Traumatic Brain Injury-Related Emergency Department Visits, Hospitalizations, and Deaths - United States, 2007 and 2013

A Small Molecule Spinogenic Compound Enhances Functional Outcome and Dendritic Spine Plasticity in a Rat Model of Traumatic Brain Injury

The tetra (ethylene glycol) derivative of benzothiazole aniline (SPG101) has been shown to improve dendritic spine density and cognitive memory in the triple transgenic mouse model of Alzheimer disease (AD) when administered intraperitoneally. The present study was designed to investigate the therapeutic effects of SPG101 on dendritic spine density and morphology and sensorimotor and cognitive functional recovery in a rat model of traumatic brain injury (TBI) induced by controlled cortical impact (CCI). Young adult male Wistar rats with CCI were randomly divided into the following two groups (n = 7/group): (1) Vehicle, and (2) SPG101. SPG101 (30 mg/kg) dissolved in vehicle (1% dimethyl sulfoxide in phosphate buffered saline) or Vehicle were intraperitoneally administered starting at 1 h post-injury and once daily for the next 34 days. Sensorimotor deficits were assessed using a modified neurological severity score and adhesive removal and foot fault tests. Cognitive function was measured by Morris water maze, novel object recognition (NOR), and three-chamber social recognition tests. The animals were sacrificed 35 days after injury, and their brains were processed for measurement of dendritic spine density and morphology using ballistic dye labeling. Compared with the vehicle treatment, SPG101 treatment initiated 1 h post-injury significantly improved sensorimotor functional recovery (days 7-35, p < 0.0001), spatial learning (days 32-35, p < 0.0001), NOR (days 14 and 35, p < 0.0001), social recognition (days 14 and 35, p < 0.0001). Further, treatment significantly increased dendritic spine density in the injured cortex (p < 0.05), decreased heterogeneous distribution of spine lengths in the injured cortex and hippocampus (p < 0.0001), modifications that are associated with the promotion of spine maturation in these brain regions. In summary, treatment with SPG101 initiated 1 h post-injury and continued for an additional 34 days improves both sensorimotor and cognitive functional recovery, indicating that SPG101 acts as a spinogenic agent and may have potential as a novel treatment of TBI.

Repetitive Transcranial Magnetic Stimulation for Treatment of Depression in a Patient With Severe Traumatic Brain Injury

Background

Traumatic brain injury (TBI) commonly presents with a constellation of findings, including physical, cognitive, and psychological disturbances. Traditionally, few options have been available for long-term management of mood symptoms for post-TBI patients who are refractory to medications. Repetitive transcranial magnetic stimulation (rTMS) is a promising alternative treatment.

Case Report

A 37-year-old male with history of anxiety and bipolar depression incurred a TBI after a 60-foot fall. After his physical recovery, the patient had refractory depression. Eight months after the TBI event, he underwent a 6-week course of rTMS treatment and had a 70.8% improvement in mood symptoms by the end of the therapy as indicated by the Patient Health Questionnaire-9, transitioning from severe to mild depression according to the scoring system. Clinical correlation during the months following conclusion of rTMS therapy showed no signs of remission or adverse side effects. The patient remains stable and lives independently 1 year after treatment with mood-stabilizing medications.

Conclusion

This case provides evidence for successful treatment of refractory depressive symptoms after severe TBI with the addition of rTMS to psychotherapy and mood-stabilizing medications, supporting the safety and tolerability of this novel therapeutic approach. Further studies are needed to validate the contribution of rTMS for management of mood symptoms in patients with TBI.

Exploratory Application of Neuropharmacometabolomics in Severe Childhood Traumatic Brain Injury

OBJECTIVES

To employ metabolomics-based pathway and network analyses to evaluate the cerebrospinal fluid metabolome after severe traumatic brain injury in children and the capacity of combination therapy with probenecid and N-acetylcysteine to impact glutathione-related and other pathways and networks, relative to placebo treatment.

DESIGN

Analysis of cerebrospinal fluid obtained from children enrolled in an Institutional Review Board-approved, randomized, placebo-controlled trial of a combination of probenecid and N-acetylcysteine after severe traumatic brain injury (Trial Registration NCT01322009).

SETTING

Thirty-six-bed PICU in a university-affiliated children's hospital.

PATIENTS AND SUBJECTS

Twelve children 2-18 years old after severe traumatic brain injury and five age-matched control subjects.

INTERVENTION

Probenecid (25 mg/kg) and N-acetylcysteine (140 mg/kg) or placebo administered via naso/orogastric tube.

MEASUREMENTS AND MAIN RESULTS

The cerebrospinal fluid metabolome was analyzed in samples from traumatic brain injury patients 24 hours after the first dose of drugs or placebo and control subjects. Feature detection, retention time, alignment, annotation, and principal component analysis and statistical analysis were conducted using XCMS-online. The software "mummichog" was used for pathway and network analyses. A two-component principal component analysis revealed clustering of each of the groups, with distinct metabolomics signatures. Several novel pathways with plausible mechanistic involvement in traumatic brain injury were identified. A combination of metabolomics and pathway/network analyses showed that seven glutathione-centered pathways and two networks were enriched in the cerebrospinal fluid of traumatic brain injury patients treated with probenecid and N-acetylcysteine versus placebo-treated patients. Several additional pathways/networks consisting of components that are known substrates of probenecid-inhibitable transporters were also identified, providing additional mechanistic validation.

CONCLUSIONS

This proof-of-concept neuropharmacometabolomics assessment reveals alterations in known and previously unidentified metabolic pathways and supports therapeutic target engagement of the combination of probenecid and N-acetylcysteine treatment after severe traumatic brain injury in children.

Adult Firearm-Related Traumatic Brain Injury in United States Trauma Centers

Civilian firearm injury is an important public health concern in the United States. Gunshot wounds to the head (GSWH) remain in need of update and systematic characterization. We identify predictors of prolonged hospital length of stay (HLOS), intensive care unit length of stay (ICU LOS), medical complications, mortality, and discharge disposition from a population-based sample using the National Sample Program (NSP) of the National Trauma Data Bank (NTDB), years 2003-2012. Statistical significance was assessed at α < 0.001 to correct for multiple comparisons. In total, 8148 adult GSWH patients were included extrapolating to 32,439 national incidents. Age was 36.6 ± 16.4 years and 64.4% were severe traumatic brain injury (TBI; Glasgow Coma Scale [GCS] score 3-8). Assault (49.2%), handgun (50.3%), and residential injury (43.2%) were of highest incidence. HLOS and ICU LOS were 7.7 ± 14.2 and 5.7 ± 13.4 days, respectively. Overall mortality was 54.6%; suicide/self-injury was associated with the highest mortality rate (71.6%). GCS, Injury Severity Score, and hypotension were significant predictors for outcomes overall. Medicare/Medicaid patients had longer HLOS compared to private/commercial insured (mean increase, 4.4 days; 95% confidence interval [2.6-6.3]). Compared to the Midwest, the South had longer HLOS (mean increase, 3.7 days; [2.0-5.4]) and higher odds of complications (odds ratio [OR], 1.7 [1.4-2.0]); the West had lower odds of complications (OR, 0.6; [0.5-0.7]). Versus handgun, shotgun (OR, 0.3; [0.2-0.4]) and hunting rifle (OR, 0.5; [0.4-0.8]) resulted in lower mortality. Patients with government/other insurance had higher odds of discharging home compared to private/commercially insured (OR, 1.7; [1.3-2.3]). In comparison to level I trauma centers, level II trauma centers had lower odds of discharge to home (OR, 0.7; [0.5-0.8]). Our results support hypotension, injury severity, injury intent, firearm type, and U.S. geographical location as important prognostic variables in firearm-related TBI. Improved understanding of civilian GSWH is critical to promoting increased awareness of firearm injuries as a public health concern and reducing its debilitating injury burden to patients, families, and healthcare systems.

Perioperative Management of Severe Traumatic Brain Injury: What Is New?

PURPOSE OF THE REVIEW

Severe traumatic brain injury (TBI) continues to represent a global public health issue, and mortality and morbidity in TBI patients remain substantial. There are ongoing international collaborations to provide guidelines for perioperative care and management of severe TBI patients. In addition, new pharmacologic agents are being tested along with cognitive rehabilitation to improve functional independence and outcome in TBI patients. This review will discuss the current updates in the guidelines for the perioperative management of TBI patients and describe potential new therapies to improve functional outcomes.

RECENT FINDINGS

In the most recent guidelines published by The Brain Trauma Foundation, therapeutic options were reviewed based on new and revised evidence or lack of evidence. For example, changes and/or updates were made to the recommendations for the use of sedation and hypothermia in TBI patients, and new evidence was provided for the use of cerebrospinal fluid drainage as a first-line treatment for increased intracranial pressure (ICP). In addition to the guidelines, new 'multi-potential' agents that can target several mechanisms are being tested along with cognitive rehabilitation.

SUMMARY

The major goal of perioperative management of TBI patients is to prevent secondary damage. Therapeutic measures based on established guidelines and recommendations must be instituted promptly throughout the perioperative course to reduce morbidity and mortality.

Visual Pathway Injuries in Pediatric Ocular Trauma-A Survey of the National Trauma Data Bank From 2008 to 2014

BACKGROUND

Traumatic visual pathway injuries are often associated with severe head trauma and can have profound deleterious effects in developing children and their rehabilitation. We sought to elucidate the epidemiology of pediatric visual pathway injuries in the United States.

MATERIALS AND METHODS

This study is a retrospective evaluation of pediatric patients (less than 21 years of age) with visual pathway injuries that were submitted to the National Trauma Data Bank between 2008 to 2014. Patients were identified using the International Classification of Diseases, Ninth Revision Clinical Modification codes. Statistical analysis was performed with SPSS software. Variables were correlated using Student t test, chi-squared test, and logistic regression analyses.

RESULTS

Of the 58,765 pediatric patients (1.7%) who were admitted with ocular injuries, 970 had visual pathway injuries. The majority of these patients were male (69.2%), and the mean age was 11.6 years (±7.2). Traumatic optic neuropathy was the most common (86.1%) visual pathway injury. It had the greatest odds of occurring with oculomotor nerve injury (odds ratio = 3.84; P < 0.001). Associated ocular injuries were open adnexal wounds (87.4%) and orbital fractures (23%). Common mechanisms were motor vehicle occupant (21.5%) and firearms (15.6%). Motor vehicle occupants were most likely white and firearms injury, black. In the zero to three years age group, most injuries were due to falls; injuries in the 19 to 21 years age group had the greatest association with firearms. Overall mortality was 17.6%.

CONCLUSIONS

Visual pathway injuries may have devastatating sequelae and should be considered in pediatric ocular injuries. The clear majority were traumatic optic neuropathies. The common mechanisms, motor vehicle occupant and firearms, revealed age and race disparities.

Role of Toll-like receptor mediated signaling in traumatic brain injury

The mechanisms underlying secondary brain damage following traumatic brain injury (TBI) remain unclear. A great many studies have demonstrated that inflammatory cascades contribute to brain damage through the activation of immune/inflammatory responses, including the increased release of cytokines and chemokines, and the recruitment of leukocytes. The cells and tissues damaged by primary mechanical injury release a number of endogenous factors acting as damage-associated molecular patterns (DAMPs), which initiate and perpetuate noninfectious inflammatory responses through transduction signaling pathways. Toll-like receptors (TLRs) are a transmembrane receptor family that can recognize the specific DAMPs released from damaged cells and recruit a set of adaptors leading to the activation of downstream kinases and nuclear factors which regulate the expression of inflammatory genes. The activation of inflammatory responses mediated by TLR signaling is closely associated with brain tissue damage and neurological dysfunction following TBI. TLRs and their downstream protein kinases may be potential targets for the treatment of TBI. Modulation of TLR-mediated signaling may attenuate brain damage and improve TBI outcome. In this review, we briefly discuss the role of TLR-mediated signaling in TBI and the new treatments targeting TLR signaling. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".

Safety of Antidepressant Classes Used Following Traumatic Brain Injury Among Medicare Beneficiaries: A Retrospective Cohort Study

OBJECTIVE

There is poor evidence supporting the use of any pharmacologic treatments for neuropsychiatric disorders following traumatic brain injury (TBI), especially among older adults. Informed by our recent characterization of psychotropic medication use among Medicare beneficiaries with TBI, the objective of this study was to compare the risk of several adverse events associated with use of the three most commonly used classes of antidepressants following TBI in this population.

METHODS

We conducted a retrospective cohort study using administrative claims data from US Medicare beneficiaries hospitalized with TBI between 2006 and 2010 (n = 30,886). We assessed monthly selective serotonin reuptake inhibitor (SSRI), serotonin-norepinephrine reuptake inhibitor (SNRI), and tricyclic antidepressant (TCA) use. We identified adverse events associated with these drug classes that were available in administrative claims data from studies in TBI and non-TBI populations: seizures, hemorrhagic stroke, ischemic stroke, gastrointestinal bleed, hyponatremia, and fractures. We made comparisons between antidepressant classes to assess excess risk of each adverse event using discrete time analysis and controlling for potential confounders.

RESULTS

SSRIs were the most commonly used of the antidepressant classes, followed by SNRIs and TCAs. We observed a total of 23,021 adverse events. Ischemic stroke was the most frequent (8296 events). Hemorrhagic stroke (1706 events) and seizures (1841) were least often observed. Compared with TCAs, SSRI use was associated with an increased risk of hemorrhagic stroke (risk ratio 2.47; 95% confidence interval 1.30-4.70). No other antidepressant class comparisons were associated with increased risk of adverse events.

CONCLUSION

Compared with SSRIs, use of SNRIs and TCAs following hospitalization for TBI among Medicare beneficiaries was not associated with an increased risk of any of the studied adverse events. Compared to TCAs, SSRI use was associated with increased risk of hemorrhagic stroke. This information may help guide patients and prescribers in selecting antidepressants for older adults following TBI.

Comprehensive analysis of the predictors of neurobehavioral symptom reporting in veterans

OBJECTIVE

This study assessed the strength of military-related concussion-, psychological-, and behavioral-related measures to predict neurobehavioral symptom (NBS) reporting in order to help clarify the extent to which persistent NBS reflect lingering effects of concussion vs other psychological/behavioral factors among veterans.

METHODS

Baseline analysis included 351 consecutively enrolled veterans in the Translational Research Center for Traumatic Brain Injury and Stress Disorders longitudinal cohort study. One hundred eighty-six returned for a follow-up evaluation averaging 24 months post baseline. The Neurobehavioral Symptom Inventory (NSI) was used to measure NBS reporting. Predictor variables included diagnosis of military-related mild traumatic brain injury (M-mTBI), psychological measures, including posttraumatic stress disorder, mood, anxiety, and substance abuse disorders, and behavioral measures, including self-reported current pain and sleep impairment. Hierarchical and multivariable regression analyses examined the relationships between the predictor variables and NSI scores. The k-fold cross-validation assessed generalizability and validity of the regressions.

RESULTS

Baseline analysis revealed that psychological and behavioral conditions independently accounted for 42.5% of variance in the NSI total score compared to 1.5% for M-mTBI after controlling for psychological and behavioral conditions. Prospective analysis revealed that M-mTBI at baseline did not significantly predict NSI score at follow-up, while psychological and behavioral measures at baseline independently accounted for 24.5% of NSI variance. Posttraumatic stress disorder was the most consistent predictor. Cross-validation analyses supported generalizability of the results.

CONCLUSIONS

Psychological and behavioral-related measures are strong predictors of persistent NBS reporting in veterans, while M-mTBI is negligible. NBS more likely reflect influential comorbidities as opposed to brain injury, per se.

Balance and Mobility Improvements During Inpatient Rehabilitation Are Similar in Young-Old, Mid-Old, and Old-Old Adults With Traumatic Brain Injury

OBJECTIVE

To compare balance, mobility, and functional outcomes across 3 age groups of older adults with traumatic brain injury; to describe differences between those discharged to private residences versus institutional care.

SETTING

Acute inpatient rehabilitation facility.

PARTICIPANTS

One hundred adults, mean age of 78.6 ± 7.9 years (range = 65-95 years), with an admitting diagnosis of traumatic brain injury.

DESIGN

Retrospective case series.

MAIN MEASURES

Functional Independence Measure (FIM) for Cognition and Mobility; Berg Balance Scale; Timed Up and Go; and gait speed, at admission to and discharge from an inpatient rehabilitation facility.

RESULTS

Statistically significant improvements (P < .01) were made on the Timed Up and Go, Berg Balance Scale, and gait speed for young-old, mid-old, and old-old adults, with no differences among the 3 age groups. Substantial balance and mobility deficits remained. The FIM cognition (P = .013), FIM Walk (P = .009), and FIM Transfer (P = .013) scores were significantly better in individuals discharged home or home with family versus those discharged to an institution.

CONCLUSION

Preliminary outcome data for specific balance and mobility measures are reported in 3 subgroups of older adults following traumatic brain injury, each of which made significant and similar improvements. Some FIM item scores discriminated between those discharged to a private residence versus a higher level of care.

Severe Traumatic Brain Injury Requiring Surgical Decompression in the Young Adult: Factors Influencing Morbidity and Mortality - A Retrospective Analysis

INTRODUCTION

Severe traumatic brain injury (TBI) is a leading cause of morbidity and mortality among young adults. The clinical outcome may also be difficult to predict. We aim to identify the factors predictive of favorable and unfavorable clinical outcomes for youthful patients with severe TBI who have the option of surgical craniotomy or surgical craniectomy.

METHODS

A retrospective review at a single Level II trauma center was conducted, identifying patients aged 18 to 30 years with isolated severe TBI with a mass-occupying lesion requiring emergent (< 6 hours from time of arrival) surgical decompression. Glasgow Coma Scale (GCS) score on arrival, type of surgery performed, mechanism of injury, length of hospital stay, Glasgow Outcome Score (GOS), mortality, and radiographic findings were recorded. A favorable outcome was a GOS of four or five at 30 days post operation, while an unfavorable outcome was GOS of 1 to 3.

RESULTS

Fifty patients were included in the final analysis. Closed head injuries (skull and dura intact), effacement of basal cisterns, disproportional midline shift (MLS), and GCS 3-5 on arrival all correlated with statistically significant higher rate of mortality and poor 30-day functional outcome. All mortalities (6/50 patients) were positive for each of these findings.

CONCLUSIONS

Closed head injuries, the presenting GCS 3-5, the presence of MLS disproportional to the space occupying lesion (SOL), and effacement of basal cisterns on the initial computed tomography of the head all correlated with unfavorable 30-day outcome. Future prospective studies investigating a larger cohort may provide further insight into patients suffering from severe TBI.

Neuroprotective Effects of Cyclosporine in a Porcine Pre-Clinical Trial of Focal Traumatic Brain Injury

Mitochondrial dysfunction is thought to be a hallmark of traumatic brain injury (TBI) and plays a pivotal role in the resulting cellular injury. Cyclophilin D-mediated activation of the mitochondrial permeability transition pore has been suggested to contribute to this secondary injury cascade. Cyclosporine possesses neuroprotective properties that have been attributed to the desensitization of mitochondrial permeability transition pore activation. In vivo animal experiments have demonstrated neuroprotective effects of cyclosporine in more than 20 independent experimental studies in a multitude of different experimental models. However, the majority of these studies have been carried out in rodents. The aim of the present study was to evaluate the efficacy of a novel and cremophor/kolliphor EL-free lipid emulsion formulation of cyclosporine in a translational large animal model of TBI. A mild-to-moderate focal contusion injury was induced in piglets using a controlled cortical impact device. After initial step-wise analyses of pharmacokinetics and comparing with exposure of cyclosporine in clinical TBI trials, a 5-day dosing regimen with continuous intravenous cyclosporine infusion (20 mg/kg/day) was evaluated in a randomized and blinded placebo-controlled setting. Cyclosporine reduced the volume of parenchymal injury by 35%, as well as improved markers of neuronal injury, as measured with magnetic resonance spectroscopic imaging. Further, a consistent trend toward positive improvements in brain metabolism and mitochondrial function was observed in the pericontusional tissue. In this study, we have demonstrated efficacy using a novel cyclosporine formulation in clinically relevant and translatable outcome metrics in a large animal model of focal TBI.

Comparative effectiveness of family problem-solving therapy (F-PST) for adolescents after traumatic brain injury: Protocol for a randomized, multicenter, clinical trial

Introduction

The objective of this manuscript is to describe the methodology that will be used to test the comparative effectiveness, feasibility, and acceptability of three formats of family problem solving therapy (F-PST) for improving functional outcomes of complicated mild to severe adolescent TBI.

Methods

Three-arm comparative effectiveness, randomized clinical trial (RCT) design. We describe the protocol of a three-arm RCT comparing the effectiveness of three modalities of F-PST to reduce executive dysfunction and behavior problems following TBI in adolescence. The RCT will compare the relative effectiveness among face-to-face; online and self-directed; and therapist-supported online modes of treatment.

Ethics and dissemination

It is anticipated that findings from this work will inform future clinical care practices, with implications for treatment of other patient populations of youth with psychological symptoms arising from neurological conditions. Institutional review board approval will be obtained from all sites prior to commencement of the study.

Effect of the Hybrid Emergency Room System on Functional Outcome in Patients with Severe Traumatic Brain Injury

OBJECTIVE

The timely treatment of severe traumatic brain injury (TBI) is essential for limiting the effects of damage; however, there is no consensus regarding an effective method for early intervention. In August 2011, our hospital launched a novel trauma workflow using the hybrid emergency room (ER), consisting of an interventional radiology-computed tomography (CT) unit installed in the trauma resuscitation room to facilitate early interventions. The aim of this study was to evaluate effects of the hybrid ER system on functional outcomes in patients with severe TBI.

METHODS

We conducted a retrospective historical control study of patients with severe TBI (Glasgow Coma Scale score ≤8) who received conventional treatment (August 2007-July 2011) or treatment in the hybrid ER (August 2011-July 2015). The primary end point was unfavorable outcome at 6 months after injury (death, vegetative state, or lower severe disability) as evaluated by the Glasgow Outcome Scale-Extended. Secondary end points included time from arrival to the start of CT examination and emergency intracranial operation. Potential confounders were adjusted with multivariable logistic regressions.

RESULTS

Among 158 included patients, 88 were in the conventional group and 70 were in the hybrid ER group. After model adjustment, the hybrid ER group was significantly associated with a reduction in unfavorable outcomes. Times to CT examination and intracranial operation were significantly shorter in the hybrid ER group than that in the conventional group.

CONCLUSIONS

The hybrid ER system is useful for realizing immediate CT examination and emergency surgery and improving functional outcomes in patients with severe TBI.

Sensory Sensitivity in TBI: Implications for Chronic Disability

PURPOSE OF REVIEW

This review investigates the relationship between sensory sensitivity and traumatic brain injury (TBI), and the role sensory sensitivity plays in chronic disability.

RECENT FINDINGS

TBI is a significant cause of disability with a range of physical, cognitive, and mental health consequences. Sensory sensitivities (e.g., noise and light) are among the most frequently reported, yet least outwardly recognizable symptoms following TBI. Clinicians and scientists alike have yet to identify consistent nomenclature for defining noise and light sensitivity, making it difficult to accurately and reliably assess their influence. Noise and light sensitivity can profoundly affect critical aspects of independent function including communication, productivity, socialization, cognition, sleep, and mental health. Research examining the prevalence of sensory sensitivity and evidence for the association of sensory sensitivity with TBI is inconclusive. Evidence-based interventions for sensory sensitivity, particularly following TBI, are lacking.

The Moderating Effect of the Ankyrin Repeat and Kinase Domain Containing One Gene on the Association of Family Environment with Longitudinal Executive Function following Traumatic Brain Injury in Early Childhood: A Preliminary Study

This study examined whether the ankyrin repeat and kinase domain containing 1 gene (ANKK1) C/T single-nucleotide polymorphism (SNP) rs1800497 moderated the association of family environment with long-term executive function (EF) following traumatic injury in early childhood. Caregivers of children with traumatic brain injury (TBI) and children with orthopedic injury completed the Behavior Rating Inventory of Executive Function (BRIEF) at post-injury visits. DNA was collected to identify the rs1800497 genotype in the ANKK1 gene. General linear models examined gene-environment interactions as moderators of the effects of TBI on EF at two times post-injury (12 months and 7 years). At 12 months post-injury, analyses revealed a significant three-way interaction of genotype with level of permissive parenting and injury type. Post hoc analyses showed genetic effects were more pronounced for children with TBI from more positive family environments, such that children with TBI who were carriers of the risk allele (T-allele) had significantly poorer EF compared with non-carriers only when they were from more advantaged environments. At 7 years post-injury, analyses revealed a significant two-way interaction of genotype with level of authoritarian parenting. Post hoc analyses found that carriers of the risk allele had significantly poorer EF compared with non-carriers only when they were from more advantaged environments. These results suggest a gene-environment interaction involving the ANKK1 gene as a predictor of EF in a pediatric injury population. The findings highlight the importance of considering environmental influences in future genetic studies on recovery following TBI and other traumatic injuries in childhood.

The Effect of the Relationship of APOE Polymorphisms and Cerebral Vasospasm on Functional Outcomes in Children With Traumatic Brain Injury

BACKGROUND

Pediatric traumatic brain injury (TBI) is a leading cause of death and disability. Polymorphisms in the apolipoprotein E ( APOE) gene have been linked to cerebral vasospasm (CV) and poor outcomes in adults with TBI, yet these associations remain poorly defined in children.

OBJECTIVE

We examined the effect of the relationship between APOE polymorphisms and CV on functional outcomes in children with a TBI.

METHOD

This prospective, descriptive study examined 60 children (aged 10 days to 15 years) with a TBI. Data included demographic information, genetic sampling for the APOE gene and single-nucleotide polymorphisms (SNPs; rs405509, rs429358, rs7412), and daily transcranial Doppler ultrasounds to evaluate for CV. We examined Glasgow Outcome Scale-Extended Pediatrics (GOS-E Peds) scores at the time of discharge and 4-6 weeks after discharge.

RESULTS

More than half (56.7%) of the 60 children ( M_age = 5.9 years) were male. Twenty-six participants (43.3%) experienced an occurrence of CV. There were significant differences in injury mechanism (unadjusted p = .048) and age (unadjusted p = .02) between those with and without CV. Also, the noncoding promoter SNP rs405509 T/T, when considered with injury severity, appeared to modify the relationship of APOE genotype to CV. The relationship between APOE and CV had no significant effect on GOS-E Peds scores.

CONCLUSION

Injury severity and the APOE noncoding promoter SNP rs405509 may modify the relationship between APOE and CV in children with TBI. More studies are needed to understand the role of APOE polymorphisms in outcomes in children with TBI.

A Sub-acute Cerebral Contusion Presenting with Medication-resistant Psychosis

The most common symptoms of a cerebral contusion include headache, dizziness, concentration problems, and memory loss. Insomnia is reported by more than half of the patients and can exacerbate symptoms. A 24-year-old previously healthy male presented with psychosis, acute personality changes, auditory and visual hallucinations three weeks after falling 15 feet with concurrent head trauma. A right-sided cerebral contusion with concussion was diagnosed on initial admission with increasing homicidal and suicidal ideations after 26 hours of insomnia. The patient accomplished rest after seven days of medication-resistant insomnia with the final combination of ziprasidone and lorazepam. After one night of sleep, the patient was alert and oriented with normal mood, affect, and cognition. The insomnia appeared to exacerbate this patient’s symptoms, and an atypical insomnia treatment regimen was required to induce somnolence and restore function in this patient. The combination of this abnormal patient presentation along with the unorthodox medication regimen makes this case unique compared to other traumatic brain injury symptoms and treatments.

Concussion

Concussions are a common injury for which patients often present first to primary care physicians. They can affect the day-to-day function of patients in school and work, as well as in sports and recreational activities. Recognizing common physical signs and symptoms after injury facilitates timely diagnosis and treatment, permitting initiation of an active management approach to recovery while preventing secondary injury. For persons with persistent symptoms, active rehabilitation may be utilized, with the goal of returning patients to full function.

Effects of Mild Blast Traumatic Brain Injury on Cognitive- and Addiction-Related Behaviors

Traumatic brain injury (TBI) commonly results in cognitive and psychiatric problems. Cognitive impairments occur in approximately 30% of patients suffering from mild TBI (mTBI), and correlational evidence from clinical studies indicates that substance abuse may be increased following mTBI. However, understanding the lasting cognitive and psychiatric problems stemming from mTBI is difficult in clinical settings where pre-injury assessment may not be possible or accurate. Therefore, we used a previously characterized blast model of mTBI (bTBI) to examine cognitive- and addiction-related outcomes. We previously demonstrated that this model leads to bilateral damage of the medial prefrontal cortex (mPFC), a region critical for cognitive function and addiction. Rats were exposed to bTBI and tested in operant learning tasks several weeks after injury. bTBI rats made more errors during acquisition of a cue discrimination task compared to sham treated rats. Surprisingly, we observed no differences between groups in set shifting and delayed matching to sample, tasks known to require the mPFC. Separate rats performed cocaine self-administration. No group differences were found in intake or extinction, and only subtle differences were observed in drug-primed reinstatement 3-4 months after injury. These findings indicate that bTBI impairs acquisition of a visual discrimination task and that bTBI does not significantly increase the ability of cocaine exposure to trigger drug seeking.

Age-Related Differences in Diagnostic Accuracy of Plasma Glial Fibrillary Acidic Protein and Tau for Identifying Acute Intracranial Trauma on Computed Tomography: A TRACK-TBI Study

Plasma tau and glial fibrillary acidic protein (GFAP) are promising biomarkers for identifying traumatic brain injury (TBI) patients with intracranial trauma on computed tomography (CT). Accuracy in older adults with mild TBI (mTBI), the fastest growing TBI population, is unknown. Our aim was to assess for age-related differences in diagnostic accuracy of plasma tau and GFAP for identifying intracranial trauma on CT. Samples from 169 patients (age <40 years [n = 79], age 40-59 years [n = 60], age 60 years+ [n = 30]), a subset of patients from the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) Pilot study who presented with mTBI (Glasgow Coma Scale score of 13-15), received head CT, and consented to blood draw within 24 h of injury, were assayed for hyperphosphorylated-tau (P-tau), total-tau (T-tau; both via amplification-linked enhanced immunoassay using multi-arrayed fiberoptics), and GFAP (via sandwich enzyme-linked immunosorbent assay). P-tau, T-tau, P-tau:T-tau ratio, and GFAP concentration were significantly associated with CT findings. Overall, discriminative ability declined with increasing age for all assays, but this decline was only statistically significant for GFAP (area under the receiver operating characteristic curve [AUC]: old 0.73 [reference group; ref] vs. young 0.93 [p = 0.037] or middle-aged 0.92 [p = 0.0497]). P-tau concentration consistently showed the highest diagnostic accuracy across all age-groups (AUC: old 0.84 [ref] vs. young 0.95 [p = 0.274] or middle-aged 0.93 [p = 0.367]). Comparison of models including P-tau alone versus P-tau plus GFAP revealed significant added value of GFAP. In conclusion, the GFAP assay was less accurate for identifying intracranial trauma on CT among older versus younger mTBI patients. Mechanisms of this age-related difference, including role of assay methodology, specific TBI neuroanatomy, pre-existing conditions, and anti-thrombotic use, warrant further study.

Healthcare professional involvement and RTP compliance in high school athletes with concussion

OBJECTIVES

To describe concussion rates in high school athletes and involvement of healthcare professionals in concussion diagnosis, management and compliance with return to play (RTP) guidelines.

METHODS

Data were analysed from injury reports in the National High School Sports-Related Injury Surveillance System between 2009/2010 and 2012/2013 to identify student athletes with concussion and determine compliance with RTP guidelines. Compliance with RTP guidelines was examined using logistic regression, adjusting for sport and injury-related variables.

RESULTS

There were 5611 concussions recorded during 15 712 475 athlete exposures (AEs), a rate of 3.6 concussions per 10 000 AEs. Rates were higher during competition and among girls compared to boys in gender equitable sports. Healthcare professionals were less likely to be present at the time of concussion for girls' sports, lower competition levels and practices. Compliance with RTP guidelines was higher for athletes with recurrent concussions, those sustained in collision sports, for athletes reporting more symptoms and when a physician made the RTP decision.

CONCLUSIONS

Presence of healthcare professionals and compliance with RTP guidelines varied by sport, gender, level of play and exposure type. High school athletes with concussion are best served by assessment teams with athletic trainers and physicians working together to manage concussions and contribute to RTP decisions.

Impact of age on acute post-TBI neuropathology in mice expressing humanized tau: a Chronic Effects of Neurotrauma Consortium Study

OBJECTIVES

We hypothesized that polypathology is more severe in older than younger mice during the acute phase following repetitive mild traumatic brain injury (r-mTBI).

METHODS

Young and aged male and female mice transgenic for human tau (hTau) were exposed to r-mTBI or a sham procedure. Twenty-four hours post-last injury, mouse brain tissue was immunostained for alterations in astrogliosis, microgliosis, tau pathology, and axonal injury.

RESULTS

Quantitative analysis revealed a greater percent distribution of glial fibrillary acid protein and Iba-1 reactivity in the brains of all mice exposed to r-mTBI compared to sham controls. With respect to axonal injury, the number of amyloid precursor protein-positive profiles was increased in young vs aged mice post r-mTBI. An increase in tau immunoreactivity was found in young and aged injured male hTau mice.

CONCLUSIONS

We report the first evidence in our model that r-mTBI precipitates a complex sequelae of events in aged vs young hTau mice at an acute time point, typified by an increase in phosphorylated tau and astroglisosis, and a diminished microgliosis response and axonal injury in aged mice. These findings suggest differential age-dependent effects in TBI pathobiology.

Therapeutic strategies to target acute and long-term sequelae of pediatric traumatic brain injury

Pediatric traumatic brain injury (TBI) remains one of the leading causes of morbidity and mortality in children. Experimental and clinical studies demonstrate that the developmental age, the type of injury (diffuse vs. focal) and sex may play important roles in the response of the developing brain to a traumatic injury. Advancements in acute neurosurgical interventions and neurocritical care have improved and led to a decrease in mortality rates over the past decades. However, survivors are left with life-long behavioral deficits underscoring the need to better define the cellular mechanisms underlying these functional changes. A better understanding of these mechanisms some of which begin in the acute post-traumatic period may likely lead to targeted treatment strategies. Key considerations in designing pre-clinical experiments to test therapeutic strategies in pediatric TBI include the use of age-appropriate and pathologically-relevant models, functional outcomes that are tested as animals age into adolescence and beyond, sex as a biological variable and the recognition that doses and dosing strategies that have been demonstrated to be effective in animal models of adult TBI may not be effective in the developing brain. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".

Mitochondrial therapy promotes regeneration of injured hippocampal neurons

Due to the inhibitory microenvironment and reduced intrinsic growth capacity of neurons, neuronal regeneration of central nervous system remains challenging. Neurons are highly energy demanding and require sufficient mitochondria to support cellular activities. In response to stimuli, mitochondria undergo fusion/fission cycles to adapt to environment. It is thus logical to hypothesize that the plasticity of mitochondrial dynamics is required for neuronal regeneration. In this study, we examined the role of mitochondrial dynamics during regeneration of rat hippocampal neurons. Quantitative analysis showed that injury induced mitochondrial fission. As mitochondrial dysfunction has been implicated in neurodegenerative diseases, we tested the possibility that the mitochondrial therapy may promote neuronal regeneration. Supplying freshly isolated mitochondria to the injured hippocampal neurons not only significantly increased neurite re-growth but also restored membrane potential of injured hippocampal neurons. Together, our findings support the importance of mitochondrial dynamics during regeneration of injured hippocampal neurons and highlight the therapeutic prospect of mitochondria to the injured central nervous system.

MicroRNA Signature of Traumatic Brain Injury: From the Biomarker Discovery to the Point-of-Care

Traumatic brain injury (TBI) is a serious problem that causes high morbidity and mortality around the world. Currently, no reliable biomarkers are used to assess the severity and predict the recovery. Many protein biomarkers were extensively studied for diagnosis and prognosis of different TBI severities such as S-100β, glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), neurofilament light chain (NFL), cleaved tau protein (C-tau), and ubiquitin C-terminal hydrolase-L1 (UCH-L1). However, none of these candidates is currently used in the clinical practice, due to relatively low sensitivity, for the diagnosis of mild TBI (mTBI) or mild to moderate TBI (MMTBI) patients who are clinically well and do not have a detectable intracranial pathology on the scans. MicroRNAs (miRNAs or miRs) are a class of small endogenous molecular regulators, which showed to be altered in different pathologies, including TBI and for this reason, their potential role in diagnosis, prognosis and therapeutic applications, is explored. Promising miRNAs such as miR-21, miR-16 or let-7i were identified as suitable candidate biomarkers for TBI and can differentiate mild from severe TBI. Also, they might represent new potential therapeutic targets. Identification of miRNA signature in tissue or biofluids, for several pathological conditions, is now possible thanks to the introduction of new high-throughput technologies such as microarray platform, Nanostring technologies or Next Generation Sequencing. This review has the aim to describe the role of microRNA in TBI and to explore the most commonly used techniques to identify microRNA profile. Understanding the strengths and limitations of the different methods can aid in the practical use of miRNA profiling for diverse clinical applications, including the development of a point-of-care device.

Prevalence of concomitant traumatic cranio-spinal injury: a systematic review and meta-analysis

The biomechanical relationship between cranial and spinal structures makes concomitant injury likely. Concomitant cranio-spinal injuries are important to consider following trauma due to the serious consequences of a missed injury. The objective of this review was to estimate the prevalence of concomitant cranio-spinal injury in the adult trauma population. A systematic search of MEDLINE and EMBASE databases to identify observational studies reporting the prevalence of concomitant cranio-spinal injury in the general adult trauma population was conducted on 21 March 2017. The prevalence of concomitant cervical spinal injury in patients with a traumatic brain injury (TBI); the prevalence of concomitant spinal injury in patients with a TBI; the prevalence of concomitant TBI in patients with a cervical spinal injury; and the prevalence of concomitant TBI in patients with a spinal injury were calculated by meta-analysis. Twenty-one studies met the inclusion criteria and were included in this review. The prevalence of concomitant cervical spinal injury in patients with a TBI was found to be 6.5% (95% CI 6.0-7.1%); the prevalence of concomitant spinal injury in patients with a TBI to be 12.4-12.5%; the prevalence of concomitant TBI in patients with a cervical spinal injury to be 40.4% (95% CI 33.0-48.0%); and the prevalence of concomitant TBI in patients with a spinal injury to be 32.5% (95% CI 10.8-59.3%). This review reports the prevalence of concomitant cranio-spinal injury and highlights the importance of considering concomitant injury in patients with a cranial or spinal traumatic injury.

Polarization of Microglia to the M2 Phenotype in a Peroxisome Proliferator-Activated Receptor Gamma-Dependent Manner Attenuates Axonal Injury Induced by Traumatic Brain Injury in Mice

Increasing evidence indicates that activated microglia play an important role in the inflammatory response following traumatic brain injury (TBI). Inhibiting M1 and stimulating M2 activated microglia have demonstrated protective effects in several animal models of central nervous system diseases. However, it is not clear whether the polarization of microglia to M2 attenuates axonal injury following TBI. In this study, we used a lateral fluid percussion injury device to induce axonal injury in mice. Mice were randomly assigned to the sham, TBI, TBI + rosiglitazone (peroxisome proliferator-activated receptor gamma [PPAR-γ] agonist), and TBI + GW9662 (PPAR-γ antagonist) groups. Axonal injury was assessed using immunohistochemical staining for beta amyloid precursor protein. The inflammatory response was assessed by enzyme-linked immunosorbent assay, microglia polarization was assessed using specific markers of M1 and M2 microglia, and neurological function was assessed using the neurological severity score. Following TBI, microglia of the M1 phenotype increased significantly, while those of the M2 phenotype decreased. Rosiglitazone-induced PPAR-γ activation promoted microglia polarization to the M2 phenotype, which reduced the inflammatory response, attenuated axonal injury in the cerebral cortex, and improved neurological function. Conversely, GW9662 inhibited the polarization of microglia to M2 and aggravated inflammation and axonal injury. Our in vitro findings in lipopolysaccharide-induced microglia were consistent with those of our in vivo experiments. In conclusion, the polarization of microglia to the M2 phenotype via PPAR-γ activation attenuated axonal injury following TBI in mice, which may be a potential therapeutic approach for TBI-induced axonal injury.

Physical Biology of Axonal Damage

Excessive physical impacts to the head have direct implications on the structural integrity at the axonal level. Increasing evidence suggests that tau, an intrinsically disordered protein that stabilizes axonal microtubules, plays a critical role in the physical biology of axonal injury. However, the precise mechanisms of axonal damage remain incompletely understood. Here we propose a biophysical model of the axon to correlate the dynamic behavior of individual tau proteins under external physical forces to the evolution of axonal damage. To propagate damage across the scales, we adopt a consistent three-step strategy: First, we characterize the axonal response to external stretches and stretch rates for varying tau crosslink bond strengths using a discrete axonal damage model. Then, for each combination of stretch rates and bond strengths, we average the axonal force-stretch response of n = 10 discrete simulations, from which we derive and calibrate a homogenized constitutive model. Finally, we embed this homogenized model into a continuum axonal damage model of [1-d]-type in which d is a scalar damage parameter that is driven by the axonal stretch and stretch rate. We demonstrate that axonal damage emerges naturally from the interplay of physical forces and biological crosslinking. Our study reveals an emergent feature of the crosslink dynamics: With increasing loading rate, the axonal failure stretch increases, but axonal damage evolves earlier in time. For a wide range of physical stretch rates, from 0.1 to 10 /s, and biological bond strengths, from 1 to 100 pN, our model predicts a relatively narrow window of critical damage stretch thresholds, from 1.01 to 1.30, which agrees well with experimental observations. Our biophysical damage model can help explain the development and progression of axonal damage across the scales and will provide useful guidelines to identify critical damage level thresholds in response to excessive physical forces.

Continuous Infusion of Phenelzine, Cyclosporine A, or Their Combination: Evaluation of Mitochondrial Bioenergetics, Oxidative Damage, and Cytoskeletal Degradation following Severe Controlled Cortical Impact Traumatic Brain Injury in Rats

To date, all monotherapy clinical traumatic brain injury (TBI) trials have failed, and there are currently no Food and Drug Administration (FDA)-approved pharmacotherapies for the acute treatment of severe TBI. Due to the complex secondary injury cascade following injury, there is a need to develop multi-mechanistic combinational neuroprotective approaches for the treatment of acute TBI. As central mediators of the TBI secondary injury cascade, both mitochondria and lipid peroxidation-derived aldehydes make promising therapeutic targets. Cyclosporine A (CsA), an FDA-approved immunosuppressant capable of inhibiting the mitochondrial permeability transition pore, and phenelzine (PZ), an FDA-approved monoamine oxidase inhibitor capable of scavenging neurotoxic lipid peroxidation-derived aldehydes, have both been shown to be partially neuroprotective following experimental TBI. Therefore, it follows that the combination of PZ and CsA may enhance neuroprotection over either agent alone through the combining of distinct but complementary mechanisms of action. Additionally, as the first 72 h represents a critical time period following injury, it follows that continuous drug infusion over the first 72 h following injury may also lead to optimal neuroprotective effects. This is the first study to examine the effects of a 72 h subcutaneous continuous infusion of PZ, CsA, and the combination of these two agents on mitochondrial respiration, mitochondrial bound 4-hydroxynonenal (4-HNE), and acrolein, and α-spectrin degradation 72 h following a severe controlled cortical impact injury in rats. Our results indicate that individually, both CsA and PZ are able to attenuate mitochondrial 4-HNE and acrolein, PZ is able to maintain mitochondrial respiratory control ratio and cytoskeletal integrity but together, PZ and CsA are unable to maintain neuroprotective effects.

NADPH oxidases in traumatic brain injury - Promising therapeutic targets?

Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Despite intense investigation, no neuroprotective agents for TBI have yet translated to the clinic. Recent efforts have focused on identifying potential therapeutic targets that underlie the secondary TBI pathology that evolves minutes to years following the initial injury. Oxidative stress is a key player in this complex cascade of secondary injury mechanisms and prominently contributes to neurodegeneration and neuroinflammation. NADPH oxidase (NOX) is a family of enzymes whose unique function is to produce reactive oxygen species (ROS). Human post-mortem and animal studies have identified elevated NOX2 and NOX4 levels in the injured brain, suggesting that these two NOXs are involved in the pathogenesis of TBI. In support of this, NOX2 and NOX4 deletion studies have collectively revealed that targeting NOX enzymes can reduce oxidative stress, attenuate neuroinflammation, promote neuronal survival, and improve functional outcomes following TBI. In addition, NOX inhibitor studies have confirmed these findings and demonstrated an extended critical window of efficacious TBI treatment. Finally, the translational potential, caveats, and future directions of the field are highlighted and discussed throughout the review.

Variations in Mechanisms of Injury for Children with Concussion

OBJECTIVES

To assess the distribution of injury mechanisms and activities among children with concussions in a large pediatric healthcare system.

STUDY DESIGN

All patients, age 0-17 years, who had at least 1 clinical encounter with an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis of concussion in the Children's Hospital of Philadelphia's electronic health record system from July 1, 2012 to June 30, 2014, were selected (N = 8233) and their initial concussion-related visit identified. Approximately, 20% of the patients (n = 1625) were randomly selected for manual record review to examine injury mechanisms and activities.

RESULTS

Overall, 70% of concussions were sports related; however, this proportion varied by age. Only 18% of concussions sustained by children aged 0-4 were sports related, compared with greater proportions for older children (67% for age 5-11, 77% for age 12-14, and 73% for age 15-17). When the concussion was not sports related, the primary mechanisms of injury were struck by an object (30%) and falls (30%).

CONCLUSIONS

Sports-related injuries in children older than 6 years of age contributed to the majority of concussions in this cohort; however, it is important to note that approximately one-third of concussions were from non-sports-related activities. Although there is increased participation in community and organized sports activities among children, a focus on prevention efforts in other activities where concussions occur is needed.

Potential immunotherapies for traumatic brain and spinal cord injury

Traumatic injury of the central nervous system (CNS) including brain and spinal cord remains a leading cause of morbidity and disability in the world. Delineating the mechanisms underlying the secondary and persistent injury versus the primary and transient injury has been drawing extensive attention for study during the past few decades. The sterile neuroinflammation during the secondary phase of injury has been frequently identified substrate underlying CNS injury, but as of now, no conclusive studies have determined whether this is a beneficial or detrimental role in the context of repair. Recent pioneering studies have demonstrated the key roles for the innate and adaptive immune responses in regulating sterile neuroinflammation and CNS repair. Some promising immunotherapeutic strategies have been recently developed for the treatment of CNS injury. This review updates the recent progress on elucidating the roles of the innate and adaptive immune responses in the context of CNS injury, the development and characterization of potential immunotherapeutics, as well as outstanding questions in this field.

Paediatric traumatic brain injury: prognostic insights and outlooks

PURPOSE OF REVIEW

Traumatic brain injury (TBI) is a leading cause of death and disability in children. Prognostication of outcome following TBI is challenging in this population and likely requires complex, multimodal models to achieve clinically relevant accuracy. This review highlights injury characteristics, physiological indicators, biomarkers and neuromonitoring modalities predictive of outcome that may be integrated for future development of sensitive and specific prognostic models.

RECENT FINDINGS

Paediatric TBI is responsible for physical, psychosocial and neurocognitive deficits that may significantly impact quality of life. Outcome prognostication can be difficult in the immature brain, but is aided by the identification of novel biomarkers (neuronal, astroglial, myelin, inflammatory, apoptotic and autophagic) and neuromonitoring techniques (electroencephalogram and MRI). Investigation in the future may focus on assessing the prognostic ability of combinations of biochemical, protein, neuroimaging and functional biomarkers and the use of mathematical models to develop multivariable predication tools to improve the prognostic ability following childhood TBI.

SUMMARY

Prognostication of outcome following paediatric TBI is multidimensional, influenced by injury severity, age, physiological factors, biomarkers, electroencephalogram and neuroimaging. Further development, integration and validation of combinatorial prognostic algorithms are necessary to improve the accuracy and timeliness of prognosis in a meaningful fashion.

Assessment of Follow-up Care After Emergency Department Presentation for Mild Traumatic Brain Injury and Concussion: Results From the TRACK-TBI Study

IMPORTANCE

Mild traumatic brain injury (mTBI) affects millions of Americans each year. Lack of consistent clinical practice raises concern that many patients with mTBI may not receive adequate follow-up care.

OBJECTIVE

To characterize the provision of follow-up care to patients with mTBI during the first 3 months after injury.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data on patients with mTBI enrolled in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study between February 26, 2014, and August 25, 2016. We examined site-specific variations in follow-up care, the types of clinicians seen by patients receiving follow-up care, and patient and injury characteristics associated with a higher likelihood of receiving follow-up care. The TRACK-TBI study is a prospective, multicenter, longitudinal observational study of patients with TBI presenting to the emergency department of 1 of 11 level I US trauma centers. Study data included patients with head trauma who underwent a computed tomography (CT) scan within 24 hours of injury, had a Glasgow Coma Scale score of 13 to 15, were aged 17 years or older, and completed follow-up care surveys at 2 weeks and 3 months after injury (N = 831).

MAIN OUTCOMES AND MEASURES

Follow-up care was defined as hospitals providing TBI educational material at discharge, hospitals calling patients to follow up, and patients seeing a physician or other medical practitioner within 3 months after the injury. Unfavorable outcomes were assessed with the Rivermead Post Concussion Symptoms Questionnaire.

RESULTS

Of 831 patients (289 [35%] female; 483 [58%] non-Hispanic white; mean [SD] age, 40.3 [16.9] years), less than half self-reported receiving TBI educational material at discharge (353 patients [42%]) or seeing a physician or other health care practitioner within 3 months after injury (367 patients [44%]). Follow-up care varied by study site; adjusting for patient characteristics, the provision of educational material varied from 19% to 72% across sites. Of 236 patients with a positive finding on a CT scan, 92 (39%) had not seen a medical practitioner 3 months after the injury. Adjusting for injury severity and demographics, patient admission to the hospital ward or intensive care unit, patient income, and insurance status were not associated with the probability of seeing a medical practitioner. Among the patients with 3 or more moderate to severe postconcussive symptoms, only 145 of 279 (52%) reported having seen a medical practitioner by 3 months.

CONCLUSIONS AND RELEVANCE

There are gaps in follow-up care for patients with mTBI after hospital discharge, even those with a positive finding on CT or who continue to experience postconcussive symptoms.

Acute Physiology and Neurologic Outcomes after Brain Injury in SCOP/PHLPP1 KO Mice

Suprachiasmatic nucleus circadian oscillatory protein (SCOP) (a.k.a. PHLPP1) regulates long-term memory consolidation in the brain. Using a mouse model of controlled cortical impact (CCI) we tested if (1) brain tissue levels of SCOP/PHLPP1 increase after a traumatic brain injury (TBI), and (2) if SCOP/PHLPP1 gene knockout (KO) mice have improved (or worse) neurologic outcomes. Blood chemistry (pH, pCO₂, pO₂, pSO₂, base excess, sodium bicarbonate, and osmolarity) and arterial pressure (MAP) differed in isoflurane anesthetized WT vs. KOs at baseline and up to 1 h post-injury. CCI injury increased cortical/hippocampal SCOP/PHLPP1 levels in WTs 7d and 14d post-injury. Injured KOs had higher brain tissue levels of phosphorylated AKT (pAKT) in cortex (14d post-injury), and higher levels of phosphorylated MEK (pMEK) in hippocampus (7d and 14d post-injury) and in cortex (7d post-injury). Consistent with an important role of SCOP/PHLPP1 on memory function, injured-KOs had near normal performance on the probe trial of the Morris water maze, whereas injured-WTs were impaired. CA1/CA3 hippocampal survival was lower in KOs vs. WTs 24 h post-injury but equivalent by 7d. No difference in 21d cortical lesion volume was detected. SCOP/PHLPP1 overexpression in cultured rat cortical neurons had no effect on 24 h cell death after a mechanical stretch-injury.

Secondary Attention-Deficit/Hyperactivity Disorder in Children and Adolescents 5 to 10 Years After Traumatic Brain Injury

IMPORTANCE

After traumatic brain injury (TBI), children often experience impairment when faced with tasks and situations of increasing complexity. Studies have failed to consider the potential for attention problems to develop many years after TBI or factors that may predict the development of secondary attention-deficit/hyperactivity disorder (SADHD). Understanding these patterns will aid in timely identification of clinically significant problems and appropriate initiation of treatment with the hope of limiting additional functional impairment.

OBJECTIVE

To examine the development of SADHD during the 5 to 10 years after TBI and individual (sex, age at injury, and injury characteristics) and environmental (socioeconomic status and family functioning) factors that may be associated with SADHD.

DESIGN, SETTING, AND PARTICIPANTS

Concurrent cohort/prospective study of children aged 3 to 7 years hospitalized overnight for TBI or orthopedic injury (OI; used as control group) who were screened at 3 tertiary care children's hospitals and 1 general hospital in Ohio from January 2003 to June 2008. Parents completed assessments at baseline (0-3 months), 6 months, 12 months, 18 months, 3.4 years, and 6.8 years after injury. A total of 187 children and adolescents were included in the analyses: 81 in the TBI group and 106 in the OI group.

MAIN OUTCOMES AND MEASURES

Diagnosis of SADHD was the primary outcome. Assessments were all completed by parents. Secondary ADHD was defined as an elevated T score on the DSM-Oriented Attention-Deficit/Hyperactivity Problems Scale of the parent-reported Child Behavior Checklist, report of an ADHD diagnosis, and/or current treatment with stimulant medication not present at the baseline assessment. The Family Assessment Device-Global Functioning measurement was used to assess family functioning; scores ranged from 1 to 4, with greater scores indicating poorer family functioning.

RESULTS

The analyzed sample included 187 children with no preinjury ADHD. Mean (SD) age was 5.1 (1.1) years; 108 (57.8%) were male, and 50 (26.7%) were of nonwhite race/ethnicity. Of the 187 children, 48 (25.7%) met our definition of SADHD. Severe TBI (hazard ratio [HR], 3.62; 95% CI, 1.59-8.26) was associated with SADHD compared with the OI group. Higher levels of maternal education (HR, 0.33; 95% CI, 0.17-0.62) were associated with a lower risk of SADHD. Family dysfunction was associated with increased risk of SADHD within the TBI group (HR, 4.24; 95% CI, 1.91-9.43), with minimal association within the OI group (HR, 1.32; 95% CI, 0.36-4.91).

CONCLUSIONS AND RELEVANCE

Early childhood TBI was associated with increased risk for SADHD. This finding supports the need for postinjury monitoring for attention problems. Consideration of factors that may interact with injury characteristics, such as family functioning, will be important in planning clinical follow-up of children with TBI.

Systematic review of hearing loss after traumatic brain injury without associated temporal bone fracture

OBJECTIVE

While hearing loss following temporal bone fracture is a well-described phenomenon, few data exist on auditory dysfunction in patients with traumatic brain injury (TBI) without temporal bone fracture. Herein, we aim to systematically review hearing loss after TBI without bony fracture and describe its etiologies.

DATA SOURCES

Pubmed, Embase, Cochrane databases.

REVIEW METHODS

A systematic review of the literature from 1966 to January 2017 was performed using Preferred Reporting Items for Systematic Reviews and Meta-analyses recommendations. Data were obtained from studies that investigated hearing loss in TBI without skull fracture according to an a priori protocol with inclusion and exclusion criteria. Variables included type and severity of hearing loss, as well as pathophysiology of hearing loss.

RESULTS

There were 13 studies with 773 patients that met study criteria. Overall, there was one prospective cohort study, four retrospective cohort studies, two case-control studies, and six case reports. The studies with the highest level of evidence report a change in hearing of at least 10-15 dB across a range of frequencies in as many as 58% percent of TBI patients without bony fracture, which was transient or chronic. The mechanism/severity of injury may impact the rate of hearing loss.

CONCLUSIONS

Hearing loss after TBI in the absence of bony injury appears to be a clinically significant but poorly characterized phenomenon.

Feasibility and Preliminary Validation of an Online Version of the Ohio State University Traumatic Brain Injury Identification Method

OBJECTIVE

To test the feasibility and validity of an online version of an established interview designed to determine a lifetime history of traumatic brain injury (TBI).

DESIGN

Cross-sectional.

SETTING

General community.

PARTICIPANTS

A volunteer sample of individuals (N= 265) from the general population across the United States.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

Online version of the Ohio State University Traumatic Brain Injury Identification Method, Rivermead Postconcussion Symptoms Questionnaire (RPQ), Patient-Reported Outcomes Measurement Information System Cognitive Concerns Scale.

RESULTS

The measure was completed by 89.4% of the sample with most participants completing the measure in <8 minutes. After controlling for age, sex, psychiatric history, drug or alcohol history, and history of developmental disability, worst TBI severity was significantly associated with scores on the RPQ, F(2,230)=4.56, P=.011, and having a TBI within the past 2 years was associated with higher scores on the cognitive factor subscale of the RPQ, F(1,75)=7.7, P=.007.

CONCLUSIONS

The online administration of the Ohio State University Traumatic Brain Injury Identification Method appears to be feasible in the general population. Preliminary validity was demonstrated for the indices of worst TBI severity and time since most recent TBI.

Likelihood Ratios for the Emergency Physician

The concept of likelihood ratios was introduced more than 40 years ago, yet this powerful metric has still not seen wider application or discussion in the medical decision-making process. There is concern that clinicians-in-training are still being taught an oversimplified approach to diagnostic test performance and have limited exposure to likelihood ratios. Even for those familiar with likelihood ratios, they might perceive them as mathematically cumbersome in application, if not difficult to determine for a particular disease process. This article takes a conceptual approach to likelihood ratios and applies them to two clinical settings: 1) severe intracranial injury after minor head trauma and 2) suspected pulmonary embolism with shortness of breath. Likelihood ratios are the most appropriate metric for efficient rational clinical examination and can prevent unnecessary and wasteful treatments and procedures.

Exosomes in Acquired Neurological Disorders: New Insights into Pathophysiology and Treatment

Exosomes are endogenous nanovesicles that play critical roles in intercellular signaling by conveying functional genetic information and proteins between cells. Exosomes readily cross the blood-brain barrier and have promise as therapeutic delivery vehicles that have the potential to specifically deliver molecules to the central nervous system (CNS). This unique feature also makes exosomes attractive as biomarkers in diagnostics, prognostics, and therapeutics in the context of multiple significant public health conditions, including acquired neurological disorders. The purpose of this review is to summarize the state of the science surrounding the relevance of extracellular vesicles (EVs), particularly exosomes, to acquire neurological disorders, specifically traumatic brain injury (TBI), spinal cord injury (SCI), and ischemic stroke. In total, ten research articles were identified that examined exosomes in the context of TBI, SCI, or stroke; these manuscripts were reviewed and synthesized to further understand the current role of exosomes in the context of acquired neurological disorders. Of the ten published studies, four focused exclusively on TBI, one on both TBI and SCI, and five on ischemic stroke; notably, eight of the ten studies were limited to pre-clinical samples. The present review is the first to discuss the current body of knowledge surrounding the role of exosomes in the pathophysiology, diagnosis, and prognosis, as well as promising therapeutic strategies in TBI, SCI, and stroke research.

Concussion knowledge and experience among a sample of American adults

Background:

Recently, there has been a strong emphasis on educating athletes, parents, coaches, and health care providers about concussions. However, not much is known about whether these efforts are affecting the general public’s level of concussion knowledge.

Purpose:

To determine what is currently known among the public about concussions and where education campaigns may be targeted in order to fill in the gaps.

Methods:

In order to achieve the project’s objective, CDC analyzed self-reported data from Porter Novelli’s 2017 SummerStyles survey, an annual survey of American adults aged 18 and older across the United States. The questions focused on personal concussion experiences, basic concussion knowledge, knowledge of prevention strategies, and perceived best sources of information about concussion.

Results:

Analysis of the data showed that approximately 18% of respondents reported that they had personally experienced a concussion in their lifetime, and about two-thirds of these respondents were evaluated by a health care provider after their injury. In terms of concussion knowledge, the majority were aware of common causes of concussion. While 94% knew that headache was a symptom of concussion, just over half were aware that sleep problems were as well. Most respondents (>78%) correctly identified that wearing seat-belts, preventing falls, and reducing participation in contact sports were ways to prevent a concussion, while installing baby-gates across stairs was less frequently known (65.5%) as a prevention technique. Nearly all of the respondents believed that a doctor or other health professional was a good source of information about concussions. These results varied by age, sex, race/ethnicity, and education.

Conclusion:

The results demonstrate that even though the public has a relatively high knowledge level of concussion, targeted education is needed to teach American adults about the symptoms and ways of getting a concussion.

Combined Blockade of Interleukin-1α and -1β Signaling Protects Mice from Cognitive Dysfunction after Traumatic Brain Injury

Diffuse activation of interleukin-1 inflammatory cytokine signaling after traumatic brain injury (TBI) elicits progressive neurodegeneration and neuropsychiatric dysfunction, and thus represents a potential opportunity for therapeutic intervention. Although interleukin (IL)-1α and IL-1β both activate the common type 1 IL-1 receptor (IL-1RI), they manifest distinct injury-specific roles in some models of neurodegeneration. Despite its potential relevance to treating patients with TBI, however, the individual contributions of IL-1α and IL-1β to TBI-pathology have not been previously investigated. To address this need, we applied genetic and pharmacologic approaches in mice to dissect the individual contributions of IL-1α, IL-β, and IL-1RI signaling to the pathophysiology of fluid percussion–mediated TBI, a model of mixed focal and diffuse TBI. IL-1RI ablation conferred a greater protective effect on brain cytokine expression and cognitive function after TBI than did individual IL-1α or IL-1β ablation. This protective effect was recapitulated by treatment with the drug anakinra, a recombinant naturally occurring IL-1RI antagonist. Our data thus suggest that broad targeting of IL-1RI signaling is more likely to reduce neuroinflammation and preserve cognitive function after TBI than are approaches that individually target IL-1α or IL-1β signaling.