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

Preamble This paper is a revision and update of the recommendations developed following the 1st (Vienna) and 2nd (Prague) International Symposia on Concussion in Sport.1,2 The Zurich Consensus statement is designed to build on the principles outlined in the original Vienna and Prague documents and to develop further conceptual understanding of this problem using a formal consensus-based approach. A detailed description of the consensus process is outlined at the end of this document under the “Background” section (see Section 11). This document is developed for use by physicians, therapists, certified athletic trainers, health professionals, coaches and other people involved in the care of injured athletes, whether at the recreational, elite or professional level. While agreement exists pertaining to principal messages conveyed within this document, the authors acknowledge that the science of concussion is evolving and therefore management and return to play decisions remain in the realm of clinical judgment on an individualized basis. Readers are encouraged to copy and distribute freely the Zurich Consensus document and/or the Sport Concussion Assessment Tool (SCAT2) card, and neither is subject to any copyright restriction. The authors request, however, that the document and/or the SCAT2 card be distributed in their full and complete format. The following focus questions formed the foundation for the Zurich concussion consensus statement: Acute Simple Concussion Which symptom scale and which sideline assessment tool is best for diagnosis and/or follow up? How extensive should the cognitive assessment be in elite athletes? How extensive should clinical and neuropsychological (NP) testing be at non-elite level? Who should do/interpret the cognitive assessment? Is there a gender difference in concussion incidence and outcomes? Return to Play (RTP) Issues Is provocative exercise testing useful in guiding RTP? What is the best RTP strategy for elite athletes? What is the best RTP strategy for non-elite athletes? Is protective equipment (eg, mouthguards and helmets) useful in reducing concussion incidence and/or severity? Complex Concussion and Long-term Issues Is the Simple versus Complex classification a valid and useful differentiation? Are there specific patient populations at risk of long-term problems? Is there a role for additional tests (eg, structural and/or functional MR Imaging, balance testing, biomarkers)? Should athletes with persistent symptoms be screened for depression/anxiety? Paediatric Concussion Which symptoms scale is appropriate for this age group? Which tests are useful and how often should baseline testing be performed in this age group? What is the most appropriate RTP guideline for elite and non-elite child and adolescent athletes? Future Directions What is the best method of knowledge transfer and education? Is there evidence that new and novel injury prevention strategies work (eg, changes to rules of the game, fair play strategies, etc.)? The Zurich document additionally examines the management issues raised in the previous Prague and Vienna documents and applies the consensus questions to these areas. SPECIFIC RESEARCH QUESTIONS AND CONSENSUS DISCUSSION 1. CONCUSSION 1.1 Definition of Concussion Panel discussion regarding the definition of concussion and its separation from mild traumatic brain injury (mTBI) was held. Although there was acknowledgement that the terms refer to different injury constructs and should not be used interchangeably, it was not felt that the panel would define mTBI for the purpose of this document. There was unanimous agreement, however, that concussion is defined as follows: Concussion is defined as a complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces. Several common features that incorporate clinical, pathologic and biomechanical injury constructs that may be utilized in defining the nature of a concussive head injury include: Concussion may be caused either by a direct blow to the head, face, neck or elsewhere on the body with an ‘‘impulsive’’ force transmitted to the head. Concussion typically results in the rapid onset of short-lived impairment of neurologic function that resolves spontaneously. Concussion may result in neuropathological changes, but the acute clinical symptoms largely reflect a functional disturbance rather than a structural injury. Concussion results in a graded set of clinical symptoms that may or may not involve loss of consciousness. Resolution of the clinical and cognitive symptoms typically follows a sequential course; however, it is important to note that, in a small percentage of cases, post-concussive symptoms may be prolonged. No abnormality on standard structural neuroimaging studies is seen in concussion. 1.2 Classification of Concussion There was unanimous agreement to abandon the Simple vs. Complex terminology that had been proposed in the Prague agreement statement, as the panel felt that the terminology itself did not fully describe the entities. However, the panel unanimously retained the concept that the majority (80%-90%) of concussions resolve in a short (7-10 day) period, although the recovery time frame may be longer in children and adolescents.2 2. CONCUSSION EVALUATION 2.1 Symptoms and Signs of Acute Concussion The panel agreed that the diagnosis of acute concussion usually involves the assessment of a range of domains including clinical symptoms, physical signs, behavior, balance, sleep and cognition. Furthermore, a detailed concussion history is an important part of the evaluation both in the injured athlete and when conducting a pre-participation examination. The detailed clinical assessment of concussion is outlined in the SCAT2 form, which is an appendix to this document. The suspected diagnosis of concussion can include one or more of the following clinical domains: (a) Symptoms: somatic (eg, headache), cognitive (eg, feeling like in a fog) and/or emotional symptoms (eg, lability) (b) Physical signs (eg, loss of consciousness, amnesia) (c) Behavioural changes (eg, irritablity) (d) Cognitive impairment (eg, slowed reaction times) (e) Sleep disturbance (eg, drowsiness) If any one or more of these components is present, a concussion should be suspected and the appropriate management strategy instituted. 2.2 On-field or Sideline Evaluation of Acute Concussion When a player shows ANY features of a concussion: (a) The player should be medically evaluated onsite using standard emergency management principles, and particular attention should be given to excluding a cervical spine injury. (b) The appropriate disposition of the player must be determined by the treating healthcare provider in a timely manner. If no healthcare provider is available, the player should be safely removed from practice or play and urgent referral to a physician arranged. (c) Once the first aid issues are addressed, then an assessment of the concussive injury should be made using the SCAT2 or other similar tool. (d) The player should not be left alone following the injury, and serial monitoring for deterioration is essential over the initial few hours following injury. (e) A player with diagnosed concussion should not be allowed to return to play on the day of injury. Occasionally, in adult athletes, there may be return to play on the same day as the injury. (See section 4.2.) It was unanimously agreed that sufficient time for assessment and adequate facilities should be provided for the appropriate medical assessment both on and off the field for all injured athletes. In some sports this may require rule change to allow an off-field medical assessment to occur without affecting the flow of the game or unduly penalizing the injured player's team. Sideline evaluation of cognitive function is an essential component in the assessment of this injury. Brief neuropsychological test batteries that assess attention and memory function have been shown to be practical and effective. Such tests include the Maddocks questions3,4 and the Standardized Assessment of Concussion (SAC).5-7 It is worth noting that standard orientation questions (eg, time, place, person) have been shown to be unreliable in the sporting situation when compared with memory assessment.4,8 It is recognized, however, that abbreviated testing paradigms are designed for rapid concussion screening on the sidelines and are not meant to replace comprehensive neuropsychological testing which is sensitive to detect subtle deficits that may exist beyond the acute episode nor should they be used as a stand-alone tool for the ongoing management of sports concussions. It should also be recognized that the appearance of symptoms might be delayed several hours following a concussive episode. 2.3 Evaluation in Emergency Room or Office by Medical Personnel An athlete with concussion may be evaluated in the emergency room or doctor's office as a point of first contact following injury or may have been referred from another care provider. In addition to the points outlined above, the key features of this exam should encompass: (a) A medical assessment including a comprehensive history and detailed neurological examination including a thorough assessment of mental status, cognitive functioning and gait and balance. (b) A determination of the clinical status of the patient including whether there has been improvement or deterioration since the time of injury. This may involve seeking additional information from parents, coaches, teammates and eyewitness to the injury. (c) A determination of the need for emergent neuroimaging in order to exclude a more severe brain injury involving a structural abnormality. In large part, these points above are included in the SCAT2 assessment, which forms part of the Zurich consensus statement. 3. CONCUSSION INVESTIGATIONS A range of additional investigations may be utilized to assist in the diagnosis and/or exclusion of injury. These include: 3.1 Neuroimaging It was recognized by the panelists that conventional structural neuroimaging is normal in concussive injury. Given that caveat, the following suggestions are made: Brain CT (or, where available, MR brain scan) contributes little to concussion evaluation but should be employed whenever suspicion of an intra-cerebral structural lesion exists. Examples of such situations may include prolonged disturbance of conscious state, focal neurological deficit or worsening symptoms. Newer structural MRI modalities including gradient echo, perfusion and diffusion imaging have greater sensitivity for structural abnormalities. However, the lack of published studies, as well as absent pre-injury neuroimaging data, limits the usefulness of this approach in clinical management at the present time. In addition, the predictive value of various MR abnormalities that may be incidentally discovered is not established at the present time. Other imaging modalities such as fMRI demonstrate activation patterns that correlate with symptom and recovery in not part of assessment at the present time, they additional to pathophysiological imaging (eg, diffusion functional some are at of and be other than in a Assessment studies using both force as well as using clinical balance tests (eg, have deficits hours following concussion. It that testing a useful tool for the of neurologic functioning and should be a and valid addition to the assessment of athletes from where symptoms or signs a balance Assessment The of neuropsychological (NP) testing in concussion has been shown to be of clinical value and to information in concussion Although in most cognitive recovery largely with the time of symptom it has been that cognitive recovery may or more follow clinical symptom that the assessment of cognitive function should be an important component in any return to play It must be however, that assessment should not be the of management it should be seen as an aid to the clinical process in with a range of clinical domains and are in the best to tests by of their and However, there may be situations where are not and other medical may or screening The return to play should remain a medical one in which a when has been In the of and other (eg, formal balance testing, a more return to play approach may be In the majority of cases, testing be used to assist return to play decisions and not be the patient is symptom There may be situations (eg, child and adolescent where testing may be performed the patient is to assist in This be best determined in with a The of and other in the management of sports concussion risk or injury is at this from and studies in more severe traumatic brain injury of a of and such and such are in sporting concussion is not at this Concussion Assessment (eg, and have abnormalities in the concussive however, not all studies athletes from The clinical of these changes to be In addition, and of brain injury specific have been proposed as by which may be There is however, to the use of these CONCUSSION The of concussion management is physical and cognitive symptoms resolve and then a graded of to medical and return to The recovery and of this injury may be by a of that may require more management These are outlined in the section on above, the majority of over several In these it is that an athlete a return to play this of following an injury, it is important to to the athlete that physical AND cognitive is that require and attention (eg, may symptoms and In such cases, from physical and cognitive other for no further is the of and the athlete typically without further Return to Play Return to play following a concussion follows a process as outlined in Return to Play this the athlete should to to the at the level. should hours that an athlete would one to the full they are at and with provocative If any symptoms occur in the then the patient should to the previous and to a further of has RTP adult athletes, in some where there are in concussion management and sufficient (eg, to as well as to assessment, return to play management may be more The RTP strategy must follow the same management principles, full clinical and cognitive recovery of return to This approach is by published such as the of Consensus and This was by the consensus and it was that there is evidence that some professional are to RTP more with same day RTP by studies without a risk of or There is data, however, that, at the and athletes allowed to RTP on the same day may demonstrate deficits that may not be on the sidelines and are more to have delayed onset of It should be however, that the elite athlete should be more the may be the same as an professional (See section and Issues In addition, may have in this injury, with the are also encouraged to the athlete for symptoms such as as these symptoms may be common in The of in sports concussion may be in The first of these situations is the management of specific prolonged symptoms (eg, sleep The situation is where is used to the of the with the of the of the concussion In this approach to management should be by in concussion An important in RTP is that athletes should not be symptom but also should not be any that may or the symptoms of concussion. may be the management of a the to return to play on such must be by the treating The of Concussion Evaluation the of a concussion and the that athletes not all the concussions they may have in the a detailed concussion history is of Such a history may athletes that a risk and an for the healthcare provider to the athlete in to the of concussive injury. A concussion history should include specific questions as to previous symptoms of a not the of concussions. It is also worth noting that the of concussive by teammates or coaches has been to be The clinical history should also include information all previous head, or cervical spine as these may also have clinical It is worth that, in the of and cervical spine concussive may be pertaining to versus symptom may the to a to injury. part of the clinical history it is that regarding protective equipment employed at time of injury be both for and The a comprehensive pre-participation concussion evaluation for and of protective and is an for CONCUSSION The consensus panel agreed that a range of may the and management of concussion and in some may the for prolonged or persistent symptoms. These would also be important to in a detailed concussion history and are outlined in Concussion this there may be additional management beyond RTP There may be a more important role for additional investigations including formal testing, balance assessment, and It is that athletes with such features would be in a by a physician with specific in the management of concussive injury. The role of gender as a in the management of concussion was at by the There was not unanimous agreement that the published evidence is that this should be included as a although it was that gender may be a risk for injury and/or injury The of of In the management of to severe traumatic brain injury, of is an of published in concussion describe with specific cognitive it has not been as a of injury Consensus discussion determined that prolonged would be as a that may The of and Other Symptoms There is in the role of and its role as a of injury evidence that the and of the clinical post-concussive symptoms may be more important than the or of it must be that with the time of and is of injury and A of (eg, or may a concussion. Although these clinical features are and require no specific management beyond the standard of the concussive health issues as have been as a long-term of traumatic brain injury including sports concussion. Neuroimaging studies using fMRI that a following concussion may reflect an pathophysiological abnormality with a of The and There was unanimous agreement by the panel that the evaluation and management recommendations be to children and to the age of that age children concussion symptoms different from and would require symptom as a component of An additional in the child or adolescent athlete with a concussion is that in the clinical evaluation by the healthcare professional there may be the need to include both patient and as well as and when The to use testing is the same as the adult assessment However, of testing may in order to assist in and management may be performed the patient is If cognitive testing is performed then it must be sensitive to the ongoing cognitive that this in the of to either the baseline or to In this age it is more important to the use of to assessment data, in children with and/or may need more assessment The panel the that children should not be to practice or play symptom which may require a longer time frame than for In addition, the concept of was with to a need to with of and to and other cognitive (eg, and may also need to be to of symptoms. of the different and longer recovery concussion and specific (eg, to head and a more return to play approach is It is appropriate to the of time of and/or the of the graded in children and It is not appropriate for a child or adolescent athlete with concussion to RTP on the same day as the injury of the of athletic Concussion more to this than and may more RTP vs. The panel unanimously agreed that all athletes, of of should be using the same and return to play A more useful was agreed the and in concussion evaluation of more in management than a separation elite and non-elite athlete Although formal baseline screening may be beyond the of sports or it is that in all sports be given to this cognitive evaluation of the age or of Brain studies have an sports concussions a and cognitive have where evidence of traumatic was in Panel discussion was and no consensus was on the of such at this need to be of the for long-term in the management of all athletes. and There is no clinical evidence that protective equipment although mouthguards have a role in and injury. studies have shown a in to the brain with the use of head and but these have not been to a in concussion and there are a of studies to that head and injury and should be for in In specific sports such as and protective may other forms of head injury (eg, that are to on and these may be an important injury prevention for of rule changes to head injury incidence or may be appropriate where a is in a particular An of this is in where studies that to head contact in for of rule changes also may be in some sports to allow an off-field medical assessment to occur without the affecting the flow of the game or unduly penalizing the player's team. It is important to note that rule may be a of injury risk in these and play an important role in this An important in the use of protective equipment is the concept of risk This is where the use of protective equipment results in change such as the of more which can result in a in injury This may be a particular in child and adolescent athletes where head injury are often than in adult vs. in Sport The nature of which it to play and should not be However, sporting should be encouraged to that may concussion play and should be as key of the to or the of concussive injury the is of athletes, and the is a of in this parents, coaches and health care must be regarding the of its clinical assessment and principles of return to to including and are important in the In addition, concussion the and of such as International International and International this have value and must be play and for are that should be encouraged in all sports and sporting coaches, and play an important part in these are on the field of The consensus panelists that is a range of in order to some The key for include: of the SCAT2 on injury and Paediatric injury and management paradigms in the assessment of injury strategies (eg, exercise imaging modalities and their role in clinical assessment Concussion using and assessment where no baseline assessment has been performed neuropsychological testing Long-term On-field injury This consensus document the of knowledge and need to be to the of new It an of issues that may be of to healthcare involved in the management of sports concussion. It is not as a standard of care and should not be as This document is a and is of a nature with the practice of a healthcare on the and specific to It is that this document be and to CONSENSUS In the 1st International on Concussion in Sport was in This was by the in with and the Medical of the part of the for the the need for and The 2nd International on Concussion in Sport was by the same with the additional of the and was in in The original of the to recommendations for the improvement of and health of athletes concussive in as well as other this a range of to both to specific issues of and clinical injury cognitive assessment, new protective prevention and long-term The International on Concussion in Sport was in on and was designed as a formal consensus following the set by the of of the consensus can be at The principles the of a consensus are A panel was to and attention to the Panel with or of and included in clinical sports athletic and sports These in a by and The panel then in an to the consensus statement. A of specific questions and in to define the and the of the The of the panel was to to these These questions are outlined A was and in for use by the panel in the The consensus statement is to as the of the The consensus statement be to on both health care practice and medical The panel did not with any The was for the consensus and guiding the from clinical and in the field of sports concussion. not but for their and understanding of this

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