Tracy Blake

The impact of concussion on cardiac autonomic function: A systematic review

Abstract Primary objective: To evaluate the evidence regarding the effect of concussion on cardiac autonomic function (CAF). Inclusion criteria: Original research; available in English; included participants with concussion or mild traumatic brain injury (mTBI) and a comparison group; included measures of heart rate (HR) and/or heart rate variability (HRV) as outcomes. Studies of humans (greater than 6 years old) and animals were included. Critical appraisal tools: The Downs and Black (DB) criteria and Structured Effectiveness Quality Evaluation Scale (SEQES). Results: Nine full-length articles and four abstracts were identified. There is conflicting evidence regarding CAF at rest following concussion. There is evidence of elevated HR and reduced HRV with low-intensity, steady-state exercise up to 10 days following concussion. There was no significant difference in HRV during isometric handgrip testing or HR while performing cognitive tasks following concussion. The validity of current literature is limited by small sample sizes, lack of female or paediatric participants, methodological heterogeneity and lack of follow-up. Conclusions: While there is some evidence to suggest CAF is altered during physical activity following concussion, methodological limitations highlight the need for further research. Understanding the effect of concussion on CAF will contribute to the development of more comprehensive concussion management strategies.

The Effect of the “Zero Tolerance for Head Contact” Rule Change on the Risk of Concussions in Youth Ice Hockey Players

Background: Ice hockey is a popular winter sport in Canada. Concussions account for the greatest proportion of all injuries in youth ice hockey. In 2011, a policy change enforcing “zero tolerance for head contact” was implemented in all leagues in Canada. Purpose: To determine if the risk of game-related concussions and more severe concussions (ie, resulting in >10 days of time loss) and the mechanisms of a concussion differed for Pee Wee class (ages 11-12 years) and Bantam class (ages 13-14 years) players after the 2011 “zero tolerance for head contact” policy change compared with players in similar divisions before the policy change. Study Design: Cohort study; Level of evidence, 3. Methods: The retrospective cohort included Pee Wee (most elite 70%, 2007-2008; n = 891) and Bantam (most elite 30%, 2008-2009; n = 378) players before the rule change and Pee Wee (2011-2012; n = 588) and Bantam (2011-2012; n = 242) players in the same levels of play after the policy change. Suspected concussions were identified by a team designate and referred to a sport medicine physician for diagnosis. Incidence rate ratios (IRRs) were estimated based on multiple Poisson regression analysis, controlling for clustering by team and other important covariates and offset by game-exposure hours. Incidence rates based on the mechanisms of a concussion were estimated based on univariate Poisson regression analysis. Results: The risk of game-related concussions increased after the head contact rule in Pee Wee (IRR, 1.85; 95% CI, 1.20-2.86) and Bantam (IRR, 2.48; 95% CI, 1.17-5.24) players. The risk of more severe concussions increased after the head contact rule in Pee Wee (IRR, 4.12; 95% CI, 2.00-8.50) and Bantam (IRR, 7.91; 95% CI, 3.13-19.94) players. The rates of concussions due to body checking and direct head contact increased after the rule change. Conclusion: The “zero tolerance for head contact” policy change did not reduce the risk of game-related concussions in Pee Wee or Bantam class ice hockey players. Increased concussion awareness and education after the policy change may have contributed to the increased risk of concussions found after the policy change.

DO RISK FACTORS DIFFER FOR CONCUSSION AND PROLONGED RECOVERY FOLLOWING CONCUSSION IN ELITE YOUTH ICE HOCKEY PLAYERS

Background Pediatric concussion risk factor identification will facilitate targeted injury prevention strategy development. Objective To examine risk factors for concussion and prolonged recovery amongst elite youth ice hockey players. Design Cohort study. Setting Community ice rinks and sport medicine clinic (2011/12 season). Participants Male and female elite Bantam (13–14 years) and Midget (15-17 years) ice hockey players (n=780). Assessment of risk factors Baseline age group, sex, previous concussion history and SCAT2 component scores [Total Symptom Score (TSS), Balance Error Score (BES) and Standardized Assessment of Concussion (SAC) score] were evaluated. Main outcome measurements Players with a suspected concussion were referred to a sport medicine physician by team therapists/trainers (n=137). Concussions with time loss of >10 days were defined as prolonged recovery. Results Concussion incidence rate ratios (IRR) were estimated using multivariate (concussion) and univariate (prolonged recovery) Poisson regression analyses (cluster and exposure hours adjusted). Males were at greater risk than females [IRR=1.44 (95% CI: 1.09–1.90)]. In females with no concussion history, Bantam players were at greater risk than Midget players [IRR=4.04 (95% CI: 1.24–13.19)]. In Midget players, those with a history of concussion were at greater risk than those with no concussion history [IRR=2.68 (95% CI: 1.61–4.46)]. Players with baseline TSS in the lowest 25th %ile were at greater risk of concussion [IRR=1.50 (95% CI: 1.03–2.18)] and prolonged recovery [IRR=1.88 (95% CI: 1.18–2.99)]. Players with a history of concussion were at increased risk for prolonged recovery [IRR=2.02 (95% CI: 1.29–3.16)]. SAC and BES were not risk factors. Conclusions Age group, sex, previous concussion history, and baseline symptom reporting affected the risk of concussion and prolonged recovery in elite youth ice hockey players. This study will inform the development of youth sport concussion prevention strategies.

THE IMPACT OF CONCUSSION ON CARDIAC AUTONOMIC FUNCTION: A SYSTEMATIC REVIEW OF EVIDENCE FOR RECOVERY AND PREVENTION

Background Concussions can negatively impact cognitive, behavioural, and physiological function. The current standard of care does not account for the physiological impact of concussion. Cardiac autonomic function (CAF) is responsive to changes in physical and cognitive exertion in healthy populations. The influence of concussion on CAF is not well understood. Objective To evaluate the evidence regarding the effect of concussion on cardiac autonomic function. Design Systematic Review. Setting Databases [Medline, SportDiscus, HealthSTAR, PsycINFO, Web of Science, CINAHL, Cochrane Central Register of Controlled Trials, EMBASE, PubMed and ProQuest, Web of Science and Google Scholar] were systematically searched using keywords and MeSH terms. Sample Inclusion criteria: original research, available in English, included participants with concussion or mild traumatic brain injury (mTBI) and had a comparison group. Studies of humans (greater than 6 years old) and animals were included. Ten articles were identified for critical appraisal (six cohort studies, four cross-sectional). Independent variable Diagnosis of a concussion or mTBI. Main outcome measurements Heart rate (HR) and/or heart rate variability (HRV). Critical appraisal was conducted using the Downs and Black criteria. Results There is conflicting evidence regarding CAF at rest following concussion/mTBI. There is evidence of elevated HR and reduced HRV with low intensity, steady-state exercise up to 10 days following concussion. No significant difference in HRV was found during isometric handgrip testing following concussion. The validity of current literature is limited by small sample sizes, lack of female or pediatric participants, varying methodologies and lack of follow-up. No studies evaluating CAF during cognitive exertion following concussion were found. Conclusions There is evidence to suggest that CAF is altered during physical activity following concussion. The limitations in available literature highlight the need further research. Understanding the effect of concussion on CAF will contribute to the development of more comprehensive concussion management and prevention strategies.

We need to talk about manels: the problem of implicit gender bias in sport and exercise medicine

In 2015, a website (www.allmalepanels.tumblr.com/) began documenting instances of all-male panels (colloquially known as a ‘manel’). This, along with the Twitter hashtag #manel, has helped drive recognition of the persistent and pervasive gender bias in the composition of experts assembled to present at conferences and other events. Recent social media discussions have similarly highlighted the prevalence of all-male panels in Sport and Exercise Medicine (SEM). While, to our knowledge, all-male panel trends in SEM have not yet formally been documented or published, one need look no further than SEM conference committees, keynote speaker lists, panels and other events to see that it exists in practice. Why, in 2018, is SEM and its related disciplines still failing to identify and acknowledge the role that implicit bias plays in the very structure of our own research, practice and education? SEM is, after all, a profession that contains experts, and serves populations, of all genders. This editorial will introduce the definition, implications and manifestations of implicit gender bias and then explore how the SEM community can begin to address this issue, advance the discussion and develop a more equitable global community. Social cognitive theory describes ‘implicit bias’ as the unconscious …

The value of computerised neurocognitive testing at medical clearance to return to play following a sport-related concussion in youth ice hockey players

Objective To determine the value of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) tool in measuring neurocognitive recovery following concussion. Design Nested case-control. Setting Sport Medicine Centre, Alberta, Canada. Participants Ice hockey players (n=96; 88.5% male, 11-17 years old) following concussion who completed ImPACT at baseline and medical clearance to return to play (RTP) were compared to controls (n=31) matched for age, sex, and testing time interval. Assessment of risk factors Players who sustained a concussion were referred to a study physician for assessment and RTP clearance based on clinical assessment and SCAT2/3. Physicians were blinded to ImPACT scores. Outcome measures ImPACT composite scores were measured (i.?e., verbal memory, visual memory, reaction time, visual motor) at each time interval [i.e., baseline and RTP (cases)/second measurement (controls)]. Between-interval ImPACT reliable change scores (80%CI) were compared. Main results At RTP (Median days since injury: 22, range: 2–84), 43/96 (44.8%) concussed players and 11/31 (35.5%) controls had ≥1 composite scores reliably worse than at baseline. Conditional logistic regression analysis (n=31 matched pairs) did not demonstrate a difference in the odds of having ≥1 reliably worse composite score between concussed and controls [OR=2.00 (95% CI: 0.5–8.0)] or ≥1 reliably better composite score [OR=1.2 (95% CI: 0.37–3.93)]. Conclusions The utility of baseline ImPACT scores in medical decisions to RTP may be limited by the reliability of composite scores in youth populations. Caution is warranted when interpreting ImPACT scores post-concussion on an individual level using baseline performance. Future research including multivariable analyses is warranted in a larger sample. Competing interests Brian Brooks is a co-author of a paediatric memory test for which he receives royalties. No financial interests in ImPACT are declared. None for all other authors.

NEUROCOGNITIVE PERFORMANCE AT RETURN TO PLAY IN ELITE YOUTH HOCKEY PLAYERS WITH SPORT-RELATED CONCUSSION

Background Neurocognitive recovery following sport-related concussion is important for re-injury risk reduction. In elite youth hockey, it is unknown if neurocognitive function returns to baseline values at the time of medical clearance to return to play (RTP). Objective To determine if ImPACT composite scores have returned to baseline values at the time of medical clearance to RTP. Design Prospective case series. Setting Sport Medicine Clinics (Alberta, Canada). Participants Concussed elite male and female youth (13–17 years) ice hockey players (n=68) and healthy controls (n=22) completed ImPACT and SCAT2 testing at baseline and RTP following concussion. Main outcome measurements Team therapists/trainers referred concussed players to the study sport medicine physician. The physician determined RTP via symptom resolution and SCAT2 score normalization. Physicians were blinded to ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) composite scores (verbal memory, visual memory, reaction time and visual motor), which were used to evaluate neurocognitive performance. Results Comparisons between baseline and RTP ImPACT scores were based on reliable change (RC) scores derived from a sample of healthy players tested twice at baseline within 2 weeks (RC scores with 90% CI: verbal memory +/−14; visual memory, +/−15; reaction time, +/−0.1; and visual motor, +/−8). All four ImPACT composite scores were normalized at RTP in 73.5% (95C% CI: 61.5–82.8) of concussed participants and all but one [95.5%; 95% CI:70.39–99.46) controls. In the concussed players, 25.0% (95% CI: 16.0–36.9) had 1 composite score not return to baseline at RTP. One player had three composite scores not return to baseline at RTP. Conclusions Elite hockey players are often cleared for RTP without the benefit of knowing neurocognitive performance on ImPACT. In this cohort, 25% of concussed players who were cleared to return to hockey had 1 composite score that had not yet returned to baseline. These results may have implications for tertiary prevention.

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.

Educating the masses: suggestions for improving online concussion information via the mainstream media

It was said by Jim Morrison that “whoever controls the media controls the mind” [1] and the power of the media to shape and inform opinions has never been greater. Mainstream news outlets play a pivotal role in the modern age, and public health is included in the scope of influence of the media [2]. Previous research has explored how social media has portrayed sports concussion; Twitter has been highlighted for its rapid dissemination mechanisms [3], while concussion-related content on YouTube predominantly arose from news and media organizations [4]. Given the current high profile of sports concussion in the news, it is unsurprising that attention has turned toward its representation and portrayal in the media. A recent study from Ahmed and Hall [5] discussed the description of sports concussion in online news articles, and demonstrated inconsistencies in the terminology used to describe concussion. From 200 news articles retrieved, the terms ‘head injury’ and ‘brain injury’ were only used in 30 and 21% of cases, respectively, suggesting that the seriousness of these injuries may be downplayed by the terminology used to describe them. In addition, 10% of the articles used inappropriate modifiers, that is, words such as ‘mild’ or ‘moderate’ to describe the concussive injury. These descriptions were often made by journalists, leading the authors to create a checklist (the ‘Media Concussion Checklist’) in order to educate journalists and facilitate consistency in reporting about concussions. The descriptions used by the media in reference to concussion-related decision-making are noteworthy; for example, the decision by a 2016 Olympic Games gymnast to continue competing after a head injury being described as ‘lionhearted’ [6]. This phrasing creates a link between an individual’s personal character and healthcare decision-making that is inherently problematic. Although this scenario generated a debate regarding the logic of their decision to continue competing [7], this form of value-based description of concussion decision-making opens the doors for the opposite decision (i.e., removal from play) to be construed negatively (e.g., using descriptors such as ‘mouselike’ or ‘cowardly’). This is especially true given that decisionmaking processes surrounding injury disclosure and return to play are complex and multifactorial. Symptom-reporting remains a cornerstone of current concussion evaluation practice standards, however studies have demonstrated that athletes are not always consistent in disclosing potential concussive injuries [8]. The role that masculinity plays in association with concussion reporting has also been explored; Anderson and Kian [9] have suggested that there is a historical underpinning of masculinity to concussion reporting with regard to football in the USA, and similar cultural underpinnings are discussed by Hokowhitu toward Maori rugby Educating the masses: suggestions for improving online concussion information via the mainstream media “...the medical community should not attempt to shackle the journalistic world; rather they should work symbiotically with journalists, to allow them to create more medically accurate content for their readers.”

Clinical characteristics, referral patterns and time to recovery in youth and adults following a sport-related concussion (src)

Objective To describe the clinical characteristics, referral patterns and time to recovery in an acute sport-related concussion (SRC) clinic population. Design Prospective Case Series Setting Acute Sport Concussion Clinic (ASCC) Participants Patients aged 13-60 years seen within 4 weeks of SRC at the ASCC from September 2015–April 2016. Outcome measures Frequency, proportions, medians and interquartile ranges (IQR) were used to describe sex, age group, time from injury to assessment, referral sources, time to recovery (days), referrals to additional services, and attrition. Results ASCC assessments were requested by 111 patients a median of 9 days (IQR:4-17) post-concussion [33% female; 60 children [median age 15 years (IQR:14-16)], 51 adults [median age 31 years (IQR:21-42)]; attrition rate=10%]. Referral sources included: self-referral [n=94 (85%)], emergency department [n=9 (8%)], primary care physician [n=7 (5%)], and athletic therapist (n=1). Initial assessment occurred a median of 7 days (IQR:2-9) following the evaluation request. Patients underwent a standardised assessment including symptom scores, neurological, cervical spine and vestibulo-ocular screening a median of 17 days (IQR:9-25) post-concussion. There were 94 (85%) patients with clinical findings of cervical spine and/or vestibulo-ocular dysfunction. Treatment was received by 71/94 (76%) of patients with observed dysfunction. Medical clearance to return to play occurred a median of 30 days (IQR:21-107) post-concussion (n=51) . Conclusions A novel direct-access clinic specific to SRC assists in early triage, leading to expedited assessment, management and treatment in the early post-concussion period. Focused assessment assists in management and recovery with accelerated referral to appropriate services. Competing interests None.