Identification and management of children with sport-related concussion

Healthy Active Living Committee, Canadian Paediatric Society (CPS)

Paediatr Child Health 2006;11(7):420-8
Reference No. HAL 2006-01

Parent handout: Sport-related concussion: Information for parents, coaches and trainers

Index of position statements from the Healthy Active Living and Sports Medicine Committee

Contents

• Definition of concussion
• Signs and symptoms of concussion
• Investigations
  • Diagnostic imaging
  • Neuropsychological testing
• Management
• Return-to-play guidelines
• Multiple concussions
• Prevention
• Concussion education
• Advocacy issues in sport concussion
• Recommendations
• References

Concussion is a common injury sustained by children participating in many different sports. In children 15 years of age and younger, the estimated incidence of traumatic brain injury, including concussions, is 180 per 100,000 children per year, accounting for more than 10% of all visits to emergency departments (1). A recent Canadian emergency department study (2) demonstrated that 3% of all sport-related injuries were head injuries. The majority of sport-related head injuries occurred in individuals younger than 20 years of age (66%) (2). Sport-related head injuries accounted for 18.2% of all serious head injuries in children younger than 10 years, 53.4% in 10- to 14-year-old children and 42.9% in 15- to 19-year olds (2) (level of evidence: III [Appendix 1]). However, concussion can be difficult to diagnose because the signs and symptoms may be subtle and easily overlooked (level of evidence: III) (3-5). Athletes may minimize or not recognize the signs and symptoms of concussion and, therefore, may not seek medical attention (6,7).

Despite significant concussion-based research, there are no specific guidelines for the management of sport-related concussion in children. Both the Canadian Paediatric Society (8) and the American Academy of Pediatrics (9) have published position statements on managing head trauma; however, these statements do not address sport-related concussion and, in particular, return-to-play guidelines. Although adult guidelines are often used, there are age-related differences in recovery following head injury, with younger children taking longer to recover from concussions (level of evidence: II-2). Concussions in children may be more difficult to diagnose than in adults because they are often unrecognized by the child or adult witnesses. Therefore, paediatric sport-related concussion guidelines are necessary (10).

The present statement has been written to assist physicians in the management of children aged five to 18 years with sport-related concussion. The recommendations are guidelines only, and are based on currently available data as well as expert opinion. They are intended to review the definition, signs and symptoms of concussion; the need for investigations; management principles, emphasizing return-to-play guidelines; and prevention strategies. Because of the paucity of quality research available, physicians are urged to use a conservative approach in the management of children with sport-related concussion.

DEFINITION OF CONCUSSION

Concussion is defined as “a complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces” resulting “in the rapid onset of short-lived impairment of neurological function that resolves spontaneously” (11). Concussion may be sustained by a direct blow to the head, face or neck, or by a blow to somewhere else on the body that transmits an impulsive force to the head (11-15). Most concussions do not cause a loss of consciousness or cause only a transient (ie, lasting seconds) loss of consciousness (11).

SIGNS AND SYMPTOMS OF CONCUSSION

Athletes may exhibit many signs or symptoms following a head injury (Table 1). If any of these are present, a head injury should be suspected and appropriate management instituted (11-14,16). Younger children may complain of abdominal pain or discomfort more than headache or cognitive symptoms in the setting of concussion; therefore, a concussion may be easily overlooked. Concussive symptoms may be prolonged, sometimes lasting weeks to months (level of evidence: II-2) (5,17-20).

Significant cognitive sequelae may result from concussion, including poor attention and concentration, reduced speed of information processing, and impaired memory and learning (level of evidence: II-2) (19,21,22). There may also be a significant negative secondary impact on educational and social attainment because these cognitive functions are critical for performing normal daily activities during childhood and adolescence, such as learning new skills and attending to schoolwork (level of evidence: II-2) (1,19,20,22).

A rare complication following head injury in children is diffuse cerebral swelling, also known as the malignant brain edema syndrome (level of evidence: III) (1,18,23-27). This phenomenon occurs almost exclusively in children and adolescents. The proposed mechanism for this entity is a loss of autoregulation of the brain’s blood supply, resulting in rapid cerebrovascular congestion and increased intracranial pressure, which may progress to brainstem herniation, coma and death (1,5,18,23-26). This loss of cerebral vascular autoregulation is believed to be responsible for the second impact syndrome, a rare event that occurs in young athletes. Second impact syndrome is believed to occur when an athlete sustains a second concussive injury while still symptomatic from a previous concussive injury (5,18,23). The ‘second’ injury may be seemingly very minor, but within seconds to minutes of impact, the athlete collapses and rapidly becomes comatose. This is almost universally fatal. Although this entity is widely feared, the evidence that these catastrophic events are the result of a second impact is lacking (level of evidence: III) (24,27). It is more likely that these are incidences of diffuse cerebral swelling occurring after mild injury to the immature brain (24,27).

CLASSIFICATION OF CONCUSSION SEVERITY
Most concussion grading systems are based on anecdotal experience and lack validation (level of evidence: III) (11,12,15,17,27,28). Loss of consciousness or amnesia has traditionally been used as an indication of injury severity. However, brief losses of consciousness (less than 1 min) do not correlate with severity of sporting concussive injury (11,12,14). In addition, the type and duration of symptoms may be more important than the presence or duration of amnesia alone (11,12). It is now recognized that the severity of concussions can best be determined retrospectively, after all concussive symptoms and signs have cleared and cognitive function has normalized (level of evidence: III) (12).

A simplified system of classification was recently proposed, classifying concussion into ‘simple’ and ‘complex’ (Table 2) (12). Athletes who have complex concussions should be managed by physicians with specific concussion expertise (strength of recommendation: B [Appendix 1]) (12).

INVESTIGATIONS

Diagnostic imaging
Concussion results in an aberration in brain physiology and function rather than a structural injury. Structural lesions can usually be ruled out based on a complete history and thorough physical examination. Skull x-rays and computed tomography scans usually do not demonstrate any visible injury and, therefore, are not routinely recommended (level of evidence: III) (5,11,12,15). If there is suspicion of a structural lesion (focal neurological deficit, seizure activity or prolonged unconsciousness), appropriate imaging should be performed (strength of recommendation: A) (8,9,11,12,15).

In complex concussions (eg, prolonged symptoms), imaging studies may be appropriate (level of evidence: III; strength of recommendation: B) (11,12,17). Magnetic resonance imaging is a more sensitive modality to detect subtle structural injuries such as contusions and diffuse axonal injury (29). More specialized imaging techniques, such as single photon emission computed tomography, positron emission tomography and functional magnetic resonance imaging, may be able to demonstrate pathophysiological and functional abnormalities following concussion (29).

Neuropsychological testing
Cognitive deficits associated with minor head injury include impaired attention and concentration, mild disorientation and memory difficulties. Numerous studies have evaluated brief (30 min) neuropsychological testing in the athletic population, including traditional pen and paper tests (10,19,21,22,30-32) and, more recently, computer-based programs (1,33-35). In the acute assessment of a concussed athlete, brief neuropsychological test batteries that assess attention and memory function have been shown to be practical and effective (level of evidence: II-2) (21,31,36). The Standardized Assessment of Concussion has been studied in healthy children aged nine to 14 years and is reliable in this age group (level of evidence: II-2) (37). The Sport Concussion Assessment Tool, which incorporates aspects of the Standardized Assessment of Concussion, has been developed for use on the field (Appendix 2) (12). This tool has not yet been validated in children.

Neuropsychological tests can be used to aid the return-to-play decision but not in isolation; repeated clinical assessments are key. If neuropsychological tests are used, preinjury baselines should be established in all athletes at the beginning of each sport season to maximize the clinical utility (level of evidence: II-2) (11,12,14,30,36). Following a concussive injury, athletes can then be compared to their own baseline value to determine whether there are any deficits. Because neuropsychological tests can be affected by many factors (including previous head injury, test anxiety, attention deficit disorder, psychiatric conditions and learning disabilities), without baseline data, an athlete’s test result would have to be compared with population normal values, which may lead to test misinterpretation (30). For instance, test results for an athlete with high cognitive ability may be falsely interpreted as normal and lead to a premature return to sport; conversely, an athlete with low baseline functioning may be kept out of play unnecessarily long (30).

Another limitation of neuropsychological tests is practice or learning effect (11,12,30). The more an athlete performs a test, the better he or she performs because of prior exposure, particularly in tests of memory (30). This can be minimized by limiting retesting, using different versions of pen and paper tests, or by using computer-based tests that have infinitely variable paradigms (level of evidence: II-2) (11,12,30). In addition, no study has demonstrated that cognitive deficits persist after concussive symptoms have resolved. In fact, athletes may return to their baseline levels on neuropsychological tests while still experiencing concussive symptoms (30).

A unique concern regarding neuropsychological testing in the paediatric population is that children are undergoing rapid cognitive development. Computerized neurocognitive studies (1,35) have demonstrated that a substantial improvement in performance occurs between ages nine and 18 years on tests of simple and choice reaction time, working memory and new learning, with the largest changes seen between nine and 15 years (level of evidence: II-2). These developmental changes can potentially confound postinjury assessments because maturational improvements may offset any injury-related cognitive impairment; therefore, children and youth may require baseline testing as often as every six months (strength of recommendation: A) (1). However, the clinical implementation of baseline testing, particularly in the paediatric age group, is premature until sound scientific evidence is available to justify the financial costs, time and energy required to implement them.

Because of these concerns, neuropsychological testing is not indicated in the management of simple concussions. However, in those athletes who have sustained multiple concussions or who demonstrate prolonged postconcussive symptoms (ie, complex concussions), age-appropriate, detailed neuropsychological testing may be useful to help identify specific cognitive deficits, which may aid in educational planning (level of evidence: III; strength of recommendation: B) (12,30).

MANAGEMENT
If a young athlete is suspected to have sustained a concussion, he or she should immediately be removed from the game or practice. If the athlete is unconscious, a cervical spine injury must be assumed and appropriate cervical spine precautions undertaken (collar and board, and ambulance transfer to emergency department). Airway, breathing and circulation must be assessed in any unconscious athlete (strength of recommendation: A) (5,8,9,15,17,18,38).

The conscious athlete should be observed closely for any signs of deterioration (15). Symptoms may get worse later that day or the next day. Every concussed athlete should be medically evaluated by a physician, including a full neurological and mental functioning assessment, as soon as possible (15). A player should never return to sport if symptomatic (strength of recommendation: A) (5,11-13,17,18,28,38). Concussed athletes frequently have reduced attention, impaired response times and memory deficits, which may result in a decreased ability to avoid dangerous situations, thus putting them at risk for another concussion or other injury (level of evidence: II-2) (19,21,30). If in doubt, it is important to sit them out.

Following medical evaluation for a concussion, an athlete should not be left alone. A responsible adult, ideally a parent, should monitor the child for worsening symptoms, such as severe headache, persistent vomiting or seizure activity. The child should be checked through the night, but should not be awakened unless there is evidence of deterioration (abnormal breathing, seizures or vomiting). If there is any deterioration, the child should be immediately re-evaluated by a physician (strength of recommendation: A).

The most important aspect of concussion management is physical and cognitive rest (strength of recommendation: A) (11-14). The child should not play sports, exercise or participate in recreational activities, such as riding a bike, or wrestling with friends or siblings. Cognitive rest includes avoiding activities that require mental concentration, such as reading, watching television, working on a computer and playing electronic games. They may even need to miss school while symptomatic because the mental effort required to perform schoolwork may make symptoms worse and prolong recovery (level of evidence: II-2) (20). If school absence is necessary to allow symptoms to resolve, children should subsequently return gradually (including half days) once symptoms have resolved. If they do not have worsening or recurring symptoms, they may return full time (level of evidence: III; strength of recommendation: B). If prolonged absence from school (more than two weeks) is necessary due to persistent symptoms, a neurological consultation may be of value (strength of recommendation: I).

RETURN-TO-PLAY GUIDELINES
An athlete with a concussive injury should not be allowed to return to activity until all signs and symptoms have resolved, and the athlete has been cleared to do so by a physician

(level of evidence: II-2; strength of recommendation: A) (5,11-15,17,18,28,38). The ideal length of the symptom-free period has not been established; however, athletes should be symptom free for several days before beginning a medically supervised, stepwise return-to-play protocol (Table 3) (strength of recommendation: B) (11-14,28). Each step should take a minimum of 24 h. As long as symptoms do not return, athletes may progress to the next step. If symptoms recur, athletes should rest for 24 h to 48 h and try to progress again, starting at the level where they were asymptomatic.

MULTIPLE CONCUSSIONS
Management of an athlete who has sustained multiple concussions is controversial. A concussed athlete may be at increased risk for subsequent head injuries, which may be cumulative (level of evidence: III) (27,28). Many published guidelines recommend termination of the sport season and lifetime avoidance of contact sports with repeated concussions (strength of recommendation: B) (5,14,17,28). Each athlete should be evaluated individually. Athletes should be advised to avoid contact sports if subsequent concussions result in more severe symptoms, if symptoms occur with less force, if their playing style or sport puts them at increased risk of future injuries, or if they have a learning disability or persistent cognitive symptoms (level of evidence: III; strength of recommendation: B) (28).

PREVENTION
Head injuries can be prevented or minimized by wearing the appropriate protective equipment for the specific sport (level of evidence: II-2) (11,12,15,28,39-42). Approved helmets should be worn in all contact sports and in all activities with a risk of head injury (eg, cycling, skateboarding, in-line skating, skiing, snowboarding and equestrian activities) (strength of recommendation: A) (11-15,28,43). Appendix 3 contains a list of approved helmets for wheeled sports. It is important that the equipment be worn properly and be well maintained (44,45). Any damaged equipment should be replaced promptly.

It is critical to recognize that there is no such entity as a ‘concussion-proof’ helmet. Players may feel they are not at risk for head injury if wearing their helmet and may adopt a more aggressive playing style, thereby putting themselves at greater risk of injury (11,12,45). To minimize risk of concussion, athletes should respect the rules of their sport and practice fair play.

Coaches and trainers play an important role in reducing the number of concussions. They must ensure that their athletes are taught the proper sport techniques, such as correct body checking in hockey, tackling in football and heading the ball in soccer. Neck muscle strengthening programs may help reduce the risk of concussion by reducing the impact forces transmitted to the brain, although evidence for this is currently lacking (11). Coaches and trainers should be familiar with the signs and symptoms of concussion and immediately remove players from play if a head injury has occurred. They should ensure that athletes are medically evaluated and are not allowed to return to play until medical clearance has been obtained.

Rule changes and enforcement can also decrease the risk and incidence of concussive injuries (11,12,45). Rules mandating padded goal posts in soccer and football, and the banning of spearing in football have been shown to reduce the number of concussive injuries (level of evidence: III) (28,45). In hockey, eliminating hits to the head, not allowing checking from behind and eliminating fighting may help to reduce head injuries (11,12). Discouraging enrolment in sports where intentional head injury is promoted, such as boxing, may also decrease the risk of concussion in children (46).

CONCUSSION EDUCATION
It is vital that athletes, coaches and trainers, parents and health care providers be aware of the symptoms and signs of concussion and the appropriate management of concussive injuries (6). More information can be found on the following Web sites: <www.casm-acms.org>, <www.thinkfirst.ca> and <www.cdc.gov/ncipc/tbi/Coaches_Tool_Kit.htm>.

ADVOCACY ISSUES IN SPORT CONCUSSION
Paediatricians can advocate for their patients in the following ways:

• Discouraging patients from participating in sports, such as boxing, in which intentional injury to the head is promoted;

• Educating coaches and trainers, schools and policy-makers in sport regarding the signs and symptoms of concussion, and the need for medical evaluation or clearance before an athlete returns to play;

• Encouraging patients, particularly those who have sustained repeated concussions, to participate in noncontact versions of their chosen sport; and

• Supporting legislation requiring mandatory wearing of helmets for all sports in which there is a significant risk of head injury, including all wheeled sports, skiing, snowboarding and equestrian sports.

RECOMMENDATIONS
The Canadian Paediatric Society makes the following recommendations regarding sport-related concussion in children:

• Anyone working with children involved in sports should educate themselves on the signs and symptoms of sport-related concussion (Table 1). Loss of consciousness is not required to sustain a concussion.

• An athlete who has sustained a head injury during sport should be immediately removed from play and not allowed to return to play that game. The athlete should be closely monitored for any signs of deterioration and should not be left alone. Importantly, a symptomatic athlete should never return to play.

• An unconscious athlete should be assumed to have a cervical spine injury and should be appropriately immobilized before ambulance transportation to hospital.

• All athletes sustaining a head injury should be evaluated by a physician as soon as possible. Following medical evaluation, they should be monitored by a parent for the next 24 h to 48 h for signs of deterioration. If any signs of deterioration occur, the athlete should immediately be re-evaluated by a physician.

• Diagnostic imaging and neuropsychological testing are not routinely recommended.

• The athlete should rest until all symptoms have resolved. This includes both physical and cognitive rest.

• Once the athlete has been symptom free for several days, he or she can begin a medically supervised, stepwise return-to-play protocol (Table 3).

• Return to sport following a sport-related concussion should only occur after medical clearance by a trained physician.

ACKNOWLEDGEMENTS: This position statement was reviewed by the CPS Injury Prevention Committee, Paediatric Sport and Exercise Medicine Section, Emergency Paediatrics Section, the Canadian Academy of Sports Medicine and ThinkFirst Canada. The authors would like to thank the following reviewers for their invaluable input into the content of this statement: Dr Karen Johnston, neurosurgeon, Concussion in Sport Group, Canadian Academy of Sport Medicine; Dr James Kissick, sport medicine physician, Canadian Academy of Sport Medicine; Dr Craig Campbell, paediatric neurologist, Children’s Hospital of Western Ontario, London, Ontario; and Dr Kevin Gordon, paediatric neurologist, IWK Health Centre, Halifax, Nova Scotia.  

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HEALTHY ACTIVE LIVING COMMITTEE
Members: Drs Tracy Bridger, Janeway Child Health Centre, St John’s, Newfoundland; Claire LeBlanc, Children’s Hospital of Eastern Ontario, Ottawa, Ontario (chair); Stan Lipnowski, Children’s Hospital, Winnipeg, Manitoba; Peter Nieman, University of Calgary, Calgary, Alberta; Glen Ward, Surrey, British Columbia (board representative); Tom Warshawski, Kelowna, British Columbia
Liaison: Dr Laura Purcell, University of Western Ontario, London, Ontario (Paediatric Sport and Exercise Medicine Section, Canadian Paediatric Society)
Principal author: Dr Laura Purcell, University of Western Ontario, London, Ontario  
Co-authors: Drs. Claire LeBlanc, Children's Hospital of Eastern Ontario, Ottawa, Ontario; Michelle McTimoney, IWK  Health Centre, Halifax , Nova Scotia; John Philpott, University of Toronto, Toronto , Ontario; Merrilee Zetaruk, Winnipeg Children's Hospital, Winnipeg, Manitoba