When should an athlete retire or discontinue participating in contact or collision sports following sport-related concussion? A systematic review.

OBJECTIVE: To systematically review the scientific literature regarding factors to consider when providing advice or guidance to athletes about retirement from contact or collision sport following sport-related concussion (SRC), and to define contraindications to children/adolescent athletes entering or continuing with contact or collision sports after SRC. DATA SOURCES: Medline, Embase, SPORTSDiscus, APA PsycINFO, CINAHL and Cochrane Central Register of Controlled Trials were searched systematically. STUDY ELIGIBILITY CRITERIA: Studies were included if they were (1) original research, (2) reported on SRC as the primary source of injury, (3) evaluated the history, clinical assessment and/or investigation of findings that may preclude participation in sport and (4) evaluated mood disturbance and/or neurocognitive deficits, evidence of structural brain injury or risk factors for increased risk of subsequent SRC or prolonged recovery. RESULTS: Of 4355 articles identified, 93 met the inclusion criteria. None of the included articles directly examined retirement and/or discontinuation from contact or collision sport. Included studies examined factors associated with increased risk of recurrent SRC or prolonged recovery following SRC. In general, these were low-quality cohort studies with heterogeneous results and moderate risk of bias. Higher number and/or severity of symptoms at presentation, sleep disturbance and symptom reproduction with Vestibular Ocular Motor Screen testing were associated with prolonged recovery and history of previous concussion was associated with a risk of further SRC. CONCLUSION: No evidence was identified to support the inclusion of any patient-specific, injury-specific or other factors (eg, imaging findings) as absolute indications for retirement or discontinued participation in contact or collision sport following SRC. PROSPERO REGISTRATION NUMBER: CRD42022155121.

Clinical recovery from concussion-return to school and sport: a systematic review and meta-analysis.

OBJECTIVE: To define the time frames, measures used and modifying factors influencing recovery, return to school/learn (RTL) and return to sport (RTS) after sport-related concussion (SRC). DESIGN: Systematic review and meta-analysis. DATA SOURCES: 8 databases searched through 22 March 2022. ELIGIBILITY CRITERIA: Studies with diagnosed/suspected SRC and interventions facilitating RTL/RTS or investigating the time and modifying factors for clinical recovery. Outcomes included days until symptom free, days until RTL and days until RTS. We documented study design, population, methodology and results. Risk of bias was evaluated using a modified Scottish Intercollegiate Guidelines Network tool. RESULTS: 278 studies were included (80.6% cohort studies and 92.8% from North America). 7.9% were considered high-quality studies, while 23.0% were considered high risk of bias and inadmissible. The mean days until symptom free was 14.0 days (95% CI: 12.7, 15.4; I2=98.0%). The mean days until RTL was 8.3 (95% CI: 5.6, 11.1; I2=99.3%), with 93% of athletes having a full RTL by 10 days without new academic support. The mean days until RTS was 19.8 days (95% CI: 18.8, 20.7; I2=99.3%), with high heterogeneity between studies. Several measures define and track recovery, with initial symptom burden remaining the strongest predictor of longer days until RTS. Continuing to play and delayed access to healthcare providers were associated with longer recovery. Premorbid and postmorbid factors (eg, depression/anxiety, migraine history) may modify recovery time frames. Though point estimates suggest that female sex or younger age cohorts take longer to recover, the heterogeneity of study designs, outcomes and overlap in CIs with male sex or older age cohorts suggests that all have similar recovery patterns. CONCLUSION: Most athletes have full RTL by 10 days but take twice as long for an RTS. PROSPERO REGISTRATION NUMBER: CRD42020159928.

Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport-Amsterdam, October 2022.

For over two decades, the Concussion in Sport Group has held meetings and developed five international statements on concussion in sport. This 6th statement summarises the processes and outcomes of the 6th International Conference on Concussion in Sport held in Amsterdam on 27-30 October 2022 and should be read in conjunction with the (1) methodology paper that outlines the consensus process in detail and (2) 10 systematic reviews that informed the conference outcomes. Over 3½ years, author groups conducted systematic reviews of predetermined priority topics relevant to concussion in sport. The format of the conference, expert panel meetings and workshops to revise or develop new clinical assessment tools, as described in the methodology paper, evolved from previous consensus meetings with several new components. Apart from this consensus statement, the conference process yielded revised tools including the Concussion Recognition Tool-6 (CRT6) and Sport Concussion Assessment Tool-6 (SCAT6, Child SCAT6), as well as a new tool, the Sport Concussion Office Assessment Tool-6 (SCOAT6, Child SCOAT6). This consensus process also integrated new features including a focus on the para athlete, the athlete's perspective, concussion-specific medical ethics and matters related to both athlete retirement and the potential long-term effects of SRC, including neurodegenerative disease. This statement summarises evidence-informed principles of concussion prevention, assessment and management, and emphasises those areas requiring more research.

A Review of Legal, Ethical, and Governance Issues for Team Doctors.

OBJECTIVE: To provide a review and discussion of a range of legal and ethical issues commonly faced by team physicians, with reference to high-profile international integrity crises in sport that have involved doctors. The article also presents some recommendations and guidance for team doctors and sporting organizations. DATA SOURCES: Media reports, legal cases, and journal articles describing recent sporting integrity crises that have involved medical issues and governance reforms which are emerging in response. MAIN RESULTS: Many of the modern "integrity crises" in sport have a medical aspect (eg, doping cases, catastrophic injuries and illnesses, "Bloodgate" and other "medical cheating," sexual contact between doctors and athletes, harassment/bullying of doctors, concussion mismanagement, and management of the coronavirus pandemic in sport). A key issue is that while doctors bear ultimate responsibility for any perceived medical negligence, they do not always have ultimate power in decision-making. This is common in the traditional governance structure where the coach/manager "outranks" the doctor and can overrule medical decisions. There can be a blurring of the traditional doctor-patient relationship, especially on tour, and conflicts of interests occur when the needs of the employer/sporting organization differ from the player (patient). Further issues can arise in treating other staff members and players' family members. CONCLUSIONS: Doctors must be aware of range of important legal and ethical issues that arise in the team setting. Medical integrity crises have inspired governance reforms, such as policy development, appointment of chief medical officers, medical staff reporting to integrity departments, and sanctions of teams that breach medical integrity requirements. Sporting organizations must continue to implement and strengthen frameworks reinforcing doctors' seniority in the medical area.

Consent, capacity and compliance in concussion management: cave ergo medicus (let the doctor beware).

While the acute effects of concussion and mild traumatic brain injury (TBI) are well understood, the certainty in the medical literature regarding the long-term outcomes of sports-related concussion is limited. Long-term deficits that may result from single, repeated concussions, and possibly subconcussive impacts, include cognitive dysfunction, depression and executive dysfunction. Perhaps most troublingly, repetitive head impacts have been linked to neurodegenerative diseases, including chronic traumatic encephalopathy (CTE), although the precise risk of long-term consequences remains unknown. CTE represents a distinct tauopathy with an unknown incidence in athletic populations; however, a cause and effect relationship has not yet been demonstrated between CTE and concussions or between CTE and exposure to contact sports, as no prospective longitudinal studies have been performed to address that question. Studies of high-school sports exposure and long-term outcomes have not demonstrated consistent findings.Medical advice regarding return to play and the risk of acute and/or long-term consequences is therefore problematic. It is important that the individual's right to make their own choices regarding their health is respected. Team, coach, parental, peer or financial pressures should not influence this decision. The choice to return to play after a concussion or mild TBI injury is the athlete's decision once they have (1) recovered from their injury and have the legal capacity to make an informed decision; (2) been medically assessed and (3) been informed of any possible long-term risks in a language that they can understand.Given the current lack of certainty in relation to long-term outcomes from concussion, is it possible to provide a framework to inform players of current evidence, as part of a consent process, even if the information upon which the decision to return to sport is based remains uncertain and evolving?

What strategies can be used to effectively reduce the risk of concussion in sport? A systematic review.

AIM OR OBJECTIVE: To examine the effectiveness of concussion prevention strategies in reducing concussion risk in sport. DESIGN: Systematic review according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. DATA SOURCES: Eleven electronic databases searched and hand-search of references from selected studies. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: The following were the study inclusion criteria: (1) contained original human research data; (2) investigated an outcome of concussion or head impact; (3) evaluated a concussion prevention intervention; (4) included sport participants; (5) analytical study designand (6) peer-reviewed. The following were the exclusion criteria: (1) review articles, case series or case studies and (2) not in English. RESULTS: The studies selected (n=48) provided evidence related to protective gear (helmets, headgear, mouthguards) (n=25), policy and rule changes (n=13) and other interventions (training, education, facilities) (n=10). Meta-analyses demonstrate a combined effect of a 70% reduction (incidence rate ratio (IRR)=0.3 (95% CI: 0.22 to 0.41)) in concussion risk in youth ice hockey leagues where policy disallows body checking, and the point estimate (IRR=0.8 (95% CI: 0.6 to 1.1)) suggests a protective effect of mouthguards in contact and collision sport (basketball, ice hockey, rugby). SUMMARY/CONCLUSIONS: Highlights include a protective effect of helmets in skiing/snowboarding and the effectiveness of policy eliminating body checking in youth ice hockey. Future research should examine mouthguards in contact sport, football helmet padding, helmet fit in collision sport, policy limiting contact practice in youth football, rule enforcement to reduce head contact in ice hockey and soccer, ice surface size and board/glass flexibility in ice hockey and training strategies targeting intrinsic risk factors (eg, visual training). SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2016:CRD42016039162.

Cognitive and physical symptoms of concussive injury in children: a detailed longitudinal recovery study.

BACKGROUND: Recovery from concussion sustained in childhood and adolescence is poorly understood. We explored patterns of recovery for neurocognition and postconcussive symptoms following concussion in children and adolescents. METHODS: Using a prospective, longitudinal design, we collected baseline data on 728 children and adolescents aged 10-17 years. 10 participants sustained a concussive injury (n=10) in the 12 months following baseline testing and they were reviewed at day 5, 10 and 30 postconcussion. Assessments included the CogSport for Kids computerised test battery to evaluate neurocognitive function and self-report, and parent measures of postconcussive symptoms. At day 30, parents also completed measures rating their child's quality of life and executive functions. RESULTS: Children and adolescents displayed a gradual reduction in postconcussive symptoms over the 30 days following injury. At day 5, 87% of participants were reporting physical and cognitive symptoms, with a generalised reduction in all symptoms by day 10 (40% of participants). On the computerised measure, reaction time was slower after concussion, but returned to baseline levels by day 30. At day 30, 10% of participants demonstrated ongoing postconcussive symptoms. Number of previous concussions was related to speed of symptom resolution. CONCLUSIONS: At 5 days postconcussion, the majority of children and adolescents experienced debilitating postconcussive symptoms. However, by 30 days postinjury, 90% demonstrated recovery to normal for both neurocognition and postconcussive symptoms.

What are the most effective risk-reduction strategies in sport concussion?

AIM: To critically review the evidence to determine the efficacy and effectiveness of protective equipment, rule changes, neck strength and legislation in reducing sport concussion risk. METHODS: Electronic databases, grey literature and bibliographies were used to search the evidence using Medical Subject Headings and text words. Inclusion/exclusion criteria were used to select articles for the clinical equipment studies. The quality of evidence was assessed using epidemiological criteria regarding internal/external validity (eg, strength of design, sample size/power, bias and confounding). RESULTS: No new valid, conclusive evidence was provided to suggest the use of headgear in rugby, or mouth guards in American football, significantly reduced players' risk of concussion. No evidence was provided to suggest an association between neck strength increases and concussion risk reduction. There was evidence in ice hockey to suggest fair-play rules and eliminating body checking among 11-years-olds to 12-years-olds were effective injury prevention strategies. Evidence is lacking on the effects of legislation on concussion prevention. Equipment self-selection bias was a common limitation, as was the lack of measurement and control for potential confounding variables. Lastly, helmets need to be able to protect from impacts resulting in a head change in velocities of up to 10 and 7 m/s in professional American and Australian football, respectively, as well as reduce head resultant linear and angular acceleration to below 50 g and 1500 rad/s(2), respectively, to optimise their effectiveness. CONCLUSIONS: A multifactorial approach is needed for concussion prevention. Future well-designed and sport-specific prospective analytical studies of sufficient power are warranted.

Developmental Trajectory of Information-Processing Skills in Children: Computer-Based Assessment.

There are significant merits to a comprehensive cognitive assessment, but they are also time-consuming, costly, and susceptible to practice effects and may not detect change in the context of medical interventions or minor brain disruptions. Brief computer-based assessments focused on "fluid" cognitive domains (e.g., information-processing skills), which are vulnerable to disruption as a result of a brain injury, may provide an alternative assessment option. This study sought to: (a) examine the utility of a well-established, adult-based computerized tool, CogSport for Kids (CogState), for evaluating information-processing skills in children and adolescents; and (b) to report normative data for healthy children and adolescents. The study was a cross-sectional, community-based observational study of typically developing children aged 9 to 17 years old (N = 832). Participants completed the CogSport for Kids test battery, which includes six brief computerized tasks that assess cognitive functions including processing speed, attention, and working memory. Results showed an improvement with age for response speed and accuracy. The greatest change occurred between 9 and 12 years with performance stabilizing at 15 years. This brief screening tool is appropriate for clinical and research use in children aged 9 years and older and may be used to track cognitive development from childhood into adulthood and to identify children who deviate from normal expectations.