The International Incidence of Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Objective Cognitive Outcomes and Subjective Emotional Sequelae in Litigating Adults with a Traumatic Brain Injury: The Impact of Performance and Symptom Validity Measures

OBJECTIVE

This study examined the relative contribution of performance and symptom validity in litigating adults with traumatic brain injury (TBI), as a function of TBI severity, and examined the relationship between self-reported emotional symptoms and cognitive tests scores while controlling for validity test performance.

METHOD

Participants underwent neuropsychological assessment between January 2012 and June 2021 in the context of compensation-seeking claims related to a TBI. All participants completed a cognitive test battery, the Personality Assessment Inventory (including symptom validity tests; SVTs), and multiple performance validity tests (PVTs). Data analyses included independent t-tests, one-way ANOVAs, correlation analyses, and hierarchical multiple regression.

RESULTS

A total of 370 participants were included. Atypical PVT and SVT performance were associated with poorer cognitive test performance and higher emotional symptom report, irrespective of TBI severity. PVTs and SVTs had an additive effect on cognitive test performance for uncomplicated mTBI, but less so for more severe TBI. The relationship between emotional symptoms and cognitive test performance diminished substantially when validity test performance was controlled, and validity test performance had a substantially larger impact than emotional symptoms on cognitive test performance.

CONCLUSION

Validity test performance has a significant impact on the neuropsychological profiles of people with TBI, irrespective of TBI severity, and plays a significant role in the relationship between emotional symptoms and cognitive test performance. Adequate validity testing should be incorporated into every neuropsychological assessment, and associations between emotional symptoms and cognitive outcomes that do not consider validity testing should be interpreted with extreme caution.

Pramipexole Protects Against Traumatic Brain Injury-Induced Blood-Brain Barrier (BBB) Dysfunction

Traumatic brain injury (TBI) is a severe disease of brain damage accompanied by blood-brain barrier (BBB) dysfunction. The BBB is composed of brain microvascular endothelial cells (BMECs), astrocyte terminus, pericytes, and a basement membrane. Tight junction proteins expressed by BMECs play important roles in preserving BBB integrity. Pramipexole is a selective dopamine agonist applied for treating Parkinson's disease and has been recently claimed with neuroprotective capacity. This study will further explore the impact of Pramipexole on tight junctions and BBB integrity to provide the potential treatment strategy for TBI-induced BBB damage. The TBI model was established in mice and was identified by the promoted brain water content, declined Garcia scores, reduced latency of the rotarod test, aggravated pathological changes in the brain cortex, and excessively released inflammatory factors. After treatment with Pramipexole, the neurofunctional deficits, behavioral disability, and aggravated pathological changes were dramatically reversed, accompanied by the alleviated BBB permeability, and upregulated occludin, an important tight junction protein. TBI model cells were established by the scratching bEnd.3 cells method. Cells were stimulated with 10 and 20 μM Pramipexole, followed by exposure to TBI. Increased fluorescence intensity of FITC-dextran, reduced value of TEER, and downregulated occludin and KLF2 were observed in TBI-exposed cells, all of which were greatly reversed by 10 and 20 μM Pramipexole. Furthermore, in KLF2-silenced bEnd.3 cells, the protective ability of Pramipexole against endothelial permeability and the expression level of occludin were dramatically abolished. Collectively, our results suggest that Pramipexole protected against TBI-induced BBB dysfunction by mediating KLF2.

Canadians Reporting Sport-Related Concussions: Increasing and Now Stabilizing

BACKGROUND

Canada is currently engaged in a national harmonization of strategies to prevent and manage sport-related concussions.

OBJECTIVE

To examine the annual incidence rates of reported sport-related concussions or other brain injuries by participants in the Canadian Community Health Survey, a national public health survey which provides nearly 2 decades of serial data using consistent methodology.

DESIGN

Serial cross-sectional survey.

SETTING

Population-based Canadian survey from 2000 to 2018 that collects data on "concussions or other brain injuries."

PARTICIPANTS

Respondents 12 years and older.

INDEPENDENT VARIABLES

Sex and age categorized 12 to 14 years, 15 to 19 years, 20 to 29 years, and 30+ years.

OUTCOME MEASURES

National incidence rates of participants reporting concussions or other brain injuries occurring within the previous year while engaged in "organized sports/leisure sports or physical exercise."

RESULTS

Data were available for 2000/01, 2003, 2005/6, 2009/10, 2013/4, and 2017/8 (N = 757 383). A previously stable annual incidence of reported sport-related concussions or other brain injuries increased nearly 2 and a half-fold from 2005/06 through 2013/14 (P < 0.0001) but seems to have stabilized recently (2013/14 vs 2017/8, P = 0.35). This trend is similar for both men and women but is manifest primarily within youth (12-19 years) as opposed to adults (>19 years). Approximately 1 in 450 Canadians 12 years and older report sport-related concussions or other brain injuries as their most significant injury associated with disability in the previous year (2017-2018: 221 per 100 000 population, 95% confidence interval: 179-264).

CONCLUSIONS

In Canada, the annual incidence rates of reported sport-related concussions or other brain injuries is changing and may reflect improved reporting and recognition.

Subacute cytokine changes after a traumatic brain injury predict chronic brain microstructural alterations on advanced diffusion imaging in the male rat

INTRODUCTION

The process of neuroinflammation occurring after traumatic brain injury (TBI) has received significant attention as a potential prognostic indicator and interventional target to improve patients' outcomes. Indeed, many of the secondary consequences of TBI have been attributed to neuroinflammation and peripheral inflammatory changes. However, inflammatory biomarkers in blood have not yet emerged as a clinical tool for diagnosis of TBI and predicting outcome. The controlled cortical impact model of TBI in the rodent gives reliable readouts of the dynamics of post-TBI neuroinflammation. We now extend this model to include a panel of plasma cytokine biomarkers measured at different time points post-injury, to test the hypothesis that these markers can predict brain microstructural outcome as quantified by advanced diffusion-weighted magnetic resonance imaging (MRI).

METHODS

Fourteen 8-10-week-old male rats were randomly assigned to sham surgery (n = 6) and TBI (n = 8) treatment with a single moderate-severe controlled cortical impact. We collected blood samples for cytokine analysis at days 1, 3, 7, and 60 post-surgery, and carried out standard structural and advanced diffusion-weighted MRI at day 60. We then utilized principal component regression to build an equation predicting different aspects of microstructural changes from the plasma inflammatory marker concentrations measured at different time points.

RESULTS

The TBI group had elevated plasma levels of IL-1β and several neuroprotective cytokines and chemokines (IL-7, CCL3, and GM-CSF) compared to the sham group from days 3 to 60 post-injury. The plasma marker panels obtained at day 7 were significantly associated with the outcome at day 60 of the trans-hemispheric cortical map transfer process that is a frequent finding in unilateral TBI models.

DISCUSSION

These results confirm and extend prior studies showing that day 7 post-injury is a critical temporal window for the reorganisation process following TBI. High plasma level of IL-1β and low plasma levels of the neuroprotective IL-7, CCL3, and GM-CSF of TBI animals at day 60 were associated with greater TBI pathology.

Longitudinal white matter microstructural changes in pediatric mild traumatic brain injury: An A-CAP study

In the largest sample studied to date, white matter microstructural trajectories and their relation to persistent symptoms were examined after pediatric mild traumatic brain injury (mTBI). This prospective, longitudinal cohort study recruited children aged 8–16.99 years with mTBI or mild orthopedic injury (OI) from five pediatric emergency departments. Children's pre‐injury and 1‐month post‐injury symptom ratings were used to classify mTBI with or without persistent symptoms. Children completed diffusion‐weighted imaging at post‐acute (2–33 days post‐injury) and chronic (3 or 6 months via random assignment) post‐injury assessments. Mean diffusivity (MD) and fractional anisotropy (FA) were derived for 18 white matter tracts in 560 children (362 mTBI/198 OI), 407 with longitudinal data. Superior longitudinal fasciculus FA was higher in mTBI without persistent symptoms relative to OI, d (95% confidence interval) = 0.31 to 0.37 (0.02, 0.68), across time. In younger children, MD of the anterior thalamic radiations was higher in mTBI with persistent symptoms relative to both mTBI without persistent symptoms, 1.43 (0.59, 2.27), and OI, 1.94 (1.07, 2.81). MD of the arcuate fasciculus, −0.58 (−1.04, −0.11), and superior longitudinal fasciculus, −0.49 (−0.90, −0.09) was lower in mTBI without persistent symptoms relative to OI at 6 months post‐injury. White matter microstructural changes suggesting neuroinflammation and axonal swelling occurred chronically and continued 6 months post injury in children with mTBI, especially in younger children with persistent symptoms, relative to OI. White matter microstructure appears more organized in children without persistent symptoms, consistent with their better clinical outcomes.

Tau pathology, metal dyshomeostasis and repetitive mild traumatic brain injury: an unexplored link paving the way for neurodegeneration

Repetitive mild traumatic brain injury (r-mTBI), commonly experienced by athletes and military personnel, causes changes in multiple intracellular pathways, one of which involves the tau protein. Tau phosphorylation plays a role in several neurodegenerative conditions including chronic traumatic encephalopathy (CTE), a progressive neurodegenerative disorder linked to repeated head trauma. There is now mounting evidence suggesting that tau phosphorylation may be regulated by metal ions (such as iron, zinc and copper), which themselves are implicated in ageing and neurodegenerative disorders such as Alzheimer's disease (AD). Recent work has also shown that a single TBI can result in age-dependent and region-specific modulation of metal ions. As such, this review explores the link between TBI, CTE, ageing and neurodegeneration with a specific focus on the involvement of (and interaction between) tau pathology and metal dyshomeostasis. The authors highlight that metal dyshomeostasis has yet to be investigated in the context of repeat head trauma or CTE. Given the evidence that metal dyshomeostasis contributes to the onset and/or progression of neurodegeneration, and that CTE itself is a neurodegenerative condition, this brings to light an uncharted link that should be explored. The development of adequate models of r-mTBI and/or CTE will be crucial in deepening our understanding of the pathological mechanisms that drive the clinical manifestations in these conditions and also in the development of effective therapeutics targeted towards slowing progressive neurodegenerative disorders.

Fractures and skin lesions in pediatric abusive head trauma: a forensic multi-center study

Abusive head trauma (AHT) and its most common variant, the shaken baby syndrome (SBS), are predominantly characterized by central nervous system-associated lesions. Relatively little data are available on the value of skeletal and skin injuries for the diagnosis of SBS or AHT. Thus, the present study retrospectively investigated 72 cases of living children diagnosed with the explicit diagnosis of SBS during medico-legal examinations at three German university institutes of legal medicine. The risk of circular reasoning was reduced by the presence of 15 cases with confession by perpetrators. Accordingly, the comparison with the 57 non-confession cases yielded no significant differences. Skeletal survey by conventional projection radiography, often incomplete, was found to be performed in 78% of the cases only. Fractures were found in 32% of the cases. The skull (43%) and ribs (48%) were affected most frequently; only 8% of the cases showed classic metaphyseal lesions. In 48% of the cases, healing fractures were present. Skin lesions (hematomas and abrasions) were found in 53% of the cases with the face (76%), scalp (26%), and trunk (50%) being the major sites. In 48% of the cases, healing skin lesions were observed. Nearly 80% of the cases with fractures also showed skin lesions. The data prove that SBS is frequently accompanied by other forms of physical abuse. Therefore, skeletal survey is indispensable and should always be done completely and according to existing imaging guidelines if child abuse is suspected.

Prevalence of suicidal ideation and suicide attempt among patients with traumatic brain injury: A meta-analysis

BACKGROUND

Suicidality is common among patients with traumatic brain injury (TBI). This meta-analysis aimed to assess the prevalence of suicidal ideation (SI) and suicide attempt (SA) in TBI patients.

METHODS

Databases including PubMed, Cochrane Library, Embase, CINAHL, Web of Science, PsycINFO, China National Knowledge Infrastructure (CNKI), VIP, WanFang Data, and Chinese Biomedical Literature Database (CBM) were searched for relevant literature from inception to 9th January 2021. Random effects models were used to estimate the prevalence of SI and SA. The methodological quality of the included studies was assessed using the modified Newcastle-Ottawa Scale. Subgroup analysis was performed based on the geographical location of the institutions.

RESULTS

A total of 16 studies involving 1,146,271 patients with TBI were included in our meta-analysis. The prevalence of SI and SA were 19.1% (95% CI 13.6-24.6%) and 2.1% (95% CI 1.8-2.4%), respectively, while the prevalence of SA in Asian and non-Asian countries were 2.0% (95% CI 0.3-3.7%) and 2.0% (95% CI 1.6-2.3%). Meta-regression analyses revealed that the publication year and age were positively associated, while the geographical location of the institution and sample size were negatively associated with the pooled prevalence of SI. On the other hand, the geographical location of the institution, sample size and age were negatively associated with the pooled prevalence of SA.

LIMITATIONS

The overall heterogeneity between studies was high.

CONCLUSION

SI and SA are common among TBI patients. Therefore, targeted preventive measures are paramount to manage TBI-related suicide.

Epidemiology of Male Hypogonadism

The epidemiology of male hypogonadism has been understudied. Of the known causes of endogenous androgen deficiency, only Klinefelter syndrome is common with a likely population prevalence of greater than 5:10,000 men (possibly as high as 10-25:10,000). Mild traumatic injury might also be a common cause of androgen deficiency (prevalence 5-10:10,000 men), but large, long-term studies must be completed to confirm this prevalence estimation that might be too high. The classic causes of male androgen deficiency-hyperprolactinemia, pituitary macroadenoma, endogenous Cushing syndrome, and iron overload syndrome-are rare (prevalence < 10,000 men).

Hyperbaric oxygen therapy for cognitive impairments in patients with traumatic brain injury: A systematic review

Cognitive deficits are the most common impairments after traumatic brain injury (TBI). It can be linked with poor physical function. Hyperbaric oxygen therapy (HBOT) increases blood flow and oxygen supply to the brain. This review aimed to summarize and evaluate the available literature on the influences of HBOT on cognitive deficits in patients with TBI. PubMed, SCOPUS, PEDro, REHABDATA, MIDLINE, CHINAL, EMBASE, and Web of Science were searched from inception until June 2021. The methodological quality was measured using the physiotherapy evidence database (PEDro) scale. Ten studies met the eligibility criteria. Six studies were randomized controlled trials, and four were pilot studies. The scores on the PEDro scale ranged from two to nine, with a median score of seven. The included studies showed heterogeneity results for the beneficial effects of HBOT on improving cognitive functions in patients with TBI. The evidence for the beneficial effects of HBOT on cognitive functions post-TBI was limited. Further randomized controlled trials with large sample sizes are strongly needed to understand the effects of HBOT on cognitive functions in patients with TBI.

Cerebrospinal fluid purinomics as a biomarker approach to predict outcome after severe traumatic brain injury

Severe traumatic brain injury (TBI) is associated with high rates of mortality and long-term disability linked to neurochemical abnormalities. Although purine-derivatives play important roles in TBI pathogenesis in preclinical models, little is known about potential changes in purine levels and their implications in human TBI. We assessed cerebrospinal fluid (CSF) levels of purines in severe TBI patients as potential biomarkers that predict mortality and long-term dysfunction. This was a cross-sectional study performed in 17 severe TBI patients (Glasgow Coma Scale < 8) and 51 controls. Two to four hours after admission to ICU, patients were submitted to ventricular drainage and CSF collection for quantification of adenine and guanine purine-derivatives by HPLC. TBI patients survival was followed up to 3 days from admission. A neurofunctional assessment was performed through the modified Rankin Scale (mRS) two years after ICU admission. Purine levels were compared between control and TBI patients, and between surviving and non-surviving patients. Relative to controls, TBI patients presented increased CSF levels of GDP, guanosine, adenosine, inosine, hypoxanthine, and xanthine. Further, GTP, GDP, IMP, and xanthine levels were different between surviving and non-surviving patients. Among the purines, guanosine was associated with improved mRS (p=0.042; r= -0.506). Remarkably, GTP displayed predictive value (AUC=0.841, p=0.024) for discriminating survival vs. non-survival patients up to three days from admission. These results support TBI-specific purine signatures, suggesting GTP as a promising biomarker of mortality, and guanosine as an indicator of long-term functional disability.

The Impact of Preinjury Use of Antiplatelet Drugs on Outcomes of Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Objective

The study aimed to compare outcomes of traumatic brain injury (TBI) in patients on pre-injury antiplatelet drugs vs. those, not on any antiplatelet or anticoagulant drugs.

Methods

PubMed, Embase, and Google Scholar databases were searched up to 15th May 2021. All cohort studies comparing outcomes of TBI between antiplatelet users vs. non-users were included.

Results

Twenty studies were included. On comparison of data of 2,447 patients on pre-injury antiplatelet drugs with 4,814 controls, our analysis revealed no statistically significant difference in early mortality between the two groups (OR: 1.30 95% CI: 0.85, 1.98 I² = 80% p = 0.23). Meta-analysis of adjusted data also revealed no statistically significant difference in early mortality between antiplatelet users vs. controls (OR: 1.24 95% CI: 0.93, 1.65 I² = 41% p = 0.14). Results were similar for subgroup analysis of aspirin users and clopidogrel users. Data on functional outcomes was scarce and only descriptive analysis could be carried out. For the need for surgical intervention, pooled analysis did not demonstrate any statistically significant difference between the two groups (OR: 1.11 95% CI: 0.83, 1.48 I² = 55% p = 0.50). Length of hospital stay (LOS) was also not found to be significantly different between antiplatelet users vs. non-users (MD: −1.00 95% CI: −2.17, 0.17 I² = 97% p = 0.09).

Conclusion

Our results demonstrate that patients on pre-injury antiplatelet drugs do not have worse early mortality rates as compared to patients, not on any antiplatelet or anticoagulant drugs. The use of antiplatelets is not associated with an increased need for neurosurgical intervention and prolonged LOS.

Traumatic brain injury in precariously housed persons: Incidence and risks

BACKGROUND

Homeless and precarious housed persons are particularly prone to traumatic brain injuries (TBIs), but existent incidence rates are hampered by poor case acquisition. We rigorously documented TBIs in precariously housed persons transitioning in and out of homelessness.

METHODS

Between December 2016 and May 2018, 326 precariously housed participants enrolled in a longitudinal study in Vancouver, Canada were assessed monthly for TBI occurrences after education on sequelae. Over one participant-year, 2433 TBI screenings were acquired for 326 person-years and variables associated with odds of incident TBI were evaluated.

FINDINGS

One hundred participants acquired 175 TBIs, yielding an observed incidence proportion of 30·7% and event proportion of 53·7%. Of the injured, 61% reported one TBI and 39% reported multiple injuries. Acute intoxication was present for more than half of the TBI events assessed. Additionally, 9·7% of TBI events occurred in the context of a drug overdose. Common injury mechanisms were falls (45·1%), assaults (25·1%), and hitting one's head on an object (13·1%). In this community-based but non-randomly recruited sample, exploratory analyses identified factors associated with odds of an incident TBI over one year of follow-up, including: schizophrenia disorders (odds ratio (OR) = 0·43, 95% confidence interval (CI) 0·19, 0·94), role functioning (OR = 0·69, 95% CI 0·52, 0·91), opioid dependence (OR = 2·17, 95% CI 1·27, 3·72) and those reporting past TBIs (OR = 1·99, 95% CI 1·13, 3·52).

INTERPRETATION

Given the ubiquity of TBIs revealed in this precariously housed sample, we identify an underappreciated and urgent healthcare priority. Several factors modified the odds of incident TBI, which can facilitate investigations into targeted prevention efforts.

FUNDING

Canadian Institutes of Health Research, Natural Sciences and Engineering Research Council of Canada, William and Ada Isabelle Steel Research Fund, Simon Fraser University Vice-President Research Undergraduate Student Research Award and Simon Fraser University Psychology Department Research Grant.

Thyroid function in the subacute phase of traumatic brain injury: a potential predictor of post-traumatic neurological and functional outcomes

PURPOSE

That thyroid hormones exert pleiotropic effects and have a contributory role in triggering seizures in patients with traumatic brain injury (TBI) can be hypothesized. We aimed at investigating thyroid function tests as prognostic factors of the development of seizures and of functional outcome in TBI.

METHODS

This retrospective study enrolled 243 adult patients with a diagnosis of mild-to-severe TBI, consecutively admitted to our rehabilitation unit for a 6-month neurorehabilitation program. Data on occurrence of seizures, brain imaging, injury characteristics, associated neurosurgical procedures, neurologic and functional assessments, and death during hospitalization were collected at baseline, during the workup and on discharge. Thyroid function tests (serum TSH, fT4, and fT3 levels) were performed upon admission to neurorehabilitation.

RESULTS

Serum fT3 levels were positively associated with an increased risk of late post-traumatic seizures (LPTS) in post-TBI patients independent of age, sex and TBI severity (OR = 1.85, CI 95% 1.22-2.61, p < 0.01). Measured at admission, fT3 values higher than 2.76 pg/mL discriminated patients with late post-traumatic seizures from those without, with a sensitivity of 74.2% and a specificity of 60.9%. Independently from the presence of post-traumatic epilepsy and TBI severity, increasing TSH levels and decreasing fT3 levels were associated with worse neurological and functional outcome, as well as with higher risk of mortality within 6 months from the TBI event.

CONCLUSIONS

Serum fT3 levels assessed in the subacute phase post-TBI are associated with neurological and functional outcome as well as with the risk of seizure occurrence. Further studies are needed to investigate the mechanisms underlying these associations.

Rehabilitation interventions after traumatic brain injury: a scoping review

PURPOSE

To (1) identify interventional research topics in traumatic brain injury (TBI) rehabilitation, (2) describe potential knowledge gaps, and (3) uncover further needs for interventional TBI rehabilitation research for patients and families.

METHOD

We searched three databases (2006-2019) and screened 1552 non-duplicate articles. Titles and abstracts were screened for relevance, yielding 754 articles for full-text review. Of these, 425 were included, as relevant to the purpose of the scoping review.

FINDINGS

Among articles on TBI rehabilitation, the majority (71.8%) applied quantitative methodology; of these only 19.7% were randomized controlled trials. Severe TBI was described more often than mild/moderate TBI populations. Hospital vs community/home rehabilitation was 55.1% vs 37.2%; rehabilitation at workplace/school was described in only 4.5% articles, while in 7.2% the setting was undisclosed. Of 83 articles describing work/education, only 14 were in a work/school context. An additional focus in the work/education articles was activities of daily living (n = 28), cognition (n = 33) and emotions (n = 23), few targeted family or network.

CONCLUSION

The main attention of interventional TBI rehabilitation studies has been on severe TBI and long-term rehabilitation. Gaps identified were rehabilitation of mild/moderate TBI populations, older populations, acute/sub-phase rehabilitation, return to work issues and studies including the family.Implications for rehabilitationA substantial number of interventional studies exist to guide long-term rehabilitation after traumatic brain injury with focus on daily life, physical, emotional and cognitive functioning.We recommend a stronger focus in the clinic on the following groups; people with mild/moderate traumatic brain injury, people in the acute and sub-acute phase, and older people with traumatic brain injury.Issues that target challenges returning to work should be addressed, while they are of importance to patients and families.Emphasis should be put on continuity of care and peer-support.

Sex-specific analysis of traumatic brain injury events: applying computational and data visualization techniques to inform prevention and management

BACKGROUND

The interplay of host, agent, and environment implicated in traumatic brain injury (TBI) events is difficult to account for in hypothesis-driven research. Data-driven analysis of injury data can enable insight into injury events in novel ways. This research dissected complex and multidimensional data at the time of the TBI event by exploiting data mining and information visualization methods.

METHODS

We drew upon population-based decade-long health administrative data collected through the routine operation of the publicly funded health system in Ontario, Canada. We applied a computational approach to categorize health records of 235,003 patients with TBI versus the same number of reference patients without TBI, individually matched based on sex, age, place of residence, and neighbourhood income quantile. We adopted the basic concepts of the Haddon Matrix (host, agent, environment) to organize emerging factors significantly related to TBI versus non-TBI events. To explore sex differences, the data of male and female patients with TBI were plotted on heatmaps and clustered using hierarchical clustering algorithms.

RESULTS

Based on detected similarities, the computational technique yielded 34 factors on which individual TBI-event codes were loaded, allowing observation of a set of definable patterns within the host, the agent, and the environment. Differences in the patterns of host, agent and environment were found between male and female patients with TBI, which are currently not identified based on data from injury surveillance databases. The results were internally validated.

CONCLUSIONS

The study outlines novel areas for research relevant to TBI and offers insight into how computational and visual techniques can be applied to advance the understanding of TBI event. Results highlight unique aspects of sex differences of the host and agent at the injury event, as well as differences in exposure to adverse social and environmental circumstances, which can be a function of gender, aiding in future studies of injury prevention and gender-transformative care.

Post-concussive mTBI in Student Athletes: MRI Features and Machine Learning

Purpose: To determine and characterize the radiomics features from structural MRI (MPRAGE) and Diffusion Tensor Imaging (DTI) associated with the presence of mild traumatic brain injuries on student athletes with post-concussive syndrome (PCS).

Material and Methods: 122 student athletes (65 M, 57 F), median (IQR) age 18.8 (15–20) years, with a mixed level of play and sports activities, with a known history of concussion and clinical PCS, and 27 (15 M, 12 F), median (IQR) age 20 (19, 21) years, concussion free athlete subjects were MRI imaged in a clinical MR machine. MPRAGE and DTI-FA and DTI-ADC images were used to extract radiomic features from white and gray matter regions within the entire brain (2 ROI) and the eight main lobes of the brain (16 ROI) for a total of 18 analyzed regions. Radiomic features were divided into five different data sets used to train and cross-validate five different filter-based Support Vector Machines. The top selected features of the top model were described. Furthermore, the test predictions of the top four models were ensembled into a single average prediction. The average prediction was evaluated for the association to the number of concussions and time from injury.

Results: Ninety-one PCS subjects passed inclusion criteria (91 Cases, 27 controls). The average prediction of the top four models had a sensitivity of 0.80, 95% CI: [0.71, 0.88] and specificity of 0.74 95%CI [0.54, 0.89] for distinguishing subjects from controls. The white matter features were strongly associated with mTBI, while the whole-brain analysis of gray matter showed the worst association. The predictive index was significantly associated with the number of concussions (p < 0.0001) and associated with the time from injury (p < 0.01).

Conclusion: MRI Radiomic features are associated with a history of mTBI and they were successfully used to build a predictive machine learning model for mTBI for subjects with PCS associated with a history of one or more concussions.

Trends and external causes of traumatic brain injury and spinal cord injury mortality in south China, 2014-2018: an ecological study

BACKGROUND

The epidemiological evidence of traumatic brain injury (TBI) and spinal cord injury (SCI) mortality in mainland China is lacking. We aimed to assess the trends of TBI and SCI mortality, and their association with sex, age, location and external causes of injury in south China.

METHODS

Mortality data were derived from the Disease Surveillance Points (DSPs) system of Guangdong province between 2014 and 2018. We examined the trends in mortality with Cochran-Armitage trend test, and the association between the socio-demographic factors and the TBI and SCI mortality by using negative binomial models. Subgroup analysis was performed by stratifying the external causes of TBI and SCI.

RESULTS

The age-standardized TBI mortality remained relatively stable (from 11.6 to 15.4 per 100,000), while the SCI mortality increased by 148.3% from 2014 to 2018. Compared with females and urban residents, the adjusted mortality rate ratios of males and rural residents were 2.3 and 2.0 for TBI, and 2.2 and 4.6 for SCI, respectively. TBI and SCI mortality increased substantially with age. Motor vehicle crashes and falls were the leading causes of TBI mortality in residents aged under 75 years and over 75 years, respectively. Falls were the most important external cause for SCI death of all ages.

CONCLUSIONS

Being male, rural and elderly residents are at higher risk of dying from TBI and SCI. The substantial burden of TBI and SCI caused by road traffic crashes and falls has called for the urgent need to improve injury prevention, pre-hospital aid, hospital treatment and recovery.

Epilepsy Due to Mild TBI in Children: An Experience at a Tertiary Referral Center

Rationale: Posttraumatic epilepsy (PTE) is a common cause of morbidity in children after a traumatic brain injury (TBI), occurring in 10–20% of children following severe TBI. PTE is diagnosed after two or more unprovoked seizures occurring 1-week post TBI. More often, studies have focused on children with epilepsy due to severe TBI. We aim to understand the utility of head computed tomography (HCT), EEG, and the risk of developing drug-resistant epilepsy in children after mild TBI. Method: We retrospectively studied 321 children with TBI at a tertiary pediatric referral center during a 10-year period. Mild TBI was defined as loss of consciousness (LOC) or amnesia < 30 min, moderate TBI as LOC or amnesia between 30 min and 1 day, and severe TBI as LOC or amnesia > 1 day, subdural hemorrhage, or contusion. Multiple clinical variables were reviewed, including past and present antiepileptic drug(s), seizure control, and mode of injury. First and subsequent post-TBI EEGs/prolonged video-EEGs were obtained acutely, subacutely, and/or chronically (range, day 1–3 years, median 1 month). Descriptive analyses were conducted using medians and ranges for continuous data. Categorical data were reported using frequencies and percentages, while comparisons between groups were made using Fisher’s exact test for small sample sizes. Results: Forty-seven children were diagnosed with posttraumatic epilepsy: eight children (17%) due to mild TBI, 39 children (83%) due to severe TBI. For the eight children with mild TBI whom all had an accidental trauma (non-inflicted), the median follow-up time was 25 months (range 1.5 months–84 months). The median age was 10 years (range 4–18 years), and the median age at the time of injury was seven years (range: 23 months–13 years). No relevant previous medical history was present for six patients (80%), and two patients’ (20%) relevant previous medical histories were unknown. Seven patients (88%) had no history of seizures, and patient #6 (12%) had unknown seizure history. Six patients (75%) had normal routine EEG(s). Patient #6 (13%) had an abnormal VEEG 3 months after the initial normal routine EEG, while patient #1 (13%) had an initial prolonged EEG 8 months after TBI. Compared to the 39 patients with severe TBI, 31 (79%) of whom had abnormal EEGs (routine and/or prolonged with video), mild TBI patients were more likely to have normal EEGs, p = 0.005. Head CT scans were obtained acutely for seven patients (90%), all of which were normal. One patient only had brain magnetic resonance imaging (MRI) 8 months after the injury. Compared to the 39 patients with severe TBI, all of whom had abnormal HCTs, mild TBI patients were less likely to have abnormal HCTs, p < 0.0001. In patients with mild TBI, no patient had both abnormal EEG/VEEG and HCT, and no one was on more than one Antiepileptic drug (AED), p < 0.005. Six patients (75%) had MRIs, of which five (63%) were normal. Two patients (#1, 7) did not have MRIs, while one patient’s (#4) MRI was unavailable. Five patients (63%) had a seizure <24 h post TBI, while the rest had seizures after the first week of injury. Conclusion: Children with epilepsy due to mild TBI, loss of consciousness, or amnesia < 30 min are more likely to have normal HCT and EEG and to be on 0–1 AED. Limitations of our study include the small sample size and retrospective design. The current findings add to the paucity of data in children who suffer from epilepsy due to mild TBI.

Effect of functional electrical stimulation combined with stationary cycling and sit to stand training on mobility and balance performance in a patient with traumatic brain injury: A case report

INTRODUCTION AND IMPORTANCE

This case study investigates the effects of functional electrical stimulation, stationary cycling, and sit-to-stand training in a patient with severe chronic traumatic brain injury.

CASE PRESENTATION

The participant was a 24-year-old man with a traumatic brain injury two years prior to the intervention described in this case report. The accident caused right hemiplegia, right foot drop, aphasia, and poor coordination of movement in both upper and lower limbs. He was using a wheeled walker for functional mobility and was receiving routine rehabilitation before the initiation of treatment. A four week intervention in this study included functional electrical stimulation of the quadriceps and tibialis anterior muscles combined with stationary cycling and sit-to-stand training.

CLINICAL DISCUSSION

Active and passive range of motion of right ankle dorsiflexion, strength of ankle dorsiflexor, balance performance, and mobility were measured before and after the intervention. Active range of motion of right ankle dorsiflexion increased by 8°. In addition, manual muscle test and Brief-BESTest scores increased from 3+ to 5 and from 7 to 9, respectively. Walking speed over the 10-m distance and timed up and go test score improved.

CONCLUSION

Functional electrical stimulation combined with stationary cycling and sit-to-stand training resulted in increased muscle strength and range of motion, improved balance performance, and improved mobility in an individual with a traumatic brain injury.

WNK3 Promotes Neuronal Survival after Traumatic Brain Injury in Rats

With-no-lysine kinase 3 (WNK3) is a key regulator of chloride ion transport and neuronal survival in diverse cell types. WNK3 was previously found to regulate the activity of Na⁺-K⁺-2Cl^- cotransporter-1 (NKCC1) in ischemia-associated brain damage. However, the role of WNK3 in traumatic brain injury (TBI) has not yet been studied. A weight-drop TBI model was established in Sprague-Dawley rats. Overexpression and specific inhibition were used to investigate the role of WNK3 in TBI via Western blot, immunofluorescence, neuronal apoptosis, brain water content, and neurological score analyses. We found pronounced TBI-induced downregulation of WNK3 expression and upregulation of NKCC1 expression in neurons, especially at 48 h. Overexpression of WNK3 significantly ameliorated neuronal apoptosis, blood-brain barrier (BBB) disruption, brain edema and neurological deficits at 48 h after TBI. These effects were concomitant with reductions in p-NKCC1 and phosphorylated extracellular signal-regulated kinase (p-ERK1/2) expression. Furthermore, bumetanide administration enhanced the neuroprotective effects of WNK3 overexpression against brain injury. Thus, WNK3 plays a neuroprotective role in TBI, and overexpression of WNK3 may increase cell resistance to apoptotic insults and brain edema, thereby alleviating secondary brain injury.

Subdural and epidural hematoma occurrence in relation to the head impact site: An autopsy study

Blunt head injury is a major public health and socioeconomic problem causing death and disability particularly among the young population throughout the world. The purpose of the present study was to evaluate if the impact site is correlated with the subdural and epidural hematoma occurrence. A retrospective analysis of consecutive autopsy cases submitted to our Department during a 5-year period was performed. The basic criterion for inclusion in the study was death due to blunt head injury. The recorded variables included the circumstances of death, the existence, and location of head injuries, the primary impact site, age, gender, and toxicological results. A total number of 683 fatal head injury cases was recorded, with most of them being male (74.1%). In 424 cases (62.1%) fatal head injuries were due to road traffic accidents. Fall (from height or on the ground) was the cause of death in 220 (32.2%) cases followed by inflicted impact-assault in 26 (3.8%) cases. A subdural hematoma was found more frequently (26.9%) than epidural (5.0%). Epidural hematomas were found only under the primary impact site, whereas subdural hematomas were coup, contrecoup, or bilateral. An epidural hematoma was found to be almost 5 times more frequent in cases in which a subdural hematoma was present. A higher proportion of subdural, as well as epidural hematoma, was found when the site of impact was the temporal region, followed by the parietal one. Sex did not exert any influence on the probability of subdural and epidural hematoma, whereas for age, a 10% increase in the probability of subdural hematoma occurrence was observed with 10-year age increase.

A machine learning model for predicting favorable outcome in severe traumatic brain injury patients after 6 months

Traumatic brain injury (TBI), which occurs commonly worldwide, is among the more costly of health and socioeconomic problems. Accurate prediction of favorable outcome in severe TBI patients could assist with optimizing treatment procedures, predicting clinical outcomes, and result in substantial economic savings. In this study, we examined the capability of a machine learning-based model in predicting "favorable" or "unfavorable" outcome after 6 months in severe TBI patients using only parameters measured on admission. Three models were developed using logistic regression, random forest, and support vector machines trained on parameters recorded from 2,381 severe TBI patients admitted to the neuro-intensive care unit of Rajaee (Emtiaz) Hospital (Shiraz, Iran) between 2015 and 2017. Model performance was evaluated using three indices: sensitivity, specificity, accuracy, and area under the curve (AUC). Ten-fold cross-validation method was used to estimate these indices. Overall, the developed models showed excellent performance with AUC >0.81, sensitivity and specificity of > 0.78. The top-three factors important in predicting 6-month post-trauma survival status in TBI patients are "GCS motor response," "pupillary reactivity," and "age." Machine learning techniques might be used to predict the 6-month outcome in TBI patients using only the parameters measured on admission when the machine learning is trained using a large data set.

Incidence of post-traumatic epilepsy following paediatric traumatic brain injury: protocol for systematic review and meta-analysis

INTRODUCTION

Post-traumatic epilepsy (PTE) is a recognised complication of traumatic brain injury (TBI), and is associated with higher rates of mortality and morbidity when compared with patients with TBI who do not develop PTE. The majority of the literature on PTE has focused on adult populations, and consequently there is a paucity of information regarding paediatric cohorts. Additionally, there is considerable heterogeneity surrounding the reported incidence of PTE following childhood TBI in the current literature. The primary aim of our study is to summarise reported PTE incidences in paediatric populations to derive an accurate estimate of the global incidence of PTE following childhood TBI. Our secondary aim is to explore risk factors that increase the likelihood of developing PTE.

METHODS AND ANALYSIS

A systematic literature search of Embase (1947-2021), PubMed (1996-2021) and Web of Science (1900-2021) will be conducted. Publications in English that report the incidence of PTE in populations under 18 years of age will be included. Publications that evaluate fewer than 10 patients, report an alternative cause of epilepsy, or in which a paediatric cohort is not discernable, will be excluded. Independent investigators will identify the relevant publications, and discrepancies will be adjudicated by a third independent investigator. Data extracted will include incidence of PTE, time intervals between TBI and PTE, seizure characteristics, injury characteristics, patient demographics and clinical data. Data extraction will be performed by two independent investigators and cross-checked by a third investigator. A descriptive analysis of PTE incidence will be conducted and a weighted mean will be calculated. If sufficient data are available, stratified meta-analysis of subgroups will also be conducted.

ETHICS AND DISSEMINATION

Ethics approval was not required for this study. We intend to publish our findings in a high-quality peer-reviewed journal on completion.

PROSPERO REGISTRATION NUMBER

CRD42021245802.

Real-Time Noninvasive Bioluminescence, Ultrasound and Photoacoustic Imaging in NFκB-RE-Luc Transgenic Mice Reveal Glia Maturation Factor-Mediated Immediate and Sustained Spatio-Temporal Activation of NFκB Signaling Post-Traumatic Brain Injury in a Gender-Specific Manner

Neurotrauma especially traumatic brain injury (TBI) is the leading cause of death and disability worldwide. To improve upon the early diagnosis and develop precision-targeted therapies for TBI, it is critical to understand the underlying molecular mechanisms and signaling pathways. The transcription factor, nuclear factor kappa B (NFκB), which is ubiquitously expressed, plays a crucial role in the normal cell survival, proliferation, differentiation, function, as well as in disease states like neuroinflammation and neurodegeneration. Here, we hypothesized that real-time noninvasive bioluminescence molecular imaging allows rapid and precise monitoring of TBI-induced immediate and rapid spatio-temporal activation of NFκB signaling pathway in response to Glia maturation factor (GMF) upregulation which in turn leads to neuroinflammation and neurodegeneration post-TBI. To test and validate our hypothesis and to gain novel mechanistic insights, we subjected NFκB-RE-Luc transgenic male and female mice to TBI and performed real-time noninvasive bioluminescence imaging (BLI) as well as photoacoustic and ultrasound imaging (PAI). Our BLI data revealed that TBI leads to an immediate and sustained activation of NFκB signaling. Further, our BLI data suggest that especially in male NFκB-RE-Luc transgenic mice subjected to TBI, in addition to brain, there is widespread activation of NFκB signaling in multiple organs. However, in the case of the female NFκB-RE-Luc transgenic mice, TBI induces a very specific and localized activation of NFκB signaling in the brain. Further, our microRNA data suggest that TBI induces significant upregulation of mir-9-5p, mir-21a-5p, mir-34a-5p, mir-16-3p, as well as mir-155-5p within 24 h and these microRNAs can be successfully used as TBI-specific biomarkers. To the best of our knowledge, this is one of the first and unique study of its kind to report immediate and sustained activation of NFκB signaling post-TBI in a gender-specific manner by utilizing real-time non-invasive BLI and PAI in NFκB-RE-Luc transgenic mice. Our study will prove immensely beneficial to gain novel mechanistic insights underlying TBI, unravel novel therapeutic targets, as well as enable us to monitor in real-time the response to innovative TBI-specific precision-targeted gene and stem cell-based precision medicine.

The radiological interpretation of possible microbleeds after moderate or severe traumatic brain injury: a longitudinal study

Introduction

In order to augment the certainty of the radiological interpretation of “possible microbleeds” after traumatic brain injury (TBI), we assessed their longitudinal evolution on 3-T SWI in patients with moderate/severe TBI.

Methods

Standardized 3-T SWI and T1-weighted imaging were obtained 3 and 26 weeks after TBI in 31 patients. Their microbleeds were computer-aided detected and classified by a neuroradiologist as no, possible, or definite at baseline and follow-up, separately (single-scan evaluation). Thereafter, the classifications were re-evaluated after comparison between the time-points (post-comparison evaluation). We selected the possible microbleeds at baseline at single-scan evaluation and recorded their post-comparison classification at follow-up.

Results

Of the 1038 microbleeds at baseline, 173 were possible microbleeds. Of these, 53.8% corresponded to no microbleed at follow-up. At follow-up, 30.6% were possible and 15.6% were definite. Of the 120 differences between baseline and follow-up, 10% showed evidence of a pathophysiological change over time. Proximity to extra-axial injury and proximity to definite microbleeds were independently predictive of becoming a definite microbleed at follow-up. The reclassification level differed between anatomical locations.

Conclusions

Our findings support disregarding possible microbleeds in the absence of clinical consequences. In selected cases, however, a follow-up SWI-scan could be considered to exclude evolution into a definite microbleed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00234-021-02839-z.

Hospitalised traumatic brain injury victims in France: An analysis of the French hospital discharge database for 2011-2016

BACKGROUND

Traumatic brain injury (TBI) is a major public health problem because of its severity and frequency. No recent national epidemiological study on TBI victims is currently available in France.

OBJECTIVE

This study aimed to quantify and characterise TBI victims and analyse temporal trends.

METHODS

French hospitalisation data were used in this study. All hospitalised patients residing in France with at least one International Classification of Disease, 10th revision, code S06.0 to S06.9 during 2011-2016 were selected. Incidence and hospital case-fatality rates were calculated. Quasi-Poisson models were used to analyse temporal trends.

RESULTS

In 2016, the incidence rate was 230.6/100,000 people, higher among men than women regardless of age. Incidence and hospital case-fatality rates were also higher among older than younger people. Incidence rates increased during 2011-2016, mainly due to the higher incidence rate with age ≥65 years than younger age. During 2011-2016, hospital case-fatality rates decreased, mainly due to the decrease in the older age group (≥65 years old).

CONCLUSIONS

To our knowledge, this is the first national study in France to provide recent data on hospitalised TBI victims. Our study shows that TBI is a major public health concern in France. As a priority, older people represent a risk group that should be targeted with preventive actions because they have both the highest incidence and case-fatality rates and had the largest increase in incidence rates over the study period.

Mechanical characterisation of the human dura mater, falx cerebri and superior sagittal sinus

The cranial meninges have been shown to play a pivotal role in traumatic brain injury mechanopathology. However, while the mechanical response of the brain and its many subregions have been studied extensively, the meninges have conventionally been overlooked. This paper presents the first comparative mechanical analysis of human dura mater, falx cerebri and superior sagittal sinus tissues. Biaxial tensile analysis identified that these tissues are mechanically heterogeneous, in contrast to the assumption that the tissues are mechanically homogeneous which is typically employed in FE model design. A thickness of 0.91 ± 0.05 (standard error) mm for the falx cerebri was also identified. This data can aid in improving the biofidelity of the influential falx structure in FE models. Additionally, the use of a collagen hybridizing peptide on the superior sagittal sinus suggests this structure is particularly susceptible to the effects of circumferential stretch, which may have important implications for clinical treatment of dural venous sinus pathologies. Collectively, this research progresses understanding of meningeal mechanical and structural characteristics and may aid in elucidating the behaviour of these tissues in healthy and diseased conditions. STATEMENT OF SIGNIFICANCE: This study presents the first evaluation of human falx cerebri and superior sagittal sinus mechanical, geometrical and structural properties, along with a comparison to cranial dura mater. To mechanically characterise the tissues, biaxial tensile testing is conducted on the tissues. This analysis identifies, for the first time, mechanical stiffness differences between these tissues. Additionally, geometrical analysis identifies that there are thickness differences between the tissues. The evaluation of human meningeal tissues allows for direct implementation of the novel data to finite element head injury models to enable improved biofidelity of these influential structures in traumatic brain injury simulations. This work also identifies that the superior sagittal sinus may be easily damaged during clinical angioplasty procedures, which may inform the treatment of dural sinus pathologies.

Moderate and Severe Traumatic Brain Injury

PURPOSE OF REVIEW

Traumatic brain injury (TBI) encompasses a group of heterogeneous manifestations of a disease process with high neurologic morbidity and, for severe TBI, high probability of mortality and poor neurologic outcomes. This article reviews TBI in neurocritical care, hence focusing on moderate and severe TBI, and includes an up-to-date review of the many variables to be considered in clinical care.

RECENT FINDINGS

With advances in medicine and biotechnology, understanding of the impact of TBI has substantially elucidated the distinction between primary and secondary brain injury. Consequently, care of TBI is evolving, with intervention-based modalities targeting multiple physiologic variables. Multimodality monitoring to assess intracranial pressure, cerebral oxygenation, cerebral metabolism, cerebral blood flow, and autoregulation is at the forefront of such advances.

SUMMARY

Understanding the anatomic and physiologic principles of acute brain injury is necessary in managing moderate to severe TBI. Management is based on the prevention of secondary brain injury from resultant trauma. Care of patients with TBI should occur in a dedicated critical care unit with subspecialty expertise. With the advent of multimodality monitoring and targeted biomarkers in TBI, patient outcomes have a higher probability of improving in the future.

Role of copeptin in the diagnosis of traumatic neuroendocrine dysfunction

Traumatic neuroendocrine dysfunction may present with diabetes insipidus (DI) or with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Both these pathologies involve a disturbance in the antidiuretic hormone (ADH) secretion, causing dysnatremias. Diagnosis of posttraumatic ADH dysfunction is hampered by technical difficulties in ADH assessment, and relies mostly on non-specific serum sodium, serum and urine osmolality and diuresis, often leading to misdiagnosis in the acute care setting. Research now focuses on the diagnostic role of copeptin, a peptide secreted together with ADH in an equimolar fashion, and which can be accurately evaluated. Recent studies identified cut-off values of 2.6 pmol/L for baseline copeptin and of 4.9 and 3.8 pmol/L for hypertonic saline infusion and arginine infusion stimulated copeptin, respectively, for the diagnosis of DI in patients with polyuria-polydipsia syndrome. Although SIADH is more difficult to be explored due to its heterogeneity, a ratio of copeptin to urinary sodium below 30 pmol/mmol identifies euvolemic hyponatremia. Exploring the role of copeptin assessment in patients with traumatic brain injury (TBI) in the acute phase may improve their diagnosis accuracy, management and outcome.

Association of Attention-Deficit/Hyperactivity Disorder Diagnoses With Pediatric Traumatic Brain Injury: A Meta-analysis

IMPORTANCE

There are conflicting accounts about the risk for attention-deficit/hyperactivity disorder (ADHD) following traumatic brain injury (TBI), possibly owing to variations between studies in acute TBI severity or when ADHD was assessed postinjury. Analysis of these variations may aid in identifying the risk.

OBJECTIVE

To conduct a meta-analysis of studies assessing ADHD diagnoses in children between ages 4 and 18 years following concussions and mild, moderate, or severe TBI.

DATA SOURCES

PubMed, PsycInfo, and Cochrane Central Register of Controlled Trials (1981-December 19, 2019) were searched including the terms traumatic brain injury, brain injuries, closed head injury, blunt head trauma, concussion, attention deficit disorders, ADHD, and ADD in combination with childhood, adolescence, pediatric, infant, child, young adult, or teen.

STUDY SELECTION

Limited to English-language publications in peer-reviewed journals and patient age (4-18 years). Differences about inclusion were resolved through consensus of 3 authors.

DATA EXTRACTION AND SYNTHESIS

MOOSE guidelines for abstracting and assessing data quality and validity were used. Odds ratios with 95% credible intervals (CrIs) are reported.

MAIN OUTCOMES AND MEASURES

The planned study outcome was rate of ADHD diagnoses.

RESULTS

A total of 12 374 unique patients with TBI of all severity levels and 43 491 unique controls were included in the 24 studies in this review (predominantly male: TBI, 61.8%; noninjury control, 60.9%; other injury control, 66.1%). The rate of pre-TBI ADHD diagnoses was 16.0% (95% CrI, 11.3%-21.7%), which was significantly greater than the 10.8% (95% CrI, 10.2%-11.4%) incidence of ADHD in the general pediatric population. Compared with children without injuries, the odds for ADHD were not significantly increased following concussion (≤1 year: OR, 0.32; 95% CrI, 0.05-1.13), mild TBI (≤1 year: OR, 0.56; 0.16-1.43; >1 year: OR, 1.07; 95% CrI, 0.35-2.48), and moderate TBI (≤1 year: OR, 1.28; 95% CrI, 0.35-3.34; >1 year: OR, 3.67; 95% CrI, 0.83-10.56). The odds for ADHD also were not significantly increased compared with children with other injuries following mild TBI (≤1 year: OR, 1.07; 95% CrI, 0.33-2.47; >1 year: OR, 1.18; 95% CrI, 0.32-3.12) and moderate TBI (≤1 year: OR, 2.34; 95% CrI, 0.78-5.47; >1 year: OR, 3.78; 95% CrI, 0.93-10.33). In contrast, the odds for ADHD following severe TBI were increased at both time points following TBI compared with children with other injuries (≤1 year: OR, 4.81; 95% CrI, 1.66-11.03; >1 year: OR, 6.70; 95% CrI, 2.02-16.82) and noninjured controls (≤1 year: OR, 2.62; 95% CrI, 0.76-6.64; >1 year: OR, 6.25; 95% CrI, 2.06-15.06), as well as those with mild TBI (≤1 year OR, 5.69; 1.46-15.67: >1 year OR, 6.65; 2.14-16.44). Of 5920 children with severe TBI, 35.5% (95% CrI, 20.6%-53.2%) had ADHD more than 1 year postinjury.

CONCLUSIONS AND RELEVANCE

This study noted a significant association between TBI severity and ADHD diagnosis. In children with severe but not mild and moderate TBI, there was an association with an increase in risk for ADHD. The high rate of preinjury ADHD in children with TBI suggests that clinicians should carefully review functioning before a TBI before initiating treatment.

The functional indexes of RBCs and microcirculation in the traumatic brain injury with the action of 2-ethil-6-methil-3-hydroxypiridin succinate

RESEARCH AIM

To study the RBCs functional and metabolic parameters and the microcirculatory brain structure at traumatic brain injury (TBI) under the action of 2-ethyl-6-methyl-3-hydroxypyridine succinate.

METHODS

A closed TBI was modeled by the free fall of a load on the parietooccipital regions of head. We made studies of the influence of 2-ethil-6-methil-3-hydroxipiridin succinate on aggregation and electrophoretic mobility of RBCs, catalase activity, malonic dialdehyde concentration, adenosine triphosphate and 2.3-biphosphoglycerate (2.3 - BPG) concentrations in RBCs. The state of parenchyma and microcirculatory brain mainstream in post-traumatic period of TBI have been studied on micro-preparations.

RESULTS

The use of 2-ethyl-6-methyl-3-hydroxypyridine succinate under conditions of head injury leads to a decrease in MDA concentration and in aggregation of RBCs, to an increase in the 2.3-BPG concentration and RBC electrophoretic mobility compared to the control (group value). The most pronounced changes under the action of 2-ethyl-6-methyl-3-hydroxypyridine succinate were observed 3-7 days after the TBI. Significant indicators of the restoration of the microvasculature and brain tissue provoked by the use of 2-ethyl-6-methyl-3-hydroxypyridine succinate of were evident from the 7th day unlike the control group, where the restoration of structural morphological parameters was observed only on the 12th day of the post-traumatic period. Fast recovery of blood flow under the action of 2-ethyl-6-methyl-3-hydroxypyridine succinate ensured effective restoration of neurons and glia in comparison with the control group.

CONCLUSIONS

Early and long-term cytoprotective correction intensifies the oxygen transport function of the blood, prevents and / or reduces disorders of microvessels, neurons and glia in the post-traumatic period, thereby provides correction of hypoxic state and drives to the restoration of brain tissues homeostasis.

Changes in Mortality Related to Traumatic Brain Injuries in the Seychelles from 1989 to 2018

Introduction: Traumatic Brain Injuries (TBIs) are a significant source of disability and mortality, which disproportionately affect low- and middle-income countries. The Republic of Seychelles is a country in the African region that has experienced rapid socio-economic development and one in which all deaths and the age distribution of the population have been enumerated for the past few decades. The aim of this study was to investigate TBI-related mortality changes in the Republic of Seychelles during 1989–2018.

Methods: All TBI-related deaths were ascertained using the national Civil Registration and Vital Statistics System. Age- and sex-standardised mortality rates (per 100,000 person-years) were standardised to the age distribution of the World Health Organisation standard population.

Results: The 30-year age-standardised TBI-related mortality rates were 22.6 (95% CI 19.9, 25.2) in males and 4.0 (95% CI 2.9, 5.1) in females. Road traffic collisions were the leading contributor to TBI-related mortality [10.0 (95% CI 8.2, 11.8) in males and 2.7 (95% CI 1.8, 3.6) in females, P > 0.05]. TBI-related mortality was most frequent at age 20–39 years in males (8.0) and at age 0–19 in females (1.4). Comparing 2004–2018 vs. 1989–2003, the age-standardised mortality rates changed in males/females by −20%/−11% (all cause mortality), −24%/+39.4% (TBIs) and +1%/+34.8% (road traffic injury-related TBI).

Conclusion: TBI-related mortality rates were much higher in males but decreased over time. Road traffic collisions were the single greatest contributor to TBI mortality, emphasising the importance of road safety measures.

The development and the inter-rater agreement of a treatment protocol for vestibular/oculomotor rehabilitation in children and adolescents post-moderate-severe TBI

Introduction:There is limited evidence investigating the effect of vestibular/oculomotor rehabilitation programs in children and adolescents post moderate-severe TBI at the sub-acute stage.Objective:To describe the development of a treatment protocol for vestibular/oculomotor interventions in this population, and to assess the inter-rater agreement of this protocol as an initial step of a clinical trial.Method:The protocol was developed by 10 health professionals, address the high variability of balance performance, the high prevalence of vestibular/oculomotor abnormalities and the low prevalence of symptoms reported in this population.Results:The protocol enables the clinician to use the assessment during the treatment exercise selection. The training position was defined by the Pediatric Balance Scale. Vestibular/oculomotor exercises were selected using a quantified version of the Vestibular/Ocular Motor Screening. The exercise protocol was selected based on impairment in function or reproduction of symptoms. The protocol planning was implemented by two assessors in 27 children and adolescents post-moderate-severe TBI (median age 14.1 [6-18.4] years) in the sub-acute stage (median 40 [14-162] days since injury). Very high agreement was found (k > 0.72) in all the parameters.Conclusion: This protocol could reliably be used in a randomized control trial that assesses the effect of vestibular/oculomotor rehabilitation program in children and adolescents post moderate-severe TBI at the sub-acute stage.

Predictors of neurosurgical intervention in complicated mild traumatic brain injury patients: a retrospective cohort study

OBJECTIVES

To determine the predicting demographic, clinical and radiological factors for neurosurgical intervention in complicated mild traumatic brain injury (mTBI) patients.

METHODS

Design: retrospective multicenter cohort study. Participants: patients aged ≥16 presenting to all level-I trauma centers in Quebec between 09/2016 and 12/2017 with mTBI(GCS 13-15) and complication on initial head CT (intracranial hemorrhage/skull fracture). Procedure: Consecutive medical records were reviewed and separated into two groups: no neurosurgical intervention and neurosurgical intervention (NSI). Main outcome: neurosurgical intervention. Analysis: multiple logistic regression model.

RESULTS

Four hundred and seventy-eight patients were included and 40 underwent NSI. One patient had radiological deterioration but no clinical deterioration prior to surgery. Subdural hemorrhage ≥4 mm width (OR:3.755 [95% CI:1.290-10.928]) and midline shift (OR:7.507 [95% CI: 3.317-16.989]) increased the risk of NSI. Subarachnoid hemorrhage was associated with a lower risk of NSI (OR:0.312 [95% CI: 0.136-0.713]). All other intracranial hemorrhages were not associated with NSI.

CONCLUSION

Radiological deterioration was not associated with the incidence of NSI. Subdural hemorrhage and midline shift should be predicting factors for neurosurgery. Some patients with isolated findings such as subarachnoid hemorrhage could be safely managed in their original center without being transferred to a level-I trauma center.

Epidemiology of Chronic Effects of Traumatic Brain Injury

Although many patients diagnosed with traumatic brain injury (TBI), particularly mild TBI, recover from their symptoms within a few weeks, a small but meaningful subset experience symptoms that persist for months or years after injury and significantly impact quality of life for the person and their family. Factors associated with an increased likelihood of negative TBI outcomes include not only characteristics of the injury and injury mechanism, but also the person’s age, pre-injury status, comorbid conditions, environment, and propensity for resilience. In this article, as part of the Brain Trauma Blueprint: TBI State of the Science framework, we examine the epidemiology of long-term outcomes of TBI, including incidence, prevalence, and risk factors. We identify the need for increased longitudinal, global, standardized, and validated assessments on incidence, recovery, and treatments, as well as standardized assessments of the influence of genetics, race, ethnicity, sex, and environment on TBI outcomes. By identifying how epidemiological factors contribute to TBI outcomes in different groups of persons and potentially impact differential disease progression, we can guide investigators and clinicians toward more-precise patient diagnosis, along with tailored management, and improve clinical trial designs, data evaluation, and patient selection criteria.

Effect of medication on risk of traumatic brain injury in patients with bipolar disorder: A nationwide population-based cohort study

BACKGROUND

Increased traumatic brain injury (TBI) risk was found in patients with bipolar disorder (BPD). Whether the medications for BPD and dosage moderate the risk of TBI is not clear.

AIM

This study aimed to determine whether an association exists between BPD and TBI and whether the prescription of psychotropics moderates TBI risk.

METHODS

A total of 5606 individuals who had received diagnoses of BPD between January 1, 1997 and December 31, 2013 and 56,060 matched controls without BPD were identified from Taiwan's National Health Insurance Research Database. Cases and controls were followed until the date of TBI diagnosis.

RESULTS

BPD was associated with a high risk of TBI (adjusted hazard ratio (aHR): 1.85; 95% CI: 1.62-2.11). Patients with BPD, with or without a history of psychiatric hospitalization, had increased risks of TBI (aHR: 1.94, 95% CI: 1.57-2.4 and aHR: 1.82, 95% CI: 1.55-2.1, respectively). The prescription of typical antipsychotics (0 < defined daily dose (DDD) < 28: hazard ratio (HR) = 1.52, 95% CI: 1.19-1.94; ⩾28 DDD: HR = 1.54, 95% CI: 1.15-2.06) and tricyclic antidepressants (TCAs) (0 < DDD < 28: HR = 1.73, 95% CI: 1.26-2.39; ⩾28 DDD: HR = 1.52, 95% CI: 1.02-2.25) was associated with higher TBI risk. Patients receiving higher doses of benzodiazepines (BZDs) (cumulative dose ⩾28 DDD) had a higher TBI risk (HR = 1.53, 95% CI: 1.13-2.06).

CONCLUSION

Patients with BPD have a higher risk of TBI. The use of typical antipsychotics, TCAs, or high-dose BZDs increases the risk of TBI in BPD.

Manifestation of renin angiotensin system modulation in traumatic brain injury

Traumatic brain injury (TBI) alters brain function and is a crucial public health concern worldwide. TBI triggers the release of inflammatory mediators (cytokines) that aggravate cerebral damage, thereby affecting clinical prognosis. The renin angiotensin system (RAS) plays a critical role in TBI pathophysiology. RAS is widely expressed in many organs including the brain. Modulation of the RAS in the brain via angiotensin type 1 (AT₁) and type 2 (AT₂) receptor signaling affects many pathophysiological processes, including TBI. AT₁R is highly expressed in neurons and astrocytes. The upregulation of AT₁R mediates the effects of angiotensin II (ANG II) including release of proinflammatory cytokines, cell death, oxidative stress, and vasoconstriction. The AT₂R, mainly expressed in the fetal brain during development, is also related to cognitive function. Activation of this receptor pathway decreases neuroinflammation and oxidative stress and improves overall cell survival. Numerous studies have illustrated the therapeutic potential of inhibiting AT₁R and activating AT₂R for treatment of TBI with variable outcomes. In this review, we summarize studies that describe the role of brain RAS signaling, through AT₁R and AT₂R in TBI, and its modulation with pharmacological approaches.

Neurological deteriorations in mild brain injuries: the strategy of evaluation and management

PURPOSE

Most mild traumatic brain injuries (TBIs) can be treated conservatively. However, some patients deteriorate during observation. Therefore, we tried to evaluate the characteristics of deterioration and requirement for further management in mild TBI patients.

METHODS

From 1/1/2017 to 12/31/2017, patients with mild TBI and positive results on CT scans of the brain were retrospectively studied. Patients with and without neurological deteriorations were compared. The characteristics of mild TBI patients with further neurological deterioration or the requirement for interventions were delineated.

RESULTS

One hundred ninety-two patients were enrolled. Twenty-three (12.0%) had neurological deteriorations. The proportions of deterioration occurring within 24 h, 48 h and 72 h were 23.5, 41.2 and 58%, respectively. Deteriorated patients were significantly older than those without neurological deteriorations (69.7 vs. 60.2; p = 0.020). More associated extracranial injuries were observed in deteriorated patients [injury severity score (ISS): 20.2 vs. 15.9; p = 0.005). Significantly higher proportions of intraventricular hemorrhage (8.7 vs. 1.2%; p = 0.018) and multiple lesions (78.3 vs. 53.8%; p = 0.027) were observed on the CT scans of patients with neurological deteriorations. Subset analysis showed that deteriorated patients who required neurosurgical interventions (N = 7) had significantly more initial GCS defects (13 or 14) (71.4 vs. 12.5%; p = 0.005) and more initial decreased muscle power of extremities (85.7 vs. 18.8%; p = 0.002).

CONCLUSION

More attention should be given to mild TBI patients with older age, GCS defects, decreased muscle power of the extremities, multiple lesions on CT scans and other systemic injuries (high ISS). Most deteriorations occur within 72 h after trauma.

Recent Advances in the Application of Two-Dimensional Nanomaterials for Neural Tissue Engineering and Regeneration

The complexity of the nervous system structure and function, and its slow regeneration rate, makes it more difficult to treat compared to other tissues in the human body when an injury occurs. Moreover, the current therapeutic approaches including the use of autografts, allografts, and pharmacological agents have several drawbacks and can not fully restore nervous system injuries. Recently, nanotechnology and tissue engineering approaches have attracted many researchers to guide tissue regeneration in an effective manner. Owing to their remarkable physicochemical and biological properties, two-dimensional (2D) nanomaterials have been extensively studied in the tissue engineering and regenerative medicine field. The great conductivity of these materials makes them a promising candidate for the development of novel scaffolds for neural tissue engineering application. Moreover, the high loading capacity of 2D nanomaterials also has attracted many researchers to utilize them as a drug/gene delivery method to treat various devastating nervous system disorders. This review will first introduce the fundamental physicochemical properties of 2D nanomaterials used in biomedicine and the supporting biological properties of 2D nanomaterials for inducing neuroregeneration, including their biocompatibility on neural cells, the ability to promote the neural differentiation of stem cells, and their immunomodulatory properties which are beneficial for alleviating chronic inflammation at the site of the nervous system injury. It also discusses various types of 2D nanomaterials-based scaffolds for neural tissue engineering applications. Then, the latest progress on the use of 2D nanomaterials for nervous system disorder treatment is summarized. Finally, a discussion of the challenges and prospects of 2D nanomaterials-based applications in neural tissue engineering is provided.

Visuospatial Attention Allocation as an Indicator of Cognitive Deficit in Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Traumatic Brain Injury (TBI) is defined by changes in brain function resulting from external forces acting on the brain and is typically characterized by a host of physiological and functional changes such as cognitive deficits including attention problems. In the present study, we focused on the effect of TBI on the ability to allocate attention in vision (i.e., the use of endogenous and exogenous visual cues) by systematically reviewing previous literature on the topic. We conducted quantitative synthesis of 16 selected studies of visual attention following TBI, calculating 80 effect size estimates. The combined effect size was large (g = 0.79, p < 0.0001) with medium heterogeneity (I² = 68.39%). Subgroup analyses revealed an increase in deficit with moderate-to-severe and severe TBI as compared to mild TBI [F_{(2, 76)} = 24.14, p < 0.0001]. Task type was another key source of variability and subgroup analyses indicated that higher order attention processes were severely affected by TBI [F_{(2, 77)} = 5.66, p = 0.0051). Meta-regression analyses revealed significant improvement in visual attention deficit with time [p(mild) = 0.031, p(moderate-to-severe) = 0.002, p(severe) < 0.0001]. Taken together, these results demonstrate that visual attention is affected by TBI and that regular assessment of visual attention, using a systematic attention allocation task, may provide a useful clinical measure of cognitive impairment and change after TBI.

Living with embodied vibrations: Sensory experiences following a traumatic brain injury

Based on autoethnography, this article adopts a (neuro)phenomenological lens to explore sensory experiences following a traumatic brain injury (TBI). Although focussing particularly on pain, vision, hearing, and somatic experiences connected with sleep, we also touch on how these are interwoven with other symptoms associated with TBIs. We use these experiences to enliven, and thereby enrich, clinical constructions and understandings of 'sensitivity' to light and to noise, as well as 'sleep disturbance'. We conclude with a discussion of how these sensory experiences can be understood in relation to embodied dynamics of vibration, oscillation, and (stochastic) resonance. The article closes with the suggestion that an embodied, sensorial, and phenomenologically informed analysis of the experiences of people with TBIs, particularly in relation, for example, to embodied sensations and perceptions of vibration, might provide novel insights for research and clinical practice.

Gastrointestinal Decompression on Computed Tomography Examination for Patients with Craniocerebral Injury

Objective: Patients with craniocerebral injury usually accompanied by intracranial hypertension and vomiting, which affect the effect of CT scanning. The aim of this study was to discuss the application effects of gastrointestinal decompression on computed tomography (CT) examination for patients with craniocerebral injury. Methods: A total of 80 patients with craniocerebral injury in our hospital were randomly selected and divided into control and observation groups, 40 cases in each group. The observation group was given gastrointestinal decompression before the CT examination, while the control group received routine examination. The success rate of CT examination, CT scanning effect, examination, and complication during scanning were recorded and compared in two groups. Results: The one-time success rate (100.0%) of CT examination was 100.0% (40/40) in the observation group was significantly higher than the rate in the control group (82.5%, P = 0.034). The CT examination clearly showed in the types of craniocerebral injury, the brain tissue injury, the ventricular compression and the midline displacement. The CT examination time of observation group was shorter than that of control group (P < 0.001), while there was no significant difference in the whole examination time spent on both gastrointestinal decompression operation and CT examination between the two groups (P = 0.301). In the observation group, there was only 1 case of retching, and no cases of vomiting or aspiration during scanning. The incidence of various complications in observation group was significantly lesser than the incidence in control group (P = 0.034). Conclusions: Continue gastrointestinal decompression can significantly reduce the incidence of vomiting and other complication in patients with craniocerebral injury during CT examination, reduce the CT examination time, and improve the success rate of one-time scanning.

Emotion Recognition and Traumatic Brain Injury: a Systematic Review and Meta-Analysis

Traumatic brain injury (TBI) can lead to impairments in emotion recognition that can present considerable challenges to social communication and the maintenance of interpersonal relationships. This review aimed to estimate the magnitude of emotion recognition impairments in TBI patients overall, and at the emotion category level, and to determine if the magnitude of observed impairments were moderated by modality (e.g., face, voice, multi-modal) of emotional expression, and severity of injury. Searches of PubMed, Scopus, PsycINFO, and Medline databases identified 17 studies which satisfied strict inclusion and exclusion criteria for the systematic review (comparing TBI patients to matched controls). Of these studies, 15 were included in the meta-analysis (N_TBI = 474; N_Control = 461). Moderate/large average deficits emerged for TBI patients relative to controls (Hedges' g = 0.79, 95% CI: 0.61 - 0.96, p < .001; Q = 22.53, p = .068, τ² = 0.04, I² = 37.84; indicating low heterogeneity). TBI patients were impaired across all emotion categories, with moderate/large effect sizes observed for fear and anger, moderate effect sizes for disgust, neutral and sadness, while effect sizes for happiness and surprise were small. The magnitude of impairment for individuals with TBI severity classified as moderate/severe TBI was moderate, whereas severe TBI was large. Moderate/large effect sizes were observed across the different modalities of presentation. This meta-analysis provides evidence for marked global impairments in emotion recognition, with the magnitude of impairment greatest for negative emotions (i.e., anger and fear). This meta-analysis provided no evidence to suggest that the magnitude of impairment is influenced by injury severity or modality of stimulus presentation. Recommendations for future research are discussed.

Long-Term Trends in the Epidemiology of Major Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability among adults. Falls and motor vehicle collisions (MVCs) are the most common causes of TBI hospitalizations in Canada. The purpose of this study was to determine whether, at the provincial level, there have been significant changes in the injury rate and causes of major TBI. This was a retrospective cohort study of all patients in Nova Scotia who presented with major TBI (Abbreviated Injury Scale Head score ≥ 3) between 2002 and 2018. Prospectively entered data were collected from the Nova Scotia Trauma Registry. Annual injury rates were calculated based on 100,000 population (all ages) using population estimates from Statistics Canada. Linear regression was performed to analyze annual trends of major TBI within the province. There were 5590 major TBI patients in Nova Scotia during the 16-year study period. The overall annual rate of major TBI was 37 per 100,000 population. There was a 39% increase in the rate of major TBI over the study period (r =  - 0.72, R2 = 0.51, p < 0.002). Patients had a mean age of 51 ± 25 years; 72% were male. The proportion of TBIs in males decreased significantly from 76% in 2002 to 69% in 2017 (p < 0.001). Mechanisms of injury were predominantly falls (45%) and MVCs (29%); the proportion of violent injuries was 11.5%. The rate of fall-related TBIs more than doubled between 2002 and 2017, increasing from 9.1 to 20.5 injuries per 100,000 (p < 0.001). Our findings demonstrate an increasing incidence of major TBI over a 16-year period with a greater than two-fold increase in the rate of fall-related TBI. These results are important for targeting TBI prevention efforts in reducing falls, especially in older adults.

Emerging Applications for Quantitative Susceptibility Mapping in the Detection of Traumatic Brain Injury Pathology

Traumatic brain injury (TBI) is a common but heterogeneous injury underpinned by numerous complex and interrelated pathophysiological mechanisms. An essential trace element, iron is abundant within the brain and involved in many fundamental neurobiological processes, including oxygen transportation, oxidative phosphorylation, myelin production and maintenance, as well as neurotransmitter synthesis and metabolism. Excessive levels of iron are neurotoxic and thus iron homeostasis is tightly regulated in the brain, however, many details about the mechanisms by which this is achieved are yet to be elucidated. A key mediator of oxidative stress, mitochondrial dysfunction and neuroinflammatory response, iron dysregulation is an important contributor to secondary injury in TBI. Advances in neuroimaging that leverage magnetic susceptibility properties have enabled increasingly comprehensive investigations into the distribution and behaviour of iron in the brain amongst healthy individuals as well as disease states such as TBI. Quantitative Susceptibility Mapping (QSM) is an advanced neuroimaging technique that promises quantitative estimation of local magnetic susceptibility at the voxel level. In this review, we provide an overview of brain iron and its homeostasis, describe recent advances enabling applications of QSM within the context of TBI and summarise the current state of the literature. Although limited, the emergent research suggests that QSM is a promising neuroimaging technique that can be used to investigate a host of pathophysiological changes that are associated with TBI.

Effect of Growth Hormone on Neuropsychological Outcomes and Quality of Life of Patients with Traumatic Brain Injury: A Systematic Review

One of the most devastating chronic consequences of traumatic brain injury (TBI) is cognitive impairment. One of the possible underlying causes is growth hormone deficiency (GHD) caused by TBI-induced hypopituitarism. Currently, TBI patients are not routinely screened for pituitary function, and there are no standard therapies when GHD is diagnosed. Further, the possible positive effects of GH replacement on cognitive function and quality of life after TBI are not well established. We aimed to assess the current knowledge regarding the effect of GH therapy on cognitive function and quality of life after TBI. We performed a literature search in PubMed, Embase, and Central® databases from inception to October 2019. We extracted data on each term of severity (mild-moderate-severe) of TBI with and without GHD, time since injury, parameters of growth hormone treatment (dosing, length), and cognitive outcomes in terms of verbal and non-verbal memory, and executive, emotional, and motor functions, and performed a meta-analysis on the results of a digit span test assessing working memory. We identified 12 studies (containing two randomized controlled trials) with 264 mild-to-moderate-to-severe TBI patients (Glasgow Coma Score [GCS] varied between 6 and 15) with (n = 255) or without (n = 9) GHD who received GH therapy. GH was administered subcutaneously in gradually increasing doses, monitoring serum insulin-like growth factor-I (IGF-I) level. After TBI, regardless of GCS, 6-12 months of GH therapy, started in the chronic phase post-TBI, induced a moderate improvement in processing speed and memory capacities, decreased the severity of depression, and led to a marked improvement in quality of life. Limitations include the relatively low number of patients involved and the divergent neuropsychological tests used. These results indicate the need for further multi-centric controlled studies to substantiate the use of GH replacement therapy as a potential tool to alleviate TBI-related cognitive impairment and improve quality of life.

Recurrent Traumatic Brain Injury Surveillance Using Administrative Health Data: A Bayesian Latent Class Analysis

Background: The initial injury burden from incident TBI is significantly amplified by recurrent TBI (rTBI). Unfortunately, research assessing the accuracy to conduct rTBI surveillance is not available. Accurate surveillance information on recurrent injuries is needed to justify the allocation of resources to rTBI prevention and to conduct high quality epidemiological research on interventions that mitigate this injury burden. This study evaluates the accuracy of administrative health data (AHD) surveillance case definitions for rTBI and estimates the 1-year rTBI incidence adjusted for measurement error. Methods: A 25% random sample of AHD for Montreal residents from 2000 to 2014 was used in this study. Four widely used TBI surveillance case definitions, based on the International Classification of Disease and on radiological exams of the head, were applied to ascertain suspected rTBI cases. Bayesian latent class models were used to estimate the accuracy of each case definition and the 1-year rTBI measurement-error-adjusted incidence without relying on a gold standard rTBI definition that does not exist, across children (<18 years), adults (18-64 years), and elderly (> =65 years). Results: The adjusted 1-year rTBI incidence was 4.48 (95% CrI 3.42, 6.20) per 100 person-years across all age groups, as opposed to a crude estimate of 8.03 (95% CrI 7.86, 8.21) per 100 person-years. Patients with higher severity index TBI had a significantly higher incidence of rTBI compared to patients with lower severity index TBI. The case definition that identified patients undergoing a radiological examination of the head in the context of any traumatic injury was the most sensitive across children [0.46 (95% CrI 0.33, 0.61)], adults [0.79 (95% CrI 0.64, 0.94)], and elderly [0.87 (95% CrI 0.78, 0.95)]. The most specific case definition was the discharge abstract database in children [0.99 (95% CrI 0.99, 1.00)], and emergency room visits claims in adults/elderly [0.99 (95% CrI 0.99, 0.99)]. Median time to rTBI was the shortest in adults (75 days) and the longest in children (120 days). Conclusion: Conducting accurate surveillance and valid epidemiological research for rTBI using AHD is feasible when measurement error is accounted for.

Inflammation in Traumatic Brain Injury

There is an increasing evidence that inflammation contributes to clinical and functional outcomes in traumatic brain injury (TBI). Many successful target-engaging, lesion-reducing, symptom-alleviating, and function-improving interventions in animal models of TBI have failed to show efficacy in clinical trials. Timing and immunological context are paramount for the direction, quality, and intensity of immune responses to TBI and the resulting neuroanatomical, clinical, and functional course. We present components of the immune system implicated in TBI, potential immune targets, and target-engaging interventions. The main objective of our article is to point toward modifiable molecular and cellular mechanisms that may modify the outcomes in TBI, and contribute to increasing the translational value of interventions that have been identified in animal models of TBI.