Comparison of effectiveness between different interventions in postconcussive symptoms in adolescents and young people: a literature review

INTRODUCTION

Currently, concussion considers a problem of great magnitude, adolescents and young people being the population at risk, since it is in the process of maturation. Our goal has been to compare the effectiveness of different interventions (exercise therapy, vestibular rehabilitation and rest) in adolescents and young people with concussion.

DEVELOPMENT

A bibliographic search was carried out in the main databases. Once the inclusion/exclusion criteria and the PEDro methodological scale were applied, 6 articles were reviewed. The results support the use of exercise and vestibular rehabilitation in the initial stages to reduce post-concussion symptoms. According to most authors, therapeutic physical exercise and vestibular rehabilitation report greater benefits, although a protocol that unifies assessment scales, study variables and analysis parameters would be needed to be able to make the inference in the target population. CONCLUSIóN: From the moment of hospital discharge, the combined application of exercise and vestibular rehabilitation could be the best option to reduce post-concussion symptoms.

The Postconcussion Syndrome and Posttraumatic Headaches in Civilians, Soldiers, and Athletes

Posttraumatic headaches are one of the most common and controversial secondary headache types. After a mild traumatic brain, an estimated 11% to 82% of people develop a postconcussion syndrome, which has been controversial for more than 160 years. Headache is estimated as present in 30% to 90% of patients after a mild head injury. Most headaches are tension-type-like or migraine-like. Headaches in civilians, soldiers, athletes, and postcraniotomy are reviewed. The treatments are the same as for the primary headaches. Persistent posttraumatic headaches can continue for many years.

Baseline ImPACT Composite Scores in Student-Athletes With Attention-Deficit/Hyperactivity Disorder

BACKGROUND

Athletes who are diagnosed with attention-deficit/hyperactivity disorder (ADHD) are at increased risk of concussion compared to other athletes. Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is a widely used concussion tool, but it relies on pre-injury baseline testing that can be affected by psychiatric conditions. This research aims to determine if there are differences in pre-injury testing composite scores in student-athletes with ADHD compared to those without ADHD diagnosis.

METHODS

We obtained 11,563 pre-season ImPACT assessments of 7,454 student-athletes (ages: 12-22) from 2009 to 2019. After exclusions, there were 6,920 control and 276 ADHD subjects. Multivariable linear regression analyses compared the independent effect of ADHD on the six ImPACT composite score metrics with Bonferroni correction for multiple comparisons with a = 0.008.

RESULTS

Univariate analyses indicated ADHD is associated with more symptoms as measured by the Post-Concussion Symptom Scale (PCSS) (β = 2.67, 95% CI: 1.47-3.87, p < .0001) and worse Impulse Control scores (β = 0.93, 95% CI: 0.33-1.53, p = .002). In multivariate analysis, this association was the same for symptom score (β = 2.48, 95% CI: 1.22-3.74, p < .0001), but Impulse Control was not significantly different after multiple comparison adjustment (β = 0.87, 95% CI: 0.22-1.15, p = .009).

CONCLUSIONS

The ADHD subjects reported worse symptoms at baseline and had worse Impulse Control in univariate analysis, but not multivariate analysis. These results can further guide clinicians in concussion diagnosis and test interpretations for student-athletes with ADHD, considering the symptom burden at baseline.

Traumatic Brain Injury Characteristics Are Not Related to Neurocognitive Decline in Older Adults: A Nationwide Longitudinal Cohort Study

OBJECTIVE

Evaluate whether traumatic brain injury (TBI) characteristics, age of injury, or recency of injury predicts the course of neurocognitive decline and/or increases conversion rates to mild cognitive impairment (MCI) or dementia.

METHODS

Data were obtained from the National Alzheimer's Coordinating Center for participants 50-85 years old with 3-5 visits from 2015 to 2022, with or without TBI history (TBI+ = 508; TBI- = 2,382). Groups were stratified by self-reported TBI history (i.e., single TBI without loss of consciousness [LOC], single TBI with LOC, multiple TBI without LOC, and multiple TBI with LOC), age of most recent TBI, and recency of TBI. Mixed linear models compared neuropsychological composite trajectories (executive functioning/attention/speed, language, memory, and global), co-varying for age, gender, education, apolipoprotein E4 status, race/ethnicity, and baseline diagnosis (normal aging n = 1,720, MCI n = 749, or dementia n = 417). Logistic binary regression examined MCI/dementia conversion rates.

RESULTS

There was a slightly higher frequency of MCI/dementia in those with multiple TBIs (50% to 60% with and without LOC, compared to 39% with no TBI) at baseline, but longitudinal trajectories were similar. TBI history, age of injury, or recency of injury did not impact neurocognitive trajectories or conversion rates to MCI/dementia (all p's > .01).

CONCLUSIONS

TBI history, regardless of injury characteristics, age of injury, or recency of injury, did not worsen neurocognitive decline or MCI/dementia conversion. Additional longitudinal research in more diverse cohorts with a wider range of TBI severity is needed to evaluate the specific factors and possible mechanisms in which TBI may increase dementia risk.

Variables associated with days of school missed following concussion: results from the Sport Concussion Outcomes in PEdiatrics (SCOPE) study

OBJECTIVE

To understand factors associated with missed academic time after concussion to improve support for patients. Our goal was to assess patient-specific predictors of total school time lost after pediatric/adolescent concussion.

STUDY DESIGN

We performed a prospective cohort study of children and adolescents (8-18 years of age) seen within 14 days of concussion from seven pediatric medical centers across the United States. We collected outcomes via the Concussion Learning Assessment & School Survey (CLASS) and constructed a multivariable predictive model evaluating patient factors associated with school time loss.

RESULTS

167 patients participated (mean age = 14.5 ± 2.2 years; 46% female). Patients were assessed initially at 5.0 ± 3.0 days post-injury and had a final follow-up assessment 24.5 ± 20.0 days post-concussion. Participants missed a median of 2 days of school (IQR = 0.5-4), and 21% reported their grades dropped after concussion. Higher initial symptom severity rating (β = 0.06, 95% CI = 0.03-0.08, p < 0.001) and perception of grades dropping after concussion (β = 1.37, 95% CI = 0.28-2.45, p = 0.01) were significantly associated with more days of school time missed after concussion. Those who reported their grades dropping reported missing significantly more school (mean = 5.0, SD = 4.7 days missed of school) than those who reported their grades did not drop (mean = 2.2, SD = 2.6 days missed of school; p < 0.001; Cohen's d = 0.87).

CONCLUSIONS

Children and adolescents reported missing a median of 2 days of school following concussion, and more missed school time after a concussion was associated with more severe concussion symptoms and perception of grades dropping. These findings may support recommendations for minimal delays in return-to-learn after concussion.

Serum neurofilament light chain, inflammatory markers, and kynurenine metabolites in patients with persistent post-concussion symptoms: A cohort study

BACKGROUND

Concussion leads to persistent post-concussion symptoms (PPCS) in up to one-third of those affected. While previous research has linked the initial trauma to elevated serum levels of neurofilament light chain (NFL), inflammatory markers, and neurotoxic metabolites within the kynurenine pathway, few studies have explored their relevance in PPCS. This study aims to investigate these biomarkers in PPCS patients, elucidating their relevance in the prolonged phase of concussion.

METHODS

Serum samples from 86 PPCS individuals aged 18-30 years, 2-6 months post-trauma were analyzed, with 54 providing follow-up samples after seven months. NFL was measured using single-molecule array (Simoa) technology, 13 inflammatory markers via a Luminex immunoassay, and five kynurenine metabolites using liquid chromatography-mass spectrometry. A control group of 120 healthy anonymous blood donors was recruited for comparison.

RESULTS

No significant NFL differences were found in PPCS participants compared with healthy individuals (p = 0.22). Intriguingly, a subset (9.3%) of PPCS participants initially exhibited abnormally high NFL levels (>9.7 pg/mL), which normalized upon follow-up (p = 0.032). Additionally, serum levels of the inflammatory markers, monocyte chemoattractant protein-1 (MCP-1/CCL2), and eotaxin-1/CCL11 were 25-40% lower than in healthy individuals (p ≤ 0.001). As hypothesized, PPCS participants exhibited a 22% reduction in the ratio of kynurenic acid to quinolinic acid (neuroprotective index) (p < 0.0001), indicating a shift towards the formation of neurotoxic metabolites.

CONCLUSION

NFL may serve as a biomarker to monitor recovery, and future studies should investigate the potential therapeutic benefits of modulating the kynurenine pathway to improve PPCS.

Functional connectivity changes in neurodegenerative biomarker-positive athletes with repeated concussions

Multimodal biomarkers may identify former contact sports athletes with repeated concussions and at risk for dementia. Our study aims to investigate whether biomarker evidence of neurodegeneration in former professional athletes with repetitive concussions (ExPro) is associated with worse cognition and mood/behavior, brain atrophy, and altered functional connectivity. Forty-one contact sports athletes with repeated concussions were divided into neurodegenerative biomarker-positive (n = 16) and biomarker-negative (n = 25) groups based on positivity of serum neurofilament light-chain. Six healthy controls (negative for biomarkers) with no history of concussions were also analyzed. We calculated cognitive and mood/behavior composite scores from neuropsychological assessments. Gray matter volume maps and functional connectivity of the default mode, salience, and frontoparietal networks were compared between groups using ANCOVAs, controlling for age, and total intracranial volume. The association between the connectivity networks and sports characteristics was analyzed by multiple regression analysis in all ExPro. Participants presented normal-range mean performance in executive function, memory, and mood/behavior tests. The ExPro groups did not differ in professional years played, age at first participation in contact sports, and number of concussions. There were no differences in gray matter volume between groups. The neurodegenerative biomarker-positive group had lower connectivity in the default mode network (DMN) compared to the healthy controls and the neurodegenerative biomarker-negative group. DMN disconnection was associated with increased number of concussions in all ExPro. Biomarkers of neurodegeneration may be useful to detect athletes that are still cognitively normal, but with functional connectivity alterations after concussions and at risk of dementia.

Concussion can increase the risk of visually induced motion sickness

Concussion can lead to various symptoms such as balance problems, memory impairments, dizziness, and/or headaches. It has been previously suggested that during self-motion relevant tasks, individuals with concussion may rely heavily on visual information to compensate for potentially less reliable vestibular inputs and/or problems with multisensory integration. As such, concussed individuals may also be more sensitive to other visually-driven sensations such as visually induced motion sickness (VIMS). To investigate whether concussed individuals are at elevated risk of experiencing VIMS, we exposed participants with concussion (n = 16) and healthy controls (n = 15) to a virtual scene depicting visual self-motion down a grocery store aisle at different speeds. Participants with concussion were further separated into symptomatic and asymptomatic groups. VIMS was measured with the SSQ before and after stimulus exposure, and visual dependence, self-reported dizziness, and somatization were recorded at baseline. Results showed that concussed participants who were symptomatic demonstrated significantly higher SSQ scores after stimulus presentation compared to healthy controls and those who were asymptomatic. Visual dependence was positively correlated with the level of VIMS in healthy controls and participants with concussion. Our results suggest that the presence of concussion symptoms at time of testing significantly increased the risk and severity of VIMS. This finding is of relevance with regards to the use of visual display devices such as Virtual Reality applications in the assessment and rehabilitation of individuals with concussion.

Temporal expression of brainstem neurotrophic proteins following mild traumatic brain injury

BDNF, a neurotrophic factor, and its receptors have been implicated in the pathophysiology of mild traumatic brain injury (mTBI). The brainstem houses many vital functions, that are also associated with signs and symptoms of mTBI, but has been understudied in mTBI animal models. We determined the extent to which neurotrophic protein and associated receptor expression is affected within the brainstem of adult rats following mTBI. Their behavioral function was assessed and temporal expression of the 'negative' regulators of neuronal function (p75, t-TrkB, and pro-BDNF) and 'positive' neuroprotective (FL-TrkB and m-BDNF) protein isoforms were determined via western blot and immunohistochemistry at 1, 3, 7, and 14 post-injury days (PID) following mTBI or sham (control) procedure. Within the brainstem, p75 expression increased at PID 1 vs. sham animals. t-TrkB and pro-BDNF expression increased at PID 7 and 14. The 'positive' protein isoforms of FL-TrkB and m-BDNF expression were increased only at PID 7. The ratio of t-TrkB:FL-TrkB (negative:positive) was substantial across groups and time points, suggesting a negative impact of neurotrophic signaling on neuronal function. Additional NeuN experiments revealed cell death occurring within a subset of neurons within the medulla. While behavioral measures improved by PID 7-14, negative neurotrophic biochemical responses persisted. Despite the assertion that mTBI produces "mild" injury, evidence of cell death was observed in the medulla. Ratios of TrkB and BDNF isoforms with conflicting functions suggest that future work should specifically measure each subtype since they induce opposing downstream effects on neuronal function.

Association between days for concussion recovery and initial specialty clinic evaluation within 48 hours

BACKGROUND

Researchers have highlighted the importance of early access to concussion care within one week of injury in reducing recovery times. However, a persisting question for concussion researchers is "just how early is important?" The purpose of this study was to examine differences in recovery time as predicted by the number of days elapsed since injury (DSI) to initial evaluation among patients who had access to a specialty concussion clinic within seven days. We hypothesized that DSI group membership, even within seven days, would significantly predict risk of protracted recovery (i.e., beyond 21 days).

METHODS

In this archival study, retrospective data were gathered from electronic medical records between September 2020 to March 2022. Records of participants between ages 12-18, those diagnosed with a sports-related concussion based on initial clinic visit diagnosis by a medical provider and those who established care within seven days of injury at a large pediatric specialty concussion clinic were examined. Participants were divided into three DSI groups (patients seen in < 48 h: "acute", patients seen between 49 h < and < 96 h: "sub-acute", and patients seen between 97 < and < 168 h: "post-acute"). A general linear model was constructed to examine relationships between relevant concussion factors (e.g., Post Concussion Scale Score, neurodevelopmental history, psychiatric history, concussion history, migraine history, overall VOMS change score, cognitive testing, sex, age, race, and ethnicity) that were either significant in the preliminary analysis or in clinical judgement and recovery time. Adjusted odds ratios (OR) were derived from a binary logistic regression model, in which recovery time was normal (≤ 21 recovery days) or protracted (> 21 recovery days).

RESULTS

A total of 856 participants were eligible. Adolescents in the acute group (M = 15.12, SD = 8.04) had shorter recovery times in days compared to those in the sub-acute (M = 17.98, SD = 10.18) and post-acute (M = 21.12, SD = 10.12; F = 26.00, p < .001) groups. Further, participants in the acute (OR = 4.16) and sub-acute (OR = 1.37) groups who accessed specialty concussion clinics within 48 h were 4 times more likely to have a normal recovery and recovered approximately 6 days faster than the post-acute care group.

CONCLUSIONS

Earlier concussion care access predicted recovery times and was associated with lower risk for protracted recovery.

Association between sports-related concussions and the risk of self-injury thoughts and behaviors: Who, and under what circumstances?

BACKGROUND

Understanding the association between sport-related concussions and the risk of suicidal and non-suicidal self-injury thoughts and behaviors (SITBs), including non-suicidal self-injury (NSSI), suicidal ideation (SI), suicidal plan (SP), and suicidal attempt (SA), is crucial for suicide prevention. We aimed to identify the circumstances in which individuals with or without a concussion are vulnerable to SITBs.

METHODS

The cross-sectional study included 85,469 students from 63 Chinese university with a mean age of 19.6 years. Firstly, propensity score matching, and inverse probability of treatment weighting (IPTW) were used to match the concussion and non-concussion group based on a range of biological, social, and psychological factors. Subsequently, multivariable logistic regression and a decision tree algorithm were employed to evaluate the interaction and cumulative impact of these risk factors and concussion on the probability of SITBs.

RESULTS

In the unmatched sample, concussion exposures were associated with all SITBs, with NSSI (OR, 1.41), SI (OR, 1.10), SP (OR, 1.23), and SA (OR, 1.28). However, the matched and weighted sample only had a significant association with NSSI and SI. The decision tree model revealed that, in the unmatched sample, among individuals without depressive symptoms or childhood emotional abuse, the risk of concussion on SITBs increased from 45.5 % to 65.2 % (χ2, 9.370; adjusted P = .002) after experiencing sexual abuse and verbal bullying. In the matched sample, the risk increased from 46.2 % to 64.6 % (χ2, 6.848; adjusted P = .009).

CONCLUSION

Our study revealed that individuals who suffered concussions exhibited a significantly higher risk of SITBs.

Concussion incidence and mechanisms differ between elite females and males in Australian Football

OBJECTIVES

To investigate the incidence and the game circumstances of concussion in the professional female (AFLW) and male (AFL) competitions of Australian Football, to identify potential targets for risk reduction.

DESIGN

Retrospective cohort.

METHODS

Concussion data were obtained from the AFL injury database, which included all concussions sustained by AFL (Male) players from 2015 to 18 and AFLW (Female) players from 2017 to 19. Concussions were diagnosed by experienced clinicians utilising standardised concussion assessment tools and injury definitions, as well as video review. Video footage was analysed to determine the circumstances each concussion occurred, which included the action and the contact-point of impact.

RESULTS

The incidence of concussion was higher in the AFLW (Female) compared to the AFL (Male) (IRR = 2.12, 95 %CI 1.54 to 2.92). Video footage was available for 194/252 (77 %) concussions in the AFL and 35/44 (80 %) concussions in the AFLW. Male players were most frequently concussed during marking contests (28 %) with primary impact from the upper limb (22 %) or the shoulder (19 %). Conversely, being bumped (23 %) or tackled (20 %) were the main actions associated with concussion in female players, with the head (29 %) or the ground (23 %) the most common contact-points of impact.

CONCLUSIONS

In elite Australian Football a higher incidence of concussion was demonstrated in female compared to male players. The mechanisms associated with concussion were also found to differ between male and female competitions, suggesting that different injury prevention interventions may be beneficial. In particular, a review of tackling and bumping skills training and education in the AFLW may reduce the risk of concussion.

Evaluation of Quantitative Pupillometry in Acute Postinjury Pediatric Concussion

BACKGROUND

Although millions of children sustain concussions each year, a rapid and objective test for concussion has remained elusive. The aim of this study was to investigate quantitative pupillometry in pediatric patients in the acute, postinjury setting.

METHODS

This was a prospective case-control study of concussed patients presenting to the emergency department within 72 hours of injury. Pupillary measurements were gathered using NeurOptics' PLR 3000; evaluation included a symptom checklist and neurocognitive assessment. Data were analyzed using descriptive statistics and regression models.

RESULTS

A total of 126 participants were enrolled. One significant difference in pupillometry between concussed and control participants was found: left minimum pupil diameter in 12- to 18 year-olds (P = 0.02). Models demonstrating odds of a concussion revealed significant associations for time to 75% recovery (T75) of the left pupil in five- to 11-year-olds and average dilation velocity of the left pupil in 12- to 18-year-olds (P = 0.03 and 0.02 respectively). Models predicting symptom improvement showed one significant association: percent change of the right pupil in five-to-11-year-olds (P = 0.02). Models predicting neurocognitive improvement in 12- to 18-year-olds demonstrated significant association in T75 in the left pupil for visual memory, visual motor processing speed, and reaction time (P = 0.002, P = 0.04, P = 0.04).

CONCLUSIONS

The limited statistically significant associations found in this study suggest that pupillometry may not be useful in pediatrics in the acute postinjury setting for either the diagnosis of concussion or to stratify risk for prolonged recovery.

Comparison of Kinematics for Head Impacts Initiated by Helmets and Shoulder Pads Among High School American Football Athletes

Helmets and shoulder pads are required equipment intended to protect American football athletes by attenuating collision forces during participation. Surprisingly, research differentiating kinematics from head impacts initiated by helmets from those initiated by shoulder pads among adolescent athletes has not been completed. The current study's purpose was to determine the effects of equipment on head impact kinematics. Sixty-nine male American football athletes from three high schools wore helmets equipped with Head Impact Telemetry (HIT) System instrumentation to quantify peak linear (g) and rotational (rad/s2) accelerations. Data were extracted for video-confirmed impacts during two competitions. Separate multivariable linear regressions using ordinary least squares were conducted to determine if equipment type (helmet vs. shoulder pad) was associated with log-transformed linear and rotational accelerations. In total, 1150 video-confirmed impacts involved helmet (N = 960) or shoulder pad (N = 190) initiated contact. Linear (p = 0.809) and rotational (p = 0.351) acceleration were not associated with equipment type. Head impact kinematics were similar between impacts initiated by either helmets or shoulder pads and suggests an opponent's shoulder pads and helmet can deliver comparable forces to the struck player. Equipment manufacturers may need to consider the unintended role shoulder pads may contribute to head injury risk.

Efficacy of restitutive interventions for oculomotor deficits in adults with mild traumatic brain injury: a systematic review and meta-analysis

BACKGROUND

Mild traumatic brain injury (mTBI) can cause persistent symptoms suggestive of oculomotor deficits. This research synthesized evidence on restitutive interventions for reducing oculomotor deficits in adults with mTBI to understand if these interventions have clinical utility for improving recovery.

METHODS

Medline, EMBASE, CINHAL, PsychInfo, and Scopus, databases were searched for experimental studies published in English. We rated risk of bias (RoB) using recommended tools, and the certainty of the evidence according to GRADE guidelines. We conducted meta-analyses for similar outcomes reported in at least two studies.

RESULTS

Out of 5,328 citations, 12 studies (seven case series and five crossover design), with a combined sample size of 354 participants; (43% males) met the inclusion criteria and were analyzed. The analysis revealed a trend toward improvement of oculomotor deficits and visual tasks in response to restitutive intervention. None of the studies addressed sex or gender effects. All studies had high RoB, suggesting low certainty in the reported results.

DISCUSSION

Restitutive interventions may be beneficial for adults with oculomotor deficits after mTBI, however overall certainty of the evidence remains low. Future efforts must include enhancing attention to study methodology and reporting, sex and gender analyses, and reaching a consensus on outcome measures.

PROSPERO REGISTRATION NUMBER

CRD42022352276.

The Role of Puberty and Sex on Brain Structure in Adolescents With Anxiety Following Concussion

BACKGROUND

Adolescence represents a window of vulnerability for developing psychological symptoms following concussion, especially in girls. Concussion-related lesions in emotion regulation circuits may help explain these symptoms. However, the contribution of sex and pubertal maturation remains unclear. Using the neurite density index (NDI) in emotion regulation tracts (left/right cingulum bundle [CB], forceps minor [FMIN], and left/right uncinate fasciculus), we sought to elucidate these relationships.

METHODS

No adolescent had a history of anxiety and/or depression. The Screen for Child Anxiety Related Emotional Disorders and Children's Depression Rating Scale were used at scan to assess anxiety and depressive symptoms in 55 concussed adolescents (41.8% girls) and 50 control adolescents with no current/history of concussion (44% girls). We evaluated if a mediation-moderation model including the NDI (mediation) and sex or pubertal status (moderation) could help explain this relationship.

RESULTS

Relative to control adolescents, concussed adolescents showed higher anxiety (p = .003) and lower NDI, with those at more advanced pubertal maturation showing greater abnormalities in 4 clusters: the left CB frontal (p = .002), right CB frontal (p = .011), FMIN left-sided (p = .003), and FMIN right-sided (p = .003). Across all concussed adolescents, lower NDI in the left CB frontal and FMIN left-sided clusters partially mediated the association between concussion and anxiety, with the CB being specific to female adolescents. These effects did not explain depressive symptoms.

CONCLUSIONS

Our findings indicate that lower NDI in the CB and FMIN may help explain anxiety following concussion and that adolescents at more advanced (vs less advanced) status of pubertal maturation may be more vulnerable to concussion-related injuries, especially in girls.

Categorizing Sports-Related Concussion Disparities by Key Domains of Social Determinants of Health

PURPOSE OF REVIEW

To explore recently published data on disparities in concussion and best categorize these data into domains of social determinants of health (SDOH).

RECENT FINDINGS

Disparities in concussion cover a range of SDOH domains. Questions on disparities in concussion remain. Interventions to reduce these disparities and inequities are needed. Social determinants of health may play a significant role in disparities and inequities in sports related concussion. There is interplay and overlap in SDOH domains that affect concussion outcomes. It is possible that an increase in SDOH may affect concussion disparities by moderated mediation; however, further data is needed to validate this potential effect. Moreover, attention to SDOH domains in sports related concussion may provide insight on intervention targets to ameliorate disparities in sports related concussion.

Understanding the impact: an investigation into the National Brain Injury Awareness Week and public interest regarding concussion in Australia

OBJECTIVES

The purpose of this study is to analyze the relationship between the occurrence of the National Brain Injury Awareness Week and public interest in the concussion topic in Australia through an analysis of Internet search activity data from Google Trends.

STUDY DESIGN

Online retrospective observational study.

METHODS

For the keyword "concussion", the search interest rate over a period of 10 years between August 2012 and August 2022 within Australia has been analyzed using the Google Trends tool. The rising related topics that contributed to the months with the highest search interest were extracted for each year and a trendline analysis was performed to capture temporal patterns.

RESULTS

There was a significant difference in the average search interest between the month of August, when the Brain Injury Awareness Week is annually held, and the rest of the year (d = 0.09, p = 0.017). Also, May and August were the two months with the overall highest search interests (mean ± SD: 73.3 ± 5.16 and mean ± SD: 70.1 ± 5.49, respectively). Trendline analysis showed a positive slope of 0.3081 with R2 = 0.4462 for search interests of concussion over the 10-year period.

CONCLUSIONS

The data suggest that there is a growing interest and potential awareness of concussion in Australia that seems highly limited to the context of sports such as football, rugby, and soccer. Major sports events, news coverage, and media exposure appear to be associated with this trend. The study highlights the importance of more investment in producing engaging media content to educate the public on concussion of different causes and improving strategies for National Brain Injury Awareness Week.

A computational pipeline towards large-scale and multiscale modeling of traumatic axonal injury

Contemporary biomechanical modeling of traumatic brain injury (TBI) focuses on either the global brain as an organ or a representative tiny section of a single axon. In addition, while it is common for a global brain model to employ real-world impacts as input, axonal injury models have largely been limited to inputs of either tension or compression with assumed peak strain and strain rate. These major gaps between global and microscale modeling preclude a systematic and mechanistic investigation of how tissue strain from impact leads to downstream axonal damage throughout the white matter. In this study, a unique subject-specific multimodality dataset from a male ice-hockey player sustaining a diagnosed concussion is used to establish an efficient and scalable computational pipeline. It is then employed to derive voxelized brain deformation, maximum principal strains and white matter fiber strains, and finally, to produce diverse fiber strain profiles of various shapes in temporal history necessary for the development and application of a deep learning axonal injury model in the future. The pipeline employs a structured, voxelized representation of brain deformation with adjustable spatial resolution independent of model mesh resolution. The method can be easily extended to other head impacts or individuals. The framework established in this work is critical for enabling large-scale (i.e., across the entire white matter region, head impacts, and individuals) and multiscale (i.e., from organ to cell length scales) modeling for the investigation of traumatic axonal injury (TAI) triggering mechanisms. Ultimately, these efforts could enhance the assessment of concussion risks and design of protective headgear. Therefore, this work contributes to improved strategies for concussion detection, mitigation, and prevention.

Long-term effects of multiple concussions on prefrontal cortex oxygenation during a hypercapnic challenge in retired contact sport athletes

This exploratory study aimed to investigate the long-term effects of multiple concussions on prefrontal cortex oxygenation during a five-minute hypercapnic challenge using Near Infrared Spectroscopy (NIRS). 55 physically active retired contact sport male athletes with three or more previous concussions (mTBI) were recruited along with 29 physically active males with no concussions history (CTRL). Participants completed five minutes of seated rest prior to the five-minute hypercapnic challenge (20-second breath-hold, 40-second recovery breathing; five times). NIRS measured right and left side oxygenated (O2Hb), deoxygenated (HHb), total (tHb) haemoglobin, and haemoglobin difference (HbDiff) with all parameters analysed through changes in average maximal and minimal values (ΔMAX), Z-scores, and standard deviations. Right prefrontal cortex HbDiff ΔMAX was significantly higher in the mTBI compared to CTRL (p = 0.045) group. Left prefrontal cortex O2Hb ΔMAX (p = 0.040), HHb Z-Scores (p = 0.008), and HbDiff ΔMAX(p = 0.014) were significantly higher in the mTBI group. Within-group right vs left analyses demonstrated significantly lower left HbDiff ΔMAX (p = 0.048) and HbDiff Z-scores (p = 0.002) in the mTBI group, while the CTRL group had significantly lower left HHb Z-scores (p = 0.003) and left tHb Z-scores (p = 0.042). This study provides preliminary evidence that athletes with a history of three or more concussions may have impaired prefrontal cortex oxygenation parameters during a hypercapnic challenge.

A retrospective analysis of concussion and post-concussional syndrome diagnoses in Western Australian emergency departments

OBJECTIVE(S)

To determine the rate of concussion diagnoses per capita recorded in hospital emergency departments in Western Australia (WA) from 2002-2018 for ICD-10-AM concussion diagnoses S06.00-S06.05, and post-concussional syndrome (PCS) (F07.2).

DESIGN, SETTING AND ANALYSIS

Retrospective analysis of hospital Emergency Department (ED) presentations and hospital admissions from all WA hospitals for all patients with an ICD-10-AM diagnosis code for concussion and post-concussional syndrome (PCS) over the period 2002-2018. Data pertaining to concussion and PCS presentations were extracted from the WA Department of Health Emergency Department Data Collection (EDDC). Total case numbers were aggregated by year (2002-2018) and regions of WA.

MAIN OUTCOME MEASURES

The rates of diagnoses were calculated based on the population in the specific region and expressed as incidence rate per 100,000 person-years. The overall trends of diagnoses across the regions were analysed using negative binomial regression models and expressed as incidence rate ratio (IRR) with the corresponding 95 % CI, whilst adjusting for region. Tests for linearity were also performed.

RESULTS

The rate of concussion diagnosis had significantly increased linearly over the years (p for trend: p < 0.001) whilst the rate of PCS diagnosis had significantly declined linearly over the same period (p for trend: p < 0.001).

CONCLUSION

There was significant increase in all-cause ICD-10-AM concussion diagnoses in WA emergency departments. To further clarify the incidence and prevalence of all-cause concussion in Australia, investigation must focus on truly reflective S06.0 codes and include data linkage to primary care data. Conversely PCS ED presentations reduced; whether this relates to a change in where presentations occur for management of such a diagnosis, improved early intervention or an alternative explanation warrants further investigation.

Traumatic Brain Injury in Mice Generates Early-Stage Alzheimer's Disease Related Protein Pathology that Correlates with Neurobehavioral Deficits

Traumatic brain injury (TBI) increases the long-term risk of neurodegenerative diseases, including Alzheimer's disease (AD). Here, we demonstrate that protein variant pathology generated in brain tissue of an experimental TBI mouse model is similar to protein variant pathology observed during early stages of AD, and that subacute accumulation of AD associated variants of amyloid beta (Aβ) and tau in the TBI mouse model correlated with behavioral deficits. Male C57BL/6 mice were subjected to midline fluid percussion injury or to sham injury, after which sensorimotor function (rotarod, neurological severity score), cognitive deficit (novel object recognition), and affective deficits (elevated plus maze, forced swim task) were assessed post-injury (DPI). Protein pathology at 7, 14, and 28 DPI was measured in multiple brain regions using an immunostain panel of reagents selectively targeting different neurodegenerative disease-related variants of Aβ, tau, TDP-43, and alpha-synuclein. Overall, TBI resulted in sensorimotor deficits and accumulation of AD-related protein variant pathology near the impact site, both of which returned to sham levels by 14 DPI. Individual mice, however, showed persistent behavioral deficits and/or accumulation of toxic protein variants at 28 DPI. Behavioral outcomes of each mouse were correlated with levels of seven different protein variants in ten brain regions at specific DPI. Out of 21 significant correlations between protein variant levels and behavioral deficits, 18 were with variants of Aβ or tau. Correlations at 28 DPI were all between a single Aβ or tau variant, both of which are strongly associated with human AD cases. These data provide a direct mechanistic link between protein pathology resulting from TBI and the hallmarks of AD.

Mild Traumatic Brain Injury and Career Stage Associate with Visible Perivascular Spaces in Special Operations Forces Soldiers

Mild traumatic brain injury (mTBI) and occupational blast exposure in military Service Members may lead to impaired brain waste clearance which increases neurological disease risk. Perivascular spaces (PVS) are a key part of the glymphatic system which supports brain waste clearance, preferentially during sleep. Visible PVS on clinical magnetic resonance imaging have been previously observed in patients with neurodegenerative diseases and animal neurotrauma models. The purpose of this study was to determine associations between PVS morphological characteristics, military career stage, and mTBI history in Special Operations Forces (SOF) Soldiers. Participants underwent T2-weighed neuroimaging to capture three-dimensional whole brain volumes. Segmentation was performed using a previously validated, multi-scale deep convolutional encoder-decoder neural network. Only PVS clusters within the white matter mask were quantified for analyses. Due to non-normal PVS metric distribution, non-parametric Mann-Whitney U tests were used to determine group differences in PVS outcomes. In total, 223 healthy SOF combat Soldiers (age = 33.1 ± 4.3yrs) were included, 217 reported career stage. Soldiers with mTBI history had greater PVS number (z = 2.51, P = 0.013) and PVS volume (z = 2.42, P = 0.016). In-career SOF combat Soldiers had greater PVS number (z = 2.56, P = 0.01) and PVS volume (z = 2.28, P = 0.02) compared to a baseline cohort. Mild TBI history is associated with increased PVS burden in SOF combat Soldiers that are clinically recovered from mTBI. This may indicate ongoing physiological changes that could lead to impaired waste clearance via the glymphatic system. Future studies should determine if PVS number and volume are meaningful neurobiological outcomes for neurodegenerative disease risk and if clinical interventions such as improving sleep can reduce PVS burden.

Experienced Clinical Decision Making in Physical Therapist Management of Concussion: A Qualitative Study

OBJECTIVE

The recent publication of the Physical Therapy Evaluation and Treatment After Concussion Clinical Practice Guideline is intended to assist clinicians in their decision making specific to evaluation and intervention. Clinical practice guidelines are supported by best available evidence, though it is unknown what other factors drive clinical decision making in the realm of concussion management. The purpose of this study was to explore factors related to the process of clinical decision making of experienced physical therapists who treat individuals with concussion.

METHODS

This grounded theory approach utilized semi-structured interviews of physical therapists who have practiced concussion management ≥3 years and have treated ≥15 individuals for post-concussion symptoms in the last year. Following the inductive approach, deductive qualitative methodology was utilized to explore alignment with recent guidelines. Member checking was used to ensure trustworthiness.

RESULTS

Ten therapists' experience in treating concussion ranged from 5 to 20 years. Four overarching themes were identified that contribute to clinical decision making: expert practice behaviors through use of reflection in action, clinical reasoning, collaboration, and evidenced informed practice; therapeutic alliance building using individualized education, reassurance, and relationship building; adaptability in prioritizing, assessing, and responding to patient's needs; and listening and observing. Clinician decision making statements showed alignment with clinical practice guideline recommendations.

CONCLUSIONS

Experienced therapists demonstrate a consistent approach that parallels the current clinical practice guideline while building off clinical experience to tailor individualized care focusing on patient centeredness. These factors may assist more novice clinicians to develop and improve their management strategies for optimal outcomes.

IMPACT

Identified themes may broaden frameworks and guidelines for the management of individuals post-concussion specific to the field of physical therapy.

Neurocognitive Concussion Test Performance for Student Athletes on the Autism Spectrum

OBJECTIVE

To examine baseline neurocognitive functioning among adolescent athletes on the autism spectrum based on self-reported level of academic performance.

METHOD

Participants in this cross-sectional, observational study were 6,441 adolescent athletes with a self-reported diagnosis of autism who completed pre-season neurocognitive testing using Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT); 4,742 reported a co-occurring learning disorder (LD), and 6,612 individuals without autism or LD were included as a control group. The majority (57%) self-reported Average Academic Performance, 39% Above Average, and 4% Below Average performance.

RESULTS

Athletes with self-reported autism (with or without LD; 12.2%) were 2.74x (95% CI: 2.17-2.82) more likely to fall below cutoffs for ImPACT Embedded Invalidity Indicators (EVIs), with a significant interaction between self-reported Diagnosis and Academic Performance; individuals with co-occurring autism and LD who reported Below Average Academic Performance had the greatest likelihood of scoring below cutoffs (22%), followed by ASD without LD (14.8%) and Controls (14.6%) with Below Average Academic Performance. Analyses of variance (ANOVAs) revealed main effects of Diagnosis and Academic Performance on neurocognitive performance, with interactions on all ImPACT Composite Scores except Processing Speed.

CONCLUSION

Athletes with self-reported ASD are more likely to fall below ImPACT EVIs and score worse on ImPACT, with greater likelihood/worse performance related to level of academic functioning. Academic performance should be considered when interpreting neurocognitive testing data, to best index neuropsychological functioning associated with concussion in this population. The current findings highlight the importance of individual participant baseline neuropsychological testing for individuals on the autism spectrum.

Assault-related traumatic brain injury hospitalizations in Canada from 2010 to 2021: rates, trends and comorbidity

BACKGROUND

Traumatic brain injury (TBI) is a major cause of morbidity and mortality globally. TBI is often associated with other physical or psychological issues resulting in high hospitalization costs. TBI incidence and recovery can vary with the external cause being intentional or unintentional. It is important to monitor the rates of TBI hospitalizations related to different external causes. This study examined the annual rate, comorbidity and length of stay associated with assault-related TBI hospitalizations and compare it with other external causes, by age and sex in Canada from 2010 to 2021.

METHODS

Discharge Abstract Database was used to extract cases of TBI (2010-2021). ICD-10-CA codes were used to classify all cases with TBI as per assault and other external causes (falls; transport; sport, physical activity and recreation; struck by). Additional variables, including age, sex, comorbidity and length of stay, were examined. Time trends were quantified using Joinpoint regression.

RESULTS

The average annual percent increase for all TBI hospitalizations from 2010 to 2021 was not significant at 0.1%. Females accounted for 35.8% of these TBI hospitalizations. From 2010 to 2021, assault-related TBI hospitalizations showed a significant annual decline of 4.1% for males and a significant increase of 1.2% for females. Increase in TBI hospitalizations related to falls showed an average annual percent increase of 1.4% for males and 2.2% for females. A significant decrease was observed for TBI hospitalizations related to the other three (transport, SPAR and struck by) external causes for both sexes from 2010 to 2021. Infants and children under 10 years of age had higher percentages of cases with comorbidities and higher length of stay for assault-related TBI hospitalizations.

CONCLUSIONS

Assault-related TBI hospitalization rates decreased overall and among males, rates among females increased from 2010 to 2021. These results underscore the importance of targeted prevention efforts for TBI related to different external causes, age and sex, and continued surveillance to monitor the epidemiology of assault-related TBI.

Are Tai Chi and Qigong effective in the treatment of traumatic brain injury? A systematic review

BACKGROUND

Traumatic brain injury (TBI) adversely affects both young and old and is a growing public health concern. The common functional, psychological, and cognitive changes associated with TBI and recent trends in its management, such as recommending sub-threshold aerobic activity, and multi-modal treatment strategies including vestibular rehabilitation, suggest that Tai Chi/Qigong could be beneficial for TBI. Tai Chi and Qigong are aerobic mind-body practices with known benefits for maintaining health and mitigating chronic disease. To date, no systematic review has been published assessing the safety and effectiveness of Tai Chi/Qigong for traumatic injury.

METHODS

The following databases were searched: MEDLINE, CINAHL Cochrane Library, Embase, China National Knowledge Infrastructure Database, Wanfang Database, Chinese Scientific Journal Database, and Chinese Biomedical Literature Database. All people with mild, moderate, or severe TBI who were inpatients or outpatients were included. All Types of Tai Chi and Qigong, and all comparators, were included. All measured outcomes were included. A priori, we chose "return to usual activities" as the primary outcome measure as it was patient-oriented. Cochrane-based risk of bias assessments were conducted on all included trials. Quality of evidence was assessed using the grading of recommendation, assessment, development, and evaluation (GRADE) system.

RESULTS

Five trials were assessed; three randomized controlled trials (RCTs) and two non-RCTs; only two trials were conducted in the last 5 years. No trial measured "return to normal activities" or vestibular status as an outcome. Four trials - two RCTs and two non-RCTS - all found Tai Chi improved functional, psychological and/or cognitive outcomes. One RCT had a low risk of bias and a high level of certainty; one had some concerns. One non-RCTs had a moderate risk of bias and the other a serious risk of bias. The one Qigong RCT found improved psychological outcomes. It had a low risk of bias and a moderate level of certainty. Only one trial reported on adverse events and found that none were experienced by either the exercise or control group.

CONCLUSION

Based on the consistent finding of benefit in the four Tai Chi trials, including one RCT that had a high level of certainty, there is a sufficient signal to merit conducting a large, high quality multi-centre trial on Tai Chi for TBI and test it against current trends in TBI management. Based on the one RCT on TBI and Qigong, an additional confirmatory RCT is indicated. Further research is indicated that reflects current management strategies and includes adverse event documentation in both the intervention and control groups. However, these findings suggest that, in addition to Tai Chi's known health promotion and chronic disease mitigation benefits, its use for the treatment of injury, such as TBI, is potentially a new frontier.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO [ CRD42022364385 ].

Sleep loss, caffeine, sleep aids and sedation modify brain abnormalities of mild traumatic brain injury

Little evidence exists about how mild traumatic brain injury (mTBI) is affected by commonly encountered exposures of sleep loss, sleep aids, and caffeine that might be potential therapeutic opportunities. In addition, while propofol sedation is administered in severe TBI, its potential utility in mild TBI is unclear. Each of these exposures is known to have pronounced effects on cerebral metabolism and blood flow and neurochemistry. We hypothesized that they each interact with cerebral metabolic dynamics post-injury and change the subclinical characteristics of mTBI. MTBI in rats was produced by head rotational acceleration injury that mimics the biomechanics of human mTBI. Three mTBIs spaced 48 h apart were used to increase the likelihood that vulnerabilities induced by repeated mTBI would be manifested without clinically relevant structural damage. After the third mTBI, rats were immediately sleep deprived or administered caffeine or suvorexant (an orexin antagonist and sleep aid) for the next 24 h or administered propofol for 5 h. Resting state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI) were performed 24 h after the third mTBI and again after 30 days to determine changes to the brain mTBI phenotype. Multi-modal analyses on brain regions of interest included measures of functional connectivity and regional homogeneity from rs-fMRI, and mean diffusivity (MD) and fractional anisotropy (FA) from DTI. Each intervention changed the mTBI profile of subclinical effects that presumably underlie healing, compensation, damage, and plasticity. Sleep loss during the acute post-injury period resulted in dramatic changes to functional connectivity. Caffeine, propofol sedation and suvorexant were especially noteworthy for differential effects on microstructure in gray and white matter regions after mTBI. The present results indicate that commonplace exposures and short-term sedation alter the subclinical manifestations of repeated mTBI and therefore likely play roles in symptomatology and vulnerability to damage by repeated mTBI.

Capturing Head Impacts in Boxing: A Video-Based Comparison of Three Wearable Sensors

Wearable sensors are used to quantify head impacts in athletes, but recent work has shown that the number of events recorded may not be accurate. This study aimed to compare the number of head acceleration events recorded by three wearable sensors during boxing and assess how impact type and location affect the triggering of acceleration events. Seven boxers were equipped with an instrumented mouthguard, a skin patch, and a headgear patch. Contacts to participants' heads were identified via three video cameras over 115 sparring rounds. The resulting 5168 video-identified events were used as reference to quantify the sensitivity, specificity, and positive predictive value (PPV) of the sensors. The mouthguard, skin patch, and headgear patch recorded 695, 1579, and 1690 events, respectively, yielding sensitivities of 35%, 86%, and 78%, respectively, and specificities of 90%, 76%, and 75%, respectively. The mouthguard, skin patch, and headgear patch yielded 693, 1571, and 1681 true-positive events, respectively, leading to PPVs for head impacts over 96%. All three sensors were more likely to be triggered by punches landing near the sensor and cleanly on the head, although the mouthguard's sensitivity to impact location varied less than the patches. While the use of head impact sensors for assessing injury risks remains uncertain, this study provides valuable insights into the capabilities and limitations of these sensors in capturing video-verified head impact events.

The Convergent Validity of the SWAY Balance Application to Assess Postural Stability in Military Cadets Recovering from Concussion

Background

Concussions are often accompanied by balance disturbances. Clinically accurate evaluation systems are often expensive, large, and inaccessible to most clinicians. The Sway Balance Mobile Application (SWAY) is an accessible method to quantify balance changes.

Purpose

To determine the known groups and convergent validity of the SWAY to assess balance after a concussion.

Study Design

Case-Control Study.

Methods

Twenty participants with acute concussion and twenty controls were recruited. At initial, one-week, and final return to activity (RTA) evaluations, all participants completed the Sports Concussion Assessment Tool (SCAT-5), and balance control measured by SWAY mBESS and NeuroCom Balance Master Sensory Organization Test (SOT). Mixed model ANOVAs were used to detect differences in SWAY mBESS and NeuroCom SOT scores with time (initial, one-week, final RTA) as the within-subjects factor and group (concussed, healthy) as the between-subjects factor. Spearman's Rho correlations explored the associations between NeuroCom SOT scores, SWAY scores, SCAT-5 symptom scores, and time in days to final RTA.

Results

The sampled population was predominantly male and age (20 ± 1), and BMI differences were insignificant between groups. The SWAY did not detect differences between healthy and concussed participants and did not detect change over time [F(2,40) = .114, p = 0.89; F(2,40)= .276, p =0.60]. When assessing the relationship between the SWAY and the SOT, no correlation was found at any time point (r = -0.317 to -0.062, p > 0.05). Time to RTA demonstrated a moderate correlation with both SCAT-5 symptom severity score (r = .693, p < 0.01) and SCAT-5 total symptom score (r = .611, p < 0.01) at the one-week follow-up.

Conclusion

The SWAY mBESS does not appear to be a valid balance assessment for the concussed patient. The SWAY mBESS in patients with concussion failed to demonstrate convergent validity and did not demonstrate an ability to validate known groups. When assessing the time to final RTA, the one-week post-initial assessment SCAT-5 symptom severity and total scores may help determine the length of recovery in this population.

Level of Evidence

Level 3.

Corpus Callosal Hematoma by a Trivial Trauma Causing Concussion with "Blood at the Center" Radiological Sign

Hematoma of corpus callosum is a very rare phenomenon and is caused by severe trauma to head. Most common traumatic injury to corpus callosum is seen in diffuse axonal injury in form of small hemorrhagic foci and associated prolonged unconsciousness. Trivial trauma causing well defined corpus callosal hematoma in absence of coagulation defects or neurological deficits in conscious patient has not been reported in the literature. We present such a unique case and the review the corpus callosal hematoma due to trauma.

Symptoms and Engagement in Anti-social Behavior 10 Years After Mild Traumatic Brain Injury Within a Community Civilian Sample: A Prospective Cohort Study With Age-Sex Matched Control Group

OBJECTIVE

To determine if there are longer-term effects on symptoms, health status, mood, and behavior 10 years after a mild traumatic brain injury (mTBI).

DESIGN

Prospective cohort study.

SETTING

Community-based, civilian sample.

PARTICIPANTS

Adults aged ≥16 years at follow-up who experienced an mTBI 10 years ago, and an age and sex-matched non-injured control group.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

mTBI cases and controls were asked to complete self-report assessments of functioning (WHO Disability Assessment Schedule Version 2), symptoms (Rivermead Post-Concussion Symptom Questionnaire), health status (100-point scale), alcohol (Alcohol Use Disorders Identification Test) and substance use (Alcohol, Smoking and Substance Involvement Screening Test), and whether they had engaged in any anti-social behaviors over the past 12 months.

RESULTS

Data were analyzed for 368 participants (184 mTBI cases and 184 age-sex matched controls). Just over a third of mTBI cases (64, 34.8%) reported that they were still affected by their index mTBI 10 years later. After adjusting for education and ethnicity, the mTBI group had statistically higher overall symptom burden (F=22.32, P<.001, ηp2=0.07) compared with controls. This difference remained after excluding those who experienced a recurrent TBI. The mTBI group were more than 3 times as likely to have engaged in anti-social behavior during the previous 12 months (F=5.89, P=.02). There were no group differences in health status, functioning, or problematic alcohol or substance use 10 years post-injury.

CONCLUSIONS

This study provides evidence of potential longer-term associations between mTBI, post-concussion symptoms, and anti-social behavior which warrants further evaluation. Future research should also examine if longer-term effects may be preventable with access to early rehabilitation post-injury.

Stunt performers' reluctance to self-report head trauma: a qualitative study

BACKGROUND

Mild traumatic brain injuries receive voluminous attention in the research literature, but this is confined almost entirely to sports and military contexts. As an occupation, performing stunts in film, television, and entertainment places the head at high risk of repetitive impact and whiplash, but stunt performers do not enjoy the same level of healthcare supervision and access as that provided to sports participants. Therefore, the aim of this study was to evaluate stunt performers' qualitative perceptions of reporting and management of head trauma in their industry.

METHODS

After giving their informed consent, 87 motion picture and television stunt performers responded to a query about their views of ways to improve how stunt performers' occupational head trauma-specifically head impacts and head whips that could cause a concussion-are reported and managed. We analyzed their responses via content and thematic analyses. Two researchers independently marked and categorized key words, phrases, and texts to identify codes that described participants' comments. They then revised, discussed, and resolved coding discrepancies through consensus to establish inter-coder reliability. Next, we identified thematic patterns that described participants' understanding of the stunt performer industry and what must change to facilitate reporting of head trauma. We derived themes from data that occurred multiple times, both within and across short answer responses.

RESULTS

We identified three primary themes cited by the stunt performers as needs in their industry: (1) Need to Reduce the Stigma of Reporting a Stunt-Related Injury, (2) Need to Eliminate the "Cowboy Culture," and (3) Need to Improve the Quality of the Work Environment.

CONCLUSIONS

Stunt performers are crucial members of a global entertainment industry valued at approximately US$100 billion annually. A large segment of the world's population consumes their work in motion pictures, television, and live entertainment. When they are given an anonymous opportunity to speak, stunt performers offer insight into and recommendations for industry changes-primarily cultural and educational in nature-that could improve their physical and mental health, career longevity, and employability when they are confronted with head trauma.

Head Exposure to Acceleration Database in Sport (HEADSport): a kinematic signal processing method to enable instrumented mouthguard (iMG) field-based inter-study comparisons

Objective

Instrumented mouthguard (iMG) systems use different signal processing approaches limiting field-based inter-study comparisons, especially when artefacts are present in the signal. The objective of this study was to assess the frequency content and characteristics of head kinematic signals from head impact reconstruction laboratory and field-based environments to develop an artefact attenuation filtering method (HEADSport filter method).

Methods

Laboratory impacts (n=72) on a test-dummy headform ranging from 25 to 150 g were conducted and 126 rugby union players were equipped with iMGs for 209 player-matches. Power spectral density (PSD) characteristics of the laboratory impacts and on-field head acceleration events (HAEs) (n=5694) such as the 95th percentile cumulative sum PSD frequency were used to develop the HEADSport method. The HEADSport filter method was compared with two other common filtering approaches (Butterworth-200Hz and CFC180 filter) through signal-to-noise ratio (SNR) and mixed linear effects models for laboratory and on-field events, respectively.

Results

The HEADSport filter method produced marginally higher SNR than the Butterworth-200Hz and CFC180 filter and on-field peak linear acceleration (PLA) and peak angular acceleration (PAA) values within the magnitude range tested in the laboratory. Median PLA and PAA (and outlier values) were higher for the CFC180 filter than the Butterworth-200Hz and HEADSport filter method (p<0.01).

Conclusion

The HEADSport filter method could enable iMG field-based inter-study comparisons and is openly available at https://github.com/GTBiomech/HEADSport-Filter-Method.

Publicly available data sources in sport-related concussion research: a caution for missing data

BACKGROUND

Researchers often use publicly available data sources to describe injuries occurring in professional athletes, developing and testing hypotheses regarding athletic-related injury. It is reasonable to question whether publicly available data sources accurately indicate athletic-related injuries resulting from professional sport participation. We compared sport-related concussion (SRC) clinical incidence using data from publicly available sources to a recent publication reporting SRC using electronic health records (EHR) from the National Football League (NFL). We hypothesize publicly available data sources will underrepresent SRC in the NFL. We obtained SRCs reported from two publicly available data sources (NFL.com, pro-football-reference.com) and data reported from the NFL's published EHR. We computed SRC per 100 unique player signings from 2015-2019 and compared the clinical incidence from publicly available data sources to EHR rates using clinical incidence ratios (CIR) and 95% confidence intervals (CI).

FINDINGS

From 2015-2019, SRC counts from published EHR record data ranged from 135-192 during the regular season, whereas SRC counts ranged from 102-194 and 69-202 depending on the publicly available data source. In NFL.com the SRC clinical incidence was significantly and progressively lower in 2017 (CIR: 0.73, 95% CI: 0.58-0.91), 2018 (CIR: 0.66, 95% CI: 0.50-0.87), and 2019 (CIR: 0.48, 95% CI: 0.35-0.64) relative to the gold-standard EHR. In the pro-football-reference.com data, the documented SRCs in publicly available data sources for other years were ~ 20-30% lower than the gold-standard EHR numbers (CIRs 0.70-0.81).

CONCLUSIONS

Publicly available data for SRCs per 100 unique player signings did not match published data from the NFL's EHR and in several years were significantly lower. Researchers should use caution before using publicly available data sources for injury research.

Early targeted heart rate exercise is safe and May hasten return-to-duty in service members with acute concussion, a preliminary study

OBJECTIVE

To evaluate the feasibility of an exercise tolerance assessment and intervention added to the Progressive Return to Activity Clinical Recommendations (PRA-CR) in acutely concussed service members (SMs).

METHODS

This non-randomized, pilot trial was performed at one center. SMs in the experimental group (ERG) performed the Buffalo Concussion March-in-place Test (BCMT) at every clinic visit and were prescribed at least 20 minutes/day of targeted exercise in addition to PRA-CR. Data for the control group (SCG) were extracted from the same clinic immediately prior to ERG. SMs in both groups were assessed by the same clinician to determine return-to-duty.

RESULTS

BCMT identified concussion-related exercise intolerance in 100% (n = 14) at screening visit (mean 3.4 days after injury) and in 0% (n = 7) who had recovered. No adverse effects were associated with BCMT. The estimated recovery time for ERG who performed the exercise intervention (n = 12) was 17.0 (12.8, 21.2) days and for SCG (n = 15) was 23.7 (19.9, 27.5) days (p = 0.039).

CONCLUSION

Assessment of exercise tolerance was feasible and could be incorporated into the PRA-CR. Future definitive, randomized controlled trials should be performed to assess the effectiveness of exercise reset program for SMs after concussion.

Are there seasonal patterns for emergency department visits for head injuries in the USA? Findings from the National Electronic Injury Surveillance System-All Injury Program

INTRODUCTION

Previous international research suggests that the incidence of head injuries may follow seasonal patterns. However, there is limited information about how the numbers and rates of head injuries, particularly sports- and recreation-related head injuries, among adults and children evaluated in the emergency department (ED) vary by month in the USA. This information would provide the opportunity for tailored prevention strategies.

METHODS

We analysed data from the National Electronic Injury Surveillance System-All Injury Program from 2016 to 2019 to examine both monthly variation of ED visit numbers and rates for head injuries overall and those due to sports and recreation.

RESULTS

The highest number of head injuries evaluated in the ED occurred in October while the lowest number occurred in February. Among males, children ages 0-4 years were responsible for the highest rates of head injury-related ED visits each year, while in females the highest rates were seen in both children ages 0-4 and adults ages 65 and older. The highest number of head injuries evaluated in the ED due to sports and recreation were seen in September and October. Head injury-related ED visits due to sports and recreation were much more common in individuals ages 5-17 than any other age group.

CONCLUSION

This study showed that head injury-related ED visits for all mechanisms of injury, as well as those due to sports- and recreation-related activities, followed predictable patterns-peaking in the fall months. Public health professionals may use study findings to improve prevention efforts and to optimise the diagnosis and management of traumatic brain injury and other head injuries.

Reliable Change Indices for the Serial Administration of the Concussion Clinical Profiles Screening Tool

CONTEXT

The Concussion Clinical Profile Screening Tool (CP Screen) self-report concussion symptom inventory that is often administered at weekly intervals. However, 1-week reliable change indices (RCI) for clinical cutoffs and the test-retest reliability of the CP Screen is unknown.

OBJECTIVE

Document RCI cutoff scores and 1-week test-retest reliability for each profile and modifier of the CP Screen for males and females.

DESIGN

Case Series.

SETTING

A large US university.

PATIENTS OR OTHER PARTICIPANTS

173 healthy college students.

MAIN OUTCOME MEASURE(S)

Participants completed two administrations of the CP Screen 7 days apart; CP Screen items yield five clinical profiles and two modifiers. Spearman rho coefficients (rs), intraclass correlation coefficients (ICCs) single measures and Unbiased Estimates of Reliability (UER) were used to assess test-retest reliability. Wilcoxon signed-rank tests assessed differences across time. RCI values and cutoff scores are provided at 90%/95% confidence intervals (CI). All analyses were performed for the total sample and separately for males and females.

RESULTS

RCI cutoffs for clinically significant change (increase/decrease) at a 90% CI for males were as follows: Ocular, Vestibular >2/>4, Anxiety/Mood, Cognitive/Fatigue, Migraine>3/>3, Sleep >4/>6, and Neck>2/>2. RCI cutoffs for clinically significant change (increase/decrease) at a 90% CI for females were as follows: Anxiety/Mood≥2/≥4; Cognitive/Fatigue, Migraine, Ocular, Vestibular, Sleep≥3/≥3; and Neck≥1/≥1. Correlations for CP ranged from .51 (Migraine) to .79 (Anxiety/Mood) for the total sample, .48 (Migraine) to .84 (Vestibular) for males, and .51 (Migraine) to .77 (Ocular) for females. Test-retest indices for each profile and modifier were moderate to good for the total sample (ICC: .64-.82; UER: .79-.90), males (ICC: .60-.87; UER: .76-.94), and females (ICC: .64-.80; UER: .78-.89).

CONCLUSION

The CP Screen is reliable and stable across a 1-week interval, and established RCIs for males and females can help identify meaningful change throughout recovery.

Integrative data analysis to identify persistent post-concussion deficits and subsequent musculoskeletal injury risk: project structure and methods

Concussions are a serious public health problem, with significant healthcare costs and risks. One of the most serious complications of concussions is an increased risk of subsequent musculoskeletal injuries (MSKI). However, there is currently no reliable way to identify which individuals are at highest risk for post-concussion MSKIs. This study proposes a novel data analysis strategy for developing a clinically feasible risk score for post-concussion MSKIs in student-athletes. The data set consists of one-time tests (eg, mental health questionnaires), relevant information on demographics, health history (including details regarding the concussion such as day of the year and time lost) and athletic participation (current sport and contact level) that were collected at a single time point as well as multiple time points (baseline and follow-up time points after the concussion) of the clinical assessments (ie, cognitive, postural stability, reaction time and vestibular and ocular motor testing). The follow-up time point measurements were treated as individual variables and as differences from the baseline. Our approach used a weight-of-evidence (WoE) transformation to handle missing data and variable heterogeneity and machine learning methods for variable selection and model fitting. We applied a training-testing sample splitting scheme and performed variable preprocessing with the WoE transformation. Then, machine learning methods were applied to predict the MSKI indicator prediction, thereby constructing a composite risk score for the training-testing sample. This methodology demonstrates the potential of using machine learning methods to improve the accuracy and interpretability of risk scores for MSKI.

The prevalence and correlates of scores falling below ImPACT embedded validity indicators among adolescent student athletes

Objective: Valid performance on preseason baseline neurocognitive testing is essential for accurate comparison between preseason and post-concussion test results. Immediate Post-Concussion and Cognitive Testing (ImPACT) is commonly used to measure baseline neurocognitive function in athletes. We examined the prevalence of invalid performance on ImPACT baseline testing and identified correlates of invalid performance. Method: The sample included 66,998 adolescents (ages 14-18, M = 15.51 years, SD = 1.22) who completed ImPACT baseline tests between 2009 and 2019. Invalid performance was determined by the embedded validity indicators (EVI). Associations between invalid performance, demographic characteristics, and health conditions were assessed using chi-square tests and odds ratios (ORs). Results: Overall, 7.2% of adolescents had baseline tests identified as invalid by one or more of the EVIs. Individual validity indicators classified between 0.5% and 3.7% tests as invalid. Higher frequencies of invalid scores were observed among youth with neurodevelopmental, academic, and medical conditions. Youth who reported having learning disabilities (n = 3126), receiving special education (n = 3563), or problems with attention-deficit/hyperactivity disorder (ADHD; n = 5104) obtained invalid baselines at frequencies of 16.4%, 16.0%, and 11.1%, respectively. Moreover, youth who reported receiving treatment for a substance use disorder (n = 311) or epilepsy (n = 718) obtained invalid baselines at frequencies of 17.0% and 11.1%, respectively. Conclusions: The base rate of invalid performance on ImPACT's EVIs was approximately 7%, consistent with prior research. Adolescents self-reporting neurodevelopmental conditions, academic difficulties, or a history of treatment for medical conditions obtained invalid baseline tests at higher frequencies. More research is needed to better understand invalid scores in youth with pre-existing conditions.

Serum calcitonin gene-related peptide in patients with persistent post-concussion symptoms, including headache: a cohort study

BACKGROUND

Calcitonin gene-related peptide (CGRP) plays an important role in migraine pathophysiology, and post-traumatic headache (PTH) frequently presents with migraine-like features. Despite several clinical similarities, few studies have explored CGRP in PTH and concussion. This study investigates serum CGRP levels in patients with persistent post-concussion symptoms (PPCS), including PTH.

METHODS

This cohort study was based on serum samples from individuals aged 18-30 years with PPCS who participated in a previously published randomized controlled trial of a non-pharmacological intervention. The primary outcome was serum CGRP concentrations, determined at baseline before randomization and at follow-up 7 months later, using an enzyme-linked immunosorbent assay (ELISA). CGRP levels at baseline were compared with healthy anonymous blood donors in the same age group.

RESULTS

Baseline serum samples were collected from 86 participants with PPCS. The participants were most often female (78%) and migraine-like headache was the most frequent headache phenotype (74%). Serum CGRP levels were higher in participants with PPCS than in 120 healthy individuals (median: 158.5 pg/mL vs. 76.3 pg/mL, p = 0.050). A stratified analysis revealed that females with PPCS had a fivefold higher median than healthy females (166.3 pg/mL vs. 32.1 pg/mL, p = 0.0006), while no differences were observed in males (p = 0.83). At follow-up, CGRP levels decreased with a median change of  - 1.3 pg/mL (95% confidence interval:  - 17.6-0, p = 0.024).

DISCUSSION

Elevated serum levels of CGRP in patients with PPCS and a decrease over time suggest an involvement of CGRP in PTH/PPCS. If confirmed in other studies, it could pave the way for CGRP-targeted therapies, which could have clinical significance.

Disrupted Maturation of White Matter Microstructure After Concussion Is Associated With Internalizing Behavior Scores in Female Children

BACKGROUND

Some children who experience concussions, particularly females, develop long-lasting emotional and behavioral problems. Establishing the potential contribution of preexisting behavioral problems and disrupted white matter maturation has been challenging due to a lack of preinjury data.

METHODS

From the Adolescent Brain Cognitive Development cohort, 239 (90 female) children age 12.1 ± 0.6 years who experienced a concussion after study entry at 10.0 ± 0.6 years were compared to 6438 (3245 female) children without head injuries who were age 9.9 ± 0.6 years at baseline and 12.0 ± 0.6 years at follow-up. The Child Behavior Checklist was used to assess internalizing and externalizing behavior at study entry and follow-up. In the children with magnetic resonance imaging data available (concussion n = 134, comparison n = 3520), deep and superficial white matter was characterized by neurite density from restriction spectrum image modeling of diffusion magnetic resonance imaging. Longitudinal ComBat harmonization removed scanner effects. Linear regressions modeled 1) behavior problems at follow-up controlling for baseline behavior, 2) impact of concussion on white matter maturation, and 3) contribution of deviations in white matter maturation to postconcussion behavior problems.

RESULTS

Only female children with concussion had higher internalizing behavior problem scores. The youngest children with concussion showed less change in superficial white matter neurite density over 2 years than children with no concussion. In females with concussion, less change in superficial white matter neurite density was correlated with increased internalizing behavior problem scores.

CONCLUSIONS

Concussions in female children are associated with emotional problems beyond preinjury levels. Injury to superficial white matter may contribute to persistent internalizing behavior problems in females.

Symptom Attribution and Neuropsychological Outcomes Among Treatment-Seeking Veterans With a History of Traumatic Brain Injury

OBJECTIVE

In this cross-sectional study, the authors aimed to examine relationships between illness perception, measured as symptom attribution, and neurobehavioral and neurocognitive outcomes among veterans with a history of traumatic brain injury (TBI).

METHODS

This study included 55 treatment-seeking veterans (N=43 with adequate performance validity testing) with a remote history of TBI (80% with mild TBI). Veterans completed a clinical interview, self-report questionnaires, and a neuropsychological assessment. A modified version of the Neurobehavioral Symptom Inventory (NSI) was administered to assess neurobehavioral symptom endorsement and symptom attribution. Composite scores were calculated from standardized cognitive tests to assess specific aspects of objective cognitive functioning, including memory, executive functioning, attention and working memory, and processing speed.

RESULTS

The symptoms most frequently attributed to TBI included forgetfulness, poor concentration, slowed thinking, and headaches. There was a significant positive association between symptom attribution and overall symptom endorsement (NSI total score) (r=0.675) and endorsement of specific symptom domains (NSI symptom domain scores) (r=0.506-0.674), indicating that greater attribution of symptoms to TBI was associated with greater symptom endorsement. Furthermore, linear regressions showed that symptom attribution was significantly associated with objective cognitive functioning, whereas symptom endorsement generally did not show this relationship. Specifically, greater attribution of symptoms to TBI was associated with worse executive functioning (β=-0.34), attention and working memory (β=-0.43), and processing speed (β=-0.35).

CONCLUSIONS

These findings suggest that veterans who routinely attribute neurobehavioral symptoms to their TBI are at greater risk of experiencing poor long-term outcomes, including elevated symptom endorsement and worse objective cognition. Although more research is needed to understand how illness perception influences outcomes in this population, these preliminary results highlight the importance of early psychoeducation regarding the anticipated course of recovery following TBI.

Impact of Concussions on Postural Stability Performance Using the Head Shake-Sensory Organization Test

Background

A concussion is a traumatic brain injury that can result in vestibular and oculomotor dysfunctions. The Head Shake-Sensory Organization Test was developed from the original Sensory Organization Test to measure a subject's ability to maintain balance while moving their head.

Purpose

The purpose of this study was to compare the performance of adults with no history of concussion to those with a history of concussion on the Head Shake-Sensory Organization Test to determine if long-standing balance deficits are present after concussion.

Study Design

Cross-sectional study.

Methods

Subjects with a history of concussion and healthy normal controls completed the Dizziness Handicap Inventory, the Activities-Specific Balance Confidence Scale, the sensory organization test, the head shake SOT, and the Foam Head Shake-Sensory Organization test in a single testing session. Scores were analyzed for differences between the two groups.

Results

Twenty-five participants (nine patients with history of concussion and 16 healthy controls; mean age, 21.08±4.10 years) completed testing. The equilibrium scores in both groups significantly decreased with more complex tasks. Furthermore, the concussion group had significantly worse equilibrium scores than the control group during the Head Shake (p = 0.007) and Foam Head Shake-Sensory Organization Test (p = 0.002) tasks but not during the Sensory Organization Test task.

Conclusion

Adding head shake and foam cushion conditions to postural stability tests improves sensitivity in detecting balance deficits in individuals with a concussion.

Level of Evidence

3.

Post-traumatic headache pathophysiology in paediatric concussion: A systematic review

Post-traumatic headache (PTH) represents the most common acute and persistent symptom following concussion in children, yet the underlying pathophysiology remains unclear. This systematic review sought to: (i) rigorously examine the current evidence of PTH pathophysiology in paediatric concussion (0-18 years), (ii) assess the quality of evidence, and (iii) provide directions for future research in accordance with PRISMA guidelines. Eligible studies (n = 19) totalling 1214 concussion participants investigated cerebrovascular function (n = 6), white matter integrity (n = 3), functional connectivity (n = 3), electrophysiology (n = 1), neurometabolics (n = 2), biological fluid markers (n = 4), vestibular and oculomotor function (n = 4); two studies used a multi-modal approach. Majority of studies were rated as fair quality (90%) and Level 3 evidence (84%). The true underlying mechanisms of PTH following paediatric concussion remain unclear. Overall quality of the available evidence is generally weak with a fair risk of bias and characterised by relative scarcity and lack of specificity of PTH pathophysiology. Future research is required to rigorously isolate pathophysiology specific to PTH with strict adherence to clinical definitions and standardised measurement tools of PTH.

Clinical outcomes for various benign paroxysmal positional vertigo (BPPV) diagnoses in adolescents and young adults with recent concussions

OBJECTIVE

Determine how positive BPPV findings in adolescents and young adults following concussion impacted the total number of treatments required and time until discharge.

SETTING

Outpatient physical therapy clinic.

PARTICIPANTS

167 individuals who were diagnosed with concussion or brain injury.

DESIGN

Retrospective chart review.

MAIN MEASURES

Total number of treatments and days until discharge were compared for various BPPV diagnoses (anterior canal, posterior canal, horizontal canal, and combination) and for individuals with and without BPPV.

RESULTS

Fifty-one out of 167 cases (30.54%) were diagnosed with BPPV. The total number of treatments provided was statistically different across BPPV diagnoses (P = .004). However, days until discharge were not statistically different between BPPV diagnoses (P = .28). There was no significant difference between time to discharge between those with BPPV (median = 21 days, range = 7-126) and those without (median = 28 days, range = 7-84 days; P = .23, r = 0.09).

CONCLUSION

To optimize outcomes, including symptom resolution and return to sport and/or work, early identification of BPPV and subsequent intervention should be prioritized for individuals who have concussion symptoms that suggest vestibular dysfunction.

Delivering Traumatic Brain Injury to Larval Zebrafish

We describe a straightforward, scalable method for administering traumatic brain injury (TBI) to zebrafish larvae. The pathological outcomes appear generalizable for all TBI types, but perhaps most closely model closed-skull, diffuse lesion (blast injury) neurotrauma. The injury is delivered by dropping a weight onto the plunger of a fluid-filled syringe containing zebrafish larvae. This model is easy to implement, cost-effective, and provides a high-throughput system that induces brain injury in many larvae at once. Unique to vertebrate TBI models, this method can be used to deliver TBI without anesthetic or other metabolic agents. The methods simulate the main aspects of traumatic brain injury in humans, providing a preclinical model to study the consequences of this prevalent injury type and a way to explore early interventions that may ameliorate subsequent neurodegeneration. We also describe a convenient method for executing pressure measurements to calibrate and validate this method. When used in concert with the genetic tools readily available in zebrafish, this model of traumatic brain injury offers opportunities to examine many mechanisms and outcomes induced by traumatic brain injury. For example, genetically encoded fluorescent reporters have been implemented with this system to measure protein misfolding and neural activity via optogenetics.

Tackling the tackle 2: Evaluation of referee and player behavioural change as measures of implementation of a law variation in community-level male amateur rugby union

OBJECTIVES

To evaluate player and referee behaviour during a lower tackle height law variation trial in community rugby union ('rugby').

DESIGN

Prospective observational cohort study.

METHODS

In a law variation trial in male amateur community rugby, coded match video surveillance data were analysed. Referee (sanctioning rate) and player (tackler body position) behaviour changes over one season (under the lowered, armpit-level maximum legal tackle height condition) were analysed in three approximately equal periods of the season. Secondarily, an independent professional referee reviewed illegal high tackle sanctioning data.

RESULTS

Overall, 108 matches with 14,780 tackles were filmed and coded. Sanctioned illegal high tackle propensity was significantly higher in the mid-season (41 sanctioned high tackles/1000 tackle events; 95 % CI: 35-47), compared with first and last periods. Upright tacklers in tackles decreased significantly in the final vs. middle period of the season (rate ratio: 0.69; 95 % CI: 0.54-0.88; p < 0.01). Of all the coder-determined high tackles also assessed as high under the new law by the independent referee, 51 % were sanctioned by the on-field referee.

CONCLUSIONS

Positive player and referee behavioural changes were observed during a lowered legal tackle height law variation in this community rugby setting. Increased mid-phase high tackle sanctioning by referees was followed by fewer tackles with upright tacklers in the subsequent (last) phase of the season. Encouraging positive behaviour changes of this nature, particularly if sustained (beyond trial study periods), may contribute to overall injury risk reduction, and hold considerable importance to inform future injury prevention strategies in rugby.

From unequal injuries to unequal learning? Socioeconomic gradients in childhood concussions and the impact on children's academic performance

Previous research identifies stark socioeconomic disparities in child injuries, yet research on the repercussions hereof on other aspects of children's lives remains sparse. This paper tests whether social gradients in minor traumatic brain injuries (mTBIs or concussions) contribute to corresponding inequalities in children's academic performance. Previous research on this topic is mostly based on small samples and confounded by non-random selection into experiencing mTBIs. We improve on prior research by using high quality, large N, administrative registry data. Further, we control for selection into having an mTBI via comparing the test score progression of children having an mTBI with children who experience an mTBI in later years (staggered difference-in-differences). Based on Danish ER/hospital records and national test score data, we find that children from families with lower earnings and less education are more likely to experience an mTBI and that having an mTBI negatively correlates with reading test scores. However, comparing present with future mTBI cases, we show that having an mTBI within a year before a test does not negatively affect children's reading scores. Our findings suggest that negative correlations between mTBIs and academic performance more likely reflect socioeconomic gradients in mTBI incidents rather than a direct causal effect. Further, socioeconomic gradients in mTBI incidents do not significantly contribute to corresponding disparities in academic performance.

Medical Care Among Individuals with a Concussion in Ontario: A Population-based Study

BACKGROUND

Concussion affects 1.2% of the population annually; rural regions and children have higher rates of concussion.

METHODS

Using administrative health care linked databases, all residents of Ontario with a physician diagnosed concussion were identified using ICD-9 code 850 or ICD-10 code S06. Cases were tracked for 2 years for concussion-related health care utilization with relevant specialist physicians (i.e., neurology, otolaryngology, physiatry, psychiatry, ophthalmology). Billing codes, specialist codes, and time from index to visit were analyzed. Factors associated with increased specialist visits were also examined.

RESULTS

In total, 1,022,588 cases were identified between 2008 and 2014 with 2 years of post-concussion health care utilization available. Follow-up by physician within 3 days of injury occurred in only 14% of cases. Mean time between ED diagnosis and follow-up by a physician was 83.9 days, whereas for rural regions it was >100 days. About half of adults (51.9%) and children (50.3%) had at least 1 specialist visit following concussion. Mean time between injury and first specialist visit was 203.8 (SD 192.9) days for adults, 213.5 (SD 201.0) days for rural adults, and 276.0 (SD 202.6) days for children. There were 67,420 neurology visits, 70,404 psychiatry visits, 13,571 neurosurgery visits, 19,780 physiatry visits, 101,788 ENT visits, and 103,417 ophthalmology visits in the 2 years tracking period. Factors associated with more specialist use included age > 18 years, urban residence, and pre-injury psychiatric history.

CONCLUSIONS

There are discrepancies in post-concussion health care utilization based on age group and rural/urban residence. Addressing these risk factors could improve concussion care access.