Update on the epidemiology of work-related traumatic brain injury: a systematic review and meta-analysis

Mild traumatic brain injury caused by workplace violence in a US workers' compensation system

OBJECTIVES

Approximately 81% of traumatic brain injury cases are considered to be mild (mTBI), but few studies have reviewed mTBI caused by workplace violence (WPV). This study aimed to (1) determine the incidence of mTBI secondary to WPV in a statewide workers' compensation system using International Classification of Disease codes and (2) analyse and compare factors associated with return-to-work outcomes between WPV mTBI cases versus other mechanisms.

METHODS

Using a retrospective cohort of claims data from the California Workers' Compensation Information System during 2015-2019, cases with a return-to-work date were classified as WPV if the injury description contained keywords such as assault, gunpoint, harassed, intimidated, punch, threat, robbery, violent or verbal abuse.

RESULTS

Of the 14 089 mTBI claims analysed in this study, 11.2% were caused by WPV. When comparing WPV to non-WPV claims, the variables with statistically significant (p≤0.001) differences were age, income, industry and job class. There were no significant differences between groups for leave duration. In a linear mixed model, the variable of interest (WPV) was not associated with recovery duration after adjusting for other factors.

CONCLUSION

To our knowledge, this is the first study to examine WPV mTBI claims in the USA. The findings suggest that the public administration, education and healthcare and social services industries are at higher risk for WPV mTBI. WPV and job class were the only modifiable factors in the model and therefore should be the focus of additional research.

Appropriate incorporation of susceptibility-weighted magnetic resonance imaging into routine imaging protocols for accurate diagnosis of traumatic brain injuries: a systematic review

Traumatic brain injury (TBI) results from physical or traumatic injuries to the brain's surrounding bony structures and associated tissues, which can lead to various sequelae, including simple concussion, acute epidural hematoma, parenchymal contusions, subarachnoid hemorrhage, diffuse axonal injury, and chronic traumatic encephalopathy. Susceptibility-weighted imaging (SWI) has enhanced the accuracy of neuroimaging for these injuries. SWI is based on 3D gradient echo magnetic resonance imaging (MRI) with long echo times and flow compensation. Owing to its sensitivity to deoxyhemoglobin, hemosiderin, iron, and calcium, SWI is extremely informative and superior to conventional MRI for the diagnosis and follow-up of patients with acute, subacute, and prolonged hemorrhage. This systematic review aimed to evaluate and summarize the published articles that report SWI results for the evaluation of TBI and to determine correlations between clinical status and SWI results. Consequently, our analysis also aimed to identify the appropriate MRI sequences to use in the assessment of patients with TBI. We searched the Medline and Embase online electronic databases for relevant papers published from 2012 onwards. We found that SWI had higher sensitivity than gradient echo MRI in detecting and characterizing microbleeds in TBIs and was able to differentiate diamagnetic calcifications from paramagnetic microhemorrhages. However, it is important that future research not only continues to evaluate the utility of SWI in TBIs but also attempts to overcome the limitations of the studies described in this review, which should help validate the conclusions and recommendations from our analysis.

Work-related and non-work-related mild traumatic brain injury: Associations with mental health and substance use challenges in a Canadian population-level survey

BACKGROUND

Mild traumatic brain injury (mTBI) can profoundly impact overall health, employment, and family life. Incidence of mTBI in the workplace represents an important subgroup with poorer outcomes. Mental health (MH) and substance use (SU) challenges are a primary correlate of TBI, but are rarely assessed among individuals with a work-related (wr)-mTBI, particularly at a population-level.

OBJECTIVE

This study aimed to assess the association between lifetime wr-mTBI and non-wr-mTBI and the experience of MH and SU challenges.

METHODS

The 2019 Centre for Addiction and Mental Health (CAMH) Monitor is a cross-sectional telephone survey of adults aged≥18 years in Ontario, Canada, employing a stratified (six regions) two-stage (telephone number, respondent) list-assisted random digit dialing probability selection procedure (N = 1792). Adjusting for sociodemographic variables, binary logistic regression was conducted to assess the association between lifetime wr-mTBI and non-wr-mTBI (relative to no TBI) and four outcomes: hazardous use of alcohol and of cannabis, psychological distress, and fair/poor mental health.

RESULTS

Adjusting for sociodemographic variables, non-wr-mTBI demonstrated increased odds of hazardous alcohol (AOR = 2.12, 95% CI = 1.41, 3.19) and cannabis use (AOR = 1.61, 95% CI = 1.05, 2.45), psychological distress (AOR = 1.68, 95% CI = 1.14, 2.49), and fair/poor mental health (AOR = 1.70, 95% CI = 1.11, 2.59). Lifetime wr-mTBI demonstrated increased odds of reporting psychological distress (AOR = 3.40, 95% CI = 1.93, 5.97) and fair/poor mental health (AOR = 2.16, 95% CI = 1.12, 4.19) only.

CONCLUSIONS

Non-wr-mTBI was associated with both MH and SU, whereas wr-mTBI was associated with MH only. MH outcomes were more strongly associated with wr-mTBI than non-wr-mTBI. Physicians, employers, and insurers need to consider the potential association between wr-mTBI and MH, and provide care accordingly.

Overview of randomized controlled trials of moderate to severe traumatic brain injury: A systematic review

BACKGROUND

Given the complexity of post-TBI medical, surgical, and rehabilitative care, research is critical to optimize interventions across the continuum of care and improve outcomes for persons with moderate to severe TBI.

OBJECTIVE

To characterize randomized controlled trials (RCTs) of moderate to severe traumatic brain injury (TBI) in the literature.

METHOD

Systematic searches of MEDLINE, PubMed, Scopus, CINAHL, EMBASE and PsycINFO for RCTs up to December 2022 inclusive were conducted in accordance with PRISMA guidelines.

RESULTS

662 RCTs of 91,946 participants published from 1978 to 2022 met inclusion criteria. The number of RCTs published annually has increased steadily. The most reported indicator of TBI severity was the Glasgow Coma Scale (545 RCTs, 82.3%). 432 (65.3%) RCTs focused on medical/surgical interventions while 230 (34.7%) addressed rehabilitation. Medical/surgical RCTs had larger sample sizes compared to rehabilitation RCTs. Rehabilitation RCTs accounted for only one third of moderate to severe TBI RCTs and were primarily conducted in the chronic phase post-injury relying on smaller sample sizes.

CONCLUSION

Further research in the subacute and chronic phases as well as increasing rehabilitation focused TBI RCTs will be important to optimizing the long-term outcomes and quality of life for persons living with TBI.

Epidemiology of Work-Related Traumatic Brain Injury and COVID-19 Pandemic Lockdown Consequences: Experience in a Reference Center in Chile

INTRODUCTION

Work-related traumatic brain injury is a frequent cause of chronic morbidity, mortality, and high treatment costs. Its causes are highly environmentally determined and were affected by COVID-19 pandemic lockdowns.

OBJECTIVE

We aimed to describe traumatic brain injury (TBI) epidemiology in working population and evaluate its modifications during the COVID-19 pandemic.

METHODS

We performed a 2-year retrospective epidemiological analysis of TBI patients hospitalized in a tertiary work-related hospital before and during the COVID-19 pandemic.

RESULTS

In the prepandemic period, TBI patients were predominantly men, with a bimodal age distribution. Crash accidents were the leading work-related traumatic brain injury cause. During COVID-19 pandemic lockdowns, there was a positive correlation between street traffic and TBI rate, presenting increased motor crash accidents as a cause of TBI.

CONCLUSIONS

These results are relevant for planning and focalization of resources for TBI prevention.

Utility of Person-Environment-Occupation model in exploring sex-specific causes of work-related traumatic brain injury: a retrospective chart review

BACKGROUND

Work-related traumatic brain injury (wr-TBI) is on the rise. The pre-injury period, a significant consideration for preventive initiatives, is largely unexplored.

OBJECTIVES

To identify Person-Environment-Occupation (PEO) variables associated with wr-TBI to inform sex-specific primary prevention.

METHODS

Retrospective chart review data were analyses. Two-tailed t-test and chi-squared tests were used to study sex differences. Multivariate logistic regression models of wr-TBI were fit with a priori defined PEO variables.

RESULTS

The sample comprised 330 consecutive workers with wr-TBI (40.8 ± 11.1 years old, 71% male). Sex differences were observed across PEO variables. In multivariable logistic regression analyses the odds of sustaining a wr-TBI from a fall increased with the presence of a mood disorder and participation in non-labourer occupations (odds ratio (OR) 2.89 (95% CI 1.06-7.89) and OR 2.89 (95% CI 1.06-7.89), respectively) and decreased being a male (OR 0.31 (95% CI 0.17-0.54)). The odds of sustaining a wr-TBI from being striken by an object was greater in workers with prior head injury (OR 2.8 (95% CI 1.24-6.45)). None of the variables studied were associated with wr-TBI sustained from being striken against an object.

CONCLUSIONS

Workers' health status pre-injury is associated with external causes of wr-TBI. Sex differences across PEO categories warrant further study.

Head Impact Location, Speed and Angle from Falls and Trips in the Workplace

Traumatic brain injury (TBI) is a common injury in the workplace. Trips and falls are the leading causes of TBI in the workplace. However, industrial safety helmets are not designed for protecting the head under these impact conditions. Instead, they are designed to pass the regulatory standards which test head protection against falling heavy and sharp objects. This is likely to be due to the limited understanding of head impact conditions from trips and falls in workplace. In this study, we used validated human multi-body models to predict the head impact location, speed and angle (measured from the ground) during trips, forward falls and backward falls. We studied the effects of worker size, initial posture, walking speed, width and height of the tripping barrier, bracing and falling height on the head impact conditions. Overall, we performed 1692 simulations. The head impact speed was over two folds larger in falls than trips, with backward falls producing highest impact speeds. However, the trips produced impacts with smaller impact angles to the ground. Increasing the walking speed increased the head impact speed but bracing reduced it. We found that 41% of backward falls and 19% of trips/forward falls produced head impacts located outside the region of helmet coverage. Next, we grouped all the data into three sub-groups based on the head impact angle: [0°, 30°], (30°, 60°] and (60°, 90°] and excluded groups with small number of cases. We found that most trips and forward falls lead to impact angles within the (30°, 60°] and (60°, 90°] groups while all backward falls produced impact angles within (60°, 90°] group. We therefore determined five representative head impact conditions from these groups by selecting the 75th percentile speed, mean value of angle intervals and median impact location (determined by elevation and azimuth angles) of each group. This led to two representative head impact conditions for trips: 2.7 m/s at 45° and 3.9 m/s at 75°, two for forward falls: 3.8 m/s at 45° and 5.5 m/s at 75° and one for backward falls: 9.4 m/s at 75°. These impact conditions can be used to improve industrial helmet standards.

Work-related head injury and industry sectors in Finland: causes and circumstances

OBJECTIVE

Despite the continuous development of occupational safety, the prevalence of work-related head injuries is excessive. To promote prevention, we conducted a study evaluating the risks and pathways that precede head injuries in different economic activity sectors.

METHODS

In Finland, more than 90% of employees are covered by inclusive statutory workers' compensation. We obtained data on occupational head injuries in 2010-2017 from an insurance company database. The European Statistics on Accidents at Work (ESAW) variables represented the characteristics of the accidents and the injury. We analysed the risk factors, contributing events and injury mechanisms in 20 industry sectors, based on the Statistical Classification of Economic Activities in the European Community (NACE).

RESULTS

In the 32,898 cases, the most commonly affected area was the eyes (49.6%). The highest incidence of head injuries was in construction (15.7 per 1000 insurance years). Construction, manufacturing, and human health and social work activities stood out due to their distinctive ESAW category counts. 'Working with hand-held tools' [risk ratio (RR) 2.23, 95% confidence interval (CI) 2.14-2.32] in construction and 'operating machines' (RR 3.32, 95% CI 3.01-3.66) and 'working with hand-held tools' (1.99, 1.91-2.07) in manufacturing predicted head injury. The risk related to parameters of violence and threats in health and social work activities was nearly ninefold the risk of other sectors.

CONCLUSION

The risks and pathways preceding head injuries varied considerably. The highest head injury rates were in construction and manufacturing. Violence emerged as a major risk factor in human health and social work activities.

Disparities in traumatic brain injury-related deaths-United States, 2020

INTRODUCTION

Traumatic brain injury (TBI) affects how the brain functions and remains a prominent cause of death in the United States. Although preventable, anyone can experience a TBI and epidemiological research suggests some groups have worse health outcomes following the injury.

METHODS

We analyzed 2020 multiple-cause-of-death data from the National Vital Statistics System to describe TBI mortality by geography, sociodemographic characteristics, mechanism of injury (MOI), and injury intent. Deaths were included if they listed an injury International Classification of Diseases, Tenth Revision (ICD-10) underlying cause of death code and a TBI-related ICD-10 code in one of the multiple-cause-of-death fields.

RESULTS

During 2020, 64,362 TBI-related deaths occurred and age-adjusted rates, per 100,000 population, were highest among persons residing in the South (20.2). Older adults (≥75) displayed the highest number and rate of TBI-related deaths compared with other age groups and unintentional falls and suicide were the leading external causes among this older age group. The age-adjusted rate of TBI-related deaths in males was more than three times the rate of females (28.3 versus 8.4, respectively); further, males displayed higher numbers and age-adjusted rates compared with females for all the principal MOIs that contributed to a TBI-related death. American Indian or Alaska Native, Non-Hispanic (AI/AN) persons had the highest age-adjusted rate (29.0) of TBI-related deaths when compared with other racial and ethnic groups. Suicide was the leading external cause of injury contributing to a TBI-related death among AI/AN persons.

PRACTICAL APPLICATION

Prevention efforts targeting older adult falls and suicide are warranted to reduce disparities in TBI mortality among older adults and AI/AN persons. Effective strategies are described in CDC's Stopping Elderly Accidents, Deaths, & Injuries (STEADI) initiative to reduce older adult falls and CDC's Preventing Suicide: A Technical Package of Policy, Programs, and Practices for the best available evidence in suicide prevention.

The S-100B level, intracranial pressure, body temperature, and transcranial blood flow velocities predict the outcome of the treatment of severe brain injury

This study evaluates the applicability of S100B levels, mean maximum velocity (Vmean) over time, pulsatility index (PI), intracranial pressure (ICP), and body temperature (T) for the prediction of the treatment of patients with traumatic brain injury (TBI). Sixty patients defined by the Glasgow Coma Scale score ≤ 8 were stratified using the Glasgow Coma Scale into 2 groups: favorable (FG: Glasgow Outcome Scale ≥ 4) and unfavorable (UG: Glasgow Outcome Scale < 4). The S100B concentration was at the time of hospital admission. Vmean was measured using transcranial Doppler. PI was derived from a transcranial Doppler examination. T was measured in the temporal artery. The differences in mean between FG and UG were tested using a bootstrap test of 10,000 repetitions with replacement. Changes in S100B, Vmean, PI, ICP, and T levels stratified by the group were calculated using the one-way aligned rank transform for nonparametric factorial analysis of variance. The reference ranges for the levels of S100B, Vmean, and PI were 0.05 to 0.23 µg/L, 30.8 to 73.17 cm/s, and 0.62 to 1.13, respectively. Both groups were defined by an increase in Vmean, a decrease in S100B, PI, and ICP levels; and a virtually constant T. The unfavorable outcome is defined by significantly higher levels of all parameters, except T. A favorable outcome is defined by S100B < 3 mg/L, PI < 2.86, ICP > 25 mm Hg, and Vmean > 40 cm/s. The relationships provided may serve as indicators of the results of the TBI treatment.

Work-Related Injuries among Insured Construction Workers Presenting to a Swiss Adult Emergency Department: A Retrospective Study (2016-2020)

Occupational injuries are one of the main causes of Emergency Department visits and represent a substantial source of disability or even death. However, the published studies and reports on construction-occupational accidents in Switzerland are limited. We aimed to investigate the epidemiology of fatal and non-fatal injuries among construction workers older than 16 years of age over a 5-year period. Data were gathered from the emergency department (ED) of Bern University Hospital. A retrospective design was chosen to allow analysis of changes in construction accidents between 2016-2020. A total of 397 patients were enrolled. Compared to studies in other countries, we also showed that the upper extremity and falling from height is the most common injured body part and mechanism of injury. Furthermore, we were able to show that the most common age group representing was 26-35 years and the second common body part injured was the head, which is a difference from studies in other countries. Wound lacerations were the most common type of injury, followed by joint distortions. By stratifying according to the season, occupational injuries among construction workers were found to be significant higher during summer and autumn. As work-related injuries among construction workers are becoming more common, prevention strategies and safety instructions must be optimized.

Incidence of Traumatic Brain Injury by Severity Among Work-Related Injured Workers From 2010 to 2019: An Analysis of Workers' Compensation Insurance Data in Korea

OBJECTIVE

This study aimed to investigate the status of work-related traumatic brain injury (wrTBI) in Korea between 2010 and 2019.

METHODS

This study used Korea Workers' Compensation Insurance data, and the sample comprised workers who claimed compensation for wrTBI from 2010 to 2019. The annual incidence of wrTBI was calculated as the rate per 100,000 workers. Time trends over the 10-year period were assessed using Poisson regression.

RESULTS

The mean incidence of wrTBI was 28.4/100,000. Regarding the incidence rate of wrTBI by severity, mild TBI and moderate-to-severe TBI were 12.9/100,000 and 15.5/100,000, respectively. The incidence of mild TBI among workers was higher in 2010, but moderate-to-severe TBI was higher after 2011.

CONCLUSIONS

Our findings highlight the need for providing information on mild TBI to workers as part of occupational safety and health education.

Prognostic properties of the association between the S‑100B protein levels and the mean cerebral blood flow velocity in patients diagnosed with severe traumatic brain injury

Craniocerebral injury (CBI) is tissue damage caused by a sudden mechanical force. CBI can result in neurological, neuropsychological and psychiatric dysfunctions. Currently, the severity of CBI is assessed using the Glasgow Coma Scale, brain perfusion pressure measurements, transcranial Doppler tests and biochemical markers. This study aimed to determine the applicability of the S-100B protein levels and the time-averaged mean maximum cerebral blood flow velocity (V_mean) as a means of predicting the treatment outcomes of CBI in the first 4 days of hospitalization. The results validated the standard reference ranges previously proposed for the concentration of S-100B (0.05-0.23 µg/l) and the mean of cerebral blood flow velocity (30.9 to 74.1 cm/sec). The following stratification scheme was used to predict the success of treatment: Patients with a Glasgow Outcome Scale (GOS) score ≥4 or GOS <4 were stratified into ‘favorable’ and ‘unfavorable’ groups, respectively. The favorable group showed relatively constant levels of the S-100B protein close to the normal range and exhibited an increase in V_mean, but this was still within the normal range. The unfavorable group exhibited a high level of S-100B protein and increased V_mean outside of the normal ranges. The changes in the levels of S-100B in the unfavorable and favorable groups were -0.03 and -0.006 mg/l/h, respectively. Furthermore, the rate of decrease in the V_mean value in the unfavorable and favorable groups were -0.26 and -0.18 cm/sec/h, respectively. This study showed that constant levels of S-100B protein, even slightly above the normal range, associated with an increase in V_mean was indicative of a positive therapeutic outcome. However, additional research is required to obtain the appropriate statistical strength required for clinical practice.

Restraint Stress Delays the Recovery of Neurological Impairments and Exacerbates Brain Damages through Activating Endoplasmic Reticulum Stress-mediated Neurodegeneration/Autophagy/Apopotosis post Moderate Traumatic Brain Injury

Based on accumulating evidence, patients recovering from mild and moderate traumatic brain injury (TBI) often experience increased sensitivity to stressful events. However, few studies have assessed on the effects and pathophysiological mechanisms of stress on TBI. In the current study, using a mouse model of moderate TBI, we investigated whether restraint stress (RS) regulates secondary neurodegeneration and neuronal cell death, which are commonly associated with neurological dysfunctions. Our data showed that RS significantly reduced body weight recovery, delayed the recovery of neurological functions (motor function, cognitive function and anxiety-like behavior) and exacerbated the brain lesion volume after moderate TBI. Immunofluorescence results indicated that moderate TBI-induced cell insults and blood-brain barrier leakage were aggravated by RS. Further Western blotting experiments showed that RS activated endoplasmic reticulum (ER) stress excessively after moderate TBI and decreased the number of NeuN-positive cells, but increased the number of CHOP/NeuN-co-positive cells by performing immunostaining in the injured cortex after moderate TBI. Moreover, RS increased the ratios of CHOP/Aβ and CHOP/p-Tau co-positive cells in the injured cortex after moderate TBI. However, blocking ER stress with the classic ER stress inhibitor salubrinal remarkably decreased apoptosis and the levels of autophagy-related proteins in the mouse model of moderate TBI plus RS. Collectively, RS delays the recovery of neurological function and deteriorates morphological damage by excessively activating ER stress-mediated neurodegeneration, apoptosis and autophagy after moderate TBI. Thus, monitoring stress levels in patients recovering from non-severe TBI may merit consideration in the future.

Usability of the Level of the S100B Protein, the Gosling Pulsatility Index, and the Jugular Venous Oxygen Saturation for the Prediction of Mortality and Morbidity in Patients with Severe Traumatic Brain Injury

The high frequency of traumatic brain injury imposes severe economic stress on health and insurance services. The objective of this study was to analyze the association between the serum S100B protein, the Gosling pulsatility index (PI), and the level of oxygen saturation at the tip of the internal jugular vein (SjVO2%) in patients diagnosed with severe TBI. The severity of TBI was assessed by a GCS score ≤ 8 stratified by Glasgow outcome scale (GOS) measured on the day of discharge from the hospital. Two groups were included: GOS < 4 (unfavorable group (UG)) and GOS ≥ 4 (favorable group (UG)). S100B levels were higher in the UG than in the FG. PI levels in the UG were also substantially higher than in the FG. There were similar levels of SjVO2 in the two groups. This study confirmed that serum S100B levels were higher in patients with unfavorable outcomes than in those with favorable outcomes. Moreover, a clear demarcation in PI between unfavorable and FGs was observed. This report shows that mortality and morbidity rates in patients with traumatic brain injury can be assessed within the first 4 days of hospitalization using the S100B protein, PI values, and SjVO2.