Clinical policy: neuroimaging and decisionmaking in adult mild traumatic brain injury in the acute setting

A Criteria to Reduce Interhospital Transfer of Traumatic Brain Injuries in Greater East Texas

BACKGROUND

Traumatic brain injury (TBI) due to single-level falls (SLF) are frequent and often require interhospital transfer. This retrospective cohort study aimed to assess the safety of a criteria for non-transfer among a subset of TBI patients who could be observed at their local hospital, vs mandatory transfer to a level 1 trauma center (L1TC).

METHODS

We conducted a 7-year review of patients with TBI due to SLF at a rural L1TC. Patients were classified as transfer/non-transfer according to the Brain Injuries in Greater East Texas (BIGTEX) criteria. The primary outcome measure was the occurrence of a critical event defined as deteriorating repeat head computed tomography (CT) scan or neurological status, neurosurgical intervention, or death.

RESULTS

Of the 689 included patients, 63 (9.1%) were classified as non-transfer. Although there were 4 cases with a neurological change and one with a head CT change among the non-transfer group, there were no neurosurgical procedures or deaths. The Cox Proportional Hazard model showed a near 3-fold increased risk of experiencing a critical event if classified as a non-transfer. The multivariable regression model showed patients with an Abbreviated Injury Scale (AIS) of 3 was twice as likely to experience a critical event, with an AIS of 4, three times, and 3 times more likely to be classified to transfer.

DISCUSSION

The BIGTEX criteria identify a subset of patients who can safely be observed at their local hospital. To confirm the safety and efficacy of this transfer criteria recommendation, a prospective study is warranted.

Overutilization of head computed tomography in cases of mild traumatic brain injury: a systematic review and meta-analysis

Head computed tomography (CT) is the preferred imaging modality for mild traumatic brain injury (mTBI). The routine use of head CT in low-risk individuals with mild TBI offers no clinical benefit but also causes notable health and financial burden. Despite the availability of related guidelines, studies have reported considerable rate of non-indicated head CT requests. The objectives were to provide an overall estimate for the head CT overutilization rate and to identify the factors contributing to the overuse. A systematic review of PubMed, Scopus, Web of Science, and Embase databases was conducted up to November 2023, following PRISMA and MOOSE guidelines. Two reviewers independently selected eligible articles and extracted data. Quality assessment was performed using a bias risk tool, and a random-effects model was used for data synthesis. Fourteen studies, encompassing 28,612 patients, were included, with 27,809 undergoing head CT scans. Notably, 75% of the included studies exhibited a moderate to high risk of bias. The overutilization rate for pediatric and adult patients was 27% (95% CI: 5-50%) and 32% (95% CI: 21-44%), respectively. An alternative rate, focusing on low-risk pediatric patients, was 54% (95% CI: 20-89%). Overutilization rates showed no significant difference between teaching and non-teaching hospitals. Patients with mTBI from falls or assaults were less likely to receive non-indicated scans. There was no significant association between physician specialty or seniority and overuse, nor between patients' age or sex and the likelihood of receiving a non-indicated scan. Approximately one-third of head CT scans in mTBI cases are avoidable, underscoring the necessity for quality improvement programs to reduce unnecessary imaging and its associated burdens.

Advances in development of biomarkers for brain damage and ischemia

Acquired brain injury is an urgent situation that requires rapid diagnosis and treatment. Magnetic resonance imaging (MRI) and computed tomography (CT) are required for accurate diagnosis. However, these methods are costly and require substantial infrastructure and specialized staff. Circulatory biomarkers of acute brain injury may help in the management of patients with acute cerebrovascular events and prevent poor outcome and mortality. The purpose of this review is to provide an overview of the development of potential biomarkers of brain damage to increase diagnostic possibilities. For this purpose, we searched the PubMed database of studies on the diagnostic potential of brain injury biomarkers. We also accessed information from Clinicaltrials.gov to identify any clinical trials of biomarker measurements for the diagnosis of brain damage. In total, we present 41 proteins, enzymes and hormones that have been considered as biomarkers for brain injury, of which 20 have been studied in clinical trials. Several microRNAs have also emerged as potential clinical biomarkers for early diagnosis. Combining multiple biomarkers in a panel, along with other parameters, is yielding promising outcomes.

S100B vs. "GFAP and UCH-L1" assays in the management of mTBI patients

OBJECTIVES

To compare for the first time the performance of "GFAP and UCH-L1" vs. S100B in a cohort of patients managed for mild traumatic brain injury (mTBI) according to actualized French guidelines.

METHODS

A prospective study was recently carried at the Emergency Department of Clermont-Ferrand University Hospital in France. Patients with mTBI presenting a medium risk of complications were enrolled. Blood S100B and "GFAP and UCHL-1" were sampled and measured according to French guidelines. S100B was measured in patients with samples within 3 h of trauma (Cobas®, Roche Diagnostics), while GFAP and UCHL-1 were measured in all patients (samples <3 h and 3-12 h) using another automated assay (i-STAT® Alinity, Abbott).

RESULTS

For sampling <3 h, serum S100B correctly identifies intracranial lesions with a specificity of 25.7 % (95 % CI; 19.5-32.6 %), a sensitivity of 100 % (95 % CI; 66.4-100 %), and a negative predictive value of 100 % (95 % CI; 92.5-100 %). For sampling <12 h, plasma "GFAP and UCH-L1" levels correctly identify intracranial lesions with a specificity of 31.7 % (95 % CI; 25.7-38.2 %), a sensitivity of 100 % (95 % CI; 73.5-100 %), and a negative predictive value of 100 % (95 % CI; 95-100 %). Comparison of specificities (25.7 vs. 31.7 %) did not reveal a statistically significant difference (p=0.16).

CONCLUSIONS

We highlight the usefulness of measuring plasma "GFAP and UCH-L1" levels to target mTBI patients (sampling within 12 h post-injury) and optimize the reduction of CT scans.

The prevalence of persistent post-traumatic headache in adult civilian traumatic brain injury: a systematic review and meta-analysis on the past 14 years

ABSTRACT

The most recent prevalence estimate of post-traumatic headache (PTH) after traumatic brain injury (TBI) in veterans and civilians dates back to 2008. The prevalence was found to be 57.8%, with surprising higher rates (75.3%) in mild TBI when compared with those with moderate/severe TBI (32.1%). However, the revision of mild TBI diagnostic criteria and an historic peak of TBI in the elderly individuals attributed to the ageing population may lead to different results. Thus, we conducted a systematic review and meta-analysis to assess the updated prevalence of PTH during the past 14 years only in civilians. A literature search was conducted following PRISMA guidelines guided by a librarian. Screening, full-text assessment, data extraction, and risk of bias assessment were performed blindly by 2 raters. Meta-analysis of proportions using the Freeman and Tukey double arcsine method of transformation was conducted. Heterogeneity, sensitivity analysis, and meta-regressions were performed with the predictors: year of publication, mean age, sex, TBI severity, and study design. Sixteen studies were selected for the qualitative analysis and 10 for the meta-analysis. The overall prevalence estimate of PTH was 47.1%, (confidence interval = 34.6, 59.8, prediction intervals = 10.8, 85.4), being similar at different time points (3, 6, 12, and 36+ months). Heterogeneity was high, and none of the meta-regressions were significant. The overall prevalence of PTH after TBI over the past 14 years remains high even if assessed only in civilians. However, the prevalence rates attributed to mild and moderate/severe TBI were similar, differing significantly from previous reports. Efforts are needed to improve TBI outcomes.

Machine learning-based models to predict the need for neurosurgical intervention after moderate traumatic brain injury

Background and Aims

Traumatic brain injury (TBI) is a widespread global health issue with significant economic consequences. However, no existing model exists to predict the need for neurosurgical intervention in moderate TBI patients with positive initial computed tomography scans. This study determines the efficacy of machine learning (ML)-based models in predicting the need for neurosurgical intervention.

Methods

This is a retrospective study of patients admitted to the neuro-intensive care unit of Emtiaz Hospital, Shiraz, Iran, between January 2018 and December 2020. The most clinically important variables from patients that met our inclusion and exclusion criteria were collected and used as predictors. We developed models using multilayer perceptron, random forest, support vector machines (SVM), and logistic regression. To evaluate the models, their F1-score, sensitivity, specificity, and accuracy were assessed using a fourfold cross-validation method.

Results

Based on predictive models, SVM showed the highest performance in predicting the need for neurosurgical intervention, with an F1-score of 0.83, an area under curve of 0.93, sensitivity of 0.82, specificity of 0.84, a positive predictive value of 0.83, and a negative predictive value of 0.83.

Conclusion

The use of ML-based models as decision-making tools can be effective in predicting with high accuracy whether neurosurgery will be necessary after moderate TBIs. These models may ultimately be used as decision-support tools to evaluate early intervention in TBI patients.

Longitudinal Recovery Following Repetitive Traumatic Brain Injury

Importance

One traumatic brain injury (TBI) increases the risk of subsequent TBIs. Research on longitudinal outcomes of civilian repetitive TBIs is limited.

Objective

To investigate associations between sustaining 1 or more TBIs (ie, postindex TBIs) after study enrollment (ie, index TBIs) and multidimensional outcomes at 1 year and 3 to 7 years.

Design, Setting, and Participants

This cohort study included participants presenting to emergency departments enrolled within 24 hours of TBI in the prospective, 18-center Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study (enrollment years, February 2014 to July 2020). Participants who completed outcome assessments at 1 year and 3 to 7 years were included. Data were analyzed from September 2022 to August 2023.

Exposures

Postindex TBI(s).

Main Outcomes and Measures

Demographic and clinical factors, prior TBI (ie, preindex TBI), and functional (Glasgow Outcome Scale-Extended [GOSE]), postconcussive (Rivermead Post-Concussion Symptoms Questionnaire [RPQ]), psychological distress (Brief Symptom Inventory-18 [BSI-18]), depressive (Patient Health Questionnaire-9 [PHQ-9]), posttraumatic stress disorder (PTSD; PTSD Checklist for DSM-5 [PCL-5]), and health-related quality-of-life (Quality of Life After Brain Injury-Overall Scale [QOLIBRI-OS]) outcomes were assessed. Adjusted mean differences (aMDs) and adjusted relative risks are reported with 95% CIs.

Results

Of 2417 TRACK-TBI participants, 1572 completed the outcomes assessment at 1 year (1049 [66.7%] male; mean [SD] age, 41.6 [17.5] years) and 1084 completed the outcomes assessment at 3 to 7 years (714 [65.9%] male; mean [SD] age, 40.6 [17.0] years). At 1 year, a total of 60 participants (4%) were Asian, 255 (16%) were Black, 1213 (77%) were White, 39 (2%) were another race, and 5 (0.3%) had unknown race. At 3 to 7 years, 39 (4%) were Asian, 149 (14%) were Black, 868 (80%) were White, 26 (2%) had another race, and 2 (0.2%) had unknown race. A total of 50 (3.2%) and 132 (12.2%) reported 1 or more postindex TBIs at 1 year and 3 to 7 years, respectively. Risk factors for postindex TBI were psychiatric history, preindex TBI, and extracranial injury severity. At 1 year, compared with those without postindex TBI, participants with postindex TBI had worse functional recovery (GOSE score of 8: adjusted relative risk, 0.57; 95% CI, 0.34-0.96) and health-related quality of life (QOLIBRI-OS: aMD, -15.9; 95% CI, -22.6 to -9.1), and greater postconcussive symptoms (RPQ: aMD, 8.1; 95% CI, 4.2-11.9), psychological distress symptoms (BSI-18: aMD, 5.3; 95% CI, 2.1-8.6), depression symptoms (PHQ-9: aMD, 3.0; 95% CI, 1.5-4.4), and PTSD symptoms (PCL-5: aMD, 7.8; 95% CI, 3.2-12.4). At 3 to 7 years, these associations remained statistically significant. Multiple (2 or more) postindex TBIs were associated with poorer outcomes across all domains.

Conclusions and Relevance

In this cohort study of patients with acute TBI, postindex TBI was associated with worse symptomatology across outcome domains at 1 year and 3 to 7 years postinjury, and there was a dose-dependent response with multiple postindex TBIs. These results underscore the critical need to provide TBI prevention, education, counseling, and follow-up care to at-risk patients.

EEG classification of traumatic brain injury and stroke from a nonspecific population using neural networks

Traumatic Brain Injury (TBI) and stroke are devastating neurological conditions that affect hundreds of people daily. Unfortunately, detecting TBI and stroke without specific imaging techniques or access to a hospital often proves difficult. Our prior research used machine learning on electroencephalograms (EEGs) to select important features and to classify between normal, TBI, and stroke on an independent dataset from a public repository with an accuracy of 0.71. In this study, we expanded to explore whether featureless and deep learning models can provide better performance in distinguishing between TBI, stroke and normal EEGs by including more comprehensive data extraction tools to drastically increase the size of the training dataset. We compared the performance of models built upon selected features with Linear Discriminative Analysis and ReliefF with several featureless deep learning models. We achieved 0.85 area under the curve (AUC) of the receiver operating characteristic curve (ROC) using feature-based models, and 0.84 AUC with featureless models. In addition, we demonstrated that Gradient-weighted Class Activation Mapping (Grad-CAM) can provide insight into patient-specific EEG classification by highlighting problematic EEG segments during clinical review. Overall, our study suggests that machine learning and deep learning of EEG or its precomputed features can be a useful tool for TBI and stroke detection and classification. Although not surpassing the performance of feature-based models, featureless models reached similar levels without prior computation of a large feature set allowing for faster and cost-efficient deployment, analysis, and classification.

Associations of Preexisting Vascular Risk Factors With Outcomes After Traumatic Brain Injury: A TRACK-TBI Study

OBJECTIVE

To evaluate associations of preinjury vascular risk factors with traumatic brain injury (TBI) outcomes.

SETTING

The level 1 trauma center-based T ransforming R esearch a nd C linical K nowledge in TBI (TRACK-TBI) Study.

PARTICIPANTS

A total of 2361 acute TBI patients 18 years or older who presented to the emergency department within 24 hours of head trauma warranting clinical evaluation with a noncontrast head CT between February 26, 2014, and August 8, 2018.

DESIGN

A multicenter prospective cohort study.

MAIN MEASURES

Vascular risk factors (hypertension, diabetes, hyperlipidemia, and smoking) were assessed at baseline by self- or proxy-report and chart review. The primary outcome was the 6-month Glasgow Outcome Scale-Extended TBI version (GOSE-TBI). Secondary 6-month outcomes included the Rivermead Post-Concussion Symptoms Questionnaire (RPQ), the Satisfaction with Life Scale (SWLS), and the 18-item Brief Symptom Inventory Global Severity Index (BSI-18-GSI).

RESULTS

Mean age of participants was 42 years, 31% were women, and 16% were Black. Current smoking was the most common vascular risk factor (29%), followed by hypertension (17%), diabetes (8%), and hyperlipidemia (6%). Smoking was the only risk factor associated with worse scores on all 4 outcome indices. Hypertension and diabetes were associated with worse RPQ scores, and hypertension was associated with worse BSI-18-GSI scores (all P < .05). Compared with individuals with no vascular risk factors, individuals with 1 but not 2 or more vascular risk factors had significantly worse GOSE-TBI and SWLS scores, while a higher burden of vascular risk factors was significantly associated with worse RPQ and BSI-18-GSI scores.

CONCLUSION

Our study found that preinjury vascular risk factors, especially smoking, are associated with worse outcomes after TBI. Aggressive postinjury treatment of vascular risk factors may be a promising strategy to improve TBI outcomes.

Accuracy of head computed tomography scoring systems in predicting outcomes for patients with moderate to severe traumatic brain injury: A ProTECT III ancillary study

BACKGROUND

Several types of head CT classification systems have been developed to prognosticate and stratify TBI patients.

OBJECTIVE

The purpose of our study was to compare the predictive value and accuracy of the different CT scoring systems, including the Marshall, Rotterdam, Stockholm, Helsinki, and NIRIS systems, to inform specific patient management actions, using the ProTECT III population of patients with moderate to severe acute traumatic brain injury (TBI).

METHODS

We used the data collected in the patients with moderate to severe (GCS score of 4-12) TBI enrolled in the ProTECT III clinical trial. ProTECT III was a NIH-funded, prospective, multicenter, randomized, double-blind, placebo-controlled clinical trial designed to determine the efficacy of early administration of IV progesterone. The CT scoring systems listed above were applied to the baseline CT scans obtained in the trial. We assessed the predictive accuracy of these scoring systems with respect to Glasgow Outcome Scale-Extended at 6 months, disability rating scale score, and mortality.

RESULTS

A total of 882 subjects were enrolled in ProTECT III. Worse scores for each head CT scoring systems were highly correlated with unfavorable outcome, disability outcome, and mortality. The NIRIS classification was more strongly correlated than the Stockholm and Rotterdam CT scores, followed by the Helsinki and Marshall CT classification. The highest correlation was observed between NIRIS and mortality (estimated odds ratios of 4.83).

CONCLUSION

All scores were highly associated with 6-month unfavorable, disability and mortality outcomes. NIRIS was also accurate in predicting TBI patients' management and disposition.

Neuroinflammatory Biomarkers for Traumatic Brain Injury Diagnosis and Prognosis: A TRACK-TBI Pilot Study

The relationship between systemic inflammation and secondary injury in traumatic brain injury (TBI) is complex. We investigated associations between inflammatory markers and clinical confirmation of TBI diagnosis and prognosis. The prospective TRACK-TBI Pilot (Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot) study enrolled TBI patients triaged to head computed tomography (CT) and received blood draw within 24 h of injury. Healthy controls (HCs) and orthopedic controls (OCs) were included. Thirty-one inflammatory markers were analyzed from plasma. Area under the receiver operating characteristic curve (AUC) was used to evaluate discriminatory ability. AUC >0.7 was considered acceptable. Criteria included: TBI diagnosis (vs. OC/HC); moderate/severe vs. mild TBI (Glasgow Coma Scale; GCS); radiographic TBI (CT positive vs. CT negative); 3- and 6-month Glasgow Outcome Scale-Extended (GOSE) dichotomized to death/greater relative disability versus less relative disability (GOSE 1-4/5-8); and incomplete versus full recovery (GOSE <8/ = 8). One-hundred sixty TBI subjects, 28 OCs, and 18 HCs were included. Markers discriminating TBI/OC: HMGB-1 (AUC = 0.835), IL-1b (0.795), IL-16 (0.784), IL-7 (0.742), and TARC (0.731). Markers discriminating GCS 3-12/13-15: IL-6 (AUC = 0.747), CRP (0.726), IL-15 (0.720), and SAA (0.716). Markers discriminating CT positive/CT negative: SAA (AUC = 0.767), IL-6 (0.757), CRP (0.733), and IL-15 (0.724). At 3 months, IL-15 (AUC = 0.738) and IL-2 (0.705) discriminated GOSE 5-8/1-4. At 6 months, IL-15 discriminated GOSE 1-4/5-8 (AUC = 0.704) and GOSE <8/ = 8 (0.711); SAA discriminated GOSE 1-4/5-8 (0.704). We identified a profile of acute circulating inflammatory proteins with potential relevance for TBI diagnosis, severity differentiation, and prognosis. IL-15 and serum amyloid A are priority markers with acceptable discrimination across multiple diagnostic and outcome categories. Validation in larger prospective cohorts is needed. ClinicalTrials.gov Registration: NCT01565551.

Do We Need to Repeat the Initially Normal Head Computerized Tomography for Patients with Mild Head Trauma Using Anticoagulant and/or Antiplatelet Therapy?

Objective: Patients using anticoagulant and/or antiplatelet (AC/AP) medications are at an increased risk of intracranial hemorrhage (ICH) subsequent to head trauma and current guidelines recommend a head computed tomography (CT) scan for these patients. There is a lack of consensus about management recommendations for mild head trauma patients on AC/AP treatment who had an initially normal head CT. The aim of this study was to determine the rate of delayed ICH after a 24-hour observation in patients with mild head trauma using AC/AP who had an initially normal head CT. Method: Patients aged 18 and older, using AC/AP drugs with mild head trauma were included prospectively. Patients underwent head CT for suspected bleeding. A repeat CT scan was performed after a 24-hours observation period for the patients who had an initially normal head CT for detecting delayed intracranial hemorrhage. Result: A total of 101 patients were included and, 57.4% (n=58) of the patients were female. Delayed ICH was detected in 2.9% (n=3) of the patients after a 24-hour observation. None of the patients with delayed ICH needed surgical treatment or further intervention. Delayed ICH was found in patients who used acetylsalicylic acid (n=1), dabigatran (n=1), and apixaban (n=1). Conclusion: In patients with mild head trauma using AC/AP, delayed intracranial hemorrhage is rare and may be clinically insignificant. A repeat CT scanning after 24-hour observation may not be necessary for patients with mild head trauma using AC/AP therapy who had initially normal head CT.

Relationships between predisposing, precipitating, and perpetuating factors and executive functioning following mild traumatic brain injury

INTRODUCTION

The aim of this study was to determine the sociodemographic and MTBI-related variables associated with executive functioning (EF).

METHODS

Based on the theoretical model of Hou and colleagues, data on predisposing (age, education, premorbid IQ), precipitating (post-traumatic amnesia, loss of consciousness, presence of frontal lesions, post-accident time to evaluation) and perpetuating (anxious and depressive affects and post-concussive symptoms) factors were retrospectively collected from the medical records of 172 patients with MTBI. EF data based on the 3 processes included in Miyake's prediction model (2000) (updating, cognitive flexibility and inhibition) were collected using respectively the Digit span task of the Weschler - 4^th edition, the Trails A and B as well as the initiation time on the Tower of London- Drexel University.

RESULTS

Updating was significantly associated with education, premorbid IQ, age, anxiety, and depressive affect. Inhibition was associated with education and age. No variable was associated with cognitive flexibility.

CONCLUSIONS

Following a MTBI, clinicians should consider that level of education and pre-morbid IQ may "predispose" patients to higher EF performances. They should also measure level of anxiety and depressive affect knowing that these may "perpetuate" some EF impairments (specifically the updating process).

Early Changes in the White Matter Microstructure and Connectome Underlie Cognitive Deficit and Depression Symptoms After Mild Traumatic Brain Injury

Cognitive and emotional impairments are frequent among patients with mild traumatic brain injury (mTBI) and may reflect alterations in the brain structural properties. The relationship between microstructural changes and cognitive and emotional deficits remains unclear in patients with mTBI at the acute stage. The purpose of this study was to analyze the alterations in white matter microstructure and connectome of patients with mTBI within 7 days after injury and investigate whether they are related to the clinical questionnaires. A total of 79 subjects (42 mTBI and 37 healthy controls) underwent neuropsychological assessment and diffusion-tensor MRI scan. The microstructure and connectome of white matter were characterized by tract-based spatial statistics (TBSSs) and graph theory approaches, respectively. Mini-mental state examination (MMSE) and self-rating depression scale (SDS) were used to evaluate the cognitive function and depressive symptoms of all the subjects. Patients with mTBI revealed early increases of fractional anisotropy in most areas compared with the healthy controls. Graph theory analyses showed that patients with mTBI had increased nodal shortest path length, along with decreased nodal degree centrality and nodal efficiency, mainly located in the bilateral temporal lobe and right middle occipital gyrus. Moreover, lower nodal shortest path length and higher nodal efficiency of the right middle occipital gyrus were associated with higher SDS scores. Significantly, the strength of the rich club connection in the mTBI group decreased and was associated with the MMSE. Our study demonstrated that the neuroanatomical alterations of mTBI in the acute stage might be an initial step of damage leading to cognitive deficits and depression symptoms, and arguably, these occur due to distinct mechanisms.

Computational Approaches for Acute Traumatic Brain Injury Image Recognition

In recent years, there have been major advances in deep learning algorithms for image recognition in traumatic brain injury (TBI). Interest in this area has increased due to the potential for greater objectivity, reduced interpretation times and, ultimately, higher accuracy. Triage algorithms that can re-order radiological reading queues have been developed, using classification to prioritize exams with suspected critical findings. Localization models move a step further to capture more granular information such as the location and, in some cases, size and subtype, of intracranial hematomas that could aid in neurosurgical management decisions. In addition to the potential to improve the clinical management of TBI patients, the use of algorithms for the interpretation of medical images may play a transformative role in enabling the integration of medical images into precision medicine. Acute TBI is one practical example that can illustrate the application of deep learning to medical imaging. This review provides an overview of computational approaches that have been proposed for the detection and characterization of acute TBI imaging abnormalities, including intracranial hemorrhage, skull fractures, intracranial mass effect, and stroke.

Association of Posttraumatic Epilepsy With 1-Year Outcomes After Traumatic Brain Injury

IMPORTANCE

Posttraumatic epilepsy (PTE) is a recognized sequela of traumatic brain injury (TBI), but the long-term outcomes associated with PTE independent of injury severity are not precisely known.

OBJECTIVE

To determine the incidence, risk factors, and association with functional outcomes and self-reported somatic, cognitive, and psychological concerns of self-reported PTE in a large, prospectively collected TBI cohort.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, prospective cohort study was conducted as part of the Transforming Research and Clinical Knowledge in Traumatic Brain Injury study and identified patients presenting with TBI to 1 of 18 participating level 1 US trauma centers from February 2014 to July 2018. Patients with TBI, extracranial orthopedic injuries (orthopedic controls), and individuals without reported injuries (eg, friends and family of participants; hereafter friend controls) were prospectively followed for 12 months. Data were analyzed from January 2020 to April 2021.

EXPOSURE

Demographic, imaging, and clinical information was collected according to TBI Common Data Elements. Incidence of self-reported PTE was assessed using the National Institute of Neurological Disorders and Stroke Epilepsy Screening Questionnaire (NINDS-ESQ).

MAIN OUTCOMES AND MEASURES

Primary outcomes included Glasgow Outcome Scale Extended, Rivermead Cognitive Metric (RCM; derived from the Rivermead Post Concussion Symptoms Questionnaire), and the Brief Symptom Inventory-18 (BSI).

RESULTS

Of 3296 participants identified as part of the study, 3044 met inclusion criteria, and 1885 participants (mean [SD] age, 41.3 [17.1] years; 1241 [65.8%] men and 644 [34.2%] women) had follow-up information at 12 months, including 1493 patients with TBI; 182 orthopedic controls, 210 uninjured friend controls; 41 patients with TBI (2.8%) and no controls had positive screening results for PTE. Compared with a negative screening result for PTE, having a positive screening result for PTE was associated with presenting Glasgow Coma Scale score (8.1 [4.8] vs.13.5 [3.3]; P < .001) as well as with anomalous acute head imaging findings (risk ratio, 6.42 [95% CI, 2.71-15.22]). After controlling for age, initial Glasgow Coma Scale score, and imaging findings, compared with patients with TBI and without PTE, patients with TBI and with positive PTE screening results had significantly lower Glasgow Outcome Scale Extended scores (mean [SD], 6.1 [1.7] vs 4.7 [1.5]; P < .001), higher BSI scores (mean [SD], 50.2 [10.7] vs 58.6 [10.8]; P = .02), and higher RCM scores (mean [SD], 3.1 [2.6] vs 5.3 [1.9]; P = .002) at 12 months.

CONCLUSIONS AND RELEVANCE

In this cohort study, the incidence of self-reported PTE after TBI was found to be 2.8% and was independently associated with unfavorable outcomes. These findings highlight the need for effective antiepileptogenic therapies after TBI.

Comparing the Quality of Life after Brain Injury-Overall Scale and Satisfaction with Life Scale as Outcome Measures for Traumatic Brain Injury Research

It is important to measure quality of life (QoL) after traumatic brain injury (TBI), yet limited studies have compared QoL inventories. In 2579 TBI patients, orthopedic trauma controls, and healthy friend control participants, we compared the Quality of Life After Brain Injury-Overall Scale (QOLIBRI-OS), developed for TBI patients, to the Satisfaction with Life Scale (SWLS), an index of generic life satisfaction. We tested the hypothesis that group differences (TBI and orthopedic trauma vs. healthy friend controls) would be larger for the QOLIBRI-OS than the SWLS and that the QOLIBRI-OS would manifest more substantial changes over time in the injured groups, demonstrating more relevance of the QOLIBRI-OS to traumatic injury recovery. (1) We compared the group differences (TBI vs. orthopedic trauma control vs. friend control) in QoL as indexed by the SWLS versus the QOLIBRI-OS and (2) characterized changes across time in these two inventories across 1 year in these three groups. Our secondary objective was to characterize the relationship between TBI severity and QoL. As compared with healthy friend controls, the QOLIBRI reflected greater reductions in QoL than the SWLS for both the TBI group (all time points) and the orthopedic trauma control group (2 weeks and 3 months). The QOLIBRI-OS better captured expected improvements in QoL during the injury recovery course in injured groups than the SWLS, which demonstrated smaller changes over time. TBI severity was not consistently or robustly associated with self-reported QoL. The findings imply that, as compared with the SWLS, the QOLIBRI-OS appears to identify QoL issues more specifically relevant to traumatically injured patients and may be a more appropriate primary QoL outcome measure for research focused on the sequelae of traumatic injuries.

Plasma-based S100B testing for management of traumatic brain injury in emergency setting

Background

Serum biomarker S100B has been explored for its potential benefit to improve clinical decision-making in the management of patients suffering from traumatic brain injury (TBI), especially as a pre-head computed-tomography screening test for patients with mild TBI. Although being already included into some guidelines, its implementation into standard care is still lacking. This might be explained by a turnaround time (TAT) too long for serum S100B to be used in clinical decision-making in emergency settings.

Methods

S100B concentrations were determined in 136 matching pairs of serum and lithium heparin blood samples. The concordance of the test results was assessed by linear regression, Passing Pablok regression and Bland-Altman analysis. Bias and within- and between-run imprecision were determined by a 5 × 4 model using pooled patient samples. CT scans were performed as clinically indicated.

Results

Overall, S100B levels between both blood constituents correlated very well. The suitability of S100B testing from plasma was verified according to ISO15189 requirements. Using a cut-off of 0.105 ng/ml, a sensitivity and negative predictive value of 100% were obtained for identifying patients with pathologic CT scans. Importantly, plasma-based testing reduced the TAT to 26 min allowing for quicker clinical decision-making. The clinical utility of integrating S100B in TBI management is highlighted by two case reports.

Conclusions

Plasma-based S100B testing compares favorably with serum-based testing, substantially reducing processing times as the prerequisite for integrating S100B level into management of TBI patients. The proposed new clinical decision algorithm for TBI management needs to be validated in further prospective large-scale studies.

•

Plasma-based S100B testing reduces turnaround time to 26 minutes and thus enables its use in the emergency department.

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Plasma- and serum-based S100B testing demonstrate commutability of results.

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Clinical cases demonstrate the benefit of elevated S100B levels as an indicator for second-look CT re-evaluation.

High-Sensitivity C-Reactive Protein is a Prognostic Biomarker of Six-Month Disability after Traumatic Brain Injury: Results from the TRACK-TBI Study

Systemic inflammation impacts outcome after traumatic brain injury (TBI), but most TBI biomarker studies have focused on brain-specific proteins. C-reactive protein (CRP) is a widely used biomarker of inflammation with potential as a prognostic biomarker after TBI. The Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study prospectively enrolled TBI patients within 24 h of injury, as well as orthopedic injury and uninjured controls; biospecimens were collected at enrollment. A subset of hospitalized participants had blood collected on day 3, day 5, and 2 weeks. High-sensitivity CRP (hsCRP) and glial fibrillary acidic protein (GFAP) were measured. Receiver operating characteristic analysis was used to evaluate the prognostic ability of hsCRP for 6-month outcome, using the Glasgow Outcome Scale-Extended (GOSE). We included 1206 TBI subjects, 122 orthopedic trauma controls (OTCs), and 209 healthy controls (HCs). Longitudinal biomarker sampling was performed in 254 hospitalized TBI subjects and 19 OTCs. hsCRP rose between days 1 and 5 for TBI and OTC subjects, and fell by 2 weeks, but remained elevated compared with HCs (p < 0.001). Longitudinally, hsCRP was significantly higher in the first 2 weeks for subjects with death/severe disability (GOSE <5) compared with those with moderate disability/good recovery (GOSE ≥5); AUC was highest at 2 weeks (AUC = 0.892). Combining hsCRP and GFAP at 2 weeks produced AUC = 0.939 for prediction of disability. Serum hsCRP measured within 2 weeks of TBI is a prognostic biomarker for disability 6 months later. hsCRP may have utility as a biomarker of target engagement for anti-inflammatory therapies.

Translational neuroimaging in mild traumatic brain injury

Traumatic brain injuries (TBIs) are common with an estimated 27.1 million cases per year. Approximately 80% of TBIs are categorized as mild TBI (mTBI) based on initial symptom presentation. While in most individuals, symptoms resolve within days to weeks, in some, symptoms become chronic. Advanced neuroimaging has the potential to characterize brain morphometric, microstructural, biochemical, and metabolic abnormalities following mTBI. However, translational studies are needed for the interpretation of neuroimaging findings in humans with respect to the underlying pathophysiological processes, and, ultimately, for developing novel and more targeted treatment options. In this review, we introduce the most commonly used animal models for the study of mTBI. We then summarize the neuroimaging findings in humans and animals after mTBI and, wherever applicable, the translational aspects of studies available today. Finally, we highlight the importance of translational approaches and outline future perspectives in the field of translational neuroimaging in mTBI.

Rapid Assessment of Adults With Traumatic Brain Injuries

The aim of this evidence-based project was to improve the medical screening process, enhance medical decision-making, and standardize the utilization of an adult traumatic brain injury (TBI) neuroimaging guideline among advanced practice providers (APPs) in an urban emergency department (ED). Neuroimaging, specifically computed tomography (CT), helps identify life-threatening intracranial injuries when clinically appropriate. The literature supports the utilization of neuroimaging guidelines, clinical examinations, and provider expertise when identifying the need for a head CT scan. Although head CT scans are clinically useful, they increase health care costs and pose potential cancer risks from radiation exposure. Eight APPs (i.e., nurse practitioners, physician assistants) were trained in the American College of Emergency Physicians' (ACEP's) TBI clinical guideline with one-on-one education. Preintervention, retrospective, baseline data were collected for a period of 4 months (n = 152). Three months of postintervention data were collected to assess adherence to the guideline (n = 132), including physicians' charts that were reviewed as a comparison. The findings demonstrated a statistically significant reduction in head CT scans that did not meet ACEP criteria among APPs after training (p = 0.010). The results of this project suggest improved medical decision-making among APPs, avoidance of unnecessary costs, and a reduction in radiation exposure for patients. This project could be easily replicated in other ED settings using the ACEP TBI guideline as part of their standardized procedures, clinical policies, or protocols.

Incremental Risk of Intracranial Hemorrhage After Mild Traumatic Brain Injury in Patients on Antiplatelet Therapy: Systematic Review and Meta-Analysis

BACKGROUND

Mild traumatic brain injury (TBI) is a common event and antiplatelet therapy might represent a risk factor for bleeding.

OBJECTIVE

The aim of this study was to evaluate the risk of intracranial hemorrhage (ICH) after mild TBI in patients on antiplatelet therapy through a systematic review and meta-analysis.

METHODS

We conducted a systematic review and meta-analysis of prospective and retrospective observational studies on patients with mild TBI on antiplatelet therapy vs. those not on any antithrombotic therapy. The primary outcome was the risk of ICH in patients with mild TBI based on the first computed tomography scan. Secondary outcome was the risk of mortality and neurosurgery.

RESULTS

Nine studies and 14,545 patients were included. The incidence of ICH ranged from 3.6% to 29.4% in the antiplatelet group and from 1.6% to 21.1% in the control group. Patients on antiplatelet therapy had a higher risk of ICH after a mild TBI compared with patients that were not on antithrombotic therapy (risk ratio 1.51; 95% confidence interval 1.21-1.88). No difference was found in the composite outcome of mortality and neurosurgery.

CONCLUSIONS

Patients on antiplatelet therapy have an increased risk of ICH after mild TBI compared with patients not on antithrombotic therapy. However, the risk is just slightly increased, and the need to perform a computed tomography scan in patients on antiplatelet therapy after a mild TBI should be evaluated case by case, but always considered in patients with other risk factors.

Comparison of traumatic brain injury patients with brain computed tomography in the emergency department by age group

Objective

Traumatic brain injury (TBI) is an important public health concern due to its high prevalence and mortality rate among young people. We investigated the clinical and social characteristics of patients who visited the emergency department due to TBI in whom brain computed tomography, was performed by age.

Methods

We retrospectively analyzed 15,567 TBI patients who received a brain computed tomography evaluation at the emergency department of Korea University Hospital from March 2013 to February 2016. We divided patients into age groups by decade and analyzed factors such as sex, trauma mechanism, need for operation, hospitalization, and results of treatment.

Results

The mean age was 42.0±22.8 years; the most common age group was the 50s (16.5%). Except for the age group over 70 years, males predominated. Under 9 years of age, public ambulance usage rate was lower than in other age groups. Regarding severity based on the Glasgow Coma Scale score, the proportion of mild cases was higher in those under 9 years of age (99.3%) and the proportion of severe cases was higher in those in their 20s (4.6%). The most common injury mechanism was blunt trauma, followed by car accidents. For those under 9 years of age, falls were more common than in other age groups. Only 20.5% of TBI patients were hospitalized and 11.9% were treated surgically, while 70.6% of patients were discharged home after treatment.

Conclusion

TBI may present with different characteristics depending on the age of the patients, thus prevention policies and clinical practice should be tailored to age.

Concussion and Mild-Traumatic Brain Injury in Rural Settings: Epidemiology and Specific Health Care Considerations

Background  Mild-traumatic brain injury (mTBI) and concussions cause significant morbidity. To date, synthesis of specific health care disparities and gaps in care for rural mTBI/concussion patients remains needed. Methods  A comprehensive literature search was performed using PubMed database for English articles with keywords "rural" and ("concussion" or "mild traumatic brain injury") from 1991 to 2019. Eighteen articles focusing on rural epidemiology ( n = 5), management/cost ( n = 5), military ( n = 2), and concussion prevention/return to play ( n = 6) were included. Results  mTBI/concussion incidence was higher in rural compared with urban areas. Compared with urban patients, rural patients were at increased risk for vehicular injuries, lifetime number of concussions, admissions for observation without neuroimaging, and injury-related costs. Rural patients were less likely to utilize ambulatory and mental health services following mTBI/concussion. Rural secondary schools had decreased access to certified personnel for concussion evaluation, and decreased use of standardized assessment instruments/neurocognitive testing. While school coaches were aware of return-to-play laws, mTBI/concussion education rates for athletes and parents were suboptimal in both settings. Rural veterans were at increased risk for postconcussive symptoms and posttraumatic stress. Telemedicine in rural/low-resource areas is an emerging tool for rapid evaluation, triage, and follow-up. Conclusions  Rural patients are at unique risk for mTBI/concussions and health care costs. Barriers to care include lower socioeconomic status, longer distances to regional medical center, and decreased availability of neuroimaging and consultants. Due to socioeconomic and distance barriers, rural schools are less able to recruit personnel certified for concussion evaluation. Telemedicine is an emerging tool for remote triage and evaluation.

Accuracy of algorithms to predict injury severity in older adults for trauma triage

Objective: Older adults make up a rapidly increasing proportion of motor vehicle occupants and previous studies have demonstrated that this population is more susceptible to traumatic injuries. The CDC recommends that patients anticipated to have severe injuries (Injury Severity Score [ISS] ≥ 16) be transported to a trauma center. The recommended target rate for undertriage is ≤ 5% and for overtriage is ≤ 50%. Several regression-based algorithms for injury prediction have been developed in order to predict severe injury in occupants involved in a motor vehicle collision (MVC). The objective of this study to was to determine if the accuracy of regression-based injury severity prediction algorithms decreases for older adults.Methods: Data were obtained from the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) from the years 2000-2015. Adult occupants involved in non-rollover MVCs were included. Regression-based injury risk models to predict severe injury (ISS ≥ 16) were developed using random split-samples with the following variables: age, delta-V, direction of impact, belt status, and number of impacts. Separate models were trained using data from the following age groups: (1) all adults, (2) 15-54 years, (3) ≥45 years, (4) ≥55 years, and (5) ≥65 years. The models were compared using the mean receiver operating characteristic area under curve (ROC-AUC) after 1,000 iterations of training and testing. The predicted rates of overtriage were then determined for each group in order to achieve an undertriage rate of 5%.Results: There were 24,577 occupants (6,863,306 weighted) included in this analysis. The injury prediction model trained using data from all adults did not perform as well when tested on older adults (ROC-AUC: 15-54 years: 0.874 [95% CI: [0.851-0.895]; 45+ years: 0.837 [95% CI: 0.802-869]; 55+ years: 0.821 [95% CI: 0.775-0.864]; and 65+ years: 0.813 [95% CI: 0.754-0.866]). The accuracy of this model decreased in each decade of life. The performance did not change significantly when age-specific data were used to train the prediction models (ROC-AUC: 18-54 years: 0.874 [95% CI: 0.851-0.896]; 45+ years: 0.836 [95% CI: 0.798-0.871]; 55+ years: 0.822 [95% CI: 0.779-0.864]; and 65+ years: 0.808 [95% CI: 0.748-0.868]). In order to achieve an undertriage rate of 5%, the predicted overtriage rate by these models were 50% for occupants 15-54 years, 61% for occupants ≥ 55 years, 70% for occupants ≥ 55 years, and 71% for occupants ≥ 65 years.Conclusion: The results of this study indicate that it is more difficult to accurately predict severe injury in older adults involved in MVCs, which has the potential to result in significant overtriage. This decreased accuracy is likely due to variations in fragility in older adults. These findings indicate that special care should be taken when using regression-based prediction models to determine the appropriate hospital destination for older occupants.

Association between plasma GFAP concentrations and MRI abnormalities in patients with CT-negative traumatic brain injury in the TRACK-TBI cohort: a prospective multicentre study

BACKGROUND

After traumatic brain injury (TBI), plasma concentration of glial fibrillary acidic protein (GFAP) correlates with intracranial injury visible on CT scan. Some patients with suspected TBI with normal CT findings show pathology on MRI. We assessed the discriminative ability of GFAP to identify MRI abnormalities in patients with normal CT findings.

METHODS

TRACK-TBI is a prospective cohort study that enrolled patients with TBI who had a clinically indicated head CT scan within 24 h of injury at 18 level 1 trauma centres in the USA. For this analysis, we included patients with normal CT findings (Glasgow Coma Scale score 13-15) who consented to venepuncture within 24 h post injury and who had an MRI scan 7-18 days post injury. We compared MRI findings in these patients with those of orthopaedic trauma controls and healthy controls recruited from the study sites. Plasma GFAP concentrations (pg/mL) were measured using a prototype assay on a point-of-care platform. We used receiver operating characteristic (ROC) analysis to evaluate the discriminative ability of GFAP for positive MRI scans in patients with negative CT scans over 24 h (time between injury and venepuncture). The primary outcome was the area under the ROC curve (AUC) for GFAP in patients with CT-negative and MRI-positive findings versus patients with CT-negative and MRI-negative findings within 24 h of injury. The Dunn Kruskal-Wallis test was used to compare GFAP concentrations between MRI lesion types with Benjamini-Hochberg correction for multiple comparisons. This study is registered with ClinicalTrials.gov, number NCT02119182.

FINDINGS

Between Feb 26, 2014, and June 15, 2018, we recruited 450 patients with normal head CT scans (of whom 330 had negative MRI scans and 120 had positive MRI scans), 122 orthopaedic trauma controls, and 209 healthy controls. AUC for GFAP in patients with CT-negative and MRI-positive findings versus patients with CT-negative and MRI-negative findings was 0·777 (95% CI 0·726-0·829) over 24 h. Median plasma GFAP concentration was highest in patients with CT-negative and MRI-positive findings (414·4 pg/mL, 25-75th percentile 139·3-813·4), followed by patients with CT-negative and MRI-negative findings (74·0 pg/mL, 17·5-214·4), orthopaedic trauma controls (13·1 pg/mL, 6·9-20·0), and healthy controls (8·0 pg/mL, 3·0-14·0; all comparisons between patients with CT-negative MRI-positive findings and other groups p<0·0001).

INTERPRETATION

Analysis of blood GFAP concentrations using prototype assays on a point-of-care platform within 24 h of injury might improve detection of TBI and identify patients who might need subsequent MRI and follow-up.

FUNDING

National Institute of Neurological Disorders and Stroke and US Department of Defense.

Evaluation of Clinical Criteria for Performing Brain CT-Scan in Patients with Mild Traumatic Brain Injury; A New Diagnostic Probe

OBJECTIVE

To investigate the risk factors that can be proper indications for performing brain computerized tomography (CT)-scan in patients with mild and moderate traumatic brain injury (TBI) in order to avoid unnecessary exposure to radiation, saving on costs as well as time wasted in emergency wards.

METHODS

Data of patients with mild traumatic brain injury (TBI) referring to Emergency Department with age ≥2 years and primary GCS of 13-15 were examined including focal neurological deficit, anisocoria, skull fracture, multiple trauma, superior injury of clavicle, decreased consciousness, and amnesia. Brain CT-scan was performed in all the patients. Kappa Coefficient was used to determine the ratio of agreement of the CT indications (+ and ⎼) and multiple logistic regression to determine the relative odds of positive CTs.

RESULTS

Overall we included 610 patients. One-hundred and one patients (16.5%) had positive and 509 (83.5%) had negative CT findings. Of positive CTs, the highest percentage was dedicated to high-energy mechanism of trauma. High-energy trauma mechanism (OR=1.056, 95% CI, OR, 1.03-1.04, P<0.001), superior injury of clavicle (OR=1.07, 95% CI, OR, 1.03-1.1, P<0.001) and moderate to severe headache (OR=1.04, 95% CI, OR, 1.02-1.05, P<0.001) were positive predictors of CT findings. The combined mean of positive symptoms equaled 0.29 ± 0.64 in negative CTs, but 5.13 ± 2.4 in positive CTs, showing a significant difference. (P<0.001).

CONCLUSION

Abnormal positive brain CT in victims with mild TBI is predictable if one or several risk factors are taken into account such as moderate to severe headache, decreased consciousness, skull fracture, high-energy trauma mechanism, superior injury of clavicle and GCS of 13-14. The more the symptoms, the more likely the positive CT results would be.

Blood Biomarkers for Traumatic Brain Injury: A Quantitative Assessment of Diagnostic and Prognostic Accuracy

Blood biomarkers have been explored for their potential to provide objective measures in the assessment of traumatic brain injury (TBI). However, it is not clear which biomarkers are best for diagnosis and prognosis in different severities of TBI. Here, we compare existing studies on the discriminative abilities of serum biomarkers for four commonly studied clinical situations: detecting concussion, predicting intracranial damage after mild TBI (mTBI), predicting delayed recovery after mTBI, and predicting adverse outcome after severe TBI (sTBI). We conducted a literature search of publications on biomarkers in TBI published up until July 2018. Operating characteristics were pooled for each biomarker for comparison. For detecting concussion, 4 biomarker panels and creatine kinase B type had excellent discriminative ability. For detecting intracranial injury and the need for a head CT scan after mTBI, 2 biomarker panels, and hyperphosphorylated tau had excellent operating characteristics. For predicting delayed recovery after mTBI, top candidates included calpain-derived αII-spectrin N-terminal fragment, tau A, neurofilament light, and ghrelin. For predicting adverse outcome following sTBI, no biomarker had excellent performance, but several had good performance, including markers of coagulation and inflammation, structural proteins in the brain, and proteins involved in homeostasis. The highest-performing biomarkers in each of these categories may provide insight into the pathophysiologies underlying mild and severe TBI. With further study, these biomarkers have the potential to be used alongside clinical and radiological data to improve TBI diagnostics, prognostics, and evidence-based medical management.

Serum Amyloid A Protein as a Potential Biomarker for Severity and Acute Outcome in Traumatic Brain Injury

Traumatic brain injury (TBI) causes a wide variety of neuroinflammatory events. These neuroinflammatory events depend, to a greater extent, on the severity of the damage. Our previous studies have shown that the liver produces serum amyloid A (SAA) at high levels in the initial hours after controlled cortical impact (CCI) injury in mice. Clinical studies have reported detectable SAA in the plasma of brain injury patients, but it is not clear if SAA levels depend on TBI severity. To evaluate this question, we performed a mild to severe CCI injury in wild-type mice. We collected blood samples and brains at 1, 3, and 7 days after injury for protein detection by western blotting, enzyme-linked immunosorbent assay, or immunohistochemical analysis. Our results showed that severe CCI injury compared to mild CCI injury or sham mice caused an increased neuronal death, larger lesion volume, increased microglia/macrophage density, and augmented neutrophil infiltration. Furthermore, we found that the serum levels of SAA protein ascended in the blood in correlation with high neuroinflammatory and neurodegenerative responses. Altogether, these results suggest that serum SAA may be a novel neuroinflammation-based, and severity-dependent, biomarker for acute TBI.

Pre-injury Comorbidities Are Associated With Functional Impairment and Post-concussive Symptoms at 3- and 6-Months After Mild Traumatic Brain Injury: A TRACK-TBI Study

Introduction: Over 70% of traumatic brain injuries (TBI) are classified as mild (mTBI), which present heterogeneously. Associations between pre-injury comorbidities and outcomes are not well-understood, and understanding their status as risk factors may improve mTBI management and prognostication. Methods: mTBI subjects (GCS 13-15) from TRACK-TBI Pilot completing 3- and 6-month functional [Glasgow Outcome Scale-Extended (GOSE)] and post-concussive outcomes [Acute Concussion Evaluation (ACE) physical/cognitive/sleep/emotional subdomains] were extracted. Pre-injury comorbidities >10% incidence were included in regressions for functional disability (GOSE ≤ 6) and post-concussive symptoms by subdomain. Odds ratios (OR) and mean differences (B) were reported. Significance was assessed at p < 0.0083 (Bonferroni correction). Results: In 260 subjects sustaining blunt mTBI, mean age was 44.0-years and 70.4% were male. Baseline comorbidities >10% incidence included psychiatric-30.0%, cardiac (hypertension)-23.8%, cardiac (structural/valvular/ischemic)-20.4%, gastrointestinal-15.8%, pulmonary-15.0%, and headache/migraine-11.5%. At 3- and 6-months separately, 30.8% had GOSE ≤ 6. At 3-months, psychiatric (GOSE ≤ 6: OR = 2.75, 95% CI [1.44-5.27]; ACE-physical: B = 1.06 [0.38-1.73]; ACE-cognitive: B = 0.72 [0.26-1.17]; ACE-sleep: B = 0.46 [0.17-0.75]; ACE-emotional: B = 0.64 [0.25-1.03]), headache/migraine (GOSE ≤ 6: OR = 4.10 [1.67-10.07]; ACE-sleep: B = 0.57 [0.15-1.00]; ACE-emotional: B = 0.92 [0.35-1.49]), and gastrointestinal history (ACE-physical: B = 1.25 [0.41-2.10]) were multivariable predictors of worse outcomes. At 6-months, psychiatric (GOSE ≤ 6: OR = 2.57 [1.38-4.77]; ACE-physical: B = 1.38 [0.68-2.09]; ACE-cognitive: B = 0.74 [0.28-1.20]; ACE-sleep: B = 0.51 [0.20-0.83]; ACE-emotional: B = 0.93 [0.53-1.33]), and headache/migraine history (ACE-physical: B = 1.81 [0.79-2.84]) predicted worse outcomes. Conclusions: Pre-injury psychiatric and pre-injury headache/migraine symptoms are risk factors for worse functional and post-concussive outcomes at 3- and 6-months post-mTBI. mTBI patients presenting to acute care should be evaluated for psychiatric and headache/migraine history, with lower thresholds for providing TBI education/resources, surveillance, and follow-up/referrals. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT01565551.

A critical review to traumatic brain injury clinical practice guidelines

The aim of this study was to assess the quality of clinical practice guidelines of traumatic brain injury (TBI) and investigate the evidence grading systems.A systematic search of relevant guideline websites and literature databases (including PubMed, NGC, SIGN, NICE, GIN, and Google) was undertaken from inception to May 2018 to identify and select TBI guidelines. Four independent reviewers assessed the eligible guidelines using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. The degree of agreement was evaluated with intraclass correlation coefficient (ICC).From 1802 records retrieved, 12 TBI guidelines were included. The mean scores for each AGREE II domain were as follows: scope and purpose (mean ± SD= 74.2 ± 9.09); stakeholder involvement (mean± SD= 54.6 ± 11.6); rigor of development (mean ± SD=70.1 ± 13.6); clarity and presentation (mean ± SD=78.4 ± 11.5); applicability (mean ± SD= 60.5 ± 13.6); and editorial independence (mean ± SD=61.7 ± 14.8). Ten guidelines were rated as "recommended." The ICC values ranged from 0.73 to 0.95. Seven grading systems were used by TBI guidelines to rate the level of evidence and the strength of recommendation.Most TBI guidelines got a high-quality rating, whereas a standardized grading system should be adopted to provide clear information about the level of evidence and strength of recommendation in TBI guidelines.

Neuroimaging of Traumatic Brain Injury

The purpose of this article is to review conventional and advanced neuroimaging techniques performed in the setting of traumatic brain injury (TBI). The primary goal for the treatment of patients with suspected TBI is to prevent secondary injury. In the setting of a moderate to severe TBI, the most appropriate initial neuroimaging examination is a noncontrast head computed tomography (CT), which can reveal life-threatening injuries and direct emergent neurosurgical intervention. We will focus much of the article on advanced neuroimaging techniques including perfusion imaging and diffusion tensor imaging and discuss their potentials and challenges. We believe that advanced neuroimaging techniques may improve the accuracy of diagnosis of TBI and improve management of TBI.

Influence of study population definition on the effect of age on outcomes after blunt head trauma

OBJECTIVES

The purpose of this study was to assess whether study population definition influences the effect of age on outcomes after blunt head trauma. We hypothesized that examining 'all comers' receiving head computerized tomography after blunt head trauma, fewer older individuals would meet Veterans Administration and Department of Defense (VA/DoD) criteria for traumatic brain injury (TBI), and would, therefore, display better outcomes than younger cohorts. However, restricting to participants meeting VA/DoD criteria for TBI, we hypothesized that older individuals would have worse outcomes.

METHODS

Data from a recently completed prospective cohort study were analysed with age dichotomized at 65 years. Logistic regression modelling, controlled for potential confounders including head trauma severity, was estimated to measure the effect of age on functional recovery, post-concussion symptoms (PCS), and depressive symptoms at 1-month post-TBI.

RESULTS

Fewer older than younger individuals met VA/DoD criteria for TBI. Older individuals had better functional, PCS, and depressive outcomes at 1 month. Restricting to those meeting VA/DoD criteria for TBI, older individuals continued to have better functional and PCS outcomes but had outcomes comparable to younger on depressive symptoms.

CONCLUSIONS

Contrary to our hypothesis, there was a tendency for older adults to have better outcomes than younger, independent of the diagnostic criteria applied.

Comparisons of the accuracy of radiation diagnostic modalities in brain tumor: A nonrandomized, nonexperimental, cross-sectional trial

Tumor morphology improved sensitivity, accuracy, and specificity of the diagnosis, but all diagnostic techniques have attenuation correction issues.To compare computed tomographic (CT), positron emission tomographic (PET), and magnetic resonance imaging (MRI) characteristics of patients with brain tumor in a Chinese setting.A nonrandomized, nonexperimental, cross-sectional trial.Jining No. 1 People's Hospital, China.In total, 127 patients who had clinically confirmed a brain tumor were included in the cross-sectional study. Patients were subjected to brain CT, MRI, and PET. The tumors resected after brain surgery were subjected to morphological diagnosis. Statistical analysis of data of surgically removed tumor and that of different methods of diagnosis was performed using Wilcoxon test following Tukey-Kramer test. Spearmen correlation was performed between diagnostic modalities and in vivo morphology. Results were considered significant at 99% of confidence level.The data of diameter and volume of tumor derived from CT (Spearman r = 0.9845 and 0.9706), and MRI (Spearman r = 0.955 and 0.2378) were failed to correlate with that of that of the surgically removed tumor. However, prediction of diameter and volume of the tumor by PET (Spearman r = 0.9922 and 0.9921) were correlated with that of the surgically removed tumor. CT and MRI were failed to quantified pituitary adenomas.The study was recommended PET for assessment of brain tumor.

The Microtubule-Modulating Drug Epothilone D Alters Dendritic Spine Morphology in a Mouse Model of Mild Traumatic Brain Injury

Microtubule dynamics underpin a plethora of roles involved in the intricate development, structure, function, and maintenance of the central nervous system. Within the injured brain, microtubules are vulnerable to misalignment and dissolution in neurons and have been implicated in injury-induced glial responses and adaptive neuroplasticity in the aftermath of injury. Unfortunately, there is a current lack of therapeutic options for treating traumatic brain injury (TBI). Thus, using a clinically relevant model of mild TBI, lateral fluid percussion injury (FPI) in adult male Thy1-YFPH mice, we investigated the potential therapeutic effects of the brain-penetrant microtubule-stabilizing agent, epothilone D. At 7 days following a single mild lateral FPI the ipsilateral hemisphere was characterized by mild astroglial activation and a stereotypical and widespread pattern of axonal damage in the internal and external capsule white matter tracts. These alterations occurred in the absence of other overt signs of trauma: there were no alterations in cortical thickness or in the number of cortical projection neurons, axons or dendrites expressing YFP. Interestingly, a single low dose of epothilone D administered immediately following FPI (and sham-operation) caused significant alterations in the dendritic spines of layer 5 cortical projection neurons, while the astroglial response and axonal pathology were unaffected. Specifically, spine length was significantly decreased, whereas the density of mushroom spines was significantly increased following epothilone D treatment. Together, these findings have implications for the use of microtubule stabilizing agents in manipulating injury-induced synaptic plasticity and indicate that further study into the viability of microtubule stabilization as a therapeutic strategy in combating TBI is warranted.

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.

A novel method for the rapid detection of post-translationally modified visinin-like protein 1 in rat models of brain injury

BACKGROUND

Although elevated serum levels of visinin-like protein 1 (VILIP-1), a neuron-specific calcium sensor protein, are associated with ischaemic stroke, only a single study has evaluated VILIP-1 as a biomarker of traumatic brain injury (TBI). The current proof-of-concept study was designed to determine whether serum VILIP-1 levels increase post-injury in a well-characterized rat unilateral cortical contusion model.

METHODS

Lateral flow devices (LFDs) rapidly (< 20 min) detected trace serum levels (pg/mL) of VILIP-1 in a small input sample volume (10 µL). Temporal profiles of serum levels at baseline and post-injury were measured in male Sprague Dawley rats subjected to very mild-, mild unilateral-cortical contusion, or naïve surgery and in male Sprague Dawley rats following a diffuse TBI or sham surgery.

RESULTS

Mean serum levels were significantly elevated by 0.5 h post-injury and remained so throughout the temporal profile compared with baseline in very mild and mild unilateral contusions but not in naïve surgeries. Serum levels were also elevated in a small cohort of animals subjected to a diffuse TBI injury.

CONCLUSIONS

Overall, the current study demonstrates that the novel LFD is a reliable and rapid point-of-care diagnostic for the detection and quantification of serum levels of UB-VILIP-1 in a clinically relevant time frame.

Utility of the Aspirin and P2Y12 Response Assays to Determine the Effect of Antiplatelet Agents on Platelet Reactivity in Traumatic Brain Injury

BACKGROUND

Premorbid antithrombotic medication may worsen intracranial injury and outcome after traumatic brain injury (TBI). Routine laboratory tests are insufficient to evaluate platelet activity.

OBJECTIVE

To profile the spectrum of platelet inhibition, as measured by aspirin and P2Y12 response unit assays, in a TBI population on antiplatelet therapy.

METHODS

This single-center, prospective cohort study included patients presenting to our institution between November 2010 and January 2015 with a clinical history of TBI. Serum platelet reactivity levels were determined immediately on admission and analyzed using the aspirin and P2Y12 response unit assays; test results were reported as aspirin response units and P2Y12 response units. We report congruence between assay results and clinical history as well as differences in assay results between types of antiplatelet therapy.

RESULTS

A sample of 317 patients was available for analysis, of which 87% had experienced mild TBI, 7% moderate, and 6% severe; the mean age was 71.5 years. The mean aspirin response units in patients with a history of any aspirin use was 456 ± 67 (range, 350-659), with 88% demonstrating therapeutic platelet inhibition. For clopidogrel, the mean P2Y12 response unit was 191 ± 70 (range, 51-351); 77% showed therapeutic response.

CONCLUSION

Rapid measurement of antiplatelet function using the aspirin and P2Y12 response assays indicated as many as one fourth of patients on antiplatelet therapy do not have platelet dysfunction. Further research is required to develop guidelines for the use of these assays to guide platelet transfusion in the setting of TBI.

Comparing Plasma Phospho Tau, Total Tau, and Phospho Tau-Total Tau Ratio as Acute and Chronic Traumatic Brain Injury Biomarkers

Importance

Annually in the United States, at least 3.5 million people seek medical attention for traumatic brain injury (TBI). The development of therapies for TBI is limited by the absence of diagnostic and prognostic biomarkers. Microtubule-associated protein tau is an axonal phosphoprotein. To date, the presence of the hypophosphorylated tau protein (P-tau) in plasma from patients with acute TBI and chronic TBI has not been investigated.

Objective

To examine the associations between plasma P-tau and total-tau (T-tau) levels and injury presence, severity, type of pathoanatomic lesion (neuroimaging), and patient outcomes in acute and chronic TBI.

Design, Setting, and Participants

In the TRACK-TBI Pilot study, plasma was collected at a single time point from 196 patients with acute TBI admitted to 3 level I trauma centers (<24 hours after injury) and 21 patients with TBI admitted to inpatient rehabilitation units (mean [SD], 176.4 [44.5] days after injury). Control samples were purchased from a commercial vendor. The TRACK-TBI Pilot study was conducted from April 1, 2010, to June 30, 2012. Data analysis for the current investigation was performed from August 1, 2015, to March 13, 2017.

Main Outcomes and Measures

Plasma samples were assayed for P-tau (using an antibody that specifically recognizes phosphothreonine-231) and T-tau using ultra-high sensitivity laser-based immunoassay multi-arrayed fiberoptics conjugated with rolling circle amplification.

Results

In the 217 patients with TBI, 161 (74.2%) were men; mean (SD) age was 42.5 (18.1) years. The P-tau and T-tau levels and P-tau-T-tau ratio in patients with acute TBI were higher than those in healthy controls. Receiver operating characteristic analysis for the 3 tau indices demonstrated accuracy with area under the curve (AUC) of 1.000, 0.916, and 1.000, respectively, for discriminating mild TBI (Glasgow Coma Scale [GCS] score, 13-15, n = 162) from healthy controls. The P-tau level and P-tau-T-tau ratio were higher in individuals with more severe TBI (GCS, ≤12 vs 13-15). The P-tau level and P-tau-T-tau ratio outperformed the T-tau level in distinguishing cranial computed tomography-positive from -negative cases (AUC = 0.921, 0.923, and 0.646, respectively). Acute P-tau levels and P-tau-T-tau ratio weakly distinguished patients with TBI who had good outcomes (Glasgow Outcome Scale-Extended GOS-E, 7-8) (AUC = 0.663 and 0.658, respectively) and identified those with poor outcomes (GOS-E, ≤4 vs >4) (AUC = 0.771 and 0.777, respectively). Plasma samples from patients with chronic TBI also showed elevated P-tau levels and a P-tau-T-tau ratio significantly higher than that of healthy controls, with both P-tau indices strongly discriminating patients with chronic TBI from healthy controls (AUC = 1.000 and 0.963, respectively).

Conclusions and Relevance

Plasma P-tau levels and P-tau-T-tau ratio outperformed T-tau level as diagnostic and prognostic biomarkers for acute TBI. Compared with T-tau levels alone, P-tau levels and P-tau-T-tau ratios show more robust and sustained elevations among patients with chronic TBI.

Evaluation and Treatment of Mild Traumatic Brain Injury: The Role of Neuropsychology

Awareness of mild traumatic brain injury (mTBI) and persisting post-concussive syndrome (PCS) has increased substantially in the past few decades, with a corresponding increase in research on diagnosis, management, and treatment of patients with mTBI. The purpose of this article is to provide a narrative review of the current literature on behavioral assessment and management of patients presenting with mTBI/PCS, and to detail the potential role of neuropsychologists and rehabilitation psychologists in interdisciplinary care for this population during the acute, subacute, and chronic phases of recovery.

A machine learning based approach for identifying traumatic brain injury patients for whom a head CT scan can be avoided

Head CT scan is more often used to evaluate patients with suspected traumatic brain injury (TBI). However, the use of head CT scans in evaluating TBI is costly with low value endeavor. In this paper, we propose a new algorithm and a set of features to help clinicians determine which patients evaluated for TBI need a head CT scan using cost sensitive random forest (CSRF) classifier. We show that random forest (RF) and CSRF are useful methods for identifying patients likely to have a positive head CT scan. The proposed algorithm has superior diagnostic accuracy in comparison to the Canadian head CT algorithm, which is currently the most accurate and widely used algorithm for determining which TBI patients need a head CT scan. In the highest sensitivity (i.e. 100%), our method outperforms the Canadian rule in terms of specificity, accuracy and area under ROC curve using cost sensitive classifier. Clinical implementation of this algorithm can help decrease financial costs associated with Emergency Department evaluations for traumatic brain injury, while decreasing patient exposure to avoidable ionizing radiation.

Subconcussive Impact-Dependent Increase in Plasma S100β Levels in Collegiate Football Players

The current study investigates whether repetitive subconcussive impacts cause changes in plasma S100β levels, and also tests the associations between S100β changes and frequency/magnitude of impacts sustained. This prospective study of 22 Division-I collegiate football players included baseline and pre-season practices (one helmet-only and four full-gear). Blood samples were obtained and assessed for S100β levels at baseline and pre- to post-practices; symptom scores were assessed at each time-point. An accelerometer-embedded mouthguard was employed to measure the number of impacts (hits), peak linear acceleration (PLA), and peak rotational acceleration (PRA). Because we observed a distinct gap in impact exposure (hits, PLA, and PRA), players were clustered into lower (n = 7) or higher (n = 15) impact groups based on the sum of impact kinematics from all five practices. S100β levels significantly changed across the study duration. Although S100β levels remained stable from baseline to all pre-practice values, statistically significant acute increases in S100β levels were observed in all post-practice measures compared with the respective pre-practice values (range: 133-246% in the overall sample). Greater number of hits, sum of PLA, and sum of PRA were significantly associated with greater acute increases in S100β levels. There were significant differences in head impact kinematics between lower and higher impact groups (hits, 6 vs. 43 [M_lower - M_higher = 35, p < 0.001]; PLA, 99.4 vs. 1148.5 g [M_lower - M_higher = 1049.1, p < 0.001]; PRA, 7589 vs. 68,259 rad/s² [M_lower - M_higher = 60,670, p < 0.001]). Players in the higher impact group showed consistently greater increases in plasma S100β levels, but not symptom scores, at each post-practice than the lower impact group. Collectively, these data suggest that although players continued to play without noticeable change in symptoms, a brain-enriched serological factor suggests an acute burden from head impacts. Assessing the effects of repetitive subconcussive head impacts on acute changes in S100β levels may be a clinically useful blood biomarker in tracking real-time acute brain damage in collegiate football players.

A blood-based biomarker panel to risk-stratify mild traumatic brain injury

Mild traumatic brain injury (TBI) accounts for the vast majority of the nearly two million brain injuries suffered in the United States each year. Mild TBI is commonly classified as complicated (radiographic evidence of intracranial injury) or uncomplicated (radiographically negative). Such a distinction is important because it helps to determine the need for further neuroimaging, potential admission, or neurosurgical intervention. Unfortunately, imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) are costly and not without some risk. The purpose of this study was to screen 87 serum biomarkers to identify a select panel of biomarkers that would predict the presence of intracranial injury as determined by initial brain CT. Serum was collected from 110 patients who sustained a mild TBI within 24 hours of blood draw. Two models were created. In the broad inclusive model, 72kDa type IV collagenase (MMP-2), C-reactive protein (CRP), creatine kinase B type (CKBB), fatty acid binding protein-heart (hFABP), granulocyte-macrophage colony-stimulating factor (GM-CSF) and malondialdehyde modified low density lipoprotein (MDA-LDL) significantly predicted injury visualized on CT, yielding an overall c-statistic of 0.975 and a negative predictive value (NPV) of 98.6. In the parsimonious model, MMP-2, CRP, and CKBB type significantly predicted injury visualized on CT, yielding an overall c-statistic of 0.964 and a negative predictive value (NPV) of 97.2. These results suggest that a serum based biomarker panel can accurately differentiate patients with complicated mild TBI from those with uncomplicated mild TBI. Such a panel could be useful to guide early triage decisions, including the need for further evaluation or admission, especially in those environments in which resources are limited.

Head injury serum markers for assessing response to trauma: Design of the HeadSMART study

BACKGROUND

Accurate diagnosis and risk stratification of traumatic brain injury (TBI) at time of presentation remains a clinical challenge. The Head Injury Serum Markers for Assessing Response to Trauma study (HeadSMART) aims to examine blood-based biomarkers for diagnosing and determining prognosis in TBI.

METHODS

HeadSMART is a 6-month prospective cohort study comparing emergency department patients evaluated for TBI (exposure group) to (1) emergency department patients evaluated for traumatic injury without head trauma and (2) healthy persons. Study methods and characteristics of the first 300 exposure participants are discussed.

RESULTS

Of the first 300 participants in the exposure arm, 70% met the American Congress of Rehabilitation Medicine criteria for TBI, with the majority (80.1%) classified as mild TBI. The majority of subjects in the exposure arm had Glasgow Coma Scale scores of 13-15 (98.0%), normal head computed tomography (81.3%) and no prior history of concussion (71.7%).

CONCLUSION

With systematic phenotyping, HeadSMART will facilitate diagnosis and risk-stratification of the heterogeneous group of individuals currently diagnosed with TBI.

Traumatic brain injury (TBI) in older adults: aging with a TBI versus incident TBI in the aged

Approximately 39 million older adults (age >65) were evaluated for traumatic brain injury (TBI) in United States emergency departments during the 2-year period from 2009 to 2010, representing a 61% increase in estimates from prior years (Albrecht et al., 2015a). Across the lifespan, an estimated 5.3 million Americans are living with a TBI-related disability (Centers for Disease Control and Prevention (CDC), 2003). With improved recognition and management, more individuals experiencing TBI are surviving to die of other causes later in life (Flanagan et al., 2005). Taken together, these statistics highlight two important populations: those who are "aging with a TBI" and "incident TBI in the aged."

Concussion and its neurobehavioural sequelae

A concussion results from a force to the brain that results in a transient loss of connectivity within the brain. Sport psychiatrists are increasingly called to be part of the concussion team and need to be prepared to manage issues related to concussion and its behavioural sequelae. Objectively, the best evidence available suggests that deficits in attention and/or in balance are the most reliable objective findings that a concussion has occurred. Prognosis after a concussion is generally very good, although a sub-set of patients that are yet well defined seem pre-disposed to delayed recovery. Neither head CT nor MRI are sufficiently sensitive to diagnose the type of injuries that pre-dispose patients to the neurobehavioural sequelae that have been associated with a concussion; confounding this is the finding that many of these signs and symptoms associated with concussion occur in other types of non-head injuries. Brain biomarkers and functional MRI (fMRI) hold promise in both diagnosis and prognosis of concussion, but are still research tools without validated clinical utility at this time. Finally, neurocognitive testing holds promise as a diagnostic criterion to demonstrate injury but, unfortunately, these tests are also limited in their prognostic utility and are of limited value.

Quality of the Development of Traumatic Brain Injury Clinical Practice Guidelines: A Systematic Review

Traumatic brain injury (TBI) is a leading cause of death worldwide and is increasing exponentially particularly in low and middle income countries (LMIC). To inform the development of a standard Clinical Practice Guideline (CPG) for the acute management of TBI that can be implemented specifically for limited resource settings, we conducted a systematic review to identify and assess the quality of all currently available CPGs on acute TBI using the AGREE II instrument. In accordance with PRISMA guidelines, from April 2013 to December 2015 we searched MEDLINE, EMBASE, Google Scholar and the Duke University Medical Center Library Guidelines for peer-reviewed published Clinical Practice Guidelines on the acute management of TBI (less than 24 hours), for any level of traumatic brain injury in both high and low income settings. A comprehensive reference and citation analysis was performed. CPGs found were assessed using the AGREE II instrument by five independent reviewers and scores were aggregated and reported in percentage of total possible score. An initial 2742 articles were evaluated with an additional 98 articles from the citation and reference analysis, yielding 273 full texts examined. A total of 24 final CPGs were included, of which 23 were from high income countries (HIC) and 1 from LMIC. Based on the AGREE II instrument, the best score on overall assessment was 100.0 for the CPG from the National Institute for Health and Clinical Excellence (NIHCE, 2007), followed by the New Zealand Guidelines Group (NZ, 2006) and the National Clinical Guideline (SIGN, 2009) both with a score of 96.7. The CPG from a LMIC had lower scores than CPGs from higher income settings. Our study identified and evaluated 24 CPGs with the highest scores in clarity and presentation, scope and purpose, and rigor of development. Most of these CPGs were developed in HICs, with limited applicability or utility for resource limited settings. Stakeholder involvement, Applicability, and Editorial independence remain weak and insufficiently described specifically with piloting, addressing potential costs and implementation barriers, and auditing for quality improvement.

Sports-related brain injuries: connecting pathology to diagnosis

Brain injuries are becoming increasingly common in athletes and represent an important diagnostic challenge. Early detection and management of brain injuries in sports are of utmost importance in preventing chronic neurological and psychiatric decline. These types of injuries incurred during sports are referred to as mild traumatic brain injuries, which represent a heterogeneous spectrum of disease. The most dramatic manifestation of chronic mild traumatic brain injuries is termed chronic traumatic encephalopathy, which is associated with profound neuropsychiatric deficits. Because chronic traumatic encephalopathy can only be diagnosed by postmortem examination, new diagnostic methodologies are needed for early detection and amelioration of disease burden. This review examines the pathology driving changes in athletes participating in high-impact sports and how this understanding can lead to innovations in neuroimaging and biomarker discovery.