged 3−18 years with TBI 1−3 months after hospital discharge. SWDs were defined using the Sleep Disturbances Scale for Children (t-scores ≥ 60). Outcomes included the Global Executive Composite (GEC, t-score) from the Behavior Rating Inventory of Executive Function, Second and Preschool Editions, and multiple objective executive function assessments combined through Principal Components Analysis into a Neurocognitive Index (NCI, z-score). Multiple linear regression evaluated associations between SWDs and executive function outcomes, controlling for covariates. Among 131 children, 68% had clinically significant SWDs, which were associated with significantly worse median scores on the GEC (56 vs. 45) and NCI (−0.02 vs. 0.42; both p < 0.05). When controlling for baseline characteristics and injury severity in multivariable analyses, SWDs were associated with worse GEC (β-coefficient = 7.8; 95% Confidence Interval = 2.5, 13.1), and worse NCI (β-coefficient = −0.4; 95% Confidence Interval = −0.8, −0.04). SWDs in children with TBI are associated with worse executive function outcomes after hospital discharge, and may serve as modifiable targets to improve outcomes.

The Value of Patient Registries to Advance Basic and Translational Research in the Area of Traumatic Brain Injury

The number of individuals affected by traumatic brain injury (TBI) is growing globally. TBIs may cause a range of physical, cognitive, and psychiatric deficits that can negatively impact employment, academic attainment, community independence, and interpersonal relationships. Although there has been a significant decrease in the number of injury related deaths over the past several decades, there has been no corresponding reduction in injury related disability over the same time period. We propose that patient registries with large, representative samples and rich multidimensional and longitudinal data have tremendous value in advancing basic and translational research and in capturing, characterizing, and predicting individual differences in deficit profile and outcomes. Patient registries, together with recent theoretical and methodological advances in analytic approaches and neuroscience, provide powerful tools for brain injury research and for leveraging the heterogeneity that has traditionally been cited as a barrier inhibiting progress in treatment research and clinical practice. We report on our experiences, and challenges, in developing and maintaining our own patient registry. We conclude by pointing to some future opportunities for discovery that are afforded by a registry model.

Disparities in Insurance Status are Associated With Outcomes But Not Timing of Trauma Care

INTRODUCTION

Patient factors influence outcomes after injury. Delays in care have a crucial impact. We investigated the associations between patient characteristics and timing of transfer from the emergency department to definitive care.

METHODS

This was a review of adult trauma patients treated between January 1, 2016, and December 31, 2018. Bivariate analyses were used to build Cox proportional hazards models. We built separate logistic and negative binomial regression models for secondary outcomes using mixed-step selection to minimize the Akaike information criterion c.

RESULTS

A total of 1219 patients were included; 68.5% were male, 56.8% White, 11.2% Black, and 7.8% Asian/Pacific Islander. The average age was 51 ± 21 y. Overall, 13.7% of patients were uninsured. The average length of stay was 5 d and mortality was 5.9%. Shorter transfer time out of the emergency department was associated with higher tier of activation (relative risk [RR] 1.39, 95% confidence interval [CI] 1.09-1.77; P = 0.0074), Injury Severity Score between 16 and 24 points (RR 1.57, 95% CI 1.04-2.32; P = 0.0307) or ≥25 (RR 3.85, 95% CI 2.45-5.94; P = 0.0001), and penetrating injury. Longer time to event was associated with Glasgow coma scale score ≥14 points (RR 0.47, 95% CI 0.27-0.85; P = 0.0141). Uninsured patients were less likely to be admitted (odds ratio 0.29, 95% CI 0.17-0.48; P = 0.0001) and more likely to experience shorter length of stay (incidence rate ratio 0.34, 95% CI 0.24-0.51; P = 0.0001).

CONCLUSIONS

Injury characteristics and insurance status were associated with patient outcomes in this retrospective, single-center study. We found no disparity in timing of intrafacility transfer, perhaps indicating that initial management protocols preserve equity.

The effectiveness of memory remediation strategies after traumatic brain injury: Systematic review and meta-analysis

BACKGROUND

Traumatic brain injury (TBI) is a steadily rising health concern associated with significant risk of emotional, behavioral and cognitive impairments. Cognitive memory impairment is one of the most concerning outcomes after TBI, affecting a wide range of everyday activities, social interactions and employment. Several comparative and comprehensive reviews on the effects of cognitive interventions in individuals with TBI have been conducted but usually with a qualitative rather than quantitative approach. Thus, evidence synthesis of the effects of TBI interventions on memory difficulties is limited.

OBJECTIVE

In this meta-analysis, we examined the memory-remediating effects of internal and external interventions, injury severity and the interaction of both factors for patients with TBI.

METHODS

Data were extracted from studies published between 1980 and 2020 that used objective memory measures (computerized or pencil-and-paper), and multiple meta-analyses were conducted to compare effectiveness across these interventions. Publication bias was assessed, as was quality of evidence using the Cochrane Risk of Bias tool for randomized controlled studies. Our final meta-analysis included 16 studies of 17 interventions classified into 3 categories: internal, external and mixed.

RESULTS

Mixed interventions demonstrated the highest average effect size for memory difficulties (Morris d=0.79). An evaluation of injury severity yielded 2 categories: mild-moderate and moderate-severe. Analyses demonstrated a homogenous medium effect size of improvement across injury severity, with moderate-severe injury with the largest average effect size (Morris d=0.65). Further evaluation of injury severity interaction with intervention type revealed a mediating effect for both factors, demonstrating the largest effect size for mixed interventions with moderate-severe injury (Morris d=0.81).

CONCLUSION

This study highlights the effectiveness of memory remediation interventions on memory impairment after TBI. A wide range of interventions are more effective because they address individual variability for severity and memory deficits. The study further supports and expands existing intervention standards and guidelines.

Intervention Effect of Non-Invasive Brain Stimulation on Cognitive Functions among People with Traumatic Brain Injury: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aggregated and examined the treatment effect of non-invasive brain stimulation (NIBS) (transcranial direct current stimulation and transcranial magnetic stimulation) on cognitive functions in people with traumatic brain injury (TBI). A systematic search was conducted using databases (PubMed, Web of Science, Scopus, PsycINFO, EMBASE) for studies with keywords related to non-randomized and randomized control trials of NIBS among people with TBI. Nine out of 1790 NIBS studies with 197 TBI participants (103 active vs. 94 sham) that met the inclusion and exclusion criteria of the present study were finally selected for meta-analysis using Comprehensive Meta-Analysis software (version 3). Results showed that the overall effect of NIBS on cognition in people with TBI was moderately significant (g = 0.304, 95% CI = 0.055 to 0.553) with very low heterogeneity across studies (I² = 0.000, Tau = 0.000). Specifically, significant and marginally significant moderate effect sizes were found for cognitive sub-domains including attention, memory, and executive function. The present findings suggest that NIBS is moderately effective in improving cognitive functions among people with TBI. In particular, NIBS may be used as an alternative and/or an adjunct treatment to the traditional approach in rehabilitating cognitive functions in people with TBI.

Heterogeneity Is a Hallmark of Traumatic Brain Injury, Not a Limitation: A New Perspective on Study Design in Rehabilitation Research

Purpose In both basic science and intervention research in traumatic brain injury (TBI), heterogeneity in the patient population is frequently cited as a limitation and is often interpreted as a factor reducing certainty in the generalizability of research findings and as a source of conflicting findings across studies. Historically, much of TBI research in rehabilitation and cognition has relied upon case-control studies, with small to modest sample sizes. In this context, heterogeneity is indeed a significant limitation. Here, however, we argue that heterogeneity in patient profiles is a hallmark characteristic of TBI and therefore cannot be avoided or ignored. We argue that this inherent heterogeneity must be acknowledged and accounted for prior to study design. Fortunately, advances in statistical methods and computing power allow researchers to leverage heterogeneity, rather than be constrained by it. Method In this article, we review sources of heterogeneity that contribute to challenges in TBI research, highlight methodological advances in statistical analysis and in other fields with high degrees of heterogeneity (e.g., psychiatry) that may be fruitfully applied to decomposing heterogeneity in TBI, and offer an example from our research group incorporating this approach. Conclusion Only by adopting new methodological approaches can we advance the science of rehabilitation following TBI in ways that will impact clinical practice and inform decision making, allowing us to understand and respond to the range of individual differences that are a hallmark in this population.

Evaluation of Diffusion Tensor Imaging and Fluid Based Biomarkers in a Large Animal Trial of Cyclosporine in Focal Traumatic Brain Injury

All phase III trials evaluating medical treatments for traumatic brain injury (TBI), performed to date, have failed. To facilitate future success there is a need for novel outcome metrics that can bridge pre-clinical studies to clinical proof of concept trials. Our objective was to assess diffusion tensor imaging (DTI) and biofluid-based biomarkers as efficacy outcome metrics in a large animal study evaluating the efficacy of cyclosporine in TBI. This work builds on our previously published study that demonstrated a reduced volume of injury by 35% with cyclosporine treatment based on magnetic resonance imaging (MRI) results. A focal contusion injury was induced in piglets using a controlled cortical impact (CCI) device. Cyclosporine in a novel Cremophor/Kolliphor EL-free lipid emulsion, NeuroSTAT, was administered by continuous intravenous infusion for 5 days. The animals underwent DTI on day 5. Glial fibrillary acidic protein (GFAP), as a measure of astroglia injury, and neurofilament light (NF-L), as a measure of axonal injury, were measured in blood on days 1, 2, and 5, and in cerebrospinal fluid (CSF) on day 5 post-injury. Normalized fractional anisotropy (FA) was significantly (p = 0.027) higher in in the treatment group, indicating preserved tissue integrity with treatment. For the biomarkers, we observed a statistical trend of a decreased level of NF-L in CSF (p = 0.051), in the treatment group relative to placebo, indicating less axonal injury. Our findings suggest that DTI, and possibly CSF NF-L, may be feasible as translational end-points assessing neuroprotective drugs in TBI.

Traumatic brain injury modifies synaptic plasticity in newly-generated granule cells of the adult hippocampus

The hippocampus is vulnerable to traumatic brain injury (TBI), and hippocampal damage is associated with cognitive deficits that are often the hallmark of TBI. Recent studies have found that TBI induces enhanced neurogenesis in the dentate gyrus (DG) of the hippocampus, and this cellular response is related to innate cognitive recovery. However, cellular mechanisms of the role of DG neurogenesis in post-TBI recovery remain unclear. This study investigated changes in long-term potentiation (LTP) within the DG in relation to TBI-induced neurogenesis. Adult male rats received a moderate TBI or sham injury and were sacrificed for brain slice recordings at 30 or 60 days post-injury. Recordings were taken from the medial perforant path input to DG granule cells in the presence or absence of the GABAergic antagonist picrotoxin, reflecting activity of either all DG granule cells or predominately newborn granule cells, respectively. Measurements of LTP observed in the total granule cell population (with picrotoxin) showed a prolonged impairment which worsened between 30 and 60 days post-TBI. Under conditions which predominantly reflected the LTP elicited in newly born granule cells (no picrotoxin), a strikingly different pattern of post-TBI changes was observed, with a time-dependent cycle of functional impairment and recovery. At 30 days after injury this cell population showed little or no LTP, but by 60 days the capacity for LTP of the newly born granule cells was no different from that of sham controls. The time-frame of LTP improvements in the newborn cell population, comparable to that of behavioral recovery reported previously, suggests the unique functional properties of newborn granule cells enable them to contribute to restorative change following brain injury.

Risperidone versus placebo for aggression following traumatic brain injury: a feasibility randomised controlled trial

OBJECTIVES

To conduct a feasibility randomised controlled trial of risperidone for the treatment of aggression in adults with traumatic brain injury (TBI).

DESIGN

Multicentre, parallel design, placebo controlled (1:1 ratio) double-blind feasibility trial with an embedded process evaluation. No statistical comparison was performed between the two study groups.

SETTING

Four neuropsychiatric and neurology outpatient clinics in London and Kent, UK.

PARTICIPANTS

Our aim was to recruit 50 patients with TBI over 18 months. Follow-up participants at 12 weeks using a battery of assessment scales to measure changes in aggressive behaviour and irritability (Modified Overt Aggression Scale (MOAS)-primary outcome, Irritability Questionnaire) as well as global functioning (Glasgow Outcome Scale-Extended, Clinical Global impression) and quality of life (EQ-5D-5L, SF-12), mental health (Hospital Anxiety and Depression Scale) and medication adverse effects (Udvalg for Kliniske Undersøgelser).

RESULTS

Six participants were randomised to the active arm of the trial and eight to the placebo arm over a 10-month period (28% of our target). Two participants withdrew because of adverse events. Twelve out of 14 (85.7%) patients completed a follow-up assessment at 12 weeks. At follow-up, the scores of all outcome measures improved in both groups. Placebo group showed numerically better score change according to the primary outcome MOAS. No severe adverse events were reported. The overall rate of adverse events remained low. Data from the process evaluation suggest that existence of specialised TBI follow-up clinics, availability of a dedicated database of TBI patients' clinical details, simple study procedures and regular support to participants would enhance recruitment and retention in the trial. Feedback from participants showed that once in the study, they did not find the trial procedure onerous.

CONCLUSIONS

It was not feasible to conduct a successful randomised trial of risperidone versus placebo for post-TBI aggression using the methods we deployed in this study. It is not possible to draw any definitive conclusion about risperidone's efficacy from such a small trial.

TRIAL REGISTRATION NUMBER

ISRCTN30191436.

Polyplex transfection from intracerebroventricular delivery is not significantly affected by traumatic brain injury

Traumatic brain injury (TBI) is largely non-preventable and often kills or permanently disables its victims. Because current treatments for TBI merely ameliorate secondary effects of the initial injury like swelling and hemorrhaging, strategies for the induction of neuronal regeneration are desperately needed. Recent discoveries regarding the TBI-responsive migratory behavior and differentiation potential of neural progenitor cells (NPCs) found in the subventricular zone (SVZ) have prompted strategies targeting gene therapies to these cells to enhance neurogenesis after TBI. We have previously shown that plasmid polyplexes can non-virally transfect SVZ NPCs when directly injected in the lateral ventricles of uninjured mice. We describe the first reported intracerebroventricular transfections mediated by polymeric gene carriers in a murine TBI model and investigate the anatomical parameters that dictate transfection through this route of administration. Using both luciferase and GFP plasmid transfections, we show that the time delay between injury and polyplex injection directly impacts the magnitude of transfection efficiency, but that overall trends in the location of transfection are not affected by injury. Confocal microscopy of quantum dot-labeled plasmid uptake in vivo reveals association between our polymers and negatively charged NG2 chondroitin sulfate proteoglycans of the SVZ extracellular matrix. We further validate that glycosaminoglycans but not sulfate groups are required for polyplex uptake and transfection in vitro. These studies demonstrate that non-viral gene delivery is impacted by proteoglycan interactions and suggest the need for improved polyplex targeting materials that penetrate brain extracellular matrix to increase transfection efficiency in vivo.

Cell therapy for central nervous system disorders: Current obstacles to progress

Cell therapy for disorders of the central nervous system has progressed to a new level of clinical application. Various clinical studies are underway for Parkinson's disease, stroke, traumatic brain injury, and various other neurological diseases. Recent biotechnological developments in cell therapy have taken advantage of the technology of induced pluripotent stem (iPS) cells. The advent of iPS cells has provided a robust stem cell donor source for neurorestoration via transplantation. Additionally, iPS cells have served as a platform for the discovery of therapeutics drugs, allowing breakthroughs in our understanding of the pathology and treatment of neurological diseases. Despite these recent advances in iPS, adult tissue‐derived mesenchymal stem cells remain the widely used donor for cell transplantation. Mesenchymal stem cells are easily isolated and amplified toward the cells' unique trophic factor‐secretion property. In this review article, the milestone achievements of cell therapy for central nervous system disorders, with equal consideration on the present translational obstacles for clinic application, are described.

Randomised controlled clinical trial of a structured cognitive rehabilitation in patients with attention deficit following mild traumatic brain injury: study protocol

OBJECTIVES

To measure the clinical, structural and functional changes of an individualised structured cognitive rehabilitation in mild traumatic brain injury (mTBI) population.

SETTING

A single centre study, Malaysia.

PARTICIPANTS

Adults aged between 18 and 60 years with mTBI as a result of road traffic accident, with no previous history of head trauma, minimum of 9 years education and abnormal cognition at 3 months will be included. The exclusion criteria include pre-existing chronic illness or neurological/psychiatric condition, long-term medication that affects cognitive/psychological status, clinical evidence of substance intoxication at the time of injury and major polytrauma. Based on multiple estimated calculations, the minimum intended sample size is 50 participants (Cohen's d effect size=0.35; alpha level of 0.05; 85% power to detect statistical significance; 40% attrition rate).

INTERVENTIONS

Intervention group will receive individualised structured cognitive rehabilitation. Control group will receive the best patient-centred care for attention disorders. Therapy frequency for both groups will be 1 hour per week for 12 weeks.

OUTCOME MEASURES

Primary: Neuropsychological Assessment Battery-Screening Module (S-NAB) scores. Secondary: Diffusion Tensor Imaging (DTI) parameters and Goal Attainment Scaling score (GAS).

RESULTS

Results will include descriptive statistics of population demographics, CogniPlus cognitive program and metacognitive strategies. The effect of intervention will be the effect size of S-NAB scores and mean GAS T scores. DTI parameters will be compared between groups via repeated measure analysis. Correlation analysis of outcome measures will be calculated using Pearson's correlation coefficient.

CONCLUSION

This is a complex clinical intervention with multiple outcome measures to provide a comprehensive evidence-based treatment model.

ETHICS AND DISSEMINATION

The study protocol was approved by the Medical Research Ethics Committee UMMC (MREC ID NO: 2016928-4293). The findings of the trial will be disseminated through peer-reviewed journals and scientific conferences.

TRIAL REGISTRATION NUMBER

NCT03237676.

Why Does Brain Trauma Research Fail?

Traumatic brain injury (TBI) represents a major health care problem and a significant social and economic issue worldwide. Considering the generalized failure in introducing effective drugs and clinical protocols, there is an urgent need for efficient treatment modalities, able to improve devastating posttraumatic morbidity and mortality. In this work, the status of brain trauma research is analyzed in all its aspects, including basic and translational science and clinical trials. Implicit and explicit challenges to different lines of research are discussed and clinical trial structures and outcomes are scrutinized, along with possible explanations for systematic therapeutic failures and their implications for future development of drug and clinical trials. Despite significant advances in basic and clinical research in recent years, no specific therapeutic protocols for TBI have been shown to be effective. New potential therapeutic targets have been identified, following a better understanding of pathophysiologic mechanisms underlying TBI, although with disappointing results. Several reasons can be pinpointed at different levels, from inaccurate animal models of disease to faulty preclinical and clinical trials, with poor design and subjective outcome measures. Distinct strategies can be delineated to overcome specific shortcomings of research studies. Identifying and contextualizing the failures that have dominated TBI research is mandatory. This review analyzes current approaches and discusses possible strategies for improving outcomes.

Enduring Neuroprotective Effect of Subacute Neural Stem Cell Transplantation After Penetrating TBI

Traumatic brain injury (TBI) is the largest cause of death and disability of persons under 45 years old, worldwide. Independent of the distribution, outcomes such as disability are associated with huge societal costs. The heterogeneity of TBI and its complicated biological response have helped clarify the limitations of current pharmacological approaches to TBI management. Five decades of effort have made some strides in reducing TBI mortality but little progress has been made to mitigate TBI-induced disability. Lessons learned from the failure of numerous randomized clinical trials and the inability to scale up results from single center clinical trials with neuroprotective agents led to the formation of organizations such as the Neurological Emergencies Treatment Trials (NETT) Network, and international collaborative comparative effectiveness research (CER) to re-orient TBI clinical research. With initiatives such as TRACK-TBI, generating rich and comprehensive human datasets with demographic, clinical, genomic, proteomic, imaging, and detailed outcome data across multiple time points has become the focus of the field in the United States (US). In addition, government institutions such as the US Department of Defense are investing in groups such as Operation Brain Trauma Therapy (OBTT), a multicenter, pre-clinical drug-screening consortium to address the barriers in translation. The consensus from such efforts including "The Lancet Neurology Commission" and current literature is that unmitigated cell death processes, incomplete debris clearance, aberrant neurotoxic immune, and glia cell response induce progressive tissue loss and spatiotemporal magnification of primary TBI. Our analysis suggests that the focus of neuroprotection research needs to shift from protecting dying and injured neurons at acute time points to modulating the aberrant glial response in sub-acute and chronic time points. One unexpected agent with neuroprotective properties that shows promise is transplantation of neural stem cells. In this review we present (i) a short survey of TBI epidemiology and summary of current care, (ii) findings of past neuroprotective clinical trials and possible reasons for failure based upon insights from human and preclinical TBI pathophysiology studies, including our group's inflammation-centered approach, (iii) the unmet need of TBI and unproven treatments and lastly, (iv) present evidence to support the rationale for sub-acute neural stem cell therapy to mediate enduring neuroprotection.

Cerebrolysin Reduces Astrogliosis and Axonal Injury and Enhances Neurogenesis in Rats After Closed Head Injury

BACKGROUND

Cerebrolysin is a neuropeptide preparation with neuroprotective and neurotrophic properties. Our previous study demonstrates that cerebrolysin significantly improves functional recovery in rats after mild traumatic brain injury (mTBI).

OBJECTIVE

To determine histological outcomes associated with therapeutic effects of cerebrolysin on functional recovery after TBI.

METHODS

In this prospective, randomized, blinded, and placebo-controlled study, adult Wistar rats with mild TBI induced by a closed head impact were randomly assigned to one of the cerebrolysin dose groups (0.8, 2.5, 7.5 mL/kg) or placebo, which were administered 4 hours after TBI and then daily for 10 consecutive days. Functional tests assessed cognitive, behavioral, motor, and neurological performance. Study end point was day 90 after TBI. Brains were processed for histological tissue analyses of astrogliosis, axonal injury, and neurogenesis.

RESULTS

Compared with placebo, cerebrolysin significantly reduced amyloid precursor protein accumulation, astrogliosis, and axonal damage in various brain regions and increased the number of neuroblasts and neurogenesis in the dentate gyrus. There was a significant dose effect of cerebrolysin on functional outcomes at 3 months after injury compared with saline treatment. Cerebrolysin at a dose of ⩾0.8 mL/kg significantly improved cognitive function, whereas at a dose of ⩾2.5 mL/kg, cerebrolysin also significantly improved sensorimotor function at various time points. There were significant correlations between multiple histological and functional outcomes 90 days after mTBI.

CONCLUSIONS

Our findings demonstrate that cerebrolysin reduces astrogliosis and axonal injury and promotes neurogenesis, which may contribute to improved functional recovery in rats with mTBI.

Prospective, randomized, blinded, and placebo-controlled study of Cerebrolysin dose-response effects on long-term functional outcomes in a rat model of mild traumatic brain injury

Using a prospective, randomized, blinded, placebo-controlled protocol, the authors demonstrated that Cerebrolysin at doses of 0.8-7.5 ml/kg, administered 4 hours after injury and then once daily for a total of 10 consecutive days, improves long-term functional outcomes in a rat model of mild closed head injury; a 2.5-ml/kg dose was identified as optimal. These findings suggest that Cerebrolysin has the potential to treat mild traumatic brain injury, the incidence of which is high without effective treatments.

Attainment of Functional and Social Independence in Adult Survivors of Pediatric CNS Tumors: A Report From the St Jude Lifetime Cohort Study

Purpose Beyond survival, achieving independence is a primary goal for adult survivors of pediatric CNS tumors. However, the prevalence of and risk factors for failure to achieve independence, assessed with multiple concurrent indicators, have not been examined. Patients and Methods Functional and social independence was assessed in 306 survivors (astrocytoma [n = 130], medulloblastoma [n = 77], ependymoma [n = 36], and other [n = 63]; median current age, 25.3 years [range, 18.9 to 53.1 years]; time since diagnosis, 16.8 years [range, 10.6 to 41.8 years]). Six observed indicators were used to identify latent classes of independence, which included employment, living independently, assistance with personal care, assistance with routine needs, obtaining a driver's license, and marital status. Physical performance impairments were defined as scores < 10th percentile on measures of aerobic capacity, strength, flexibility, balance, mobility, and adaptive function. Multinomial logistic regression estimated odds ratios (ORs) and 95% CIs were calculated for associations of disease/treatment exposures and impairments in physical performance with nonindependence. Results Three classes of independence were identified as independent (40%), moderately independent (34%), and nonindependent (26%). In multivariable models, craniospinal irradiation (OR, 4.20; 95% CI, 1.69 to 10.44) and younger age at diagnosis (OR, 1.24; 95% CI, 1.14 to 1.35) were associated with risk of nonindependence versus independence. Beyond impaired IQ, limitations in aerobic capacity (OR, 5.47; 95% CI, 1.78 to 16.76), flexibility (OR, 3.66; 95% CI, 1.11 to 12.03), and adaptive physical function (OR, 11.54; 95% CI, 3.57 to 37.27) were associated with nonindependence versus independence. Nonindependent survivors reported reduced physical but not mental health-related quality of life compared with independent survivors. Conclusion Sixty percent of survivors of pediatric CNS tumors do not achieve complete independence as adults. Reduction in intensity of primary therapies and interventions that target physical performance and adaptive deficits may help survivors to achieve greater independence.

Does Traumatic Brain Injury Attenuate the Exposure Therapy Process?

Research indicates that exposure therapy is efficacious for combat-related posttraumatic stress disorder (PTSD) comorbid with traumatic brain injury (TBI) as is shown by reduced PTSD treatment outcome scores. What is unknown, however, is whether the process of fear extinction is attenuated in veterans with TBI history. Increased PTSD symptomatology and possible cognitive deficits associated with TBI sequelae may indicate additional or longer exposure sessions to achieve habituation and extinction comparable to individuals without TBI history. As such, a more extensive course of treatment may be necessary to achieve comparable PTSD treatment outcome scores for individuals with TBI history. Using a sample of veterans with combat-related PTSD, some of whom were comorbid for TBI, this study compared process variables considered relevant to successful treatment outcome in exposure therapy. Individuals with and without TBI demonstrated similar rates of fear activation, length and number of exposure sessions, within-session habituation, between-session habituation, and extinction rate; results remained consistent when controlling for differential PTSD symptomatology. Furthermore, results indicated that self-perception of executive dysfunction did not impact the exposure process. Results suggest that individuals with PTSD and TBI history engage successfully and no differently in the exposure therapy process as compared to individuals with PTSD alone. Findings further support exposure therapy as a first-line treatment for combat-related PTSD regardless of TBI history.

The currency, completeness and quality of systematic reviews of acute management of moderate to severe traumatic brain injury: A comprehensive evidence map

OBJECTIVE

To appraise the currency, completeness and quality of evidence from systematic reviews (SRs) of acute management of moderate to severe traumatic brain injury (TBI).

METHODS

We conducted comprehensive searches to March 2016 for published, English-language SRs and RCTs of acute management of moderate to severe TBI. Systematic reviews and RCTs were grouped under 12 broad intervention categories. For each review, we mapped the included and non-included RCTs, noting the reasons why RCTs were omitted. An SR was judged as 'current' when it included the most recently published RCT we found on their topic, and 'complete' when it included every RCT we found that met its inclusion criteria, taking account of when the review was conducted. Quality was assessed using the AMSTAR checklist (trichotomised into low, moderate and high quality).

FINDINGS

We included 85 SRs and 213 RCTs examining the effectiveness of treatments for acute management of moderate to severe TBI. The most frequently reviewed interventions were hypothermia (n = 17, 14.2%), hypertonic saline and/or mannitol (n = 9, 7.5%) and surgery (n = 8, 6.7%). Of the 80 single-intervention SRs, approximately half (n = 44, 55%) were judged as current and two-thirds (n = 52, 65.0%) as complete. When considering only the most recently published review on each intervention (n = 25), currency increased to 72.0% (n = 18). Less than half of the 85 SRs were judged as high quality (n = 38, 44.7%), and nearly 20% were low quality (n = 16, 18.8%). Only 16 (20.0%) of the single-intervention reviews (and none of the five multi-intervention reviews) were judged as current, complete and high-quality. These included reviews of red blood cell transfusion, hypothermia, management guided by intracranial pressure, pharmacological agents (various) and prehospital intubation. Over three-quarters (n = 167, 78.4%) of the 213 RCTs were included in one or more SR. Of the remainder, 17 (8.0%) RCTs post-dated or were out of scope of existing SRs, and 29 (13.6%) were on interventions that have not been assessed in SRs.

CONCLUSION

A substantial number of SRs in acute management of moderate to severe TBI lack currency, completeness and quality. We have identified both potential evidence gaps and also substantial research waste. Novel review methods, such as Living Systematic Reviews, may ameliorate these shortcomings and enhance utility and reliability of the evidence underpinning clinical care.

Granulocyte-colony stimulating factor and umbilical cord blood cell transplantation: Synergistic therapies for the treatment of traumatic brain injury

Traumatic brain injury (TBI) is now characterized as a progressive, degenerative disease and continues to stand as a prevalent cause of death and disability. The pathophysiology of TBI is complex, with a variety of secondary cell death pathways occurring which may persist chronically following the initial cerebral insult. Current therapeutic options for TBI are minimal, with surgical intervention or rehabilitation therapy existing as the only viable treatments. Considering the success of stem-cell therapies in various other neurological diseases, their use has been proposed as a potential potent therapy for patients suffering TBI. Moreover, stem cells are highly amenable to adjunctive use with other therapies, providing an opportunity to overcome the inherent limitations of using a single therapeutic agent. Our research has verified this additive potential by demonstrating the efficacy of co-delivering human umbilical cord blood (hUCB) cells with granulocyte-colony stimulating factor (G-CSF) in a murine model of TBI, providing encouraging results which support the potential of this approach to treat patients suffering from TBI. These findings justify ongoing research toward uncovering the mechanisms which underlie the functional improvements exhibited by hUCB + G-CSF combination therapy, thereby facilitating its safe and effect transition into the clinic. This paper is a review article. Referred literature in this paper has been listed in the reference section. The datasets supporting the conclusions of this article are available online by searching various databases, including PubMed. Some original points in this article come from the laboratory practice in our research center and the authors’ experiences.

Critical Evaluation of the Lund Concept for Treatment of Severe Traumatic Head Injury, 25 Years after Its Introduction

When introduced in 1992, the Lund concept (LC) was the first complete guideline for treatment of severe traumatic brain injury (s-TBI). It was a theoretical approach, based mainly on general physiological principles-i.e., of brain volume control and optimization of brain perfusion and oxygenation of the penumbra zone. The concept gave relatively strict outlines for cerebral perfusion pressure, fluid therapy, ventilation, sedation, nutrition, the use of vasopressors, and osmotherapy. The LC strives for treatment of the pathophysiological mechanisms behind symptoms rather than just treating the symptoms. The treatment is standardized, with less need for individualization. Alternative guidelines published a few years later (e.g., the Brain Trauma Foundation guidelines and European guidelines) were mainly based on meta-analytic approaches from clinical outcome studies and to some extent from systematic reviews. When introduced, they differed extensively from the LC. We still lack any large randomized outcome study comparing the whole concept of BTF guidelines with other guidelines including the LC. From that point of view, there is limited clinical evidence favoring any of the s-TBI guidelines used today. In principle, the LC has not been changed since its introduction. Some components of the alternative guidelines have approached those in the LC. In this review, I discuss some important principles of brain hemodynamics that have been lodestars during formulation of the LC. Aspects of ventilation, nutrition, and temperature control are also discussed. I critically evaluate the most important components of the LC 25 years after its introduction, based on hemodynamic principles and on the results of own an others experimental and human studies that have been published since then.

Chondroitin Sulfate Glycosaminoglycan Matrices Promote Neural Stem Cell Maintenance and Neuroprotection Post-Traumatic Brain Injury

There are currently no effective treatments for moderate-to-severe traumatic brain injuries (TBIs). The paracrine functions of undifferentiated neural stem cells (NSCs) are believed to play a significant role in stimulating the repair and regeneration of injured brain tissue. We therefore hypothesized that fibroblast growth factor (FGF2) enriching chondroitin sulfate glycosaminoglycan (CS-GAG) matrices can maintain the undifferentiated state of neural stem cells (NSCs) and facilitate brain tissue repair subacutely post-TBI. Rats subjected to a controlled cortical impactor (CCI) induced TBI were intraparenchymally injected with CS-GAG matrices alone or with CS-GAG matrices containing PKH26GL labeled allogeneic NSCs. Nissl staining of brain tissue 4 weeks post-TBI demonstrated the significantly enhanced (p < 0.05) tissue protection in CS-GAG treated animals when compared to TBI only control, and NSC only treated animals. CS-GAG-NSC treated animals demonstrated significantly enhanced (p < 0.05) FGF2 retention, and maintenance of PKH26GL labeled NSCs as indicated by enhanced Sox1+ and Ki67+ cell presence over other differentiated cell types. Lastly, all treatment groups and sham controls exhibited a significantly (p < 0.05) attenuated GFAP+ reactive astrocyte presence in the lesion site when compared to TBI only controls.

Impact of the Brain Injury Family Intervention (BIFI) training on rehabilitation providers: A mixed methods study

BACKGROUND

The psychological impact of TBI is vast, leading to adverse effects on survivors and their caregivers. Unhealthy family functioning may be mitigated by therapeutic strategies, particularly interdisciplinary family systems approaches like the well-documented Brain Injury Family Intervention (BIFI). Little is known about the experience of providers who offer such interventions.

OBJECTIVE

This mixed methods study aims to demonstrate that a structured three-day training on the BIFI protocol improves providers' knowledge and confidence in working with survivors and families, and that this outcome is sustainable.

METHODS

Participants were 34 providers who participated in an intensive training and completed a web-based survey at four points of time. Quantitative data were analyzed via Wilcoxon signed-rank tests and binomial test of proportions. Qualitative data were analyzed according to rigorous coding procedures.

RESULTS

Providers' knowledge of brain injury and their ability to conceptualize treatment models for survivors and their families increased significantly and mostly remain consistent over time. Qualitative data point to additional gains, such as understanding of family systems.

CONCLUSIONS

Past studies quantify the BIFI as an evidence-based intervention. This study supports the effectiveness of training and serves as first to demonstrate the benefit for providers short- and long-term.

Cognitive Training for Post-Acute Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Objective: To quantitatively aggregate effects of cognitive training (CT) on cognitive and functional outcome measures in patients with traumatic brain injury (TBI) more than 12-months post-injury.

Design: We systematically searched six databases for non-randomized and randomized controlled trials of CT in TBI patients at least 12-months post-injury reporting cognitive and/or functional outcomes.

Main Measures: Efficacy was measured as standardized mean difference (Hedges’ g) of post-training change. We investigated heterogeneity across studies using subgroup analyses and meta-regressions.

Results: Fourteen studies encompassing 575 patients were included. The effect of CT on overall cognition was small and statistically significant (g = 0.22, 95%CI 0.05 to 0.38; p = 0.01), with low heterogeneity (I² = 11.71%) and no evidence of publication bias. A moderate effect size was found for overall functional outcomes (g = 0.32, 95%CI 0.08 to 0.57, p = 0.01) with low heterogeneity (I² = 14.27%) and possible publication bias. Statistically significant effects were also found only for executive function (g = 0.20, 95%CI 0.02 to 0.39, p = 0.03) and verbal memory (g = 0.32, 95%CI 0.14 to 0.50, p < 0.01).

Conclusion: Despite limited studies in this field, this meta-analysis indicates that CT is modestly effective in improving cognitive and functional outcomes in patients with post-acute TBI and should therefore play a more significant role in TBI rehabilitation.

A State-of-the-Science Overview of Randomized Controlled Trials Evaluating Acute Management of Moderate-to-Severe Traumatic Brain Injury

Moderate-to-severe traumatic brain injury (TBI) remains a major global challenge, with rising incidence, unchanging mortality and lifelong impairments. State-of-the-science reviews are important for research planning and clinical decision support. This review aimed to identify randomized controlled trials (RCTs) evaluating interventions for acute management of moderate/severe TBI, synthesize key RCT characteristics and findings, and determine their implications on clinical practice and future research. RCTs were identified through comprehensive database and other searches. Key characteristics, outcomes, risk of bias, and analysis approach were extracted. Data were narratively synthesized, with a focus on robust (multi-center, low risk of bias, n > 100) RCTs, and three-dimensional graphical figures also were used to explore relationships between RCT characteristics and findings. A total of 207 RCTs were identified. The 191 completed RCTs enrolled 35,340 participants (median, 66). Most (72%) were single center and enrolled less than 100 participants (69%). There were 26 robust RCTs across 18 different interventions. For 74% of 392 comparisons across all included RCTs, there was no significant difference between groups. Positive findings were broadly distributed with respect to RCT characteristics. Less than one-third of RCTs demonstrated low risk of bias for random sequence generation or allocation concealment, less than one-quarter used covariate adjustment, and only 7% employed an ordinal analysis approach. Considerable investment of resources in producing 191 completed RCTs for acute TBI management has resulted in very little translatable evidence. This may result from broad distribution of research effort, small samples, preponderance of single-center RCTs, and methodological shortcomings. More sophisticated RCT design, large multi-center RCTs in priority areas, increased focus on pre-clinical research, and alternatives to RCTs, such as comparative effectiveness research and precision medicine, are needed to fully realize the potential of acute TBI research to benefit patients.

Developing a Cognition Endpoint for Traumatic Brain Injury Clinical Trials

Cognitive impairment is a core clinical feature of traumatic brain injury (TBI). After TBI, cognition is a key determinant of post-injury productivity, outcome, and quality of life. As a final common pathway of diverse molecular and microstructural TBI mechanisms, cognition is an ideal endpoint in clinical trials involving many candidate drugs and nonpharmacological interventions. Cognition can be reliably measured with performance-based neuropsychological tests that have greater granularity than crude rating scales, such as the Glasgow Outcome Scale-Extended, which remain the standard for clinical trials. Remarkably, however, there is no well-defined, widely accepted, and validated cognition endpoint for TBI clinical trials. A single cognition endpoint that has excellent measurement precision across a wide functional range and is sensitive to the detection of small improvements (and declines) in cognitive functioning would enhance the power and precision of TBI clinical trials and accelerate drug development research. We outline methodologies for deriving a cognition composite score and a research program for validation. Finally, we discuss regulatory issues and the limitations of a cognition endpoint.

Functional outcomes of community-based brain injury rehabilitation clients

BACKGROUND

Community-based rehabilitation can help to maximize function following acquired brain injury (ABI); however, data on treatment outcome is limited in quantity.

OBJECTIVE

To describe and evaluate client outcomes of an outpatient programme for adults with moderate-to-severe traumatic and non-traumatic ABI.

METHODS

Two phase design involving retrospective and longitudinal study of programme completers with ABI (n = 47). Changes in functioning were measured with the Mayo-Portland Inventory (MPAI-4), administered pre- and immediately post-rehabilitation and at 3 years follow-up. Self-ratings were supplemented with MPAI-4 data from significant others (n = 32) and staff (n = 32).

RESULTS

Injured individuals and informants reported improved physical and psychosocial functioning immediately following the completion of community rehabilitation, with medium-to-large and significant treatment gains noted on the MPAI-4 ability, adjustment and participation sub-scales (Cohen's d range = 0.31-1.10). A deterioration in individuals' adjustment was further reported at follow-up, although this was based on limited data. Issues with longer-term rehabilitation service provision were additionally noted.

CONCLUSIONS

The data support the need for continuity of care, including ongoing emotional support, to cater to the complex and dynamic needs of the ABI population. However, these results need to be considered in the context of a small sample size and quasi-experimental design.

Systematic Review of Traumatic Brain Injury and the Impact of Antioxidant Therapy on Clinical Outcomes

BACKGROUND

Traumatic brain injury (TBI) is an acquired brain injury that occurs when there is sudden trauma that leads to brain damage. This acute complex event can happen when the head is violently or suddenly struck or an object pierces the skull or brain. The current principal treatment of TBI includes various pharmaceutical agents, hyperbaric oxygen, and hypothermia. There is evidence that secondary injury from a TBI is specifically related to oxidative stress. However, the clinical management of TBI often does not include antioxidants to reduce oxidative stress and prevent secondary injury.

AIMS

The purpose of this article is to examine current literature regarding the use of antioxidant therapies in treating TBI. This review evaluates the evidence of antioxidant therapy as an adjunctive treatment used to reduce the underlying mechanisms involved in secondary TBI injury.

METHODS

A systematic review of the literature published between January 2005 and September 2015 was conducted. Five databases were searched including CINAHL, PubMed, the Cochrane Library, PsycINFO, and Web of Science.

FINDINGS

Critical evaluation of the six studies that met inclusion criteria suggests that antioxidant therapies such as amino acids, vitamins C and E, progesterone, N-acetylcysteine, and enzogenol may be safe and effective adjunctive therapies in adult patients with TBI. Although certain limitations were found, the overall trend of using antioxidant therapies to improve the clinical outcomes of TBI was positive.

LINKING EVIDENCE TO ACTION

By incorporating antioxidant therapies into practice, clinicians can help attenuate the oxidative posttraumatic brain damage and optimize patients' recovery.

Transplantation of human neural stem cells restores cognition in an immunodeficient rodent model of traumatic brain injury

Traumatic brain injury (TBI) in humans can result in permanent tissue damage and has been linked to cognitive impairment that lasts years beyond the initial insult. Clinically effective treatment strategies have yet to be developed. Transplantation of human neural stem cells (hNSCs) has the potential to restore cognition lost due to injury, however, the vast majority of rodent TBI/hNSC studies to date have evaluated cognition only at early time points, typically <1month post-injury and cell transplantation. Additionally, human cell engraftment and long-term survival in rodent models of TBI has been difficult to achieve due to host immunorejection of the transplanted human cells, which confounds conclusions pertaining to transplant-mediated behavioral improvement. To overcome these shortfalls, we have developed a novel TBI xenotransplantation model that utilizes immunodeficient athymic nude (ATN) rats as the host recipient for the post-TBI transplantation of human embryonic stem cell (hESC) derived NSCs and have evaluated cognition in these animals at long-term (≥2months) time points post-injury. We report that immunodeficient ATN rats demonstrate hippocampal-dependent spatial memory deficits (Novel Place, Morris Water Maze), but not non-spatial (Novel Object) or emotional/anxiety-related (Elevated Plus Maze, Conditioned Taste Aversion) deficits, at 2-3months post-TBI, confirming that ATN rats recapitulate some of the cognitive deficits found in immunosufficient animal strains. Approximately 9-25% of transplanted hNSCs survived for at least 5months post-transplantation and differentiated into mature neurons (NeuN, 18-38%), astrocytes (GFAP, 13-16%), and oligodendrocytes (Olig2, 11-13%). Furthermore, while this model of TBI (cortical impact) targets primarily cortex and the underlying hippocampus and generates a large lesion cavity, hNSC transplantation facilitated cognitive recovery without affecting either lesion volume or total spared cortical or hippocampal tissue volume. Instead, we have found an overall increase in host hippocampal neuron survival in hNSC transplanted animals and demonstrate that a correlation exists between hippocampal neuron survival and cognitive performance. Together, these findings support the use of immunodeficient rodents in models of TBI that involve the transplantation of human cells, and suggest that hNSC transplantation may be a viable, long-term therapy to restore cognition after brain injury.

Pharmacological interventions in traumatic brain injury: Can we rely on systematic reviews for evidence?

INTRODUCTION

Providing current, reliable and evidence based information for clinicians and researchers in a synthesised and summarised way can be challenging particularly in the area of traumatic brain injury where a vast number of reviews exists. These reviews vary in their methodological quality and are scattered across varying sources. In this paper, we present an overview of systematic reviews that evaluate the pharmacological interventions in traumatic brain injury (TBI). By doing this, we aim to evaluate the existing evidence for improved outcomes in TBI with pharmacological interventions, and to identify gaps in the literature to inform future research.

METHODS

We searched the Neurotrauma Evidence Map on systematic reviews relating to pharmacological interventions for managing TBI in acute phase. Two reviewers independently screened search results and appraised each systematic review using the validated AMSTAR tool and extracted data from the review.

RESULTS

A total of 288 systematic reviews relating to TBI were available on the Neurotrauma Evidence Map at the time of this study. We identified 19 systematic reviews on pharmacological management for acute TBI with publications dates ranging from 1998 to 2014. The studies were of varying methodological quality, with a mean AMSTAR score of 7.78 (range 2-11].

CONCLUSION

The evidence from high quality systematic reviews show that there is currently insufficient evidence for the use of magnesium, monoaminergic and dopamine agonists, progesterone, aminosteroids, excitatory amino acid inhibitors, haemostatic and antifibrinolytic drugs in TBI. Anti-convulsants are only effective in reducing early seizures with no significant difference between phenytoin and leviteracetam. There is no difference between propofol and midazolam for sedation in TBI patients and ketamine may not cause increased ICP. Overviews of systematic review provide informative and powerful summaries of evidence based research.

Cognitive Rehabilitation After Traumatic Brain Injury: A Reference for Occupational Therapists

Nearly 1.7 million Americans sustain a traumatic brain injury (TBI) each year. These injuries can result in physical, emotional, and cognitive consequences. While many individuals receive cognitive rehabilitation from occupational therapists (OTs), the interdisciplinary nature of TBI research makes it difficult to remain up-to-date on relevant findings. We conducted a literature review to identify and summarize interdisciplinary evidence-based practice targeting cognitive rehabilitation for civilian adults with TBI. Our review summarizes TBI background, and our cognitive remediation section focuses on the findings from 37 recent (since 2006) empirical articles directly related to cognitive rehabilitation for individuals (i.e., excluding special populations such as veterans or athletes). This manuscript is offered as a tool for OTs engaged in cognitive rehabilitation and as a means to highlight arenas where more empirical, interdisciplinary research is needed.

Pharmacotherapy for chronic cognitive impairment in traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is a major cause of chronic disability. Worldwide, it is the leading cause of disability in the under 40s, resulting in severe disability in some 150 to 200 million people per annum. In addition to mood and behavioural problems, cognition-particularly memory, attention and executive function-are commonly impaired by TBI. Cognitive problems following TBI are one of the most important factors in determining people's subjective well-being and their quality of life. Drugs are widely used in an attempt to improve cognitive functions. Whilst cholinergic agents in TBI have been reviewed, there has not yet been a systematic review or meta-analysis of the effect on chronic cognitive problems of all centrally acting pharmacological agents.

OBJECTIVES

To assess the effects of centrally acting pharmacological agents for treatment of chronic cognitive impairment subsequent to traumatic brain injury in adults.

SEARCH METHODS

We searched ALOIS-the Cochrane Dementia and Cognitive Improvement Group's Specialised Register-on 16 November 2013, 23 February 2013, 20 January 2014, and 30 December 2014 using the terms: traumatic OR TBI OR "brain injury" OR "brain injuries" OR TBIs OR "axonal injury" OR "axonal injuries". ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases, numerous trial registries and grey literature sources. Supplementary searches were also performed in MEDLINE, EMBASE, PsycINFO, The Cochrane Library, CINAHL, LILACs, ClinicalTrials.gov, the World Health Organization (WHO) Portal (ICTRP) and Web of Science with conference proceedings.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing the effectiveness of any one centrally acting pharmacological agent that affects one or more of the main neurotransmitter systems in people with chronic traumatic brain injury; and there had to be a minimum of 12 months between the injury and entry into the trial.

DATA COLLECTION AND ANALYSIS

Two review authors examined titles and abstracts of citations obtained from the search. Relevant articles were retrieved for further assessment. A bibliographic search of relevant papers was conducted. We extracted data using a standardised tool, which included data on the incidence of adverse effects. Where necessary we requested additional unpublished data from study authors. Risk of bias was assessed by a single author.

MAIN RESULTS

Only four studies met the criteria for inclusion, with a total of 274 participants. Four pharmacological agents were investigated: modafinil (51 participants); (-)-OSU6162, a monoamine stabiliser (12 participants of which six had a TBI); atomoxetine (60 participants); and rivastigmine (157 participants). A meta-analysis could not be performed due to the small number and heterogeneity of the studies.All studies examined cognitive performance, with the majority of the psychometric sub-tests showing no difference between treatment and placebo (n = 274, very low quality evidence). For (-)-OSU6162 modest superiority over placebo was demonstrated on three measures, but markedly inferior performance on another. Rivastigmine was better than placebo on one primary measure, and a single cognitive outcome in a secondary analysis of a subgroup with more severe memory impairment at baseline. The study of modafinil assessed clinical global improvement (n = 51, low quality evidence), and did not find any difference between treatment and placebo. Safety, as measured by adverse events, was reported by all studies (n = 274, very low quality evidence), with significantly more nausea reported by participants who received rivastigmine compared to placebo. There were no other differences in safety between treatment and placebo. No studies reported any deaths.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine whether pharmacological treatment is effective in chronic cognitive impairment in TBI. Whilst there is a positive finding for rivastigmine on one primary measure, all other primary measures were not better than placebo. The positive findings for (-)-OSU6162 are interpreted cautiously as the study was small (n = 6). For modafinil and atomoxetine no positive effects were found. All four drugs appear to be relatively well tolerated, although evidence is sparse.

Traumatic Brain Injury Rehabilitation in Hong Kong: A Review of Practice and Research

Background. The rising public health concern regarding traumatic brain injury (TBI) implies a growing need for rehabilitation services for patients surviving TBI. Methods. To this end, this paper reviews the practices and research on TBI rehabilitation in Hong Kong so as to inform future developments in this area. This paper begins by introducing the general situation of TBI patients in Hong Kong and the need for rehabilitation. Next, the trauma system in Hong Kong is introduced. Following that is a detailed description of the rehabilitation services for TBI patients in Hong Kong, as exemplified by a rehabilitation hospital in Hong Kong. This paper will also review intervention studies on rehabilitating brain-injured populations in Hong Kong with respect to various rehabilitation goals. Lastly, the implications of culture-related issues will be discussed in relation to TBI. Results/Conclusions. The intervention studies conducted in Hong Kong are generally successful in achieving various rehabilitative outcomes. Additionally, certain cultural-related issues, such as the stigma associated with TBI, may impede the rehabilitative process and lead to various psychosocial problems.

Pre-Clinical Traumatic Brain Injury Common Data Elements: Toward a Common Language Across Laboratories

Traumatic brain injury (TBI) is a major public health issue exacting a substantial personal and economic burden globally. With the advent of "big data" approaches to understanding complex systems, there is the potential to greatly accelerate knowledge about mechanisms of injury and how to detect and modify them to improve patient outcomes. High quality, well-defined data are critical to the success of bioinformatics platforms, and a data dictionary of "common data elements" (CDEs), as well as "unique data elements" has been created for clinical TBI research. There is no data dictionary, however, for preclinical TBI research despite similar opportunities to accelerate knowledge. To address this gap, a committee of experts was tasked with creating a defined set of data elements to further collaboration across laboratories and enable the merging of data for meta-analysis. The CDEs were subdivided into a Core module for data elements relevant to most, if not all, studies, and Injury-Model-Specific modules for non-generalizable data elements. The purpose of this article is to provide both an overview of TBI models and the CDEs pertinent to these models to facilitate a common language for preclinical TBI research.

Phosphodiesterase inhibitors as therapeutics for traumatic brain injury

Developing therapeutics for traumatic brain injury remains a challenge for all stages of recovery. The pathological features of traumatic brain injury are diverse, and it remains an obstacle to be able to target the wide range of pathologies that vary between traumatic brain injured patients and that evolve during recovery. One promising therapeutic avenue is to target the second messengers cAMP and cGMP with phosphodiesterase inhibitors due to their broad effects within the nervous system. Phosphodiesterase inhibitors have the capability to target different injury mechanisms throughout the time course of recovery after brain injury. Inflammation and neuronal death are early targets of phosphodiesterase inhibitors, and synaptic dysfunction and circuitry remodeling are late potential targets of phosphodiesterase inhibitors. This review will discuss how signaling through cyclic nucleotides contributes to the pathology of traumatic brain injury in the acute and chronic stages of recovery. We will review our current knowledge of the successes and challenges of using phosphodiesterase inhibitors for the treatment of traumatic brain injury and conclude with important considerations in developing phosphodiesterase inhibitors as therapeutics for brain trauma.

Emerging pharmacotherapy for treatment of traumatic brain injury: targeting hypopituitarism and inflammation

INTRODUCTION

Traumatic brain injury (TBI) is a common cause of morbidity and mortality in the developed world. In particular, TBI is an important cause of death and disability in young adults with consequences ranging from physical disabilities to long-term cognitive, behavioural, psychological and social defects.

AREAS COVERED

There is a large body of evidence that suggest that TBI conditions may adversely affect pituitary function in both the acute and chronic phases of recovery. Prevalence of hypopituitarism, from total to isolated pituitary deficiency, ranges from 5 to 90%. The time interval between TBI and pituitary function evaluation is one of the major factors responsible for variations in the prevalence of hypopituitarism reported. Diagnosis of hypopituitarism and accurate treatment of pituitary disorders offers the opportunity to improve mortality and outcome in TBI conditions.

EXPERT OPINION

The aim of this paper is to review the history and pathophysiology of TBI and to summarize the best evidence of TBI as a cause of pituitary deficiency. Moreover, in this article we will describe the multiple changes which occur within the hypothalamic-pituitary-thyroid axis in critical illness, giving rise to 'sick euthyroid syndrome', focus our attention on thyroid hormones circulating levels from the initial insult to critical illness.

Investigational agents for treatment of traumatic brain injury

INTRODUCTION

Traumatic brain injury (TBI) is a major cause of death and disability worldwide. To date, there are no pharmacologic agents proven to improve outcomes from TBI because all the Phase III clinical trials in TBI have failed. Thus, there is a compelling need to develop treatments for TBI.

AREAS COVERED

The following article provides an overview of select cell-based and pharmacological therapies under early development for the treatment of TBI. These therapies seek to enhance cognitive and neurological functional recovery through neuroprotective and neurorestorative strategies.

EXPERT OPINION

TBI elicits both complex degenerative and regenerative tissue responses in the brain. TBI can lead to cognitive, behavioral, and motor deficits. Although numerous promising neuroprotective treatment options have emerged from preclinical studies that mainly target the lesion, translation of preclinical effective neuroprotective drugs to clinical trials has proven challenging. Accumulating evidence indicates that the mammalian brain has a significant, albeit limited, capacity for both structural and functional plasticity, as well as regeneration essential for spontaneous functional recovery after injury. A new therapeutic approach is to stimulate neurovascular remodeling by enhancing angiogenesis, neurogenesis, oligodendrogenesis, and axonal sprouting, which in concert, may improve neurological functional recovery after TBI.

G-CSF as an adjunctive therapy with umbilical cord blood cell transplantation for traumatic brain injury

Traumatic brain injury (TBI), a major contributor to deaths and permanent disability worldwide, has been recently described as a progressive cell death process rather than an acute event. TBI pathophysiology is complicated and can be distinguished by the initial primary injury and the subsequent secondary injury that ensues days after the trauma. Therapeutic opportunities for TBI remain very limited with patients subjected to surgery or rehabilitation therapy. The efficacy of stem cell-based interventions, as well as neuroprotective agents in other neurological disorders of which pathologies overlap with TBI, indicates their potential as alternative TBI treatments. Furthermore, their therapeutic limitations may be augmented when combination therapy is pursued instead of using a single agent. Indeed, we demonstrated remarkable combined efficacy of human umbilical cord blood (hUCB) cell therapy and granulocyte-colony-stimulating factor (G-CSF) treatment in TBI models, providing essential evidence for the translation of this approach to treat TBI. Further studies are warranted to determine the mechanisms underlying therapeutic benefits exerted by hUCB + G-CSF in order to enhance its safety and efficacy in the clinic.

Cerebrolysin improves cognitive performance in rats after mild traumatic brain injury

OBJECT

Long-term memory deficits occur after mild traumatic brain injuries (mTBIs), and effective treatment modalities are currently unavailable. Cerebrolysin, a peptide preparation mimicking the action of neurotrophic factors, has beneficial effects on neurodegenerative diseases and brain injuries. The present study investigated the long-term effects of Cerebrolysin treatment on cognitive function in rats after mTBI.

METHODS

Rats subjected to closed-head mTBI were treated with saline (n = 11) or Cerebrolysin (2.5 ml/kg, n = 11) starting 24 hours after injury and then daily for 28 days. Sham animals underwent surgery without injury (n = 8). To evaluate cognitive function, the modified Morris water maze (MWM) test and a social odor-based novelty recognition task were performed after mTBI. All rats were killed on Day 90 after mTBI, and brain sections were immunostained for histological analyses of amyloid precursor protein (APP), astrogliosis, neuroblasts, and neurogenesis.

RESULTS

Mild TBI caused long-lasting cognitive memory deficits in the MWM and social odor recognition tests up to 90 days after injury. Compared with saline treatment, Cerebrolysin treatment significantly improved both long-term spatial learning and memory in the MWM test and nonspatial recognition memory in the social odor recognition task up to 90 days after mTBI (p < 0.05). Cerebrolysin significantly increased the number of neuroblasts and promoted neurogenesis in the dentate gyrus, and it reduced APP levels and astrogliosis in the corpus callosum, cortex, dentate gyrus, CA1, and CA3 regions (p < 0.05).

CONCLUSIONS

These results indicate that Cerebrolysin treatment of mTBI improves long-term cognitive function, and this improvement may be partially related to decreased brain APP accumulation and astrogliosis as well as increased neuroblasts and neurogenesis.

Long-Term Consequences of Traumatic Brain Injury: Current Status of Potential Mechanisms of Injury and Neurological Outcomes

Traumatic brain injury (TBI) is a significant clinical problem with few therapeutic interventions successfully translated to the clinic. Increased importance on the progressive, long-term consequences of TBI have been emphasized, both in the experimental and clinical literature. Thus, there is a need for a better understanding of the chronic consequences of TBI, with the ultimate goal of developing novel therapeutic interventions to treat the devastating consequences of brain injury. In models of mild, moderate, and severe TBI, histopathological and behavioral studies have emphasized the progressive nature of the initial traumatic insult and the involvement of multiple pathophysiological mechanisms, including sustained injury cascades leading to prolonged motor and cognitive deficits. Recently, the increased incidence in age-dependent neurodegenerative diseases in this patient population has also been emphasized. Pathomechanisms felt to be active in the acute and long-term consequences of TBI include excitotoxicity, apoptosis, inflammatory events, seizures, demyelination, white matter pathology, as well as decreased neurogenesis. The current article will review many of these pathophysiological mechanisms that may be important targets for limiting the chronic consequences of TBI.