Revisiting the relevance of Hirano bodies in neurodegenerative diseases.

AIMS: Hirano bodies (HBs) are eosinophilic pathological structures with two morphological phenotypes commonly found in the hippocampal CA1 region in Alzheimer's disease (AD). This study evaluated the prevalence and distribution of HBs in AD and other neurodegenerative diseases. METHODS: This cross-sectional study systematically evaluated HBs in a cohort of 193 cases with major neurodegenerative diseases, including AD (n = 91), Lewy body disease (LBD, n = 87), progressive supranuclear palsy (PSP, n = 36), multiple system atrophy (MSA, n = 14) and controls (n = 26). The prevalence, number and morphology of HBs in the stratum lacunosum (HBL) and CA1 pyramidal cell layer were examined. In addition, we investigated the presence of HBs in five additional hippocampal subregions. RESULTS: The morphological types of HBs in CA1 were divided into three, including a newly discovered type, and were evaluated separately, with their morphology confirmed in three dimensions: (1) classic rod-shaped HB (CHB), (2) balloon-shaped HB (BHB) and the newly described (3) string-shaped HB (SHB). The prevalence of each HB type differed between disease groups: Compared with controls, for CHB in AD, AD + LBD, PSP and corticobasal degeneration, for BHB in AD + LBD and PSP, and SHB in AD + LBD and PSP were significantly increased. Regression analysis showed that CHBs were independently associated with higher Braak NFT stage, BHBs with LBD and TDP-43 pathology, SHBs with higher Braak NFT stage, PSP and argyrophilic grain disease and HBLs with MSA. CONCLUSIONS: This study demonstrates that HBs are associated with diverse neurodegenerative diseases and shows that morphological types appear distinctively in various conditions.

Persisting Concussion Symptoms from Bodychecking: Unrecognized Toll in Boys' Ice Hockey.

OBJECTIVES: Youth hockey is a high-impact sport and can cause concussions with lasting effects. We hypothesized that important injury prevention information would accrue from longitudinal tracking of concussed players with persisting concussion symptoms (PCS). METHODS: This case series comprised 87 consecutive concussed ice hockey players aged 10-18 including 66 males and 21 females referred to our Concussion Clinic from 1997 to 2017 and followed longitudinally by clinic visits and questionnaires. RESULTS: PCS occurred in 70 (80.4%) of 87 concussed players and lasted 1-168 months in males and 3-26 months in females. Bodychecking was the most common concussion mechanism in 34 (39.1%) players and caused PCS in 24 (70.6%) with symptom duration 4.00 [2.75, 14.50] months (median [IQR]). The remaining 53 players had other concussion mechanisms with PCS in 86.8% (p = 0.113) with similar duration (p = 0.848). CONCLUSIONS: This is the first longitudinal study of concussion with PCS in youth hockey and showed that symptoms can last for several years. Bodychecking was the commonest mechanism of prolonged disability from concussion in boys and girls' hockey with average PCS duration of 12.3 months but several years in some players. The injury prevention message is to raise the age of permitted bodychecking to 18 in boys' hockey from age 13 to 14 where it is currently. In this case series, this change could have prevented the majority of the bodycheck concussions and several years of suffering from PCS and is strong evidence for raising the permitted age for bodychecking in boys' ice hockey to age 18.

Examining later-in-life health risks associated with sport-related concussion and repetitive head impacts: a systematic review of case-control and cohort studies.

OBJECTIVE: Concern exists about possible problems with later-in-life brain health, such as cognitive impairment, mental health problems and neurological diseases, in former athletes. We examined the future risk for adverse health effects associated with sport-related concussion, or exposure to repetitive head impacts, in former athletes. DESIGN: Systematic review. DATA SOURCES: Search of MEDLINE, Embase, Cochrane, CINAHL Plus and SPORTDiscus in October 2019 and updated in March 2022. ELIGIBILITY CRITERIA: Studies measuring future risk (cohort studies) or approximating that risk (case-control studies). RESULTS: Ten studies of former amateur athletes and 18 studies of former professional athletes were included. No postmortem neuropathology studies or neuroimaging studies met criteria for inclusion. Depression was examined in five studies in former amateur athletes, none identifying an increased risk. Nine studies examined suicidality or suicide as a manner of death, and none found an association with increased risk. Some studies comparing professional athletes with the general population reported associations between sports participation and dementia or amyotrophic lateral sclerosis (ALS) as a cause of death. Most did not control for potential confounding factors (eg, genetic, demographic, health-related or environmental), were ecological in design and had high risk of bias. CONCLUSION: Evidence does not support an increased risk of mental health or neurological diseases in former amateur athletes with exposure to repetitive head impacts. Some studies in former professional athletes suggest an increased risk of neurological disorders such as ALS and dementia; these findings need to be confirmed in higher quality studies with better control of confounding factors. PROSPERO REGISTRATION NUMBER: CRD42022159486.

Guidelines for management of pediatric acute hyperextension spinal cord injury.

Pediatric acute hyperextension spinal cord injury (SCI) named as PAHSCI by us, is a special type of thoracolumbar SCI without radiographic abnormality and highly related to back-bend in dance training, which has been increasingly reported. At present, it has become the leading cause of SCI in children, and brings a heavy social and economic burden. Both domestic and foreign academic institutions and dance education organizations lack a correct understanding of PAHSCI and relevant standards, specifications or guidelines. In order to provide standardized guidance, the expert team formulated this guideline based on the principles of science and practicability, starting from the diagnosis, differential diagnosis, etiology, admission evaluation, treatment, complications and prevention. This guideline puts forward 23 recommendations for 14 related issues.

Delayed administration of elezanumab, a human anti-RGMa neutralizing monoclonal antibody, promotes recovery following cervical spinal cord injury.

Spinal cord injury (SCI) elicits a cascade of degenerative events including cell death, axonal degeneration, and the upregulation of inhibitory molecules which limit repair. Repulsive guidance molecule A (RGMa) is an axon growth inhibitor which is also involved in neuronal cell death and differentiation. SCI causes upregulation of RGMa in the injured rodent, non-human primate, and human spinal cord. Recently, we showed that delayed administration of elezanumab, a high affinity human RGMa-specific monoclonal antibody, promoted neuroprotective and regenerative effects following thoracic SCI. Since most human traumatic SCI is at the cervical level, and level-dependent anatomical and molecular differences may influence pathophysiological responses to injury and treatment, we examined the efficacy of elezanumab and its therapeutic time window of administration in a clinically relevant rat model of cervical impact-compression SCI. Pharmacokinetic analysis of plasma and spinal cord tissue lysate showed comparable levels of RGMa antibodies with delayed administration following cervical SCI. At 12w after SCI, elezanumab promoted long term benefits including perilesional sparing of motoneurons and increased neuroplasticity of key descending pathways involved in locomotion and fine motor function. Elezanumab also promoted growth of corticospinal axons into spinal cord gray matter and enhanced serotonergic innervation of the ventral horn to form synaptic connections caudal to the cervical lesion. Significant recovery in grip and trunk/core strength, locomotion and gait, and spontaneous voiding ability was found in rats treated with elezanumab either immediately post-injury or at 3 h post-SCI, and improvements in specific gait parameters were found when elezanumab was delayed to 24 h post-injury. We also developed a new locomotor score, the Cervical Locomotor Score, a simple and sensitive measure of trunk/core and limb strength and stability during dynamic locomotion.

Elezanumab, a human anti-RGMa monoclonal antibody, promotes neuroprotection, neuroplasticity, and neurorecovery following a thoracic hemicompression spinal cord injury in non-human primates.

Spinal cord injury (SCI) is a devastating condition characterized by loss of function, secondary to damaged spinal neurons, disrupted axonal connections, and myelin loss. Spontaneous recovery is limited, and there are no approved pharmaceutical treatments to reduce ongoing damage or promote repair. Repulsive guidance molecule A (RGMa) is upregulated following injury to the central nervous system (CNS), where it is believed to induce neuronal apoptosis and inhibit axonal growth and remyelination. We evaluated elezanumab, a human anti-RGMa monoclonal antibody, in a novel, newly characterized non-human primate (NHP) hemicompression model of thoracic SCI. Systemic intravenous (IV) administration of elezanumab over 6 months was well tolerated and associated with significant improvements in locomotor function. Treatment of animals for 16 weeks with a continuous intrathecal infusion of elezanumab below the lesion was not efficacious. IV elezanumab improved microstructural integrity of extralesional tissue as reflected by higher fractional anisotropy and magnetization transfer ratios in treated vs. untreated animals. IV elezanumab also reduced SCI-induced increases in soluble RGMa in cerebrospinal fluid, and membrane bound RGMa rostral and caudal to the lesion. Anterograde tracing of the corticospinal tract (CST) from the contralesional motor cortex following 20 weeks of IV elezanumab revealed a significant increase in the density of CST fibers emerging from the ipsilesional CST into the medial/ventral gray matter. There was a significant sprouting of serotonergic (5-HT) fibers rostral to the injury and in the ventral horn of lower thoracic regions. These data demonstrate that 6 months of intermittent IV administration of elezanumab, beginning within 24 h after a thoracic SCI, promotes neuroprotection and neuroplasticity of key descending pathways involved in locomotion. These findings emphasize the mechanisms leading to improved recovery of neuromotor functions with elezanumab in acute SCI in NHPs.

Unlocking the paradoxical endogenous stem cell response after spinal cord injury.

Nearly a century ago, the concept of the secondary injury in spinal cord trauma was first proposed to explain the complex cascade of molecular and cellular events leading to widespread neuronal and glial cell death after trauma. In recent years, it has been established that the ependymal region of the adult mammalian spinal cord contains a population of multipotent neural stem/progenitor cells (NSPCs) that are activated after spinal cord injury (SCI) and likely play a key role in endogenous repair and regeneration. How these cells respond to the various components of the secondary injury remains poorly understood. Emerging evidence suggests that many of the biochemical components of the secondary injury cascade which have classically been viewed as deleterious to host neuronal and glial cells may paradoxically trigger NSPC activation, proliferation, and differentiation thus challenging our current understanding of secondary injury mechanisms in SCI. Herein, we highlight new findings describing the response of endogenous NSPCs to spinal cord trauma, redefining the secondary mechanisms of SCI through the lens of the endogenous population of stem/progenitor cells. Moreover, we outline how these insights can fuel novel stem cell-based therapeutic strategies to repair the injured spinal cord.

Delayed administration of the human anti-RGMa monoclonal antibody elezanumab promotes functional recovery including spontaneous voiding after spinal cord injury in rats.

Spinal cord injury (SCI) often results in permanent functional loss due to a series of degenerative events including cell death, axonal damage, and the upregulation of inhibitory proteins that impede regeneration. Repulsive Guidance Molecule A (RGMa) is a potent inhibitor of axonal growth that is rapidly upregulated following injury in both the rodent and human central nervous system (CNS). Previously, we showed that monoclonal antibodies that specifically block inhibitory RGMa signaling promote neuroprotective and regenerative effects when administered acutely in a clinically relevant rat model of thoracic SCI. However, it is unknown whether systemic administration of RGMa blocking antibodies are effective for SCI after delayed administration. Here, we administered elezanumab, a human monoclonal antibody targeting RGMa, intravenously either acutely or at 3 h or 24 h following thoracic clip impact-compression SCI. Rats treated with elezanumab acutely and at 3 h post-injury showed improvements in overground locomotion and fine motor function and gait. Rats treated 24 h post-SCI trended towards better recovery demonstrating significantly greater stride length and swing speed. Treated rats also showed greater tissue preservation with reduced lesion areas. As seen with acute treatment, delayed administration of elezanumab at 3 h post-SCI also increased perilesional neuronal sparing and serotonergic and corticospinal axonal plasticity. In addition, all elezanumab treated rats showed earlier spontaneous voiding ability and less post-trauma bladder wall hypertrophy. Together, our data demonstrate the therapeutic efficacy of delayed systemic administration of elezanumab in a rat model of SCI, and uncovers a new role for RGMa inhibition in bladder recovery following SCI.

Primary care management of concussion in Canada.

Concussion has emerged as an important public health issue affecting thousands of Canadians annually. Health care providers including paediatricians, family and emergency medicine physicians, nurses, and nurse practitioners are commonly tasked with the responsibility of providing primary care to patients with acute concussion and those with persistent post-concussion symptoms. In July 2017, Parachute, in collaboration with the Public Health Agency of Canada and Sport Canada released the Canadian Guideline on Concussion in Sport that outlines a standardized and evidence-based approach to the recognition, diagnosis, and management of youth and adults with suspected concussion. In this report, we provide a brief overview of the important roles of primary care providers in the medical assessment, management, and prevention of concussion as outlined in this national best practice guideline.

Is Concussion a Risk Factor for Epilepsy?

BACKGROUND: Epidemiologic studies have suggested that concussion, or mild traumatic brain injury (mTBI), is associated with a twofold or greater increase in relative risk for the development of post-traumatic epilepsy. To assess the clinical validity of these findings, we analyzed the incidence of epilepsy in a large cohort of post-concussion patients in whom concussion was strictly defined according to international guidelines. METHODS: A retrospective cohort study of 330 consecutive post-concussion patients followed by a single concussion specialist. Exclusion criteria: abnormal brain CT/MRI, Glasgow Coma Scale48 hours. Independent variable: concussion. Outcome measure: epilepsy incidence (dependent variable). RESULTS: The mean number of concussions/patient was 3.3 (±2.5), mean age at first clinic visit 28 years (±14.7), and mean follow-up after first concussion 7.6 years (±10.8). Eight patients were identified whose medical records included mention of seizures or convulsions or epilepsy. Upon review by an epileptologist none met criteria for a definite diagnosis of epilepsy: four had episodic symptoms incompatible with epileptic seizures (e.g., multifocal paraesthesiae, multimodality hallucinations, classic migraine) and normal EEG/MRI investigations; four had syncopal (n=2) or concussive (n=2) convulsions. Compared with annual incidence (0.5/1000 individuals) in the general population, there was no difference in this post-concussion cohort (p=0.49). CONCLUSION: In this large cohort of post-concussion patients we found no increased incidence of epilepsy. For at least the first 5-10 years post-injury, concussion/mTBI should not be considered a significant risk factor for epilepsy. In patients with epilepsy and a past history of concussion, the epilepsy should not be presumed to be post-traumatic.

Concussion education in Canadian medical schools: a 5 year follow-up survey.

BACKGROUND: Despite concussion now being recognized as a public health priority in Canada, recent studies-including our 2012 survey of Canadian medical schools-have revealed major gaps in concussion education at the undergraduate medical school level. METHODS: We re-surveyed all 17 Canadian medical schools using a questionnaire divided in two categories: (1) concussion-specific education (2) head injury education incorporating a concussion component to determine whether there have been any improvements in concussion education at the medical school level during the last five years. For each year of medical school, respondents were asked to provide the estimated number of hours and teaching format for each category. RESULTS: We received replies from 13 of the 17 medical schools (76%). 11 of the 13 (85%) medical schools now reported providing concussion-specific education compared to 29% in our 2012 survey. The mean number of hours dedicated to category 1 learning in 2017 was 2.65 h compared to 0.57 in 2012, and the mean number of hours of category 2 increased to 7.5 from 1.54. CONCLUSION: Our follow-up study reveals increased exposure to concussion-related teaching in Canadian medical schools during the last five years. Persistent deficiencies in a minority of schools are highlighted. These should be addressed by reiterating the importance of concussion education for undergraduate medical students and by developing clear concussion-specific objectives at the national licensure level.

Legislation for Youth Sport Concussion in Canada: Review, Conceptual Framework, and Recommendations.

In this article, we conduct a review of introduced and enacted youth concussion legislation in Canada and present a conceptual framework and recommendations for future youth sport concussion laws. We conducted online searches of federal, provincial, and territorial legislatures to identify youth concussion bills that were introduced or successfully enacted into law. Internet searches were carried out from July 26 and 27, 2016. Online searches identified six youth concussion bills that were introduced in provincial legislatures, including two in Ontario and Nova Scotia and one each in British Columbia and Quebec. One of these bills (Ontario Bill 149, Rowan's Law Advisory Committee Act, 2016) was enacted into provincial law; it is not actual concussion legislation, but rather a framework for possible enactment of legislation. Two bills have been introduced in federal parliament but neither bill has been enacted into law. At present, there is no provincial or federal concussion legislation that directly legislates concussion education, prevention, management, or policy in youth sports in Canada. The conceptual framework and recommendations presented here should be used to guide the design and implementation of future youth sport concussion laws in Canada.

A systematic review of potential long-term effects of sport-related concussion.

OBJECTIVE: Systematic review of possible long-term effects of sports-related concussion in retired athletes. DATA SOURCES: Ten electronic databases. STUDY SELECTION: Original research; incidence, risk factors or causation related to long-term mental health or neurological problems; individuals who have suffered a concussion; retired athletes as the subjects and possible long-term sequelae defined as >10 years after the injury. DATA EXTRACTION: Study population, exposure/outcome measures, clinical data, neurological examination findings, cognitive assessment, neuroimaging findings and neuropathology results. Risk of bias and level of evidence were evaluated by two authors. RESULTS: Following review of 3819 studies, 47 met inclusion criteria. Some former athletes have depression and cognitive deficits later in life, and there is an association between these deficits and multiple prior concussions. Former athletes are not at increased risk for death by suicide (two studies). Former high school American football players do not appear to be at increased risk for later life neurodegenerative diseases (two studies). Some retired professional American football players may be at increased risk for diminishment in cognitive functioning or mild cognitive impairment (several studies), and neurodegenerative diseases (one study). Neuroimaging studies show modest evidence of macrostructural, microstructural, functional and neurochemical changes in some athletes. CONCLUSION: Multiple concussions appear to be a risk factor for cognitive impairment and mental health problems in some individuals. More research is needed to better understand the prevalence of chronic traumatic encephalopathy and other neurological conditions and diseases, and the extent to which they are related to concussions and/or repetitive neurotrauma sustained in sports.

Concussion diagnosis and management: Knowledge and attitudes of family medicine residents.

OBJECTIVE: To assess the knowledge of, attitudes toward, and learning needs for concussion diagnosis and management among family medicine residents. DESIGN: E-mail survey. SETTING: University of Toronto in Ontario. PARTICIPANTS: Family medicine residents (N = 348). MAIN OUTCOME MEASURES: To describe relationships between awareness of concussion management and lifestyle, education background, and residency placement, t tests and 2 tests were used as appropriate. Linear regression was used to compare self-reported concussion knowledge with knowledge scores. Thematic analysis was used to interpret answers to the qualitative question asking residents to describe challenges they foresee physicians facing when diagnosing and managing concussion. RESULTS: The residents who responded (n = 73, response rate 21%) correctly answered an average of 5.2 questions out of 9 (58%) regarding the diagnosis and management of concussion. Postgraduate year, sex, personal history of concussion, and clinical exposure to concussion were not significant factors in predicting the number of correct answers. Several misconceptions and knowledge gaps were revealed. Of residents who responded, 71% did not recognize chronic traumatic encephalopathy and only 63% recognized second-impact syndrome as consequences of repetitive concussions. Moreover, 32% of residents did not think that every individual with a concussion should see a physician as part of management. Knowledge scores did not predict self-reported concussion knowledge. Thematic analysis revealed 4 themes related to the challenges of concussion diagnosis and management: the nonspecificity and vagueness of symptoms, lack of formal diagnostic criteria, patient compliance with management, and counseling patients with respect to return to play, work, or learning. CONCLUSION: We found substantial gaps in knowledge surrounding concussion diagnosis and management among family medicine residents. This lack of knowledge should be addressed at both the undergraduate medical education level and the residency training level to improve concussion-related care and patient outcomes.

Chronic Traumatic Encephalopathy and Movement Disorders: Update.

Association of repetitive brain trauma with progressive neurological deterioration has been described since the 1920s. Punch drunk syndrome and dementia pugilistica (DP) were introduced first to explain symptoms in boxers, and more recently, chronic traumatic encephalopathy (CTE) has been used to describe a neurodegenerative disease in athletes and military personal with a history of multiple concussions. Although there are many similarities between DP and CTE, a number of key differences are apparent especially when comparing movement impairments. The aim of this review is to compare clinical and pathological aspects of DP and CTE with a focus on disorders of movement.

Experience with Canada's First Policy on Concussion Education and Management in Schools.

BACKGROUND: In response to the rising incidence of concussions among children and adolescents, the province of Ontario recently introduced the Ontario Policy/Program Memorandum on Concussions (PPM No. 158) requiring school boards to develop a concussion protocol. As this is the first policy of its kind in Canada, the impact of the PPM is not yet known. METHODS: An electronic survey was sent to all high school principals in the Toronto District School Board 1 year after announcement of the PPM. Questions covered extent of student, parent, and staff concussion education along with concussion management protocols. RESULTS: Of 109 high school principals contacted, 39 responded (36%). Almost all schools provided concussion education to students (92%), with most education delivered through physical education classes. Nearly all schools had return to play (92%) and return to learn (77%) protocols. Although 85% of schools educated staff on concussions, training was aimed at individuals involved in sports/physical education. Only 43.6% of schools delivered concussion education to parents, and many principals requested additional resources in this area. CONCLUSIONS: One year after announcement of the PPM, high schools in the Toronto District School Board implemented significant student concussion education programs and management protocols. Staff training and parent education required further development. A series of recommendations are provided to aid in future concussion policy development.

Update and Overview of Spinal Injuries in Canadian Ice Hockey, 1943 to 2011: The Continuing Need for Injury Prevention and Education.

OBJECTIVE: To identify spinal injuries in Canadian ice hockey from 2006 to 2011 and to discuss data from 1943 to 2011 and impact of injury prevention programs. DESIGN: Data about spinal injuries with and without spinal cord injury in ice hockey have been collected by ThinkFirst's (now Parachute Canada) Canadian Ice Hockey Spinal Injuries Registry since 1981 through questionnaires from practitioners, ice hockey organizations, and media. SETTING: All Canadian provinces and territories. PARTICIPANTS: All registered Canadian ice hockey players. ASSESSMENT OF RISK FACTORS: Age, gender, level of play, location, mechanism of injury. MAIN OUTCOME MEASURES: Incidence, incidence rate, prevalence, and nature (morbidity) of the injuries. RESULTS: Between 2006 and 2011, 44 cases occurred, 4 (9.1%) of which were severe. The incidence in the recent years continues to be lower than the peak years. From 1943 to 2011, 355 cases have been documented, primarily males (97.7%) and cervical spine injuries (78.9%), resulting from impact with the boards (64.2%). Check or push from behind (36.0%) was still the most common cause of injury, although slightly lower during 2006 to 2011. From 1943 to 2011, Prince Edward Island, New Brunswick, and British Columbia/Yukon had the highest injury rates. Ontario and Quebec continued to show markedly different injury rates, with Ontario more than twice that of Quebec. CONCLUSIONS: Current data for 2006 to 2011 indicate that spinal injuries in ice hockey continue to occur, although still at lower rates than the peak years 1982 to 1995. It is imperative to continue educating players and team officials about spinal injury prevention and to reinforce the rules against checking or pushing from behind to reduce the incidence of these serious injuries.

In search of evidence-based treatment for concussion: characteristics of current clinical trials.

UNLABELLED: Abstract Objective: To assess the characteristics of current clinical trials investigating the treatment of concussion. BACKGROUND: Recent systematic literature reviews have concluded that there is minimal evidence to support any specific treatment for concussion, including the principles of return-to-activity protocols such as type or duration of rest. DESIGN/METHODS: Clinical trial data was extracted from Clinicaltrials.gov and seven additional World Health Organization primary registries. The trial databases were accessed up until 3 October 2013. This study used search terms of 'concussion' or 'mild traumatic brain injury' (mTBI) and filtered for interventional trials. Trials that were terminated, already published or not interventional trials of concussion/mTBI were excluded. RESULTS: Of the 142 concussion/mTBI interventional clinical trials identified, 71 met inclusion criteria. Trials had a median estimated enrolment of 60 participants. There was a wide-range of treatments studied, including cognitive/behavioural therapies (28.2%), medications (28.2%), devices (11.3%), dietary supplements (8.5%), return-to-activity/rest (1.4%) and others (22.4%). Heterogeneity among trials for concussion identification/diagnosis and primary outcomes utilized was evident. Symptom-based questionnaires (39.4%) and neuropsychological tests (28.2%) were the most common outcome measures. CONCLUSIONS: Diverse, potentially promising therapeutics are currently being studied for the treatment of concussion. However, several deficiencies were identified including a paucity of trials addressing return-to-activity principles. Also, small sample size and trial heterogeneity may threaten scientific evaluation and subsequent clinical application.

Recommendations for policy development regarding sport-related concussion prevention and management in Canada.

The Canadian Concussion Collaborative (CCC) is composed of health-related organisations concerned with the recognition, treatment and management of concussion. Its mission is to create synergy between organisations concerned with concussion to improve education and implementation of best practices for the prevention and management of concussions. Each of the organisations that constitute the CCC has endorsed two recommendations that address the need for relevant authorities to develop policies about concussion management in sports. The recommendations were developed to support advocacy for regulations, policies or legislation to improve concussion prevention and management at all levels of sport.