Concussion: A Global Perspective

The Concussion, Exercise, and Brain Networks (ConExNet) study: a cohort study aimed at understanding the effects of sub-maximal aerobic exercise on resting state functional brain activity in pediatric concussion

BACKGROUND

Recent scientific evidence has challenged the traditional "rest-is-best" approach for concussion management. It is now thought that "exercise-is-medicine" for concussion, owing to dozens of studies which demonstrate that sub-maximal, graded aerobic exercise can reduce symptom burden and time to symptom resolution. However, the primary neuropathology of concussion is altered functional brain activity. To date, no studies have examined the effects of sub-maximal aerobic exercise on resting state functional brain activity in pediatric concussion. In addition, although exercise is now more widely prescribed following concussion, its cardiopulmonary response is not yet well understood in this population. Our study has two main goals. The first is to understand whether there are exercise-induced resting state functional brain activity differences in children with concussion vs. healthy controls. The second is to profile the physiological response to exercise and understand whether it differs between groups.

METHODS

We will perform a single-center, controlled, prospective cohort study of pediatric concussion at a large, urban children's hospital and academic center. Children with sport-related concussion (aged 12-17 years) will be recruited within 4-weeks of injury by our clinical study team members. Key inclusion criteria include: medical clearance to exercise, no prior concussion or neurological history, and no implants that would preclude MRI. Age- and sex-matched healthy controls will be required to meet the same inclusion criteria and will be recruited through the community. The study will be performed over two visits separated by 24-48 h. Visit 1 involves exercise testing (following the current clinical standard for concussion) and breath-by-breath gas collection using a metabolic cart. Visit 2 involves two functional MRI (fMRI) scans interspersed by 10-minutes of treadmill walking at an intensity calibrated to Visit 1 findings. To address sub-objectives, all participants will be asked to self-report symptoms daily and wear a waist-worn tri-axial accelerometer for 28-days after Visit 2.

DISCUSSION

Our study will advance the growing exercise-concussion field by helping us understand whether exercise impacts outcomes beyond symptoms in pediatric concussion. We will also be able to profile the cardiopulmonary response to exercise, which may allow for further understanding (and eventual optimization) of exercise in concussion management.

TRIAL REGISTRATION

Not applicable.

Impaired episodic verbal memory recall after 1 week and elevated forgetting in children after mild traumatic brain injury - results from a short-term longitudinal study

Objective

There is preliminary evidence that children after traumatic brain injury (TBI) have accelerated long-term forgetting (ALF), i.e., an adequate learning and memory performance in standardized memory tests, but an excessive rate of forgetting over delays of days or weeks. The main aim of this study was to investigate episodic memory performance, including delayed retrieval 1 week after learning, in children after mild TBI (mTBI).

Methods

This prospective study with two time-points (T1: 1 week after injury and T2: 3-6 months after injury), included data of 64 children after mTBI and 57 healthy control children aged between 8 and 16 years. We assessed episodic learning and memory using an auditory word learning test and compared executive functions (interference control, working memory, semantic fluency and flexibility) and divided attention between groups. We explored correlations between memory performance and executive functions. Furthermore, we examined predictive factors for delayed memory retrieval 1 week after learning as well as for forgetting over time.

Results

Compared to healthy controls, patients showed an impaired delayed recall and recognition performance 3-6 months after injury. Executive functions, but not divided attention, were reduced in children after mTBI. Furthermore, parents rated episodic memory as impaired 3-6 months after injury. Additionally, verbal learning and group, but not executive functions, were predictive for delayed recall performance at both time-points, whereas forgetting was predicted by group.

Discussion

Delayed recall and forgetting over time were significantly different between groups, both post-acutely and in the chronic phase after pediatric mTBI, even in a very mildly injured patient sample. Delayed memory performance should be included in clinical evaluations of episodic memory and further research is needed to understand the mechanisms of ALF.

Geographic characteristics of sport- and non-sport-related concussions presenting to emergency departments in the United States

BACKGROUND

Concussion is a type of traumatic brain injury (TBI) that can be sustained through sport-related and non-sport-related (e.g., motor vehicle accidents, falls, assaults) mechanisms of injury (MOI). Variations in concussion incidence and MOI may be present throughout the four geographic regions (Midwest, Northeast, South, West) of the United States. However, there is limited evidence exploring concussion cause and diagnosis patterns based on geographic region and MOI. These factors have implications for better understanding the burden of concussion and necessary efforts that can translate to the mitigation of safety concerns.

PURPOSE

The purpose of this study was to identify patterns of sport-related concussion (SRC) and non-sport-related concussion (NSRC) across the four geographic regions of the United States.

METHODS

A descriptive epidemiology study of patient visits to the emergency department (ED) for concussion between 2010 and 2018, using publicly available data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) was conducted. The exposure of interest was geographic region while the main outcome measures were concussion diagnosis and MOI. Descriptive statistics were calculated using population-weighted frequencies and percentages. The association between geographic region and MOI (SRC vs. NSRC) was analyzed using logistic regression models. Odds ratios (OR) presented with 95% confidence intervals (CI) were included. Univariate analyses were conducted followed by multivariable analyses adjusting for sex, age, race/ethnicity, and primary source of payment. Statistical significance was set a priori at p < 0.05 for all analyses.

RESULTS

From 2010 to 2018, 1,161 visits resulted in a concussion diagnosis, representing an estimated 7,111,856 visits nationwide. A greater proportion of concussion diagnoses occurred within EDs in the South (38.2%) followed by the West (25.8%), Midwest (21.4%), and Northeast (14.6%). Compared to the West region, patients visiting the ED in the Midwest (OR = 0.75, 95% CI = 0.57-0.98) and Northeast (OR = 0.71, 95% CI = 0.51-0.98) had a lower odds of being diagnosed with a concussion. More patients sustained a NSRC MOI (94.3%) compared to SRC MOI (5.7%). For both mechanisms, the South region had the highest population-weighted frequency of SRC (n = 219,994) and NSRC diagnoses (n = 2,495,753). Univariate and multivariable logistic regression analyses did not reveal statistically significant associations for geographic region and MOI (p > 0.05).

CONCLUSION

Our findings showed that the Midwest and Northeast regions had a lower odds of concussion diagnoses in EDs. Overall, the vast majority of concussions were not sport-related, which has public health implications. These findings improve our understanding of how concussion injuries are being sustained geographically nationwide and help to explain care-seeking patterns for concussion in the ED setting.

Different trajectories of post-concussive symptom subscales after pediatric mild traumatic brain injury: Data from a prospective longitudinal study

PURPOSE

The aim of this study was to investigate the trajectory of parent-rated post-concussive symptoms (PCS), attentional performance and participation within 6 months in children after mild traumatic brain injury (mTBI).

METHODS

For this prospective longitudinal study, we included data on 64 children after mTBI and 57 healthy control children (age 8-16 years). Parents rated PCS using the Post-Concussion Symptom Inventory (PCSI) immediately (T0), 1 week (T1), and 3-6 months after injury (T2). Attentional performance (alertness, selective and divided attention) was measured using the Test of Attentional Performance (TAP) at T1 and T2 and participation was measured using the Child and Adolescent Scale of Participation (CASP) at T2.

RESULTS

Friedman tests showed different trajectories of PCS subscales over time: Compared to pre-injury level, the amount of somatic and cognitive PCS was still elevated at T1, while emotional PCS at T1 were already comparable to pre-injury level. The rating of sleep-related PCS at T2 was significantly elevated compared to the pre-injury rating. Quade ANCOVAs indicated group differences in PCS subscales between patients and controls at T1, but not at T2. Patients and controls showed a similar performance in tests of attention at T1 and T2, but parental rating of participation at school was significantly reduced. Although cognitive PCS and attention were not correlated, there were significantly negative Spearman correlations between participation at home and pre-injury and concurrent PCS at T2.

CONCLUSIONS

Our data imply that sleep-related PCS are still elevated weeks after injury and are thus a target for interventions after mTBI.

Epidemiology of Sports Injuries Among High School Athletes in the United States: Data From 2015 to 2019

Background

Nearly 8 million high school students in the United States participate in sports each year. With the lack of recent population data, an update to previous studies on US high school athletes is needed.

Purpose

To update the epidemiology of sports injuries in high school athletes in the United States.

Study Design

Descriptive epidemiology study.

Methods

The data from the National Health School Sports-Related Injury Surveillance Study, including 100 nationally representative high schools, were obtained for 9 high school sports (boys' football, soccer, basketball, wrestling, and baseball and girls' soccer, basketball, volleyball, and softball) between the 2015 and 2019 academic years. Injury rates were calculated as the ratio of injuries per 1000 athlete exposures (AEs), defined as 1 athlete participating in 1 practice or competition. Data on injured body area, injury type (sprains/strains, concussions, contusions, and fractures), time loss, and need for surgery were also obtained. Rate ratios (RRs) with 95% CIs and P values were calculated.

Results

Athletic trainers reported 15,531 injuries during 6,778,209 AEs, with an overall rate of 2.29 injuries per 1000 AEs. Injury rates were highest in football (3.96), girls' soccer (2.65), and boys' wrestling (2.36). The overall injury rate was lower in girls' sports (1.86) compared with boys' sports (2.52) (RR, 0.74 [95% CI, 0.71-0.76]; P < .001) and was higher in competition compared with practice (RR, 3.39 [95% CI, 3.28-3.49]; P < .001). The most commonly injured body areas were the head/face (24.2%), ankle (17.6%), and knee (14.1%). Sprains/strains (36.8%) and concussions (21.6%) were the most common diagnoses. Overall, 39.2% and 34% of injuries resulted in a time loss of <1 week and 1 to 3 weeks, respectively. Surgery was required in 6.3% of injuries, with wrestling (9.6%), girls' basketball (7.6%), and boys' baseball (7.4%) being the sports with the highest proportion of injuries needing surgery.

Conclusion

Study findings demonstrated that boys' football, girls' soccer, and boys' wrestling had the highest injury rates, with boys' sports overall having higher injury rates than girls' sports. Sprains/strains and concussions were the most common diagnoses. Few injuries required surgery.

Heart Rate Variability in Concussed College Athletes: Follow-Up Study and Biological Sex Differences

Finding reliable biomarkers to assess concussions could play a pivotal role in diagnosis, monitoring, and predicting associated risks. The present study aimed to explore the use of heart rate variability (HRV) in the follow-up of concussions among college athletes and to investigate the relationships between biological sex, symptomatology, and HRV values at baseline and after a concussion. Correlations between measures were also analyzed. A total of 169 (55 females) athletes aged 16 to 22 years old completed baseline testing, and 30 (8 females) concussion cases were followed. Baseline assessment (T1) included psychosocial and psychological questionnaires, symptoms report, and four minutes of HRV recording. In the event of a concussion, athletes underwent re-testing within 72 h (T2) and before returning to play (T3). Baseline findings revealed that girls had higher %VLF while sitting than boys, and a small negligible correlation was identified between %HF and total symptoms score as well as %HF and affective sx. Post-concussion analyses demonstrated a significant effect of time × position × biological sex for %HF, where girls exhibited higher %HF at T3. These findings suggest disruptions in HRV following a concussion and underscore biological sex as an important factor in the analysis of HRV variation in concussion recovery trajectory.

Trends in Pediatric Mild Traumatic Brain Injury During COVID-19-Related Lockdown-A Single-Center Study

BACKGROUND

A relevant number of visits to pediatric emergency departments (pED) are associated with mild traumatic brain injury (mTBI). On March 16, 2020, the Bavarian government declared a first full lockdown (LD) related to the coronavirus (COVID-19) pandemic.

AIM

The aim of the study was to investigate the impact of LD on pediatric mTBI.

METHODS

Retrospective chart review of presentations to a pED due to mTBI. Study periods covered LD (03/17/2020 through 05/05/2020) and the same time in 2017, 2018, and 2019 as reference period (RP). Comparative analyses were performed by Chi-square or Fisher's exact test.

RESULTS

Numbers of mTBI cases decreased by half. Age distribution did not differ. A significantly higher proportion of mTBI were related to falls at home (p = 0.001). Further, a higher rate of hospital admissions (p = 0.03), a higher proportion of intensive care unit admissions (p = 0.001), a longer duration of hospital stay (p = 0.02), and a higher rate of intracranial pathologies on neuroimaging were observed during LD (p = 0.007).

CONCLUSION

The decrease in mTBI presentations is likely due to an absolute decrease in numbers related to the LD measures, combined with a hesitation to present very minor mTBI to the hospital, because of fear of being infected or not to put additional strain on the healthcare system during this healthcare crisis. On the other hand, data of those that presented with mTBI tend to reflect the more severe spectrum of mTBI.

Ocular motor disorders in children and adults with mTBI: a scoping review protocol

INTRODUCTION

Ocular motor function is susceptible to neurological injury because it requires a large portion of brain circuitry including every lobe of the brain, brainstem, thalamus, basal ganglia, cerebellum, cranial nerves and visual tracts. While reports of a high frequency of ocular motor dysfunctions after mild traumatic brain injury (mTBI) span multidisciplinary journals, there is no scoping review of the signs, diagnostic assessments and criteria, and appropriate management of ocular motor disorders post-mTBI. Post-mTBI ocular motor dysfunction has been reported to respond to active treatment. The objective of this scoping review is to map the available evidence on the diagnostic assessment and treatment modalities currently used in the management of mTBI-related ocular motor disorders in children and adults. This scoping review also aims to identify gaps in the current literature and provide suggestions for future research.

METHODS AND ANALYSIS

This review will include populations with reported concussion and/or mTBI without restrictions on age, race, sex or time since injury. The review will evaluate the reported symptoms related to ocular motor dysfunction, types of assessments and diagnostic criteria used, reported treatments, and the level of evidence supporting the reported treatments. This review will exclude literature on brain injury of non-traumatic aetiology and moderate/severe traumatic brain injury. Ocular motor dysfunction after mTBI appears in journals across multiple disciplines. Thus, multiple databases will be evaluated including Pubmed, Embase, PEDro, OVID, Clinical Key, Google Scholar and REHABDATA. Literature will be searched from inception to present day. Evidence sources will include experimental study designs including randomised controlled trials, non-randomised controlled trials and interrupted time-series. Additionally, analytical observational studies including prospective and retrospective cohort studies, case series, cross-sectional studies and clinical practice guidelines will be considered for inclusion. Data will be extracted on clinical presentation, frequency, assessment, diagnostic criteria management strategies and outcomes of concussion and mTBI-related ocular motor disorders.

ETHICS AND DISSEMINATION

This scoping review will use data from existing publications and does not require ethical approval by an institutional review board. Results will be disseminated through publication in a peer-reviewed scientific journal and presented at relevant conferences and as part of future workshops with professionals involved with diagnosis and management of patients with mTBI.

Knowledge, Attitude, and Behavior of Medical Students with Regard to Concussions: A Cross-Sectional Study

BACKGROUND

Concussions, categorized as mild traumatic brain injuries, result from traumatic events and present a significant concern within the field of traumatic brain injuries. Understanding the multifaceted pathophysiology of concussions, their diverse symptomatology, and their appropriate management strategies is crucial for healthcare professionals. This study explores the knowledge, attitudes, and behaviors of medical students at King Faisal University in the Eastern Province of Saudi Arabia regarding concussions.

METHODS

A cross-sectional study design was employed to assess a diverse group of medical students at King Faisal University in the Eastern Province of Saudi Arabia. Participants were surveyed using a questionnaire covering socio-demographic information, knowledge assessment, attitude assessment, and behavior assessment.

RESULTS

Of the 315 participants, 68.3% demonstrated good knowledge about concussions. Participants generally recognized concussions as a type of traumatic brain injury (68.9%) and believed it was necessary to report concussion symptoms to a doctor (80.3%). However, certain misconceptions existed, such as the belief that all patients with concussion should rest for seven days (31.7%). Participants primarily obtained information from teachers (100%) and the internet and social media (81.6%).

CONCLUSION

While medical students at King Faisal University in the Eastern Province of Saudi Arabia generally exhibited good knowledge about concussions, specific knowledge gaps and misconceptions were seen to exist. To ensure comprehensive understanding and promote appropriate management, continuous education, and awareness campaigns are essential, with healthcare providers playing a pivotal role in knowledge dissemination.

A review of brain regions and associated post-concussion symptoms

The human brain is an exceptionally complex organ that is comprised of billions of neurons. Therefore, when a traumatic event such as a concussion occurs, somatic, cognitive, behavioral, and sleep impairments are the common outcome. Each concussion is unique in the sense that the magnitude of biomechanical forces and the direction, rotation, and source of those forces are different for each concussive event. This helps to explain the unpredictable nature of post-concussion symptoms that can arise and resolve. The purpose of this narrative review is to connect the anatomical location, healthy function, and associated post-concussion symptoms of some major cerebral gray and white matter brain regions and the cerebellum. As a non-exhaustive description of post-concussion symptoms nor comprehensive inclusion of all brain regions, we have aimed to amalgamate the research performed for specific brain regions into a single article to clarify and enhance clinical and research concussion assessment. The current status of concussion diagnosis is highly subjective and primarily based on self-report of symptoms, so this review may be able to provide a connection between brain anatomy and the clinical presentation of concussions to enhance medical imaging assessments. By explaining anatomical relevance in terms of clinical concussion symptom presentation, an increased understanding of concussions may also be achieved to improve concussion recognition and diagnosis.

Development and validation of a novel index to assess the perceived impact of sports-related oro-dental trauma among adolescents: findings from Sri Lanka

BACKGROUND

Sports-related oro- dental trauma, such as tooth fracture, displacement, mobility, and avulsion, cause significant concern among adolescent players due to detrimental impacts. The current study aims to develop, validate and assess the reliability of a simple index as a questionnaire to assess the impact of sports-related oro-dental trauma both untreated and treated, among adolescent school children in Sri Lanka.

METHODS

AODTII, an adolescent oro-dental trauma impact index, was developed and validated using a mixed-method approach. Items for the index were generated by quantitative as well as qualitative analysis of the results from Oral Health-Related Quality of Life Questionnaires, personnel interviews with experts and focus group discussions with adolescents. Principal component analysis and Exploratory factor analysis were used to create the index. The index was validated in the Sinhala language, and the reliability of the index was assessed using a separate sample in the school context in the Colombo district.

RESULTS

The initial list of 28 items was reduced to 12 by the Principal Component Analysis. Exploratory Factor Analysis categorised the variables into four latent constructs; physical impact, psychosocial effect influenced by peer pressure, the impact of oral health care and the impact caused due to unmet dental trauma treatment need. The cut-off values of the AODTII were based on PCA. The index achieved the Content Validity Ratio of 88.33. The construct validity was assessed with confirmatory factor analysis by developing a structural equation model. It obtained good model fit indices of RMSEA value of 0.067, SRMR of 0.076, CFI of 0.911 and the Goodness of Fit index of 0.95. The homogeneity was ensured with convergent and discriminant validity. The Cronbach's alpha value was 0.768, ensuring reliability. The index assesses the level of impact due to oro- dental trauma and identifies whether the adolescents perceive it significantly or not.

CONCLUSION

Twelve-item AODTII emerged as a reliable and valid tool to assess the perceived impact of untreated and treated sports-related oro- dental trauma on Sri Lankan adolescents with implications for its use in other populations. Further research is required to improve the translational value of AODTII. Moreover, the tool is potential as a patient-centred communication tool, clinical adjunct, advocacy tool and a useful OHRQoL index. However, it is needed to be supported end-users' feedback.

Prediction of motor function in patients with traumatic brain injury using genetic algorithms modified back propagation neural network: A data-based study

Objective

Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide. In this study, the characteristics of the patients, who were admitted to the China Rehabilitation Research Center, were elucidated in the TBI database, and a prediction model based on the Fugl-Meyer assessment scale (FMA) was established using this database.

Methods

A retrospective analysis of 463 TBI patients, who were hospitalized from June 2016 to June 2020, was performed. The data of the patients used for this study included the age and gender of the patients, course of TBI, complications, and concurrent dysfunctions, which were assessed using FMA and other measures. The information was collected at the time of admission to the hospital and 1 month after hospitalization. After 1 month, a prediction model, based on the correlation analyses and a 1-layer genetic algorithms modified back propagation (GA-BP) neural network with 175 patients, was established to predict the FMA. The correlations between the predicted and actual values of 58 patients (prediction set) were described.

Results

Most of the TBI patients, included in this study, had severe conditions (70%). The main causes of the TBI were car accidents (56.59%), while the most common complication and dysfunctions were hydrocephalus (46.44%) and cognitive and motor dysfunction (65.23 and 63.50%), respectively. A total of 233 patients were used in the prediction model, studying the 11 prognostic factors, such as gender, course of the disease, epilepsy, and hydrocephalus. The correlation between the predicted and the actual value of 58 patients was R ² = 0.95.

Conclusion

The genetic algorithms modified back propagation neural network can predict motor function in patients with traumatic brain injury, which can be used as a reference for risk and prognosis assessment and guide clinical decision-making.

A Scoping Review of Magnetic Resonance Modalities Used in Detection of Persistent Postconcussion Symptoms in Pediatric Populations

Up to 30% of youth with concussion experience PPCSs (PPCS) lasting 4 weeks or longer, and can significantly impact quality of life. Magnetic resonance imaging (MRI) has the potential to increase understanding of causal mechanisms underlying PPCS. However, there are no clear modalities to assist in detecting PPCS. This scoping review aims to synthesize findings on utilization of MRI among children and youth with PPCS, and summarize progress and limitations. Thirty-six studies were included from 4907 identified papers. Many studies used multiple modalities, including (1) structural (n = 27) such as T1-weighted imaging, diffusion weighted imaging, and susceptibility weighted imaging; and (2) functional (n = 23) such as functional MRI and perfusion-weighted imaging. Findings were heterogeneous among modalities and regions of interest, which warrants future reviews that report on the patterns and potential advancements in the field. Consideration of modalities that target PPCS prediction and sensitive modalities that can supplement a biopsychosocial approach to PPCS would benefit future research.

Misdiagnosis of Pediatric Concussions in the Emergency Department: A Retrospective Study

OBJECTIVE

We aimed to determine the rate and predictors of correctly diagnosed concussions in the pediatric emergency department and to describe the characteristics, presentation, and management of concussions in children presenting for minor head injury.

METHODS

We included 186 patients aged 5 to 18 years presenting within 24 hours of minor head injuries and met our diagnostic criteria for concussion. We compared patients correctly diagnosed with a concussion with those who were not. Our main outcome was the rate and predictors of misdiagnoses.

RESULTS

Of the patients, 5.4% were correctly diagnosed. Amnesia was the only variable associated with correct diagnoses (40.0% vs 10.2%, P = 0.02). The most common mechanism of injury was fall (8.4%); the most frequent symptoms were nausea/vomiting (42.5%), and 48.4% had a brain computed tomography scan done.

CONCLUSIONS

The high rate of concussion misdiagnosis puts into question the usability of current concussion guidelines, their accuracy, and barriers to translation into clinical practice.

Eye Movements in Mild Traumatic Brain Injury: Ocular Biomarkers

Mild traumatic brain injury (mTBI, or concussion), results from direct and indirect trauma to the head (i.e. a closed injury of transmitted forces), with or without loss of consciousness. The current method of diagnosis is largely based on symptom assessment and clinical history. There is an urgent need to identify an objective biomarker which can not only detect injury, but inform prognosis and recovery. Ocular motor impairment is argued to be ubiquitous across mTBI subtypes and may serve as a valuable clinical biomarker with the recent advent of more affordable and portable eye tracking technology. Many groups have positively correlated the degree of ocular motor impairment to symptom severity with a minority attempting to validate these findings with diffusion tract imaging and functional MRI. However, numerous methodological issues limit the interpretation of results, preventing any singular ocular biomarker from prevailing. This review will comprehensively describe the anatomical susceptibility, clinical measurement, and current eye tracking literature surrounding saccades, smooth pursuit, vestibulo-ocular reflex, vergence, pupillary light reflex, and accommodation in mTBI.

A non-invasive biomechanical model of mild TBI in larval zebrafish

A mild traumatic brain injury is a neurological dysfunction caused by biomechanical forces transmitted to the brain in physical impacts. The current understanding of the neuropathological cascade resulting in the manifested clinical signs and symptoms is limited due to the absence of sensitive brain imaging methods. Zebrafish are established models for the reproduction and study of neurobiological pathologies. However, all available models mostly recreate moderate-to-severe focal injuries in adult zebrafish. The present work has induced a mild brain trauma in larval zebrafish through a non-invasive biomechanical approach. A custom-made apparatus with a commercially available motor was employed to expose larvae to rapidly decelerating linear movements. The neurophysiological changes following concussion were assessed through behavioural quantifications of startle reflex locomotor distance and habituation metrics. Here we show that the injury was followed, within five minutes, by a transient anxiety state and CNS dysfunction manifested by increased startle responsivity with impaired startle habituation, putatively mirroring the human clinical sign of hypersensitivity to noise. Within a day after the injury, chronic effects arose, as evidenced by an overall reduced responsivity to sensory stimulation (lower amplitude and distance travelled along successive stimuli), reflecting the human post-concussive symptomatology. This study represents a step forward towards the establishment of a parsimonious (simple, less ethically concerning, yet sensitive) animal model of mild TBI. Our behavioural findings mimic aspects of acute and chronic effects of human concussion, which warrant further study at molecular, cellular and circuit levels. While our model opens wide avenues for studying the underlying cellular and molecular pathomechanisms, it also enables high-throughput testing of therapeutic interventions to accelerate post-concussive recovery.

Greater symptom burden results in reduced exercise tolerance in adolescents following concussion

OBJECTIVES

To explore the relationship between symptoms and exercise tolerance in adolescents following concussion.

METHODS

A retrospective analysis of 417 adolescents who attended a concussion service between January 2015 and April 2021 was performed, with 149 meeting eligibility criteria for inclusion. Post-Concussion Symptom Scale (PCSS) and graded exercise tolerance time (min) were assessed at initial and follow-up visits. Spearman's correlation was used to examine the relationship between PCSS scores and exercise time.

RESULTS

Adolescents (n = 149, 13.9 ± 1.7 years, 66.4% male) presented at 28.6 ± 19.7 days post-injury. Statistically significant correlations were identified between initial (r = -0.36, p < .001) and follow-up (r = -0.41, p < .001) PCSS scores and exercise time among all participants. Initial PCSS and initial exercise time were inversely correlated for males (r = -0.24, p = .018) and females (r = -0.22, p = .127). Follow-up PCSS and follow-up exercise time were inversely correlated for males (r = -0.30, p = .003) and females (r = -0.35, p = .014).

CONCLUSION

There is a statistically significant relationship between higher PCSS and poorer exercise time and both factors should be considered together to provide the most accurate assessment, particularly in females.

Cerebrolysin restores balance between excitatory and inhibitory amino acids in brain following concussive head injury. Superior neuroprotective effects of TiO2 nanowired drug delivery

Concussive head injury (CHI) often associated with military personnel, soccer players and related sports personnel leads to serious clinical situation causing lifetime disabilities. About 3-4k head injury per 100k populations are recorded in the United States since 2000-2014. The annual incidence of concussion has now reached to 1.2% of population in recent years. Thus, CHI inflicts a huge financial burden on the society for rehabilitation. Thus, new efforts are needed to explore novel therapeutic strategies to treat CHI cases to enhance quality of life of the victims. CHI is well known to alter endogenous balance of excitatory and inhibitory amino acid neurotransmitters in the central nervous system (CNS) leading to brain pathology. Thus, a possibility exists that restoring the balance of amino acids in the CNS following CHI using therapeutic measures may benefit the victims in improving their quality of life. In this investigation, we used a multimodal drug Cerebrolysin (Ever NeuroPharma, Austria) that is a well-balanced composition of several neurotrophic factors and active peptide fragments in exploring its effects on CHI induced alterations in key excitatory (Glutamate, Aspartate) and inhibitory (GABA, Glycine) amino acids in the CNS in relation brain pathology in dose and time-dependent manner. CHI was produced in anesthetized rats by dropping a weight of 114.6g over the right exposed parietal skull from a distance of 20cm height (0.224N impact) and blood-brain barrier (BBB), brain edema, neuronal injuries and behavioral dysfunctions were measured 8, 24, 48 and 72h after injury. Cerebrolysin (CBL) was administered (2.5, 5 or 10mL/kg, i.v.) after 4-72h following injury. Our observations show that repeated CBL induced a dose-dependent neuroprotection in CHI (5-10mL/kg) and also improved behavioral functions. Interestingly when CBL is delivered through TiO₂ nanowires superior neuroprotective effects were observed in CHI even at a lower doses (2.5-5mL/kg). These observations are the first to demonstrate that CBL is effectively capable to attenuate CHI induced brain pathology and behavioral disturbances in a dose dependent manner, not reported earlier.

Nurse-Driven Universal Concussion Screening: A Quality Improvement Initiative

BACKGROUND

The purpose of this study was to provide an evaluation of a performance improvement initiative that operationalized universal concussion screening for all pediatric trauma admissions at a Level I pediatric trauma center. Mild traumatic brain injury may be difficult to identify in injured children. We implemented a screening tool to identify the risk for concussion after traumatic injury and to improve access to cognitive evaluation and intervention in children. Prior to implementation of our screening tool, children admitted without obvious head injury or those younger than 12 years were not being screened for concussion risk.

METHODS

We employed a nurse-driven screening tool, derived from the Centers for Disease Control and Prevention Acute Concussion Evaluation, on all pediatric trauma patients ages 0-17 years. The screening tool identifies symptoms of physical, cognitive, sleep, or emotional deficits and prompts a cognitive evaluation with concussion education. The tool was administered by nursing and tracked in the electronic medical record.

RESULTS

Key stakeholders were interviewed to identify workflow barriers and education gaps following implementation. Enhancements to the electronic medical record and refocused nursing education improved compliance from 41% in the first 12 months to 91% at 24 months post-implementation (p < .001). The increasing number of evaluations additionally resulted in overall more cognitive evaluations as an initial step in identifying and treating previously unrecognized traumatic brain injury.

CONCLUSIONS

A pediatric concussion screening tool is simple to administer, applies to all developmental ages, and improves diagnostic capture of traumatic brain injury in pediatric trauma when administered by nurses with support through the electronic medical record.

Diversifying sport-related concussion measures with baseline balance and ocular-motor scores in professional Zambian football athletes

PURPOSE

Normative values of common sport-related concussion assessment tools may assist clinical diagnosis and management. However, current baseline normative values are not representative of athletic participants across international domains. This study develops healthy baseline norms on the Balance Error Scoring System (BESS), and King-Devick (K-D), providing baseline reference values for professional Zambian football athletes.

METHODS

Of the 125 male participants (aged 24.48 ± 5.41 years) screened for this study, 9 (7.2%) reported a previous history of concussion, 98 (78.4%) completed the Balance Error Scoring System and 88 (70.4%) completed the King-Devick. Descriptive statistics calculated for the BESS and the K-D test included mean, standard deviation, median, interquartile range (IQR), and percentiles ranks.

MAIN FINDINGS

Participants scored a mean ± standard deviation of 10.15 ± 5.6 and a median [IQR] of 9 [6-12.25] errors on the total BESS and completed the K-D test in a mean ± standard deviation 56.85 ± 10.55 seconds and a median [IQR] 55.28 [48.7-64.8] seconds.

CONCLUSIONS

Cross-cultural awareness and management of sport-related concussion are continuously improving the safety and well-being of athletic participants around the world. The diverse representation in these data may aid in interpretation of post-injury performance during sport-related concussion management in Zambia. This study develops baseline reference values currently lacking within African cultures and demonstrates the feasibility and global clinical utility of two sport-related concussion assessment resources.

Post-Concussion Acute Signs and Reliable Cognitive Decline in a Finnish Youth Ice Hockey Sample

OBJECTIVE

In sports concussion research, the importance of an individualized approach incorporating neuropsychological assessment data has been emphasized. This study examined the impact of acute signs of concussion on post-injury cognitive functioning using reliable change methodology in a sample of Finnish, elite-level, youth ice hockey players.

METHODS

From a sample of 1,823 players (all male, 14-20 years old) who completed preseason baseline testing with the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®) battery, two subgroups were identified. First, in total, 312 uninjured athletes, who completed baseline testing twice-1 year apart. The scores were contrasted to calculate reliable change indices (RCIs). Second, from a subsample of 570 athletes participating in an intensive follow-up arm of the project, the analysis included 32 concussed athletes. The RCIs were determined for the five ImPACT composite scores and used in identifying athletes with declined performance 3 days post-injury.

RESULTS

Test-retest reliability ranged from .39 to .71. Athletes who had experienced an acute loss of consciousness, amnesia, or postural instability had increased odds for declines in two or more areas assessed by ImPACT (odds ratio = 7.67-8.00, p < .05). In contrast, acute disorientation or vacant look did not lead to cognitive change that met the reliable change threshold.

CONCLUSIONS

The reliability coefficients and RCIs differed from those published earlier emphasizing the importance of national reference values. The presence of acute loss of consciousness, amnesia, or postural instability may indicate a more severe injury and predict the need for more intensive cognitive follow-up.

Influence of concomitant injuries on post-concussion symptoms after a mild traumatic brain injury - a prospective multicentre cohort study

Objectives: To compare post-concussion symptoms (PCS) and return to normal activities between mild Traumatic Brain Injury (mTBI) patients with or without concomitant injuries at 7-and 90 days post-mTBI.Methods: Design: Sub-analysis of a multicentre prospective cohort study.

PARTICIPANTS AND SETTING

patients with mTBI from 7 Canadian Emergency Departments.

PROCEDURE

Research assistants conducted telephone follow-ups using the Rivermead Postconcussion Symptoms Questionnaire (RPQ) at 7-, 30- and 90 days post-mTBI.

MAIN OUTCOME

Presence of PCS (RPQ: ≥3 symptoms) at 90 days.

SECONDARY OUTCOMES

RPQ score ≥21, prevalence of individual RPQ symptoms and patients' return to normal activities, at 7- and 90-days. Adjusted risk ratios (RR) were calculated.Results: 1725 mTBI patients were included and 1055 (61.1%) had concomitant injuries. Patients with concomitant injuries were at higher risk of having ≥3 symptoms on the RPQ (RR:1.26 [95% CI 1.01-1.58]) at 90 days. They were also at higher risk of experiencing specific symptoms (dizziness, fatigue, headaches and taking longer to think) and of non-return to their normal activities (RR:2.11 [95% CI 1.30-3.45]).Conclusion: Patients with concomitant injuries have slightly more PCS and seemed to be at higher risk of non-return to their normal activities 90 days, compared to patients without concomitant injuries.

Early injury evaluation following concussion is associated with improved recovery time in children and adolescents

OBJECTIVES

Delayed treatment for paediatric concussion may impact recovery trajectory. This study aims to determine the relationship between time to evaluation and concussion recovery in children and adolescents.

DESIGN

Retrospective cross-sectional study.

METHODS

Records from 341 children and adolescents, aged 7-18 years, from a tertiary referral concussion clinic were analysed. All participants were assessed using a standardised concussion test battery by a specialist concussion physician and graded exercise testing. Evaluation time was defined as the number of days from injury occurrence to first presentation at the concussion clinic. Three distinct time to evaluation periods were categorised as: early evaluation (<14 days), mid evaluation (14-28 days), and late evaluation (>28 days). The main outcome measure was recovery time (days).

RESULTS

A total of 341 participants (mean age 13.0 ± 2.3, 74% male) were included in the study. Of these, 89 received evaluation during the early phase (mean age 12.2 ± 2.5, 65% male), 124 during the mid phase (mean age 13.1 ± 2.2, 81% male) and 128 during the late phase (mean age 13.5 ± 2.1, 75% male) following injury. Participants receiving late evaluation took three times longer to recover (mean 148.0 days, 95% CI: 121.1-173.9) compared to early (mean 38.7 days, 95% CI: 30.7-46.7) and mid (mean 51.5 days, 95% CI: 39.7-63.4) evaluation. There was a strong positive correlation between recovery time and evaluation time (r = 0.66, p < 0.001).

CONCLUSIONS

Delaying time to evaluation following a concussion can significantly prolong recovery from injury in children and adolescents.

Cross-cultural exploration of baseline ImPACT Quick Test performance among football athletes in Zambia

OBJECTIVE

Concussion is a global sport injury; however, this public health issue has yet to be studied across Africa. It is unknown if tests such as the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) Quick Test (QT) are culturally appropriate for implementation as part of a concussion screening protocol in Zambia or other African nations. Study objectives included: 1) establish that Zambian athletes are able to complete the iPad-based ImPACT QT with respect to language or cultural barriers that may exist, and 2) document baseline neurocognitive percentile ranks among Zambian football athletes on the ImPACT QT.

METHODS

This study was completed with adult premiere league football athletes in Zambia (n = 125) aged 24.48 ± 5.41. Participants completed the ImPACT QT neurocognitive assessment prior to a preseason practice. Outcome measures were average performance on 3 factor scores: Motor Speed, Memory, and Attention Tracker, presented as percentile ranks using normative data built-into the ImPACT QT.

RESULTS

Zambian athletes scored nearly two standard deviations below the mean on Motor Speed (7^th percentile), using North American normative data. However, performance on Attention Tracker (44^th percentile) and Memory (56^th percentile) was within the average range.

CONCLUSION

Results of the current study show that Zambian athletes are able to complete the ImPACT QT, despite any language or cultural differences that may exist. In addition, preliminary percentile ranks suggest Zambian football athletes have average scores on Attention and Memory and below average scores on Motor Speed. These data are the first to explore Zambian athletes' performance on a cognitive concussion measure.

Analysis of invoked slips while wearing flip-flops in wet and dry conditions: Does alternative footwear alter slip kinematics?

Minimal footwear has become more ubiquitous; however, it may increase slip severity. This study specifically examined the slipping kinematics of flip-flop sandals. Invoked slips from standing were evaluated in dry and wet tile, and a unique wet footbed + wet tile condition, with 40, 50, and 60% bodyweight (BW) committed to the slipping foot. Water did not alter peak slip velocity (PV) at 40% BW, but PV increased with greater slip-foot force on wet tile by ~1 m/s. Interestingly, when floor-contact was lost during the slip, the flip-flops could come off the heel. This decoupling occurred most often when both the tile and footbed were either dry or wet. Given that both decoupling and greater PV were observed on wet tile, slipping in flip-flops under wet conditions may have more serious consequences. The results highlight that slips may occur at both the foot-flip-flop, and flip-flop-tile interfaces.

Postconcussion Syndrome: A Diagnosis of Past Diagnostic and Statistical Manual of Mental Disorders

ABSTRACT

After concussion, a subset of patients have persistent symptoms that are functionally limiting and may be difficult to treat. These symptoms were previously captured in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) under the diagnosis of "Post-Concussion Syndrome." However, in the recently published fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, postconcussion syndrome has been eliminated. The elimination of "Post-Concussion Syndrome" moves the Diagnostic and Statistical Manual of Mental Disorders further away from congruence with the International Classification of Diseases (ICD-10) with respect to the classification of postconcussion symptomology. Although this change likely had the positive effect of reducing misdiagnoses of symptoms due to other causes, the authors highlight the potential issues surrounding the elimination of postconcussion syndrome in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. This opinion piece also emphasizes the multiple diagnostic and therapeutic challenges that may result for those involved in the treatment of, or research regarding, concussion patients with persistent symptoms. Future revisions that provide clear clinical diagnostic criteria may be beneficial.

Anxiety, depression, and symptom experience in concussed children and youth

PURPOSE

To describe and explore the relationship between baseline anxiety, depression and symptom experience in children and youth assessed at a concussion clinic.

DESIGN AND METHODS

A retrospective chart review of concussed children and youth referred to a pediatric teaching hospital concussion clinic over a 15-month period was completed. Kutcher Adolescent Depression Scale (KAD-6), General Anxiety Disorder Scale (GAD-7), and the Post-Concussion Symptom Inventory (PCSI) scores were extracted.

RESULTS

A total of 155 patients were included. The most common symptoms (PCSI) at baseline were headache, fatigue, and feelings of head pressure. Symptoms were rated as mild to moderate in intensity. Overall, mean depression and anxiety scores were low. The mean anxiety scores, as measured by the GAD-7 (n = 108), was 7.4 (range, 0-24). The mean depression score, as measured by the KAD-6 (n = 94), was 4.7 (range, 0-18). A statistically significant, moderate positive correlation between PCSI scores with KAD-6 scores for male (r = .64, p < .001) and female (r = .61, p < .001) participants was identified. Similarly, a statistically significant, moderate positive correlation between PCSI scores with GAD-7 scores for male (r = .68, p < .001) and female (r = .60, p < .001) participants was identified.

PRACTICE IMPLICATIONS

Concussed children may experience a wide array of symptoms, including emotional challenges such as anxiety and depression. Feelings of anxiety and depression may contribute to overall post concussive symptoms in concussed children. The electronic health record can be leveraged to provide important patient data. Clinicians should systematically assess symptoms at each visit in concussed children and youth so that appropriate interventions can be implemented and monitored.

Mild traumatic brain injury exacerbates Parkinson's disease induced hemeoxygenase-2 expression and brain pathology: Neuroprotective effects of co-administration of TiO2 nanowired mesenchymal stem cells and cerebrolysin

Mild traumatic brain injury (mTBI) is one of the leading predisposing factors in the development of Parkinson's disease (PD). Mild or moderate TBI induces rapid production of tau protein and alpha synuclein (ASNC) in the cerebrospinal fluid (CSF) and in several brain areas. Enhanced tau-phosphorylation and ASNC alters the molecular machinery of the brain leading to PD pathology. Recent evidences show upregulation of constitutive isoform of hemeoxygenase (HO-2) in PD patients that correlates well with the brain pathology. mTBI alone induces profound upregulation of HO-2 immunoreactivity. Thus, it would be interesting to explore whether mTBI exacerbates PD pathology in relation to tau, ASNC and HO-2 expression. In addition, whether neurotrophic factors and stem cells known to reduce brain pathology in TBI could induce neuroprotection in PD following mTBI. In this review role of mesenchymal stem cells (MSCs) and cerebrolysin (CBL), a well-balanced composition of several neurotrophic factors and active peptide fragments using nanowired delivery in PD following mTBI is discussed based on our own investigation. Our results show that mTBI induces concussion exacerbates PD pathology and nanowired delivery of MSCs and CBL induces superior neuroprotection. This could be due to reduction in tau, ASNC and HO-2 expression in PD following mTBI, not reported earlier. The functional significance of our findings in relation to clinical strategies is discussed.

A Scoping Review of Registered Clinical Studies on Mild Traumatic Brain Injury and Concussion (2000 to 2019)

BACKGROUND

While many patients with mild traumatic brain injury (mTBI) or concussion recover completely, prolonged postconcussion symptoms remain a challenge for patients and an opportunity for clinical research. This has led to numerous research initiatives over the last 2 decades.

OBJECTIVE

To review the characteristics of clinical studies on management of mTBI/concussion; and to examine their definitions of mTBI/concussion.

METHODS

This scoping review included all clinical studies on diagnosis and management of patients with mTBI/concussion registered at www.clinicaltrials.gov from 2000 to June/2019. The terms “mild TBI/concussion” were used for the primary search. Definitions of mTBI/concussion were obtained from the protocols. When a definition was missing in the website, the study's investigators were contacted for clarification.

RESULTS

There were 225 interventional and 95 observational studies. Most of the studies are focused on treatment (54.7%) or diagnosis (37.5%), while 3.4% examined preventive measures, 2.8% evaluated prognostic instruments, and 1.6% developed registries. Most of the studies in this American database were single-center initiatives led by American and Canadian institutions. The definitions of mTBI/concussion differed widely among 109 studies.

CONCLUSION

The results of this review suggest that most of the clinical studies are focused on diagnosis and non-pharmacological therapies for patients with mTBI/concussion. The large number of differing definitions of mTBI/concussion among the studies creates significant limitations when comparing studies. The requirements for registering research protocols on mTBI/concussion should include the necessity to state the definition being used. There is a need for consensus on a uniform definition of concussion.

Recent Trends in Youth Concussions: A Brief Report

Objectives

Concussions and mild traumatic brain injuries are important medical issues, particularly among youth as the long-term health consequences of these injuries can become increasingly problematic. The purpose of this study was to examine recent trends in diagnosed concussions among pediatric patients in a large health care system.

Methods

This was a retrospective, population-based epidemiology study design that queried all patient files (pediatrics included) using electronic medical health records and further stratified patients based on type of concussion, age, sex, and year from 2013 to 2018.

Results

Electronic health records from a cohort of 8 832 419 (n_males = 4 246 492; n_females = 4 585 931) patient visits were assessed for concussion diagnosis and filtered for those whose concussive event led to a loss of consciousness (LOC) or not (nLOC). Of these patients, 12 068 were diagnosed with a concussion (LOC = 3 699; nLOC = 8 369) with an overall incidence rate of 1.37 concussions per 1000 patients. Overall, the number of patients diagnosed with a concussion increased by 5063 (LOC = 1351; nLOC = 3712) from 2013 to 2018. Males and females presented with similar rates of concussions 5919 (49.05%) and 6149 concussions (50.95%), respectively. Of total diagnosed concussions, 4972 (LOC = 815; nLOC = 4157) were under the age of 18 and represented 41.2% of all diagnosed concussions with an incidence rate of 6.79 per 1000 patients.

Conclusion

The number of concussions diagnosed appear to be on the rise with the largest number of concussions being diagnosed in those under the age of 18. Future studies should seek to determine primary causality and the long-term health implications of concussions with or without LOC.

Neuro-Inflammation in Pediatric Traumatic Brain Injury-from Mechanisms to Inflammatory Networks

Compared to traumatic brain injury (TBI) in the adult population, pediatric TBI has received less research attention, despite its potential long-term impact on the lives of many children around the world. After numerous clinical trials and preclinical research studies examining various secondary mechanisms of injury, no definitive treatment has been found for pediatric TBIs of any severity. With the advent of high-throughput and high-resolution molecular biology and imaging techniques, inflammation has become an appealing target, due to its mixed effects on outcome, depending on the time point examined. In this review, we outline key mechanisms of inflammation, the contribution and interactions of the peripheral and CNS-based immune cells, and highlight knowledge gaps pertaining to inflammation in pediatric TBI. We also introduce the application of network analysis to leverage growing multivariate and non-linear inflammation data sets with the goal to gain a more comprehensive view of inflammation and develop prognostic and treatment tools in pediatric TBI.