Michael G. Hutchison

Emotional response to sport concussion compared to ACL injury

Primary objectives: To ascertain and compare the nature of emotional response of athletes to concussion and to anterior cruciate ligament (ACL) injury. Research design: Pre-injury, post-injury and longitudinal emotional functioning of athletes with concussion (n = 16), athletes with ACL injuries (n = 7) and uninjured athletes (n = 28) were compared in a prospective repeated-measures design. Methods and procedures: Participants completed the short version of the Profile of Mood States (POMS). ANOVAs and trend analysis were used to examine between and within group differences across time on two sub-scales, Total Mood Disturbance and Depression. Main outcomes and results: Athletes with ACL injury reported higher levels of depression for a longer duration than athletes with concussion. Relative to un-injured controls, athletes with concussion reported significant changes in Total Mood Disturbance and Depression post-injury, whereas athletes with ACL injuries reported significant changes in Depression scores only. Different patterns of post-injury emotional disturbance for the injured groups were observed by trend analyses. Conclusions: Concussed athletes do not report as much emotional disturbance as athletes with ACL injuries. Differential patterns of emotional disturbance were detected between injured groups. The authors recommended that clinical protocols and educational programmes address emotional sequelae associated with sport concussion and ACL injury.

Differential emotional responses of varsity athletes to concussion and musculoskeletal injuries.

Objective: To determine if athletes with concussion and those with minor musculoskeletal injuries experienced differential emotional response to injury. Design: A prospective longitudinal cohort study. Setting: University of Toronto, Ontario, Canada. Participants: Thirty-four injured athletes from Canadian Interuniversity Sport (CIS) and 19 healthy, physically active undergraduate students participated in the study. Intervention: All participants completed the Profile of Mood States (POMS; short version) on 3 nonconsecutive days during a 2-week period after a baseline test. Main Outcome Measures: Emotional responses were assessed using the POMS. The 7 main outcome measures assessed by POMS were tension, depression, anger, vigor, fatigue, confusion, and total mood disturbance. Results: After injury, concussion produced an emotional profile characterized by significantly elevated fatigue and decreased vigor. In contrast, athletes with musculoskeletal injuries displayed a significant increase in anger that resolved to a pre-injury level within 2 weeks. Conclusions: The results revealed that both injured groups experienced emotional disturbance after injury. More importantly, the findings strongly suggest that the emotional reaction after concussion is different from that of musculoskeletal injury. Therefore, we concluded that assessing emotional reactions to concussion is particularly important and recommend that sports medicine professionals assess and monitor emotional functioning as well as somatic complaints and neurocognitive changes during recovery.

A systematic video analysis of National Hockey League (NHL) concussions, part I: who, when, where and what?

Background Although there is a growing understanding of the consequences of concussions in hockey, very little is known about the precipitating factors associated with this type of injury. Aim To describe player characteristics and situational factors associated with concussions in the National Hockey League (NHL). Methods Case series of medically diagnosed concussions for regular season games over a 3.5-year period during the 2006–2010 seasons using an inclusive cohort of professional hockey players. Digital video records were coded and analysed using the Heads Up Checklist. Results Of 197 medically diagnosed concussions, 88% involved contact with an opponent. Forwards accounted for more concussions than expected compared with on-ice proportional representation (95% CI 60 to 73; p=0.04). Significantly more concussions occurred in the first period (47%) compared with the second and third periods (p=0.047), with the majority of concussions occurring in the defensive zone (45%). Approximately 47% of the concussions occurred in open ice, 53% occurred in the perimeter. Finally, 37% of the concussions involved injured players’ heads contacting the boards or glass. Conclusions This study describes several specific factors associated with concussions in the NHL, including period of the game, player position, body size, and specific locations on the ice and particular situations based on a players position.

Concussions and heading in soccer: a review of the evidence of incidence, mechanisms, biomarkers and neurocognitive outcomes.

Abstract Background: Soccer is currently the most popular and fastest-growing sport worldwide. Similar to many sports, soccer carries an inherent risk of injury, including concussion. Soccer is also unique in the use of ‘heading’. The present paper provides a comprehensive review of the research examining the incidence, mechanisms, biomarkers of injury and neurocognitive outcomes of concussions and heading in soccer. Methods: Seven databases were searched for articles from 1806 to 24 May 2013. Articles obtained by the electronic search were reviewed for relevance, with 229 selected for review. Ultimately, 49 articles met criteria for inclusion in the present review. Results: Female soccer players have a higher incidence of concussions than males. The most frequent injury mechanism is player-to-player contact for both genders. Few studies examined the effects of concussion in soccer players; however, neurocognitive outcomes were similar to those reported in the larger sport concussion literature, while the effect of heading is less clear. Conclusion: Despite variation in research designs and study characteristics, the outcomes of concussions in soccer align with the greater concussion literature. This review makes recommendations for future research to increase standardization of research for improved understanding of concussions in soccer as well as the effects of heading.

Blood Biomarkers in Moderate-To-Severe Traumatic Brain Injury: Potential Utility of a Multi-Marker Approach in Characterizing Outcome

Background Blood biomarkers are valuable tools for elucidating complex cellular and molecular mechanisms underlying traumatic brain injury (TBI). Profiling distinct classes of biomarkers could aid in the identification and characterization of initial injury and secondary pathological processes. This study characterized the prognostic performance of a recently developed multi-marker panel of circulating biomarkers that reflect specific pathogenic mechanisms including neuroinflammation, oxidative damage, and neuroregeneration, in moderate-to-severe TBI patients. Materials and methods Peripheral blood was drawn from 85 isolated TBI patients (n = 60 severe, n = 25 moderate) at hospital admission, 6-, 12-, and 24-h post-injury. Mortality and neurological outcome were assessed using the extended Glasgow Outcome Scale. A multiplex platform was designed on MULTI-SPOT® plates to simultaneously analyze human plasma levels of s100 calcium binding protein beta (s100B), glial fibrillary acidic protein (GFAP), neuron specific enolase (NSE), brain-derived neurotrophic factor (BDNF), monocyte chemoattractant protein (MCP)-1, intercellular adhesion molecule (ICAM)-5, and peroxiredoxin (PRDX)-6. Multivariable logistic regression and area under the receiver-operating characteristic curve (AUC) were used to evaluate both individual and combined predictive abilities of these markers for 6-month neurological outcome and mortality after TBI. Results Unfavorable neurological outcome was associated with elevations in s100B, GFAP, and MCP-1. Mortality was related to differences in six of the seven markers analyzed. Combined admission concentrations of s100B, GFAP, and MCP-1 were able to discriminate favorable versus unfavorable outcome (AUC = 0.83), and survival versus death (AUC = 0.87), although not significantly better than s100B alone (AUC = 0.82 and 0.86, respectively). Conclusion The multi-marker panel of TBI-related biomarkers performed well in discriminating unfavorable and favorable outcomes in the acute period after moderate-to-severe TBI. However, the combination of these biomarkers did not outperform s100B alone.

The role of apolipoprotein E episilon (ɛ)-4 allele on outcome following traumatic brain injury: A systematic review

Abstract Background: The apolipoprotein E gene (APOE) has emerged as a candidate for prognosticating traumatic brain injury (TBI) recovery, with APOEɛ4 identified as a susceptibility marker for poor outcome, despite large discrepancy in its reported influence post-TBI. Methods: A systematic review was conducted, including all primary articles investigating the role of APOEɛ4 on TBI outcome. A total of 65 studies were included, including 24 predominantly investigating mild (mTBI), seven moderate (modTBI) and 33 severe (sTBI); severity was not reported in one study. Results: In mTBI studies, the association between APOEɛ4 and post-TBI outcome was concluded as non-contributory in 14 studies (58.3%), hazardous in nine (37.5%) and protective in one (4.2%). In sTBI studies, the role of APOEɛ4 was hazardous in 21 (63.6%), non-contributory in nine (27.3%) and protective in three (9.1%). Of the seven studies investigating dementia outcomes, four observed a hazardous association with APOEɛ4, while three reported no association. Six studies examined Alzheimer’s dementia pathology, of which three reported a hazardous influence of APOEɛ4. Conclusions: The influence of APOEɛ4 on neuropsychological testing, functional outcome and in paediatric populations was incongruous. This review supports the majority of research indicating APOEɛ4 adversely influences recovery following TBI, particularly with respect to dementia-related outcomes and outcomes following sTBI.

Head Trauma in Mixed Martial Arts

Background: Mixed martial arts (MMA) is a full combative sport with a recent global increase in popularity despite significant scrutiny from medical associations. To date, the empirical research of the risk of head injuries associated with this sport is limited. Youth and amateur participation is growing, warranting investigation into the burden and mechanism of injuries associated with this sport. Purpose: (1) To determine the incidence, risk factors, and characteristics of knockouts (KOs) and technical knockouts (TKOs) from repetitive strikes in professional MMA; and (2) to identify the mechanisms of head trauma and the situational factors that lead to KOs and TKOs secondary to repetitive strikes through video analysis. Study Design: Descriptive epidemiology study. Methods: Competition data and video records for all KOs and TKOs from numbered Ultimate Fighting Championship MMA events (n = 844) between 2006 to 2012. Analyses included (1) multivariate logistic regression to investigate factors associated with an increased risk of sustaining a KO or TKO secondary to repetitive strikes and (2) video analysis of all KOs and TKOs secondary to repetitive strikes with descriptive statistics. Results: During the study period, the KO rate was 6.4 per 100 athlete-exposures (AEs) (12.7% of matches), and the rate of TKOs secondary to repetitive strikes was 9.5 per 100 AEs (19.1% of matches), for a combined incidence of match-ending head trauma of 15.9 per 100 AEs (31.9% of matches). Logistic regression identified that weight class, earlier time in a round, earlier round in a match, and older age were risk factors for both KOs and TKOs secondary to repetitive strikes. Match significance and previously sustained KOs or TKOs were also risk factors for KOs. Video analysis identified that all KOs were the result of direct impact to the head, most frequently a strike to the mandibular region (53.9%). The average time between the KO-strike and match stoppage was 3.5 seconds (range, 0-20 seconds), with losers sustaining an average of 2.6 additional strikes (range, 0-20 strikes) to the head. For TKOs secondary to strikes, in the 30-second interval immediately preceding match stoppage, losers sustained, on average, 18.5 strikes (range, 5-46 strikes), with 92.3% of these being strikes to the head. Conclusion: Rates of KOs and TKOs in MMA are higher than previously reported rates in other combative and contact sports. Public health authorities and physicians should be cognizant of the rates and mechanisms of head trauma. Preventive measures to lessen the risks of head trauma for those who elect to participate in MMA are described.

A systematic video analysis of National Hockey League (NHL) concussions, part II: how concussions occur in the NHL

Background Concussions in sports are a growing cause of concern, as these injuries can have debilitating short-term effects and little is known about the potential long-term consequences. This work aims to describe how concussions occur in the National Hockey League. Methods Case series of medically diagnosed concussions for regular season games over a 3.5-year period during the 2006–2010 seasons. Digital video records were coded and analysed using a standardised protocol. Results 88% (n=174/197) of concussions involved player-to-opponent contact. 16 diagnosed concussions were a result of fighting. Of the 158 concussions that involved player-to-opponent body contact, the most common mechanisms were direct contact to the head initiated by the shoulder 42% of the time (n=66/158), by the elbow 15% (n=24/158) and by gloves in 5% of cases (n=8/158). When the results of anatomical location are combined with initial contact, almost half of these events (n=74/158) were classified as direct contact to the lateral aspect of the head. Conclusions The predominant mechanism of concussion was consistently characterised by player-to-opponent contact, typically directed to the head by the shoulder, elbow or gloves. Also, several important characteristics were apparent: (1) contact was often to the lateral aspect of the head; (2) the player who suffered a concussion was often not in possession of the puck and (3) no penalty was called on the play.

The Influence of Musculoskeletal Injury on Cognition: Implications for Concussion Research

Background: Safe return-to-play decisions after concussion can be challenging for sports medicine specialists. Neuropsychological testing is recommended to objectively measure concussion-related cognitive impairments. Purpose: The objective of this study was to measure cognitive functioning among 3 specific athletic groups: (1) athletes with no injuries (n = 36), (2) athletes with musculoskeletal injuries (n = 18), and (3) athletes with concussion (n = 18). Study Design: Case-control study; Level of evidence, 3. Methods: Seventy-two intercollegiate athletes completed preseason baseline cognitive testing and follow-up assessment using the Automated Neuropsychological Assessment Metrics (ANAM) test battery. Injured athletes were tested within 72 hours of injury. A 1-way analysis of covariance adjusted for baseline scores was performed to determine if differences existed in cognitive test scores among the 3 groups. Results: A group of athletes with concussion performed significantly worse than a group of athletes with no injuries on the following subtests of the ANAM at follow-up: Code Substitution Learning, Match to Sample, and Simple Reaction. Athletes with musculoskeletal injuries performed significantly worse than those with no injury on the Match to Sample subtest. No significant differences between athletes with concussion and athletes with musculoskeletal injuries were found on all ANAM subtests. Conclusion: Concussion produces cognitive impairment in the acute recovery period. Interestingly, athletes with musculoskeletal injuries also display a degree of cognitive impairment as measured by computerized tests. Clinical Relevance: Although these findings support previous research that neuropsychological tests can effectively measure concussion-related cognitive impairment, this study provides evidence that athletic injury, in general, also may produce a degree of cognitive disruption. Therefore, a narrow interpretation of scores of neuropsychological tests in a sports concussion context should be avoided.

Evaluating the methodological quality of sports neuropsychology concussion research: A systematic review

Primary objective: Sports-related concussion is a frequently-occurring, serious neurological event that can produce a spectrum of potentially debilitating primary and secondary problems. Many investigators—particularly neuropsychologists—have focused their efforts on identifying cognitive changes that accompany such injuries. As such, the present review evaluated the methodological quality of neuropsychological sports-related concussion research using a comprehensive, systematic method. Research design: Of 349 studies initially selected by search criteria, a total of 43 studies were evaluated using a Cochrane-style review format. Research methods: Studies were assigned a Level of Evidence using the Centre for Evidence-based Medicine (CEMB) framework. Relevant information related to the methods of each study were extracted and rated for methodological quality using a standardized form-based evaluation tool. Results: The review revealed heterogeneity among the studies in terms of research design, as well as a number of methodological weaknesses and inconsistencies. Conclusion: Despite the proliferation of neuropsychological research on sports-related concussion over the past decade, the methodological quality of studies appears to be highly variable, with many lacking proper scientific rigour. Future research in this area needs to be carefully controlled, repeatable and generalizable, which will contribute to developing practical, evidence-based guidelines for concussion management.