What is a Concussion?
Concussion is a subcategory of traumatic brain injury. In the literature, the terms “mild traumatic brain injury” and “concussion” are often used interchangeably. The 2017 consensus statement on sports concussion defines it as a “traumatic brain injury caused by” Biomechanical forces . 80-90% of concussions resolve within 7-10 days. If the concussion persists beyond 10 days, other possible diagnoses should be reconsidered and the MDT manage the player’s care. It should be noted that in some cases the recovery time may be prolonged, especially in children and adolescents. The following information is intended for persons over the age of 13. Children under this age report different symptoms than children over 13. The information below therefore does not apply to under 13s; this would require a more age-appropriate symptom checklist population.
Mechanism of Injury
Concussions can be caused by a number of different biomechanical means, including blows to the face, neck or head. Therefore, any blow that transfers force to the head can cause it .
The clinical presentation of a concussion can vary widely, from dramatic changes in balance to less obvious changes such as sleep disturbances. Clinical neurobehavioral physical and/or cognitive symptoms may occur. It is important to note that symptoms may appear immediately Minutes or hours after the event or after the event.
The 2017 consensus statement lists the following signs and symptoms of concussion:
- Symptoms – physical (eg, headache), cognitive (eg, fog) and/or emotional symptoms (eg, unsteadiness)
- Signs (eg loss of consciousness LOC). Although published concussion findings describe LOC associated with specific early cognitive deficits, it has not yet been considered as a measure of injury severity and amnesia); various immediate motor phenomena (such as tonic posturing) or spastic movements May be accompanied by a concussion. Although these clinical features are evident, they are usually benign and require no specific management other than standard management of the underlying concussion injury.
- Balance disturbance (such as unsteady gait). A systematic review (2020) showed that concussion injury was positively associated with gait deviation in concussed patients 
- Behavioural changes (eg, irritability)
- Cognitive impairment (such as slowed reaction times)
- Sleep/wake disturbances (eg, hypersomnia).
However, this list is not exhaustive and the following other signs and symptoms are cited elsewhere in the literature:
- Chronic headaches,
- Dizziness and vertigo
- Difficulty concentrating
- Word-finding problems
(DeKosky et al.. 2010) Just one of these symptoms is enough to suspect a concussion.
However, it is important to note that these symptoms and signs also do not happen to be specific to concussion, so their presence is only indicative of the inclusion of concussion in the differential diagnosis for further evaluation, but the symptoms themselves are not a diagnosis of concussion. 
Post-concussion syndrome: This occurs when concussion symptoms last longer than the usual 7-10 days. Symptoms can last weeks to months, but usually resolve within 3 months. However, cases in which symptoms persist for up to a year have been reported. Not sure what caused the posterior concussion The syndrome develops in some people and not in others. There was no proven correlation between the severity of the injury and an increased likelihood of developing a concussion. Some researchers believe the syndrome results from damage to brain structures or disruption of neurotransmitters system. However, others believe that the symptoms are more likely to be related to psychological factors. Treatment usually includes drug intervention and education. There is also evidence that moderate physical and cognitive activity rather than strict rest can Helps reduce the burden of post-concussion symptoms 
Risk Factors for Developing a Concussion
A number of different factors associated with a higher risk of developing a concussion are outlined in the literature. These are outlined below.
Gender: Men have a higher incidence of concussions in all sports. However, it seems likely that this is the result of more men taking part in the survey campaign. In an updated evidence-based guideline by Giza et al. in 2013 , it is recommended that associations Certain genders with higher concussion rates vary by sport, with women having higher concussion rates in football and basketball. Other research has suggested that the higher rate of concussions in women may be due to women reporting more concussion symptoms. female athletes, and due to their smaller head size and neck strength compared to male athletes .
Type of sport: As mentioned above, the risk of concussion associated with sports varies by sport. Australian rugby and American football were associated with the highest rates of concussion, while lower risks were associated with sports such as baseball, softball, volleyball and gymnastics. Several high-quality studies have shown that soccer is associated with the highest concussion risk among female players .
Position: Athlete’s playing position may also be associated with higher/lower concussion risk. In American football, linebackers are more risky between offensive linemen and defensive backs than are receivers. Currently there is not enough evidence to link the player Positions with greater/less concussion risk in other sports .
Athlete-related factors: Several factors specific to individual athletes are associated with greater concussion risk, including a body mass index greater than 27 kg/m2. Less than 3 hours of training per week may also increase the risk of concussion . Currently in the literature there are There was insufficient evidence to determine the association between age and level of play and concussion risk.
According to the 2017 consensus statement on concussions in sport, when a player exhibits any of the features of a concussion, management should proceed as follows;
A. Players should be evaluated on-site by a physician or other licensed healthcare provider using standard emergency management principles, and special attention should be paid to rule out cervical spine injuries. Symptomatic cognitive cranial and balance assessments should be included during the exam.
B. Proper disposition of the player must be promptly determined by the attending healthcare provider. If no healthcare provider is available, the player should be safely removed from practice or play and an emergency referral to a physician should be arranged.
C. Once first aid has been addressed, concussion injury should be assessed using SCAT 5 or other complementary assessment tools.
D. Players should not be left alone after injury, and continuous monitoring for deterioration in the first few hours after injury is essential.
E. A player who has been diagnosed with a sports-related concussion should not be allowed to return to play on the day of the injury.
As with all potentially serious injuries, allow ample time for evaluation if a concussion is suspected. The final decision on a concussion diagnosis and a player’s return to play rests with clinicians based on their clinical judgment.
Diagnosing a concussion can be difficult because the way the injury manifests itself varies widely from person to person. Things can get even more complicated for clinicians who find themselves under time pressure at sporting events. Therefore, it is important that clinicians understand the tools available to them to help them make an accurate diagnosis of concussion.
Cognitive Function: Assessment of cognitive function is an important part of the assessment. There are many short neuropsychological tests available to assess memory and attention. These include Maddocks Questions Sports Concussion Assessment Tool 5 (SCAT5) and standardized assessments Concussion (SAC).
Maddocks’ Questions: This is a list of 8 standardized memory assessment questions. These have been shown to be more reliable than using general orientation problems .
- Relatively short to administer
- More sensitive than standard orientation issues
- There are no guidelines indicating deadlines for returning to play – e.g. if a player only gets 1 of 8 questions wrong, should they be removed from the playing field/do they have to ask all 8 questions?
- There is a paucity of literature investigating the reliability and validity of these widely used questions.
- Not to be used as a standalone tool – it needs to be used in conjunction with the clinician’s judgment.
SCAT 5: A Concussion Assessment Tool for Ages 13+. The test consists of assessing the player’s level of consciousness using the Glasgow Coma Scale memory assessment using Maddocks’ questions symptom assessment cognitive screen body balance coordination Delayed recall and neck examination. Preseason baseline measurements can be used as a useful comparison to help identify concussions.
- Consolidate multiple different concussion assessments into one tool.
- Available as a phone app
- SCAT 5 takes 15-20 minutes to complete
- SCAT 5 is newly released, so its reliability and validity have not yet been evaluated. Its predecessors, SCAT 2 and SCAT 3, have also not been assessed for reliability and validity in any large-scale studies.
- Despite its widespread use in sports, a 2013 meta-analysis criticized SCAT2 design and scoring . A 2013 study by Chan et al.  found the test to have low test-retest reliability, thus questioning its suitability for diagnosing concussion.
- A high SCAT score does not necessarily mean a player does not have a concussion, as the onset of symptoms may be delayed.
- It must be noted that there have been reports of players deliberately scoring lower baseline measurements to avoid being carried off the field in the event of a concussion
Standardized Assessment of Concussion (SAC): Assesses directed immediate memory concentration and delayed recall. Administration takes about 6 minutes. Sensitivity: 80-94% Specificity: 76-91%
- Relatively short time to administer
- Assess many different functions that are often affected by concussion
- Some studies have reported that SAC has a sensitivity of only 80%, which means that a large number of concussed players cannot be identified using this tool
- No cutoff score for diagnosing concussion established for SAC
Post-Concussion Symptom Scale/Graded Symptom Checklist: Contains only a list of concussion symptoms that must be checked by trained personnel or by the athlete themselves. A baseline must be established prior to use. Study calculates sensitivity between 64–89%, with a specificity between 91–100% .
- Simple to use
- Relatively short time to administer
- The poor sensitivity means that many athletes with concussions cannot be identified using this assessment alone.
Balance Error Scoring System (BESS): Balance assessment tool. It takes about 5 minutes to complete. Assess postural stability in a number of different poses on firm and foam surfaces. Scores range from 0-60, with lower scores indicating better balance.
- Postural stability testing has been shown to be a reliable and effective tool for objectively assessing the motor domain of neurofunction .
- Relatively short time to administer
- Simple administration – consists of standardized instructions and requires no training
- Examining the Effect of Mild Head Injury on Postural Stability Without the Need for Expensive Equipment
- Execute in almost any environment
- Any other functions normally affected by concussion are not assessed
- Sensitivity is very poor, between 34–64%, and specificity is 91%
Sensory Organization Test: Use a force plate to test the player’s ability to maintain balance in response to changes in directional information available for somatosensory and/or visual input.
- Requires the use of a force plate and is therefore not suitable for sideline use.
- Expensive tests as equipment required for evaluation.
- Reported sensitivities are low, between 48-61%. Specificity was found to be between 85-90% 
Canadian CT Head Rule This measure includes a list of signs and symptoms used to determine whether a head injury or concussion warrants a scan.
- Simple to use
- High risk factors were considered 100% sensitive in predicting the need for neurointervention.
- Moderate risk factors had a sensitivity of 98.4% for predicting clinically important brain injury .
- A cross-sectional study comparing the use of the Canadian CT Head Rule compared its use to computed tomography (CT) scans, the gold standard for detecting head injuries, and agreed that it is an excellent decision tool.
- The low specificity (49-60%) means that many patients without concussion would be referred for scanning if the tool were used. More importantly, however, is the high sensitivity of the tool, so that no concussion patient will be missed using the tool.
As shown above, there are a number of different diagnostic tools available to clinicians to help them identify concussions. As mentioned above, each has its advantages and disadvantages. None of these tools should be used in isolation. Instead, they should be compared to Clinician’s clinical judgment. Combining diagnostic tests may improve the accuracy of concussion diagnosis compared to using individual tests. However, the optimal combination of tests to improve concussion recognition has not been identified.
The 2017 consensus statement made the following recommendations for determining the need for further investigation of minor head injuries:
A. The medical evaluation includes a thorough medical history and a detailed neurologic examination, including a full assessment of mental status, cognitive function, gait, and balance.
B. Determine the patient’s clinical status, including improvement or deterioration since injury. This may involve seeking additional information from parents, coaches, teammates and eyewitnesses to the injury.
C. Determining the need for urgent neuroimaging to rule out more serious brain injury involving structural abnormalities
Many different investigations can be done to help diagnose/rule out a concussion. Most commonly, structural neuroimaging is done. CT and MR brain scans of the brain have been found to be of little help in concussion assessment, but should be done if available Intracerebral or structural injury (eg, skull fracture) is suspected . Functional magnetic resonance imaging has been found to reveal activation patterns that correlate with concussion symptom severity and recovery. However, they are not part of the regular assessment. Other forms of imaging are still in their early stages development, currently not recommended.
If a concussion is suspected, the player should not be allowed to return to play on the same day. Concussion management is primarily through physical and cognitive rest. The literature suggests that rest during the immediate symptomatic phase of concussion may be beneficial. However the evidence is Sparse, especially in assessing the long-term benefits of rest and how much rest is needed . Nonetheless, consensus lays out protocols for graded return to play in sports. This uses a sensible approach to gradually resuming sport once the acute symptoms have cleared. This is Discuss later.
In sports concussion, drug therapy is often used if the patient has specific/long-term symptoms (eg, sleep disturbance) or to alter the pathophysiology of the concussion to shorten the duration of concussion symptoms.
Return to Play (RTP)
RTP decisions continue to be made on an individual basis based on the clinical judgment of the clinician. Players suspected of having a concussion should not perform RTP on the same day. Athletes who are allowed to return to competition on the same day are more likely to be delayed, study shows Neurophysiological symptoms that may not be evident off the field .
A 2017 consensus statement recommended the use of a progressive return-to-play protocol for post-concussion players. This is outlined below.
Using this protocol, athletes should gradually progress through the different levels before fully resuming competition. Athletes can only proceed to the next level of protocol if they remain asymptomatic for 24 hours at the current level. After completing this agreement, the athlete There should be no symptoms at rest or during strenuous exercise. If at any point during the protocol the athlete shows/reports concussion symptoms, they must return to their previous asymptomatic level. After an additional 24 hours of rest, the athlete can start improving again. Note: A Athletes who have had a previous concussion should only return to competition if they are asymptomatic and not taking any medications that may mask/alter concussion symptoms.
Concussion pre-screening is a valuable tool when working with a team. Not only does it help identify players with a history of concussions, but it also helps identify players who are at greater risk. It also provides an opportunity for players to learn about the signs and symptoms of a concussion And the risk of continuing to play with concussions. Any concussion pre-screen should include specific symptom questions as well as questions about the duration of any previous concussions. Note that concussion injuries are dependent on recalling other players/coaches has been proven to be unreliable .
Neck Strengthening to Reduce Concussion
In athletes, isometric neck strength is directly related to injury risk . In addition, concussed athletes had lower neck strength values in preseason games compared to athletes without a previous concussion . It has been proved that the greater Isometric neck strength reduces the kinematic response of the head during impact in female youth soccer players and male and female contact sports players (the same cannot be said for non-athletes  )  . such as large accelerations or decelerations or sudden changes in head direction In relation to concussion, reducing these forces may be beneficial in reducing the risk of concussion   . Simulations Show Neck Muscle Activity May Affect American Football and Mild Traumatic Brain Injury Risk in 6,704 Male and Female High School Students Neck strength in athletes was a significant predictor of concussion (0.004) after adjusting for sex and sport  . A one-pound increase in neck strength was associated with a 5% reduction in concussion risk . Thus, neck strengthening shows potential to reduce concussion risk Especially among teenage athletes.
To assess the athlete/patient’s neck strength, hand-held ergometers can be used. A self-administered hand-held ergometer showed a test-retest reliability of 0.87-0.97 for cervical flexion-extension, lateral flexion, and rotation in healthy male and female participants aged 18-37 years .
Self-administered dynamometer devised by Versteegh Beaudet and Greenbaum 2015
Neck Strengthening Protocol:
Fisher et al. 2016  developed a neck strengthening protocol for adolescents specifically for the prevention of sports injuries. The program is done 2 days a week for 8 weeks, completing 1 set of 8-15 repetitions to temporary muscle failure. The number of repetitions is strictly controlled at 5 Second eccentric and 3 second concentric. All exercises are done on a 4-way neck resistance machine, performing neck flexion, neck extension and lateral flexion. Conduct a familiarization session before the program begins to assess the initial training load to use. The load was increased when the participant was able to perform 2 consecutive repetitions of 15 of a given exercise.
To make the exercises easier to perform with more limited equipment, this page contains demonstrations of how to perform the exercises with a theraband or elastic resistance bands.
All exercises are performed twice a week for at least 8 weeks in one set, with 8 to 15 repetitions to achieve transient muscle failure. The concentric phase should be 3 seconds and the eccentric phase should be 5 seconds.
Starting with a standing or seated patient, secure the tension/resistance band behind the patient at head height. The strap should be secured over the patient’s forehead, and a towel may be placed under the strap for comfort. Instruct the patient to pull the chin back and lengthen the back In the neck, this should cause the upper cervical spine to flex and contract the deep cervical flexors. From this position instruct the patient to nod forward while keeping the chin tucked. Return the head to neutral flexion in a controlled manner. Repeat this action 8-15 times.
Starting with a standing or seated patient, secure the tension/resistance band at head height in front of the patient. The strap should be secured to the back of the patient’s head. Instruct the patient to push the strap back and begin to tilt the head back to observe up to the ceiling. Return to neutral. Repeat this action 8-15 times.
Starting with a standing or seated patient, secure the resistance band at head height on the opposite side to the direction of motion. The strap should be secured to the side of the head on the same side as the direction of movement. Instruct the patient to put the chin back and lengthen the back of the neck, which causes the upper cervical spine to flex and contract the deep cervical flexors and reduce any deviations in flexion or extension. Instruct the patient to turn the head to one side, as if placing the ear on the shoulder. Return to neutral. repeat the action Repeat 8-15 times
See this page for information on Post-Concussion Syndrome
Long-term Consequences of Concussion
The severity of a concussion injury is best understood by looking at the long-term consequences of the injury. This is a growing field of research. A traumatic brain injury event has been found in the history of 20-30% of Alzheimer’s/Parkinson’s patients patient. This compares to only 8-10% of the control group . Belanger et al (2010)  found that multiple concussions were associated with poorer performance on tests of delayed memory and executive function. Chronic traumatic encephalopathy (CTE) is a progressive degenerative disease brain . It is associated with a history of repetitive brain trauma and causes memory loss, confusion, depression, aggression, difficulties with impulse control, impaired judgment, and progressive dementia. It is most often associated with sports such as American football, boxing, and hockey. Symptoms may begin years after the traumatic brain injury has ceased.
- ↑ Jump up to:1.0 1.1 Dr. Mike Evans.Concussion 101, a Primer for Kids and Parents. Available from: http://www.youtube.com/watch?v=zCCD52Pty4A [last accessed 14/6/13]
- ↑ Jump up to:2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 McCrory P, Meeuwisse WH, Dvorak J, et al. Consensus statement on concussion in sport: The 5th international conference on concussion in sport, Berlin, October 2016. Bri J Sport Med. 2017;51:838-847
- ↑ Manaseer TS, Gross DP, Dennett L, Schneider K, Whittaker JL. Gait deviations associated with concussion: a systematic review. Clinical journal of sport medicine. 2020 Mar 1;30:S11-28.
- ↑ Grool AM, Aglipay M, Momoli F, et al. Association between early participation in physical activity following acute concussion and persistent postconcussive symptoms in children and adolescents. JAMA. 2016;316(23):2504-2514.
- ↑ Jump up to:5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Giza CC, Kutcher JS, Ashwal S, Barth J, Getchius TS, Gloia GA, Gronseth GS, Guskiewickz K, Mandel S, Manley G, McKeag DB, Thurman DJ, Zavonte R. Summary of evidence-based guideline update: Evaluation and management of concussion in sports: Report of the guideline development subcommittee of the American academy of neurology. Neurology [Internet]. 2013 Mar 18 [cited 2013 Jun 1]; 80(24). 2250-2257. Available from: http://neurology.org/content/early/2013/03/15/WNL.0b013e31828d57dd
- ↑ Lincoln AE, Caswell SV, Almquist JL, Dunn RE, Norris JB, Hinton RY. Trends in concussion incidence in high school sports: a prospective 11-year study. Am J Sports Med. 2011; 39(5): 958-63.
- ↑ McCrea M, Barr WB, Guskiewicz K, Randolph C, Marshall SW, Cantu R, Onate JA, Kell JP. Standard regression-based methods for measuring recovery after sport-related concussion. J Int Neuropsychol Soc. 2005; 11(1): 28-69.
- ↑ Chan M, Vielleuse JV, Vokaty S, Wener MA, Pearson I, Gagnon I. Test-retest reliability of the sport concussion assessment tool 2 (SCAT 2) for uninjured children and young adults. Br J Sports Med. 2013; 47.
- ↑ The Lancet Neurology. Time for a game changer in the management of concussion. Lancet. 2013; 12(5), 415.
- ↑ Stiell IG, Wells GA, Vandemheen K, Clement C, Lesiuk H, Laupacis A, McKnight RD, Verbeek R, Brison R, Eisenhauer ME, Greenberg G, Worthington J. The Canadian CT Head Rule for patients with minor head injury. Lancet. 2001; 357(9266): 1391-1396.
- ↑ Jump up to:11.0 11.1 Hrysomallis, C., 2016. Neck muscular strength, training, performance and sport injury risk: a review. Sports Medicine, 46(8), pp.1111-1124.
- ↑ Dezman, Z.D., Ledet, E.H. and Kerr, H.A., 2013. Neck strength imbalance correlates with increased head acceleration in soccer heading. Sports Health, 5(4), pp.320-326.
- ↑ Schmidt, J.D., Guskiewicz, K.M., Blackburn, J.T., Mihalik, J.P., Siegmund, G.P. and Marshall, S.W., 2014. The influence of cervical muscle characteristics on head impact biomechanics in football. The American journal of sports medicine, 42(9), pp.2056-2066.
- ↑ Gutierrez, G.M., Conte, C. and Lightbourne, K., 2014. The relationship between impact force, neck strength, and neurocognitive performance in soccer heading in adolescent females. Pediatric exercise science, 26(1), pp.33-40.
- ↑ Eckner, J.T., Oh, Y.K., Joshi, M.S., Richardson, J.K. and Ashton-Miller, J.A., 2014. Effect of neck muscle strength and anticipatory cervical muscle activation on the kinematic response of the head to impulsive loads. The American journal of sports medicine, 42(3), pp.566-576.
- ↑ Broglio, S.P., Schnebel, B., Sosnoff, J.J., Shin, S., Feng, X., He, X. and Zimmerman, J., 2010. The biomechanical properties of concussions in high school football. Medicine and science in sports and exercise, 42(11), p.2064.
- ↑ Blennow, K., Hardy, J. and Zetterberg, H., 2012. The neuropathology and neurobiology of traumatic brain injury. Neuron, 76(5), pp.886-899.
- ↑ Guskiewicz, K.M., Mihalik, J.P., Shankar, V., Marshall, S.W., Crowell, D.H., Oliaro, S.M., Ciocca, M.F. and Hooker, D.N., 2007. Measurement Of Head Impacts In Collegiate Football Playersrelationship Between Head Impact Biomechanics And Acute Clinical Outcome After Concussion. Neurosurgery, 61(6), pp.1244-1253.
- ↑ Jump up to:19.0 19.1 Collins, C.L., Fletcher, E.N., Fields, S.K., Kluchurosky, L., Rohrkemper, M.K., Comstock, R.D. and Cantu, R.C., 2014. Neck strength: a protective factor reducing risk for concussion in high school sports. The journal of primary prevention, 35(5), pp.309-319.
- ↑ Jin, X., Feng, Z., Mika, V., Li, H., Viano, D.C. and Yang, K.H., 2017. The role of neck muscle activities on the risk of mild traumatic brain injury in American football. Journal of biomechanical engineering, 139(10), p.101002.
- ↑ Versteegh, T., Beaudet, D., Greenbaum, M., Hellyer, L., Tritton, A. and Walton, D., 2015. Evaluating the reliability of a novel neck-strength assessment protocol for healthy adults using self-generated resistance with a hand-held dynamometer. Physiotherapy Canada, 67(1), pp.58-64.
- ↑ Fisher, J.P., Asanovich, M., Cornwell, R. and Steele, J., 2016. A neck strengthening protocol in adolescent males and females for athletic injury prevention. Journal of trainology, 5(1), pp.13-17.
- ↑ DeKosky ST, Ikonomovic MD, Gandy S. Traumatic brain injury-football, warfare and long term effects. N Engl J Med. 2010; 363(14), 1293-6.
- ↑ Belanger HE, Spiegel E, Vanderploeg RD. Neuropsychological performance following a history of multiple self-reported concussions: a meta-analysis. J Int Neuropsychol Soc. 2010; 16(2), 262-7.
- ↑ Boston University. What is Chronic Traumatic Encephalopathy? [Internet]. Boston: Boston University [undated]. Available from: http://www.bu.edu/cste/about/what-is-cte/