Consensus Statement on Concussion in Sport - The 3 rd International Conference on Concussion in Sport Held in Zurich, November 2008

A study protocol for risk stratification in children with concussion (RSiCC): Theoretical framework, design, and methods

Research shows that one in five children will experience a concussion by age 16. Compared to adults, children experience longer and more severe postconcussive symptoms (PCS), with severity and duration varying considerably among children and complicating management of these patients. Persistent PCS can result in increased school absenteeism, social isolation, and psychological distress. Although early PCS diagnosis and access to evidence-based interventions are strongly linked to positive health and academic outcomes, symptom severity and duration are not fully explained by acute post-injury symptoms. Prior research has focused on the role of neuroinflammation in mediating PCS and associated fatigue; however relationship between inflammatory biomarkers and PCS severity, has not examined longitudinally. To identify which children are at high risk for persistent PCS and poor health, academic, and social outcomes, research tracking PCS trajectories and describing school-based impacts across the entire first year postinjury is critically needed. This study will 1) define novel PCS trajectory typologies in a racially/ethnically diverse population of 500 children with concussion (11-17 years, near equal distribution by sex), 2) identify associations between these typologies and patterns of inflammatory biomarkers and genetic variants, 3) develop a risk stratification model to identify children at risk for persistent PCS; and 4) gain unique insights and describe PCS impact, including fatigue, on longer-term academic and social outcomes. We will be the first to use NIH's symptom science model and patient-reported outcomes to explore the patterns of fatigue and other physical, cognitive, psychological, emotional and academic responses to concussion in children over a full year. Our model will enable clinicians and educators to identify children most at risk for poor long-term health, social, and academic outcomes after concussion. This work is critical to meeting our long-term goal of developing personalized concussion symptom-management strategies to improve outcomes and reduce disparities in the health and quality of life of children.

Adolescent and Parent Perceptions of the Impact of Concussion/mTBI on Family Functioning and Activity Levels in Recovery

OBJECTIVE

To explore adolescent and parent perceptions of the impact of a concussion/mild traumatic brain injury (mTBI) on family functioning and activity levels in the first 4 weeks of recovery.

SETTING

Outpatient research setting.

PARTICIPANTS

Twenty-seven adolescents (aged of 13-17 years) within 1 week of a concussion/mTBI and a parent/guardian were enrolled in the study.

DESIGN

Prospective ecological study with qualitative, semistructured interviews.

MAIN MEASURES

Adolescents reported symptoms electronically every 2 days for 28 days via the Post-Concussion Symptom Inventory. Semistructured interviews were completed with each adolescent-parent dyad at the end of the 28-day period. Interview questions focused on perceptions of recovery progress and study procedures.

RESULTS

Symptom trajectories were variable across participants. Three main themes emerged from thematic analysis, including: (1) disruption of routines and activities, (2) injury management considerations, and (3) positive and negative influential factors (eg, school and coach support, timing of injury, and recovery expectations). Results highlighted nuances of recovery challenges that families specifically face and help emphasize the potential benefits of shared decision-making and where more guidance would be appreciated such as more specific self-management of symptoms and physical activity reintegration strategies.

CONCLUSIONS

Study findings support a shared decision-making approach with the identified themes as potential topics to help consider social and environmental influences on recovery. The themes presented in the results could be topics emphasized during intake and follow-up visit processes to help guide plans of care and return-to-activity decisions.

Top cited articles in concussion: A bibliometric analysis of the state of the science

Objective

Citation analyses identify the most-cited publications in a given field, which aids in understanding areas of the literature that are well-developed and those where additional research is required. Our objective was to perform a citation analysis in concussion to understand the state of the science from a bibliometric perspective.

Design

We performed a keyword search for articles related to concussion in Harzing's Publish or Perish, which scrapes Google Scholar for citation metrics. This approach was used to identify the 50 articles with the most lifetime citations as well as the 50 articles with the highest citation rate.

Main outcome measures

Citations and citation rates.

Results

Per our citation analysis, we found that concussion guidelines are among the most cited publications (comprising ≥20% of each citation cohort), yet there is a dearth of widely cited clinical trials to inform them; only one randomized trial (studying the effects of rest following concussion) was included in our citation analysis. The majority of study designs (≥40% of each citation cohort) were cross-sectional. Concussion recovery and secondary complications of concussion were common study topics, with ≥20% of publications in each citation cohort focused on these issues. The publications included in our analysis were authored by 596 authors from only 12 countries, suggesting a lack of global representation in concussion research.

Conclusions

Existing reviews and consensus statements have called for additional, high-quality research in concussion; our citation analysis quantifies this need. Further, although concussion is a global problem with its incidence and burden increasing in the developing world, our citation analysis demonstrates that the most-cited and discussed articles in concussion are published by authors from only 12 countries. Going forward, to address the global problem that is concussion, a more global research perspective is called for.

A Scoping Review of Concussion Guidelines in Amateur Sports in the United Kingdom

Objectives To investigate which United Kingdom (UK) amateur sporting organisations have published sports-related concussion (SRC) guidelines, their accessibility and the extent to which they follow the Berlin statement recommendations. This article is targeted at those involved with designing and implementing SRC guidelines in amateur sport. Design Scoping Review. Data Sources The SRC guidelines of 15 sporting organisations were accessed through public materials available from the official organisation website. Eligibility Criteria: To be included in this review, sports must enjoy broad participation by UK amateur athletes with a high risk of athletes sustaining an SRC. Results: 15 sporting organisations were included in this review with two, British Cycling and British Eventing, found not to have published SRC guidelines. There was found to be a large discrepancy between the extent to which the sport-specific guides followed the Berlin statement recommendations. Conclusions: The large discrepancy between the contents of the SRC guidelines may be putting the health of athletes at risk. We recommend the UK government publish standardised concussion guidelines based on the latest scientific research that must be used by all UK amateur sport groups.

Characterizing Head Impact Exposure in Men and Women During Boxing and Mixed Martial Arts

Background:

The accumulation of subconcussive impacts has been implicated in permanent neurological impairment. A gap in understanding the relationship between head impacts and neurological function is the lack of precise characterization and quantification of forces that individuals experience during sports training and competition.

Purpose:

To characterize impact exposure during training and competition among male and female athletes participating in boxing and mixed martial arts (MMA) via an instrumented custom-fit Impact Monitoring Mouthguard (IMM).

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

Twenty-three athletes (n = 4 women) were provided a custom-fit IMM. The IMM monitored impacts during sparring and competition. All training and competition sessions were videotaped. Video and IMM data were synchronized for post hoc data verification of true positives and substantiation of impact location. IMM data were collected from boxing and MMA athletes at a collaborating site. For each true-positive impact, peak linear acceleration and peak angular acceleration were calculated. Wilcoxon rank sum tests were used to evaluate potential differences in sport, activity type, and sex with respect to each outcome. Differences in impact location were assessed via Kruskal-Wallis tests.

Results:

IMM data were collected from 53 amateur training sessions and 6 competitions (session range, 5-20 minutes). A total of 896 head impacts (men, n = 786; women, n = 110) were identified using IMM data and video verification: 827 in practice and 69 during competition. MMA and boxers experienced a comparable number of impacts per practice session or competition. In general, MMA impacts produced significantly higher peak angular acceleration than did boxing impacts (P < .001) and were more varied in impact location on the head during competitions. In terms of sex, men experienced a greater number of impacts than women per practice session. However, there was no significant difference between men and women in terms of impact magnitude.

Conclusion:

Characteristic profiles of head impact exposure differed between boxing and MMA athletes; however, the impact magnitudes were not significantly different for male and female athletes.

Psycho-affective health, cognition, and neurophysiological functioning following sports-related concussion in symptomatic and asymptomatic athletes, and control athletes

Little is known about the neuropsychiatric and neurophysiological differences that characterize abnormal recovery following a concussion. The present study aimed to investigate the psycho-affective, cognitive, and neurophysiological profiles of symptomatic, slow-to-recover, concussed athletes, asymptomatic concussed athletes, and control athletes. Seventy-eight athletes (26 symptomatic, 26 asymptomatic, 26 control) completed the Beck Depression Inventory-II, Profile of Mood States, and 2-Back task. Additionally, event-related brain potentials were recorded during an experimental three-stimulus visual Oddball paradigm. Compared to asymptomatic and control groups, the symptomatic group reported greater depression symptoms and negatively altered mood states. Symptomatic athletes also exhibited poorer cognitive performance on the 2-Back task, indicated by more errors and slower reaction time. ERP analyses indicated prolonged P3b latency for both symptomatic and asymptomatic groups, but symptomatic athletes also exhibited reduced P3b amplitude compared to both asymptomatic and control groups. For the asymptomatic group, correlations were observed between time since last concussion and functioning, but no relations were observed within the symptomatic group for any measure. The current findings provide valuable information regarding the psycho-affective, cognitive, and neurophysiological profiles of athletes with and without persistent symptoms following a concussion and highlight the need to assess and treat symptomatic, slow-to-recover athletes from a multidimensional and integrative perspective.

Novice vs expert inter-rater reliability of the balance error scoring system in children between the ages of 5 and 14

BACKGROUND

The Balance Error Scoring System (BESS) is a tool to measure balance, however, no studies have shown its reliability between novice and expert raters.

RESEARCH QUESTION

What is the inter-rater reliability of BESS measurements when performed by novice raters compared to experts, and does completion of a focused, online training module increase the inter-rater reliability among novice raters?

METHODS

In this reliability study, 5 novice volunteers were asked to independently rate BESS tests from 50 random prerecorded BESS videos of normal healthy subjects aged 5-14. Novice raters regraded the same 50 videos after receiving a formal training. The novices' scores before and after the formal training were compared to one another and then the scores were compared to 4 expert scores. Intraclass correlation (ICC) with 95 % confidence intervals or percent agreements were calculated and compared across groups.

RESULTS

For the total BESS score, novice raters showed good reliability (ICC 0.845) which did not change with a formal training (ICC 0.846). Expert raters showed excellent reliability (ICC 0.929). Poor to moderate reliability was noted in the foam stance-single leg in the untrained novice and trained novice group (ICCs 0.452 and 0.64 L respectively).

SIGNIFICANCE

BESS testing by novice raters with only written instruction and no formal training yields good inter-rater reliability. In contrast, BESS testing by expert raters yields excellent reliability. A focused training for novice raters conferred a small improvement in the reliability of the scoring of the single leg stance on foam condition but not a significant difference to the overall BESS score. While novices demonstrated promising reliability for overall BESS scores, optimizing clinical research using the BESS with expert raters show the highest reliability.

Instrumented balance assessment in mild traumatic brain injury: Normative values and descriptive data for acute, sub-acute and chronic populations

Often the Balance Error Scoring System (BESS) is used to assess balance during a clinical evaluation of a patient presenting with mild Traumatic Brain Injury (mTBI). Although recent research has shown the benefits of using inertial sensor measures such as the Root Mean Square (RMS) of the acceleration in place of clinical scoring, few normative data are available for clinicians to reference. The purpose of this paper was to provide normative data collected using wearable sensors for healthy controls across three age groups, as well as providing cohort data for mTBI participants across three stages following injury (acute, sub-acute and chronic). The RMS in the Medio-Lateral direction (ML RMS sway) of each condition (double stance – DS; single stance – SS; and tandem stance – TS) was extracted per participant for analysis. The average ML RMS sway across all conditions was also calculated (ML RMS-Av). Percentiles were calculated to provide normative data, and two multivariate general linear models were used to evaluate differences between 1) non-athlete controls, athlete controls, and athletes with acute mTBI, and 2) non-athletic cohorts of control, sub-acute and chronic mTBI groups across young, middle-aged, and older adults. Model 1 revealed athletes with acute mTBI had more ML RMS sway than athlete controls the for the DS condition ( p < 0.001), but no differences with non-athlete controls. Athlete controls also had less ML RMS sway for the SS condition and ML RMS-Av ( p ≤ 0.022) compared with non-athlete controls. Model 2 revealed less ML RMS sway in the control group than the sub-acute and chronic mTBI groups for DS ( p ≤ 0.004), but no differences between the sub-acute and chronic group, while more ML RMS sway occurred in the chronic group compared with the control and sub-acute groups for the TS condition and ML RMS-Av ( p ≤ 0.013). Older adults had more ML RMS sway than young and middle-aged adults for SS, TS and ML RMS-Av ( p ≤ 0.019), while there were no differences between the young and middle-aged adults. Normative values presented here can help increase the practical application of instrumented balance assessment of mTBI patients through wearable sensors. ML RMS sway in the DS condition provided the clearest distinction between control and mTBI groups, but we caution that young adult athletes need to be assessed against athletic peers in the absence of baseline normative values. In non-athlete cohorts, age and gender norms may not be necessary to consider when assessing DS performance; however, age may be an important factor to consider when accessing norms for other stance conditions or the average performance across all conditions.

Prioritizing Pediatricians' Neurosurgical Education: Results From a National Survey of Primary Care Pediatricians

Introduction. We surveyed nonretired American Academy of Pediatrics-member US pediatricians regarding common neurosurgical conditions, identifying specific areas of focus in education. Methods. Data were acquired via self-administered electronic questionnaire. Results. Of 505 total respondents, 56% reported neurology was not a required residency rotation, and 86% had diagnosed craniosynostosis, plagiocephaly, or macrocephaly. Craniosynostosis can mostly be diagnosed by physical examination alone, but almost 50% reported relying on skull X-rays. Fifty-four percent reported diagnosing ocular surface disease (OSD; with 15% to 40% not screening an infant despite well-established cutaneous markers). Seventy-four screened OSD in a patient with sacral dimple. Ninety-seven percent reported treating concussion, but nearly 25% did not manage these patients alone. Two out of 3 patients indicated head injury as most important for continuing education. Conclusion. Improved education for craniosynostosis, OSD, head injury, and concussion management are important for earlier diagnosis, management, and referral of some disorders, while decreasing resource utilization in others. These results should be used when considering pediatrician educational programs.

Maximizing Recovery From Concussions for Youth Participating in Sports and Recreational Activities

Concussions have become a public health issue. This public health concern has drawn the attention of many states in which laws were created to address concussions safety, recognition of signs and symptoms, immediate removal, medical clearance, and return-to-play protocols. Most state legislation focused on student athletes participating in organized sports. However, the rise in concussion can be directly attributed to children, youth, and adolescents participating in nonsports-related events. Maximizing recovery from a concussion involves implementing education programs that focus on recognition of symptoms, treatment, and return-to-learn options. Treatment strategies used to address concussed youth include physical and cognitive rest and minimizing external stimuli that can increase symptoms. Because learning is a direct outcome for all youth, a return-to-learn protocol based on a collaborative school-based team approach is suggested.

Recent Preoperative Concussion and Postoperative Complications: A Retrospective Matched-cohort Study

BACKGROUND

Physiological alterations during the perianesthetic period may contribute to secondary neurocognitive injury after a concussion.

METHODS

Patients exposed to concussion and who received an anesthetic within 90 days were matched to unexposed patients without concussion. Intraoperative and postoperative events were compared. Subgroup analyses assessed relationships among patients with a concussion in the prior 30, 31 to 60, and 61 to 90 days and their respective unexposed matches. To facilitate identification of potential targets for further investigation, statistical comparisons are reported before, as well as after, correction for multiple comparisons.

RESULTS

Sixty concussion patients were matched to 176 unexposed patients. Before correction, 28.3% postconcussion versus 14.8% unexposed patients reported postanesthesia care unit pain score≥7 (P=0.02); 16.7% concussion versus 6.5% unexposed patients reported headache within 90 days of anesthesia (P=0.02) and 23.5% of patients who received surgery and anesthesia within 30 days of concussion experienced headache within 90 days of anesthesia compared with 7.1% in the unexposed group (P=0.01). Patients who experienced concussion and had anesthesia between 31 and 60 days after injury had a postanesthesia care unit Richmond Agitation and Sedation Scale score of -1.61±1.29 versus a score of -0.2±0.45 in unexposed patients (P=0.002). After adjusting the P-value threshold for multiple comparisons, the P-value for significance was instead 0.0016 for the overall cohort. Our study revealed no significant associations with application of adjusted significance thresholds.

CONCLUSIONS

There were no differences in intraoperative and postoperative outcomes in patients with recent concussion compared with unexposed patients. Before correction for multiple comparisons, several potential targets for further investigation are identified. Well-powered studies are warranted.

Characteristics and outcomes of physical activity interventions for individuals with mild traumatic brain injury: a scoping review protocol

INTRODUCTION

Traumatic brain injury (TBI) is a major public health problem, and it is estimated that 85% of TBIs are diagnosed as mild and are commonly referred to as a concussion. In adults, symptoms are expected to resolve within 10-14 days after the injury, but up to 15% of individuals continue to have symptoms beyond this period. Recent clinical recommendations suggest the use of physical activity (PA) as a therapy to manage persisting symptoms. However, the recommendations regarding PA lack clarity about important intervention parameters to help clinicians deliver the intervention. The objectives of this scoping review are thus to identify the characteristics, the measurement tools, the health-related outcomes and the reported effectiveness of PA-based interventions for adults with persisting symptoms of a mild TBI (mTBI).

METHODS AND ANALYSIS

This scoping review protocol will follow Arksey and O'Malley's six-step iterative process enhanced by another study and will be conducted by a team of researchers and clinical experts. Five databases (MEDLINE, CINAHL, PsycINFO, SPORTDiscuss and Embase), as well as Google, will be searched using an extensive search strategy to capture relevant scientific and grey literature. Articles will be selected if they report on an intervention designed to have an impact on health-related outcomes or participation among individuals having sustained an mTBI. A data extraction form based on the Consensus on Exercise Reporting Template and the Template for Intervention Description and Replication checklists will be created. Quantitative and qualitative data will be analysed accordingly, synthesised and collated in tables.

ETHICS AND DISSEMINATION

This scoping review generates new knowledge from published and publicly available literature; thus, an ethical approval is unnecessary to conduct this research. Dissemination of the results will involve all team members in activities aimed to facilitate knowledge uptake among TBI rehabilitation clinical experts locally, nationally and internationally.

Sex-Based Differences in Transcranial Doppler Ultrasound and Self-Reported Symptoms After Mild Traumatic Brain Injury

The possibility of sex-related differences in mild traumatic brain injury (mTBI) severity and recovery remains a controversial subject. With some studies showing that female subjects suffer a longer period of symptom recovery, while others have failed to demonstrate differences. In this study, we explored the sex-related effects of mTBI on self-reported symptoms and transcranial Doppler ultrasound (TCD) measured features in an adolescent population. Fifty-eight subjects were assessed—at different points post-injury—after suffering an mTBI. Subjects answered a series of symptom questions before the velocity from the middle cerebral artery was measured. Subjects participated in breath-holding challenges to evaluate cerebrovascular reactivity. The Pulsatility Index (PI), the ratio of the first peaks (P2R), and the Breath-Hold Index (BHI), were computed. Linear mixed effects models were developed to explore the interactions between measured features, sex, and time since injury while accounting for within subject variation. Over the first 10 days post-injury, the female group had significant interactions between sex and time since injury that was not present in the TCD features. This is the first study to compare sex-related differences in self-reported symptoms and TCD measurements in adolescents suffering an mTBI. It illustrates the pitfalls clinicians face when relying on subjective measures alone during diagnosis and tracking of mTBI patients. In addition, it highlights the need for more focused research on sex-related differences in concussion pathophysiology.

Pituitary dysfunction due to sports-related traumatic brain injury

PURPOSE

After traumatic brain injury was accepted as an important etiologic factor of pituitary dysfunction (PD), awareness of risk of developing PD following sports-related traumatic brain injury (SR-TBI) has also increased. However there are not many studies investigating PD following SR-TBIs yet. We aimed to summarize the data reported so far and to discuss screening algorithms and treatment strategies.

METHODS

Recent data on pituitary dysfunction after SR-TBIs is reviewed on basis of diagnosis, clinical perspectives, therapy, screening and possible prevention strategies.

RESULTS

Pituitary dysfunction is reported to occur in a range of 15-46.6% following SR-TBIs depending on the study design. Growth hormone is the most commonly reported pituitary hormone deficiency in athletes. Pituitary hormone deficiencies may occur during acute phase after head trauma, may improve with time or new deficiencies may develop during follow-up. Central adrenal insufficiency is the only and most critical impairment that requires urgent detection and replacement during acute phase. Decision on replacement of growth hormone and gonadal deficiencies should be individualized. Moreover these two hormones are abused by many athletes and a therapeutic use exemption from the league's drug policy may be required.

CONCLUSIONS

Even mild and forgotten SR-TBIs may cause PD that may have distressing consequences in some cases if remain undiagnosed. More studies are needed to elucidate epidemiology and pathophysiology of PD after SR-TBIs. Also studies to establish screening algorithms for PD as well as strategies for prevention of SR-TBIs are urgently required.

Repeated mild traumatic brain injuries is not associated with volumetric differences in former high school football players

We investigated potential brain volumetric differences in a sample of former high school football players many years after these injuries. Forty community-dwelling males ages 40-65 who played high school football, but not college or professional sports, were recruited. The experimental group (n = 20) endorsed experiencing two or more mTBIs on an empirically validated mTBI assessment tool (median = 3, range = 2-15). The control group (n = 20) denied ever experiencing an mTBI. Participants completed a self-report index of current mTBI symptomatology and underwent high-resolution T1-weighted MRI scanning, which were analyzed using the Freesurfer software package. A priori regions of interest (ROIs) included total intracranial volume (ICV), total gray matter, total white matter, bilateral anterior cingulate cortex, bilateral hippocampi, and lateral ventricles. ROIs were corrected for head size using a normalization method that took ICV into account. Despite an adequate sample size and being matched on age, education, estimated premorbid IQ, current concussive symptomatology, there were no statistically significant volumetric group differences across all of the ROIs. These data suggest that multiple mTBIs from high school football may not be associated with measurable brain atrophy later in life. Accounting for the severity of injury and chronicity of sport exposure may be especially important when measuring long-term neuroanatomical differences.

The Natural History of Postconcussion Recovery Among High School Athletes

OBJECTIVE

Evaluate postconcussive symptom reporting and recovery.

SETTING

Public high school.

PARTICIPANTS

Unmatched controls (n = 760); students who sustained a sports-related concussion (n = 77); matched controls (gender, grade, sport) (n = 77).

DESIGN

Prospective longitudinal cohort study.

OUTCOME MEASURE

Immediate Postconcussion Assessment and Cognitive Testing.

RESULTS

At baseline, athletes who went on to sustain concussions were more likely than unmatched controls to be younger (P = .02), male (P = .001), and participate in different sports (P < .0001) such as football (concussed = 52%, unmatched controls = 20%). Differences were also noted regarding a previous history of concussion (P = .045; concussed athletes = 26%; unmatched control athletes = 16%) and lifetime number of concussions (P = .05). At baseline, those whose sustained concussions during the study period were more likely than matched controls to report numbness (P = .01) and concentration problems (P = .01) and more likely than unmatched controls to report dizziness (P = .02), sensitivity to light (P = .01), sensitivity to noise (P = .002), and numbness (P = .02). However, when data were reanalyzed and those with a previous history of concussion were removed, differences between those who sustained concussions during the study period and matched controls were no longer significant; when compared to unmatched controls, sensitivity to light (P = .01) and vision problems (P = .04) remained significant. Among those who sustained concussions, median time to recovery was 6 days (95% confidence interval: 4-9), and 71 out of 77 (92%) recovered by the fourth postinjury evaluation (median: 20 days postinjury).

CONCLUSIONS

Course and time frame of recovery were variable. Data also suggest that a previous history of concussion may be contributing to baseline symptom reporting and highlight the potential enduring impact of history of concussion on sensorimotor function. However, further research as to whether preinjury measures of sensorimotor function may increase understanding regarding concussion risk is warranted.

A targeted neuropsychological examination of children with a history of sport-related concussion

Experimental research suggests that sport-related concussion can lead to persistent alterations in children's neurophysiology and cognition. However, the search for neuropsychological tests with a similar ability to detect long-term deficits continues.

PRIMARY OBJECTIVE

The current study assessed whether a target battery of neuropsychological measures of higher cognition and academic achievement would detect lingering deficits in children 2 years after injury.

RESEARCH DESIGN

Cross-sectional.

METHODS AND PROCEDURE

A total of 32 pre-adolescent children (16 concussion history, 16 control) completed a targeted battery of neuropsychological and academic tests.

MAIN OUTCOMES AND RESULTS

Children with a history of concussion exhibited selective deficits during the Raven's Coloured Progressive Matrices, Comprehensive Trail-Making Test, and the mathematics sub-section of the WRAT-3. Deficit magnitude was significantly related to age at injury, but not time since injury.

CONCLUSIONS

The current results suggest that neuropsychological measures of higher cognition and academic achievement may be sensitive to lingering deficits, and that children injured earlier in life may exhibit worse neuropsychological and academic performance.

Physical activity and concussion risk in youth ice hockey players: pooled prospective injury surveillance cohorts from Canada

OBJECTIVE

To examine the association between meeting physical activity (PA) volume recommendations and concussion rates in male ice hockey players aged 11-17 years.

DESIGN

Pooled prospective injury surveillance cohort data from the 2011-2012, 2013-2014 and 2014-2015 youth ice hockey seasons.

PARTICIPANTS

Male Alberta-based Pee Wee (aged 11-12 years), Bantam (aged 13-14 years) and Midget (aged 15-17 years) ice hockey players participating in any of the three cohorts were eligible (n=1726). A total of 1208 players were included after the exclusion criteria were applied (ie, players with new/unhealed injuries within 6 weeks of study entry, missing 6-week PA history questionnaires, missing game and/or practice participation exposure hours, players who sustained concussions when no participation exposure hours were collected).

OUTCOME MEASURES

Dependent variable: medically diagnosed concussion. Independent variable: whether or not players' self-reported history of PA (ie, hours of physical education and extracurricular sport participation) met the Canadian Society of Exercise Physiology and Public Health Agency of Canada recommendation of one hour daily during the 6 weeks prior to study entry (ie, 42 hours or more).

RESULTS

The PA volume recommendations were met by 65.05% of players who subsequently sustained concussions, and 75.34% of players who did not sustain concussions. The concussion incidence rate ratios (IRR) reflect higher concussion rates in players who did not meet the PA volume recommendations vs. players who met the PA volume recommendations among Pee Wee players (IRR 2.94 95% CI 1.30 to 6.64), Bantam players (IRR 2.18, 95% CI 1.21 to 3.93) and non-elite players aged 11-14 years (IRR 2.45, 95% CI 1.33 to 4.51).

CONCLUSION AND RELEVANCE

The concussion rate of players who did not meet the Canadian PA volume recommendations was more than twice the concussion rate of players who met recommendations among male Pee Wee players, Bantam players and non-elite level players. Further exploration of the impact of public health PA recommendations in a sport injury prevention context is warranted.

Aerobic Exercise for Adolescents With Prolonged Symptoms After Mild Traumatic Brain Injury: An Exploratory Randomized Clinical Trial

OBJECTIVE

To describe the methodology and report primary outcomes of an exploratory randomized clinical trial (RCT) of aerobic training for management of prolonged symptoms after a mild traumatic brain injury (mTBI) in adolescents.

SETTING

Outpatient research setting.

PARTICIPANTS

Thirty adolescents between the ages of 12 and 17 years who sustained a mTBI and had between 4 and 16 weeks of persistent symptoms.

DESIGN

Partially blinded, pilot RCT of subsymptom exacerbation aerobic training compared with a full-body stretching program.

MAIN MEASURES

The primary outcome was postinjury symptom improvement assessed by the adolescent's self-reported Post-Concussion Symptom Inventory (PCSI) repeated for at least 6 weeks of the intervention. Parent-reported PCSI and adherence are also described.

RESULTS

Twenty-two percent of eligible participants enrolled in the trial. Repeated-measures analysis of variance via mixed-models analysis demonstrated a significant group × time interaction with self-reported PCSI ratings, indicating a greater rate of improvement in the subsymptom exacerbation aerobic training group than in the full-body stretching group (F = 4.11, P = .044). Adherence to the home exercise programs was lower in the subsymptom exacerbation aerobic training group compared with the full-body stretching group (mean [SD] times per week = 4.42 [1.95] vs 5.85 [1.37], P < .0001) over the duration of the study.

CONCLUSION

Findings from this exploratory RCT suggest subsymptom exacerbation aerobic training is potentially beneficial for adolescents with persistent symptoms after an mTBI. These findings and other recent research support the potential benefit of active rehabilitation programs for adolescents with persistent symptoms after an mTBI. Larger replication studies are needed to verify findings and improve generalizability. Future work should focus on determining the optimal type, timing, and intensity of active rehabilitation programs and characteristics of individuals most likely to benefit.

Reliability Testing of the Balance Error Scoring System in Children Between the Ages of 5 and 14

OBJECTIVE

Pediatric concussion is an extensive public health concern with a complex clinical presentation. Balance assessment has been well-studied in the adult population, but has been limited in children. We aimed to assess the reliability and minimum detectable change (MDC) of the Balance Error Scoring System (BESS) in healthy children.

DESIGN

This prospective observational study included 373 healthy children aged 5 to 14. Interrater reliability was assessed by having 4 assessors review videos of 50 random subjects distributed evenly by age and sex across the entire cohort. Intrarater reliability was performed by having assessors review videos of other assessors' live evaluations. Test-retest reliability was obtained by comparing BESS scores as recorded live at the 2 separate time points by the same rater.

SETTING

Local elementary and junior high schools.

PARTICIPANTS

Three hundred and seventy three healthy children between the ages of 5 and 14.

INTERVENTIONS

The BESS was performed on all children.

MAIN OUTCOME MEASURES

Intraclass Correlation Coefficients (ICCs) and MDC Scores.

RESULTS

The overall interrater ICC was determined to be 0.93 [95% confidence interval (CI), 0.79-0.97] and intrarater ICC was 0.96 (95% CI, 0.95-0.97) with individual intrarater ICCs ranging between 0.69 and 0.99. The test-retest reliability was 0.90 (95% CI, 0.88-0.92). The MDCs were 9.6, 4.6, and 7.3 points at the 95% CIs for interrater, intrarater, and test-retest comparisons, respectively. No learning effect was seen.

CONCLUSIONS

The BESS demonstrates excellent reliability in the pediatric population without evidence of a learning effect.

The independent influence of concussive and sub-concussive impacts on soccer players' neurophysiological and neuropsychological function

Accumulating research demonstrates that repetitive sub-concussive impacts can alter the structure, function and connectivity of the brain. However, the functional significance of these alterations as well as the independent contribution of concussive and sub-concussive impacts to neurophysiological and neuropsychological health are unclear. Accordingly, we compared the neurophysiological and neuropsychological function of contact athletes with (concussion group) and without (sub-concussion group) a history of concussion, to non-contact athletes. We evaluated event-related brain potentials (ERPs) elicited during an oddball task and performance on a targeted battery of neuropsychological tasks. Athletes in the sub-concussion and concussion groups exhibited similar amplitude reductions in the ERP indices of attentional resource allocation (P3b) and attentional orienting (P3a) relative to non-contact athletes. However, only athletes in the concussion group exhibited reduced amplitude in the ERP index of perceptual attention (N1). Athletes in the sub-concussion and concussion groups also exhibited deficits in memory recall relative to non-contact athletes, but athletes in the concussion group also exhibited significantly more recall errors than athletes in the sub-concussion group. Additionally, only athletes in the concussion group exhibited response delays during the oddball task. The current findings suggest that sub-concussive impacts are associated with alterations in the neurophysiological and neuropsychological indices of essential cognitive functions, albeit to a lesser degree than the combination of sub-concussive and concussive impacts.

A Normative Dataset of the Balance Error Scoring System in Children Aged Between 5 and 14

OBJECTIVE

Pediatric head injuries occur commonly and are being reported in increasing numbers. Balance testing is a key component in the evaluation of suspected concussion, and the balance error scoring system (BESS) is likely the most well-known and widely used measure. To date, normative BESS scores for adults have been reported but not for children.

DESIGN

Normative data for BESS scores and modified BESS scores were created in a cohort of healthy children. Potential variables were analyzed as predictors of BESS performance.

SETTING

Local elementary and junior high schools.

PARTICIPANTS

A total of 373 healthy children between the ages of 5 and 14.

INTERVENTIONS

The BESS was performed on all children.

ASSESSMENT OF RISK FACTORS

Gender, body mass index percentile, previous concussions, athletic participation, age, and the parental opinion of child's balance ability were examined as factors associated with the BESS score.

MAIN OUTCOME MEASURES

BESS scores.

RESULTS

Normative data are reported, stratified by age groups of 5 to 7 years, 8 to 10 years, and 11 to 14 years of age, for both BESS and modified BESS. Median BESS scores are 23 for children aged 5 to 7, 18 for children aged 8 to 10, and 16 for children aged 11 to 14. Median modified BESS scores are 8 for children age 5 to 7, 5 for children age 8 to 10, and 4 for children age 11 to 14. Increasing age and positive parental opinion regarding their child's balance ability were independently correlated with decreasing BESS scores (P < 0.01).

CONCLUSIONS

The normative data on BESS scores for healthy children reported here provide age-stratified reference values for suspected balance alterations.

Cumulative Head Impact Exposure Predicts Later-Life Depression, Apathy, Executive Dysfunction, and Cognitive Impairment in Former High School and College Football Players

The term "repetitive head impacts" (RHI) refers to the cumulative exposure to concussive and subconcussive events. Although RHI are believed to increase risk for later-life neurological consequences (including chronic traumatic encephalopathy), quantitative analysis of this relationship has not yet been examined because of the lack of validated tools to quantify lifetime RHI exposure. The objectives of this study were: 1) to develop a metric to quantify cumulative RHI exposure from football, which we term the "cumulative head impact index" (CHII); 2) to use the CHII to examine the association between RHI exposure and long-term clinical outcomes; and 3) to evaluate its predictive properties relative to other exposure metrics (i.e., duration of play, age of first exposure, concussion history). Participants included 93 former high school and collegiate football players who completed objective cognitive and self-reported behavioral/mood tests as part of a larger ongoing longitudinal study. Using established cutoff scores, we transformed continuous outcomes into dichotomous variables (normal vs. impaired). The CHII was computed for each participant and derived from a combination of self-reported athletic history (i.e., number of seasons, position[s], levels played), and impact frequencies reported in helmet accelerometer studies. A bivariate probit, instrumental variable model revealed a threshold dose-response relationship between the CHII and risk for later-life cognitive impairment (p < 0.0001), self-reported executive dysfunction (p < 0.0001), depression (p < 0.0001), apathy (p = 0.0161), and behavioral dysregulation (p < 0.0001). Ultimately, the CHII demonstrated greater predictive validity than other individual exposure metrics.

"Playing Through It": Delayed Reporting and Removal From Athletic Activity After Concussion Predicts Prolonged Recovery

CONTEXT

Preclinical research has demonstrated a window of vulnerability in the immediate aftermath of concussion wherein continued activity and stimulation can impair or prolong neurobehavioral recovery. However, this concept has not been quantified in a human population.

OBJECTIVE

To examine the effect of delayed reporting and removal from athletic activity after concussion on recovery time.

DESIGN

Cross-sectional study.

SETTING

A National Collegiate Athletic Association Division I university.

PATIENTS OR OTHER PARTICIPANTS

Ninety-seven athletes who sustained a sport-related concussion between 2008 and 2015 were analyzed (age = 20.4 ± 1.3 years). Athletes were grouped as immediate removal from activity (I-RFA) or delayed removal from activity (D-RFA).

MAIN OUTCOME MEASURE(S)

Days missed was defined as the number of days between the concussion-causing event and clearance for return to contact. Associations between RFA group and prolonged (8 or more days') versus normal (7 or fewer days') recovery were also analyzed.

RESULTS

Fifty (51.5%) of the 97 athletes did not immediately report concussion symptoms. The D-RFA athletes averaged 4.9 more days missed than the I-RFA athletes. Membership in the specific RFA group predicted days missed even after controlling for sex, concussion history, learning disability or attention-deficit/hyperactivity disorder diagnosis, diagnosed psychological disorder, and acute symptom severity (R( 2) change = 0.097, β = .319, P = .002). The D-RFA athletes were approximately 2.2 times more likely to have a prolonged recovery (8 or more days) compared with the I-RFA athletes (χ(2) = 10.268, P = .001, ϕ = 0.325).

CONCLUSIONS

Athletes who do not immediately report symptoms of a concussion and continue to participate in athletic activity are at risk for longer recoveries than athletes who immediately report symptoms and are immediately removed from activity. Continuing to participate in athletic activity during the immediate aftermath of a concussion potentially exposes the already injured brain to compounded neuropathophysiologic processes.

Concussion recovery time among high school and collegiate athletes: a systematic review and meta-analysis

BACKGROUND

Concussion diagnosis and management is made through the clinical exam using assessment tools that include self-report symptomatology, postural control, and cognitive evaluations. The specific timing of concussion resolution varies between individuals. However, despite a lack of research in concussion recovery, it is widely accepted that the majority of young adults will recover in 7-10 days, with youth athletes taking longer.

OBJECTIVES

The purpose of this review is to directly compare the recovery duration among high school and collegiate athletes on symptom reports and cognitive assessments following concussion.

DATA SOURCES

Data were collected from a literature search comprising high school or college athletes only. This included studies (n = 6) that reported symptom or cognitive performance recovery to the exact day.

RESULTS

High school athletes self-reported symptom recovery at 15 days compared with 6 days in collegiate athletes. Both college and high school athletes showed cognitive recovery at similar rates of 5 and 7 days.

LIMITATIONS

This review only included articles that were directly related to concussed high school or college athletes. Additionally, athletes in the high school and college setting typically receive a battery of neurocognitive tests that may not be as sensitive or as comprehensive as a full neuropsychological exam.

CONCLUSION

The review finds that neurocognitive recovery rates are similar among high school and college athletes, while symptom reporting shows longer recovery time points in high school than in college.

IMPLICATIONS OF KEY FINDINGS

An individualized and stepwise concussion management plan is important for proper concussion recovery regardless of age.

Two baselines are better than one: Improving the reliability of computerized testing in sports neuropsychology

Computerized neuropsychological tests are frequently used to assist in return-to-play decisions following sports concussion. However, due to concerns about test reliability, the Centers for Disease Control and Prevention recommends yearly baseline testing. The standard practice that has developed in baseline/postinjury comparisons is to examine the difference between the most recent baseline test and postconcussion performance. Drawing from classical test theory, the present study investigated whether temporal stability could be improved by taking an alternate approach that uses the aggregate of 2 baselines to more accurately estimate baseline cognitive ability. One hundred fifteen English-speaking professional hockey players with 3 consecutive Immediate Postconcussion Assessment and Testing (ImPACT) baseline tests were extracted from a clinical program evaluation database overseen by the National Hockey League and National Hockey League Players' Association. The temporal stability of ImPACT composite scores was significantly increased by aggregating test performance during Sessions 1 and 2 to predict performance during Session 3. Using this approach, the 2-factor Memory (r = .72) and Speed (r = .79) composites of ImPACT showed acceptable long-term reliability. Using the aggregate of 2 baseline scores significantly improves temporal stability and allows for more accurate predictions of cognitive change following concussion. Clinicians are encouraged to estimate baseline abilities by taking into account all of an athlete's previous baseline scores.

Impact of preseason concussion education on knowledge, attitudes, and behaviors of high school athletes

BACKGROUND

The benefit of preseason concussion education on athletes' knowledge, attitudes, and behaviors is unclear. The purpose of the study was to determine the influence of preseason concussion education on knowledge and self-reported attitudes and reporting behaviors. We hypothesized that preseason education would lead to better knowledge and self-reported attitudes and better reporting of concussion symptoms during the season.

METHODS

This study involved a prospective cohort comparing the benefits of a preseason lectured-based concussion education session at one high school with a control school. Participants included males and females age 13 years to 18 years from two community high schools who were participating in higher concussion risk, fall or winter sports (football, soccer, wrestling, and basketball). The education school and control school included 234 and 262 participants, respectively. Outcomes were a preseason and postseason survey assessing knowledge and self-reported attitudes about concussions and an end-of-season questionnaire assessing concussion reporting behaviors during the season.

RESULTS

Total scores on the combined (p < 0.0001), knowledge-based (p = 0.016), and behavioral-based (p < 0.0001) questions demonstrated statistically significant improvement in the education group. Scores peaked immediately after education but dissipated at the end of the season. There was a lower proportion in the education school (72%) compared with the control school (88%) that reported continued play despite having concussion symptoms during the season (p = 0.025). A similar proportion of athletes diagnosed with concussion during the season in the education (27%) and control schools (23%) reported returning to play before symptoms resolved (p = 0.81).

CONCLUSION

These findings suggest that a didactic-based preseason concussion education likely has minimal benefits. Other factors besides knowledge are likely influencing student-athlete concussion reporting behavior. Future research focused on changing the culture of concussion reporting is needed.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Post-traumatic headaches correlate with migraine symptoms in youth with concussion

OBJECTIVE

The term "post-traumatic migraine" (PTM) has been used to describe post-traumatic headaches (PTHs) that have associated migraine features, but studies of this relationship are lacking. The objective of the present study was to determine whether PTH correlates strongly with migraine symptoms among youth with concussion.

METHODS

Twenty-three symptoms were analyzed from a retrospective cohort of 1953 pediatric patients with concussion. A principal component analysis (PCA) with oblique Promax rotation was conducted to explore underlying symptom relationships in the full cohort and in subcohorts stratified by the presence (n = 414) or absence (n = 1526) of premorbid headache.

RESULTS

The mean patient age was 14.1 years; 63% were male. Headache was the most common postconcussion symptom, acknowledged by 69.4% of patients. When considering the full cohort, the PCA demonstrated clustering of headache with photophobia, phonophobia, nausea, dizziness, and neck pain. Similar clustering was present among patients without premorbid headaches. Repeating the analysis in the patients with preconcussion headaches led to elimination of neck pain from the cluster.

CONCLUSIONS

PTH correlates strongly with other migraine symptoms among youth with concussion, regardless of premorbid headaches. This clustering of migraine symptoms supports the existence of PTM as a distinct clinical entity in some patients.

Athletic trainers' familiarity with and perceptions of academic accommodations in secondary school athletes after sport-related concussion

CONTEXT

Sport-related concussion can affect athletes' sport participation and academic success. With the recent emphasis on cognitive rest, student-athletes may benefit from academic accommodations (AA) in the classroom; however, athletic trainers' (ATs') perceived familiarity with, and use of, AA is unknown.

OBJECTIVE

To assess secondary school ATs' perceived familiarity with, attitudes and beliefs about, and incorporation of AA for student-athletes after sport-related concussion. A secondary purpose was to determine whether employment status altered familiarity and use of AA.

DESIGN

Cross-sectional study.

SETTING

Online survey.

PATIENTS OR OTHER PARTICIPANTS

Of 3286 possible respondents, 851 secondary school ATs accessed the survey (response rate = 25.9%; 308 men [36.2%], 376 women [44.2%], 167 respondents [19.6%] with sex information missing; age = 37.3 ± 10.1 years).

MAIN OUTCOME MEASURE(S)

Participants were solicited via e-mail to complete the Beliefs, Attitudes and Knowledge Following Pediatric Athlete Concussion among Athletic Trainers employed in the secondary school setting (BAKPAC-AT) survey. The BAKPAC-AT assessed ATs' perceived familiarity, perceptions, and roles regarding 504 plans, Individualized Education Programs (IEPs), and returning student-athletes to the classroom. Independent variables were employment status (full time versus part time), employment model (direct versus outreach), years certified, and years of experience in the secondary school setting. The dependent variables were participants' responses to the AA questions. Spearman rank-correlation coefficients were used to assess relationships and Mann-Whitney U and χ(2) tests (P < .05) were used to identify differences.

RESULTS

Respondents reported that approximately 41% of the student-athletes whose sport-related concussions they managed received AA. Respondents employed directly by the school were more familiar with 504 plans (P < .001) and IEPs (P < .001) and had a greater belief that ATs should have a role in AA. Both the number of years certified and the years of experience at the secondary school were significantly correlated with perceived familiarity regarding 504 plans and IEPs.

CONCLUSIONS

The ATs employed directly by secondary schools and those with more experience as secondary school ATs were more familiar with AA. Understanding AA is important for all ATs because cognitive rest and "return to learn" are becoming more widely recommended in concussion management.

Characteristics of prolonged concussion recovery in a pediatric subspecialty referral population

OBJECTIVE

To identify pre-existing characteristics associated with prolonged recovery from concussion in a sample of patients referred to a pediatric sports medicine clinic.

STUDY DESIGN

This was a retrospective, exploratory cohort study of 247 patients age 5-18 years with concussion referred to a tertiary pediatric hospital-affiliated sports medicine clinic from July 1, 2010, through December 31, 2011. A random sample of all eligible patient visits (3740) was chosen for further review and abstraction. Statistical comparisons between subsets of patients were conducted using exact χ(2) tests, logistic regression, quantile regression, and Kaplan-Meier survival curves.

RESULTS

The median time until returning to school part-time was 12 days (IQR 6-21); until returning to school full-time without accommodations was 35 days (IQR 11-105); until becoming symptom-free was 64 days (IQR 18-119); and until being fully cleared to return to sports was 75 days (IQR 30-153). Furthermore, 73% of all patients were symptomatic for >4 weeks, 73% were prescribed some form of school accommodation, and 61% reported a decline in grades. Characteristics associated with a prolonged recovery included a history of depression or anxiety; an initial complaint of dizziness; abnormal convergence or symptom provocation following oculomotor examination on physical examination; and history of prior concussion.

CONCLUSIONS

Pediatric and adolescent patients with concussion may experience cognitive and emotional morbidity that can last for several months following injury. Clinicians should consider specific pre-existing characteristics and presenting symptoms that may be associated with a more complicated recovery for concussion patients.

Concussion risk factors and strategies for prevention

Concussion in children is frequently related to participation in sports. It requires a traumatic event to occur that transmits acceleration to the brain. Some children may have intrinsic risk factors that place them at greater risk for this type of injury. Comorbidities such as attention-deficit/hyperactivity disorder, migraine headaches, and mood disorders may place athletes at increased risk of more severe injury. A previous concussion is probably the most important influence on risk for future injury. Extrinsic risk factors include coaching techniques, officiating, and choice of sport. Helmet choice does not diminish concussion risk, nor does the use of mouth guards. Education of athletes, coaches, parents, and physicians is very important in improving recognition of potential concussive injury and helping child athletes and their parents understand the risks involved in sport participation.

Factors that influence concussion knowledge and self-reported attitudes in high school athletes

BACKGROUND

Many organizations and health care providers support educating high school (HS) athletes about concussions to improve their attitudes and behaviors about reporting. The objectives of this study were to determine if previous education, sport played, and individual factors were associated with better knowledge about concussion and to determine if more knowledge was associated with improved self-reported attitudes toward reporting concussions among HS athletes.

METHODS

We conducted a survey of HS athletes aged 13 years to 18 years from two large, urban HSs. Players were recruited from selected seasonal (fall and winter) as well as men and women's sports. During preseason, each participant was given a survey asking about his or her previous education, current knowledge, and self-reported attitudes and behaviors about reporting concussions. Bivariate and multivariate linear regression was used to evaluate the association of age, sex, sport, and previous concussion education with knowledge and self-reported attitudes and behaviors about reporting concussions.

RESULTS

Surveys were completed by 496 athletes. The median age was 15 years, and 384 (77.4%) were male. A total of 212 (42.7%) participated in football, 123 (24.8%) in soccer, 89 (17.9%) in basketball, and 72 (14.5%) in wrestling. One hundred sixteen (23.4%) reported a history of concussion. Improved knowledge regarding concussions was not associated with improved self-reported behaviors (p = 0.63) in bivariate regression models. The multivariate model demonstrated that older age (p = 0.01) and female sex (p = 0.03) were associated with better knowledge. Younger age (p = 0.01), female sex (p = 0.0002), and soccer participation (p = 0.02) were associated with better self-reported behaviors around reporting concussions.

CONCLUSION

Previous education on concussions was less predictive of knowledge about concussions when controlling for other factors such as sport and sex. Younger age, female sex, and soccer participation were more likely to be associated with better self-reported behaviors. Future studies need to focus on the development of interventions to improve concussion-specific knowledge and behaviors.

Athletic trainers' management practices and referral patterns for adolescent athletes after sport-related concussion

BACKGROUND

Athletic trainers (ATs) play an important role in the evaluation, management, and referral of student-athletes after sport-related concussion. Understanding factors that influence ATs' patient care decisions is important to ensure best practices are followed.

PURPOSE

To identify ATs' current concussion management practices and referral patterns for adolescent student-athletes after sport-related concussion as well as the factors associated with those practices.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 851 participants from a convenience sample of 3286 ATs employed in the secondary school setting (25.9% response rate) completed the Athletic Trainers' Beliefs, Attitudes, and Knowledge of Pediatric Athletes with Concussions (BAKPAC-AT) survey. The BAKPAC-AT consists of several questions to assess ATs' concussion management, referral practices, and established relationships with other health care professionals.

RESULTS

The majority of ATs had a written concussion policy (82.4%, n = 701) and standing orders approved by their directing physician (67.3%, n = 573); 75.1% (n = 639) of ATs conduct baseline testing, with the majority using computerized neurocognitive tests (71.2%, n = 606). Follow-up concussion testing was employed by 81.8% (n = 696). Years of certification (P = 0.049) and type of secondary school (P = 0.033) predicted ATs' use of baseline testing. Nearly half of the respondents (48.8%, n = 415) refer 100% of concussion cases to a physician. The most influential factors that lead to a referral were state law (40.3%, n = 343), personal preference (34.7%, n = 295), and school district policy (24.8%, n = 211).

CONCLUSION

Of the ATs surveyed, most were engaged in baseline and follow-up testing, primarily with neurocognitive tests. Most ATs refer patients to physicians after concussion. While state regulation and personal preference were primary factors influencing referral decisions, it is unclear at what point of care the referral occurs.

Psychometric characteristics of the postconcussion symptom inventory in children and adolescents

Psychometric characteristics of the Postconcussion Symptom Inventory (PCSI) were examined in both concussed (n = 633) and uninjured (n = 1,273) 5 to 18 year olds. Parent- and self-report forms were created with developmentally appropriate wording and content. Factor analyses identified physical, cognitive, emotional, and sleep factors; that did not load strongly or discriminate between groups were eliminated. Internal consistency was strong for the total scales (α = 0.8-0.9). Test-retest reliability for the self-report forms was moderate to strong (intraclass coeffecients, ICCs = 0.65-0.89). Parent and self-report concordance was moderate (r = .44-.65), underscoring the importance of both perspectives. Convergent validity with another symptom measure was good (r = .8). Classification analyses indicated greater discriminability from parent report, but caveats to this are presented. With strong psychometric characteristics, the four versions of the PCSI capture important postconcussion symptoms and can be utilized to track recovery from pediatric concussion and guide treatment recommendations.

Sport-related concussions

Traumatic brain injury (TBI) is a major cause of lifelong disability and death worldwide. Sport-related traumatic brain injury is an important public health concern. The purpose of this review was to highlight the importance of sport-related concussions. Concussion refers to a transient alteration in consciousness induced by external biomechanical forces transmitted directly or indirectly to the brain. It is a common, although most likely underreported, condition. Contact sports such as American football, rugby, soccer, boxing, basketball and hockey are associated with a relatively high prevalence of concussion. Various factors may be associated with a greater risk of sport-related concussion, such as age, sex, sport played, level of sport played and equipment used. Physical complaints (headache, fatigue, dizziness), behavioral changes (depression, anxiety, irritability) and cognitive impairment are very common after a concussion. The risk of premature return to activities includes the prolongation of post-concussive symptoms and increased risk of concussion recurrence.

Effect of sex on symptoms and return to baseline in sport-related concussion

OBJECT

Sport-related concussions (SRCs) among youth athletes represent a significant public health concern. Prior research suggests that females fare worse symptomatically after an SRC. The authors aimed to assess sex differences in number, severity, and resolution of postconcussive symptoms using reliable change index (RCI) methodology applied to days to return to symptom baseline.

METHODS

Between 2009 and 2011, 740 youth athletes completed valid neurocognitive and symptom testing before and after an SRC using Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). A total of 122 female and 122 male athletes were matched on number of prior concussions, age, and number of days to first postconcussion test. At baseline and postconcussion, the authors compared each of the individual 22 symptoms on ImPACT to calculate individual symptom severity and aggregate symptom severity, or the Total Symptom Score (TSS). When comparing individual symptoms, the significance level for the comparison of each symptom was set at 0.05/22 = 0.0023. When comparing aggregate symptom severity, or TSS, a single value was compared, requiring an alpha set to 0.05. The number of days to return to baseline TSS was compared using RCI methods set at the 80% confidence interval, equal to a raw score point value of 9.18 on the TSS.

RESULTS

At baseline, females reported a greater severity for the symptom, "sleeping less than usual," compared with males (0.88 ± 1.49 vs 0.31 ± 0.86, p < 0.001). However, no other individual symptom severity differences were noted before or after SRC. At baseline, females exhibited a statistically significant greater aggregate symptom severity than males (7.24 ± 10.22 vs 4.10 ± 6.52, p = 0.005). Greater aggregate symptom severity for females was also found postconcussion (21.38 ± 19.02 vs 16.80 ± 17.07, p = 0.049). Females took longer to return to baseline TSS (9.1 ± 7.1 days vs 7.0 ± 5.1 days, p = 0.013).

CONCLUSIONS

The results of this retrospective study indicate that females endorse a greater severity of symptoms at baseline and postconcussion than males without significantly different symptom profiles. Furthermore, after suffering an SRC, females take longer to return to their baseline symptom level.

The Incidence of Concussion in a Professional Australian Rugby League Team, 1998-2012

Background. Rugby league is a physically demanding team sport and the National Rugby League is the highest-level competition of rugby league in Australia. Frequent tackles and collisions between players result in a high incidence of injury to players. Concussion injuries have been the source of much debate, with reporting varying greatly depending on the definition used. Method. Injury records of 239 players from one professional National Rugby League were analysed during a continuous period of 15 years, with particular interest in the incidence and recurrence of concussions and the change in incidence over time. Result. A total of 191 concussions were recorded, affecting 90 players. The incidence of concussion injuries was found to be 28.33 per 1000 player match hours, with an increase over time (P = 0.0217). Multiple concussions were recorded for 51 players. Conclusion. A statistically significant increase in the incidence of concussion injuries was found, without a concurrent increase in the number of head injuries or total injuries. New rules which mandate removal of players from the field may be beneficial for protection of players on the long term, although they risk being counterproductive, if they make players less likely to report their symptoms during matches.

Does age affect symptom recovery after sports-related concussion? A study of high school and college athletes

OBJECT

Sport-related concussions (SRCs) in high school and college athletes represent a significant public health concern. Research suggests that younger athletes fare worse symptomatically than older athletes after an SRC. Using reliable change index (RCI) methodology, the authors conducted a study to determine if there are age-related differences in number, severity, and resolution of postconcussion symptoms.

METHODS

Between 2009 and 2011, baseline measures of neurocognitive functions and symptoms in high school and college athletes were entered into a regional database. Seven hundred forty of these athletes later sustained an SRC. Ninety-two athletes in the 13- to 16-year-old group and 92 athletes in the 18- to 22-year-old group were matched for number of prior concussions, sex, biopsychosocial variables, and days to first postconcussion testing and symptom assessment. A nonparametric Mann-Whitney U-test was used to compare the severity of each of 22 symptoms comprising the Total Symptom Scale (TSS) at baseline and first postconcussion test. To obtain a family-wise p value of 0.05 for each test, the significance level for each symptom comparison was set at an alpha of 0.05/22 = 0.0023. The number of days to return to baseline TSS score was compared using the RCI methodology, set at the 80% confidence interval, equal to a change in raw score of 9.18 points on the TSS.

RESULTS

There was no statistically significant difference in symptom presence, symptom severity, and total symptoms between the age groups at baseline or at postconcussion testing. There was no statistically significant difference in return to baseline symptom scores between the age groups.

CONCLUSIONS

Using RCI methodology, there was no statistically significant difference between younger and older athletes in return to baseline symptoms postconcussion.

Baseline neurocognitive scores in athletes with attention deficit-spectrum disorders and/or learning disability

OBJECT

Up to 16% of children in the US between the ages of 3 and 17 years have either attention deficit-spectrum disorder or a learning disability (LD). Sports-related concussions among youth athletes represent a significant public health concern, and neurocognitive testing is a method to evaluate the severity of cognitive impairment and recovery after a sports-related concussion. The goal of this study was to assess baseline neurocognitive differences between athletes with attention deficit hyperactivity disorder (ADHD) and/or LD versus those with neither disorder and to establish normative data for these special populations.

METHODS

Between August 2007 and March 2012, 6636 young athletes underwent baseline neurocognitive testing performed using the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery. Of these participants, 90 had self-reported LD only, 262 had self-reported ADHD only, and 55 reported both. Those with ADHD and/or LD were matched with 407 participants with no history of ADHD or LD by age, sex, and number of prior concussions. The mean scores and SDs were calculated for each group to obtain normative values. A pairwise comparison between each diagnostic group was done to assess whether LD and/or ADHD diagnostic status predicted participants' baseline neurocognitive scores.

RESULTS

Participants with ADHD had significantly lower verbal memory, visual memory, and visual motor processing speed scores, along with significantly higher reaction time, impulse control, and symptom scores compared with those without LD or ADHD. Participants with LD had similar results, with significantly lower verbal memory, visual memory, and visual motor processing speed scores, higher reaction time and symptom score, but did not differ in their impulse control score compared with those without LD or ADHD. Participants with both LD and ADHD had a significantly lower visual motor speed score and a significantly higher reaction time and symptom score than those without LD or ADHD, but did not differ with regard to the other composite scores.

CONCLUSIONS

Athletes with ADHD and/or LD have lower baseline ImPACT neurocognitive scores compared with athletes without ADHD and LD. Preliminary normative neurocognitive data for these special populations are provided.

A pediatric perspective on concussion pathophysiology

PURPOSE OF REVIEW

According to recent Centers for Disease Control (CDC) data, the annual incidence of traumatic brain injury (TBI) in the United States is 1.6-3.2 million, of which the majority is classified as mild. Over half of these injuries occur in the pediatric population, and can often be attributed to a sports-related mechanism. Although postconcussion symptoms are usually short-lived, more lasting deficits can occur, which can be particularly disruptive to the developing brain. Recent literature detailing the pathophysiology of mild TBI (mTBI), with attention to pediatric studies, is presented.

RECENT FINDINGS

Although concussion generally does not produce any structural damage on conventional computed tomography (CT) or MRI, advanced neuroimaging modalities reveal microstructural and functional neurobiological changes. Diffuse axonal injury, metabolic impairment, alterations in neural activation and cerebral blood flow perturbations can occur and may contribute to acute symptomatology. Although these physiological changes usually recover to baseline in 7-10 days, sustaining recurrent injury before full recovery may increase the potential for persistent deficits.

SUMMARY

Understanding the pathophysiology of concussion in the pediatric population can potentially open therapeutic avenues to decrease symptom persistence and prevent further injury. Future studies in the pediatric population are necessary given the pathophysiologic differences between the developing and adult brains.