This page has been designed to provide medical practitioners with up to date information about concussion.
Please find below key information and resources to use when identifying and managing concussion.
- Concussion can be very difficult to detect. The symptoms and signs can be varied, non-specific and subtle.
- Athletes with suspected concussion should be removed from sport and assessed by a medical doctor.
- When assessing acute concussions, a standard primary survey and cervical spine precautions should be used.
- The diagnosis of concussion should be based on a clinical history and examination that includes a range of domains including mechanism of injury, symptoms and signs, cognitive functioning, neurology including balance assessment.
- The SCAT3 is the internationally recommended concussion assessment tool and covers the above mentioned domains. It can be freely downloaded and should not be used in isolation but as part of the overall clinical assessment.
- Computerised neurocognitive testing can be undertaken as part of the assessment but should not be used in isolation.
- Children and adolescents take longer to recover from concussion. A more conservative approach should be taken with those aged 18 or younger. The gradual return to sport protocol should be extended such that the child does not return to contact/collision in less than 14 days from resolution of symptoms. See child-SCAT3.
- Blood tests are not indicated for uncomplicated concussion. Medical imaging is not indicated unless there is suspicion of more serious head or brain injury.
- Standard head injury advice should be given to all athletes suffering concussion and to their carer.
- Once the diagnosis of concussion has been made, immediate management is physical and cognitive rest. This includes time off school or work and deliberate rest from cognitive activity for 2-3 days. After this period, the patient can return to moderate intensity physical activity as long as such activity does not cause a significant and sustained deterioration in symptoms. The majority of concussive symptoms should resolve in 7-10 days. Once the symptoms have resolved the patient can proceed with a graduated return to sport protocol.
- Some sports have their own guidelines or recommendations around the management of concussion in sport which should also be considered.
- If in doubt, sit them out.
Concussion is a type of brain injury. It is recognised as a complex injury that is a challenge to evaluate and manage. As defined by the Concussion in Sport Group (CISG) international consensus statement, concussion is ‘a complex pathophysiological process affecting the brain, induced by biomechanical forces’. It generally results from a knock — often to the head, face or neck but may be anywhere on the body — which transmits an impulsive force to the head. Concussion commonly involves short-lived impairment of neurological function. Concussion is an evolving injury that may change over the first few hours and sometimes over a few days. In most cases symptoms have resolved by seven days post injury.
Epidemiological data, particularly hospital data, does not distinguish between traumatic brain injury and mild traumatic brain injury or concussion.
The diagnosis of concussion can be difficult. There is no specific diagnostic test which confirms the presence or otherwise of concussion. Diagnosis of concussion relies on clinical assessment of symptoms and signs including cognitive and behavioural disturbance.
It is critical that all individuals dealing with potentially concussed athletes understand that concussion is an evolving phenomenon. Subtle symptoms and signs often become far more significant in the hours and days following the injury.
In some instances, it will be obvious that there has been a significant injury where the athlete loses consciousness, has a seizure or has significant balance difficulties. Symptoms of concussion however can be very subtle and may present as nothing more than the athlete reporting that they do not ‘feel right’. Symptoms commonly reported by concussed athletes include visual disturbance, feeling ‘foggy’, lethargic or slow, having sensitivity to light or noise, feeling dizzy or nauseous, or headache.
Signs of concussion are also variable and may be difficult to detect. The athlete may appear normal apart from appearing vacant, dazed or stunned. The athlete may be disoriented and unable to recall team plays, scores, who the opponent is or be disoriented in terms of place and time. Parents, coaches and attending medical personnel need to be alert for evidence that an athlete is behaving unusually or out of character, exhibits signs of disorientation, clumsiness or loss of balance. Amnesia is common in the setting of concussion. The athlete may ask questions repeatedly about what happened or what the score is. Concussed athletes will often have difficulty concentrating and answering specific questions. More detailed information regarding formal medical assessment of concussion is provided below.
Below is a list of symptoms and signs of concussion based on the CISG's Sport Concussion Assessment Tool 3 (SCAT3)
Sometimes there will be clear signs that an athlete has sustained a concussion. Medical practitioners covering sporting events should immediately remove an athlete with any of the following clinical features:
- loss of consciousness
- no protective action in fall to ground directly observed or on video
- impact seizure or tonic posturing
- confusion, disorientation
- memory impairment
- balance disturbance (e.g. ataxia)
- athlete reports significant, new or progressive concussion symptoms
- dazed, blank/vacant stare or not their normal selves
- behaviour change atypical of the player.
If an athlete displays these signs consider more serious injury and assess as appropriate. Consider the need for urgent emergency department referral:
- neck pain
- increasing confusion or irritability
- repeated vomiting
- seizure or convulsion
- weakness or tingling/burning in the arms or legs
- deteriorating conscious state
- severe or increasing headache
- unusual behavioural change
- double vision.
Due to the evolving nature of the injury and the varied and potentially subtle symptoms and signs, a minimum criteria for the diagnosis has been published based on a review of the literature. The recommendations include a thorough assessment looking at a variety of domains – loss of consciousness, symptoms, cognition, neurobehavioural symptoms, and balance – with any abnormality being a potential sign of concussion. Due to the complexity of the injury and the diagnostic challenge it can present, one of the outcomes from the series of International Conferences on Concussion was the development of the Sport Concussion Assessment Tool (SCAT3) aimed at improving identification, clinical assessment and diagnosis of sport-related concussion.
Recognising concussion is critical to correctly managing and preventing further injury. The Pocket Concussion Recognition Tool, developed by the Concussion in Sport Group to help those without medical training detect concussion, includes a list of these symptoms.
When an athlete is suspected of having a concussion, first-aid principles still apply, and a systematic approach to assessment of airway, breathing, circulation, disability and exposure applies in all situations. Cervical spine injuries should be suspected if there is any loss of consciousness, neck pain or a mechanism that could lead to spinal injury. Manual inline stabilisation should be undertaken and a hard collar applied until a cervical spine injury can be ruled out.
The diagnosis of concussion should be made by a medical practitioner after a clinical history and examination that includes a range of domains including mechanism of injury, symptoms and signs, cognitive functioning and neurological assessment including balance testing. The SCAT 3 is the internationally recommended concussion assessment tool and covers the above mentioned domains. This should not be used in isolation but as part of the overall clinical assessment.
Computerised neurocognitive testing can be undertaken as part of the assessment but again, should not be used in isolation. Baseline neurocognitive testing can be useful in the pre-season period for comparison with post-injury scores. Many programs however have reference ranges that can be applied in the absence of a baseline test.
There are currently no serum biomarkers that assist in the diagnosis of concussion. Blood tests are not indicated for uncomplicated concussion. Medical imaging is not indicated in the diagnosis or management of uncomplicated concussion. Medical imaging may be indicated however where there is suspicion of more serious head or brain injury.
Medical practitioners will often have to deal with a situation where an athlete presents to the clinic during the week, having suffered a potential concussive episode over the previous weekend. Such a presentation poses challenges. If there is any suspicion that a concussion occurred on the weekend, the medical practitioner should proceed on the presumption that a concussion did in fact occur. There is no test or series of tests which can conclusively indicate that a concussion did not occur.
While the medical practitioner assessing the athlete with suspected concussion should make optimal use of available assessment tools, clinical judgement remains a cornerstone of concussion diagnosis and management. Concussion modifiers are factors that may impact upon the clinician’s management of the concussed athlete. Such modifiers can be associated with a more protracted recovery time. Concussion modifiers include the following:
- a high number of concussive symptoms
- high severity of concussive symptoms
- prolonged loss of consciousness (longer than one minute)
- post-concussive seizure
- previous history of concussion
- age of the athlete
- history of depression, anxiety, migraine, learning disability, ADHD or sleep disturbance
- use of medications, especially psychoactive or anticoagulant medication.
Although the relationship is not clear, there is a potential link between mental illness and concussion. Any athletes with a history of mental illness require a more cautious approach. A conservative return to sport strategy is recommended.
Sport-related concussions are common in children and adolescents. Concussion warrants special consideration in this age group and a more conservative approach to diagnosis and management is recommended. The physical, cognitive and emotional differences in this group require that assessment tools be targeted to this population. The development of a Child Sport Concussion Assessment Tool (Child-SCAT3) at the International Consensus Conference on Concussion is intended to address these concerns. Children and adolescents seem to be more vulnerable to concussion due to a variety of factors including decreased myelination, poor cervical musculature, and increased head to neck ratio. The role of cerebral blood flow alterations in the pathophysiology of concussion may be more significant in children than in adults. There is also some evidence that components of cognitive function relating to executive functioning may be impaired in adolescents with concussion for up to two months after injury. The implications of this are not clear and further studies are required to confirm or refute this data.
The management of concussion should be more conservative in children as per the relevant section below.
Any athlete with suspected or confirmed concussion should remain in the company of a responsible adult and not be allowed to drive. They should be advised to avoid alcohol, and medications should be reviewed. Specifically, concussed patients should avoid aspirin, anti-inflammatories (such as ibuprofen, diclofenac, naproxen), sleeping tablets and sedating pain medications.
Once the diagnosis of concussion has been made, immediate management is physical and cognitive rest. Principle of rest is based on observational studies that have demonstrated improved performance on post-injury testing and reduction in symptoms after prescribed cognitive and physical rest. The optimal duration of the period of rest is not clear, but 80-90 per cent of concussions fully resolve within 7–10 days.
The guidelines surrounding management of concussion from the Concussion in Sport Group Consensus Statement 2012 include prioritising return to school and learning before commencing return to physical activity. Modification of school attendance and activities may be required allowing an increased period of asymptomatic rest and extending the graduated return to sport. A more cautious return to sport protocol is recommended when concussion modifiers are present. World Rugby recommends that children and adolescents 18 years or younger not return to contact training or competitive sport for at least two weeks after resolution of concussion symptoms.
Having rested for 2-3 days after sustaining a concussion, the patient can commence a return to moderate intensity physical activity, as long as such activity does not cause a significant and sustained deterioration in symptoms. The majority of concussive symptoms should resolve in 7-10 days. Once symptoms have resolved the patient can begin a staged return to physical activity. The activity phase should proceed as outlined below with a minimum of 24 hours spent at each level. The activity should only be upgraded if there has been no recurrence of symptoms during that time. If there is a recurrence of symptoms, there should be a ‘step down’ to the previous level for at least 24 hours after symptoms have resolved. The steps in the activity phase are:
- begin with light aerobic activity (at an intensity that can easily be maintained whilst having a conversation) until symptom-free
- basic sport-specific drills which are non-contact and with no head impact
- more complex sport-specific drills without contact, may add resistance training
- full contact practice following medical review
- normal competitive sporting activity.
The issue of concussion has received significant media attention in recent years. The focus of a large part of this attention has been around chronic traumatic encephalopathy (CTE), particularly in retired athletes from the National Football League in the USA.
CTE is described by McKee et al 2009 as a ‘progressive neurodegeneration clinically associated with memory disturbances, behavioural and personality change, Parkinsonism, and speech and gait abnormalities’. McKee describes the neuropathology as being characterised by cerebral and medial temporal lobe atrophy, ventricular enlargement, enlarged cavum septum pellucidum, and extensive deposition of tau protein. While there is significant concern about CTE and its possible relationship to concussion, it is important to note that no causative link has been clearly established. McKee concludes that evidence is ‘overwhelming’ that repeated head trauma causes the condition. Other researchers have questioned the link between sport-related concussion and CTE due to the current level of evidence published being limited to case reports, case series and retrospective analyses which cannot adequately determine causality or risk factors. Due to the nature of the condition and the reliance on retired athletes nominating to posthumously undergo autopsy as part of this research there is significant bias in the samples examined. The potential contribution of confounders, such as genetic predisposition to psychiatric illness, alcohol and drug use or co-existing dementia, is not adequately accounted for in the current literature.
Recent public health concerns about CTE have, to a large extent, driven the increased focus on forming best practice guidelines for the identification, diagnosis and management of sport-related concussions with the goal of preventing complications such as CTE. Further research is needed to understand what type of trauma is implicated, how much force is required, and how frequently, for the development of pathological changes of CTE. It is also not clear why only some athletes are affected with these symptoms. Properly designed prospective studies, which control for potential confounding variables, are required to improve our understanding of CTE and any potential link to prior concussion.
Acute cerebral oedema, or ‘second impact syndrome’ is another condition which has received a lot of media attention due to its catastrophic outcomes. This condition, along with CTE, appears to have driven much of the public awareness around concussion. Acute cerebral oedema refers to rapid cerebral swelling that can occur when a second concussive injury is sustained during a ‘vulnerable’ period when the brain has not recovered from an initial insult. Animal models have demonstrated that there is a period of vulnerability during which further injury can result in significant axonal injury with associated ion channel damage. It is thought that a second impact may not be needed for the swelling to develop. The condition is rare and the only available literature consists of case studies which are inadequate to provide a good understanding of the mechanisms and risk factors. Further research is needed to better understand the pathophysiology and risk factors for ‘second impact syndrome’.