Concussions, especially pediatric concussions, have received much attention from the media in the past few years. Concussions are commonly misdiagnosed or missed in an emergent setting, and concussions are becoming a major public health issue. Because of this attention, new guidelines are being developed and new findings are being discovered at an unprecedented pace. Emerging theories and increased understanding of the devastating consequences of concussion have even led the National Hockey League and National Football League (NFL) to review and change their concussion policies. Recognition and education about concussions are of high importance, because although we can take steps to appropriately manage a concussion, there has been little study thus far on their outright prevention.
Traumatic brain injuries (TBIs) are defined as any disruption in the normal function of the brain caused by a sudden blow to the head or a penetrating injury resulting in a period (of any length) of decreased or loss of consciousness, retrograde or posttraumatic amnesia, neurologic deficits, or any alteration in mental status. Concussions are often classified as a mild TBI and are defined as a syndrome of instantaneous and transient onset of neurologic dysfunction that may or may not include loss of consciousness. Neurologic recovery from concussions is often complete, although amnesia regarding the inciting event may last longer than other neurological symptoms.1
Vulnerable populations for concussions include children age 0 to 4 years, adolescents, and adults older than age 75 years, with males more commonly affected than females.2 It is difficult to establish the exact incidence of concussion because of variability in presentations, and in particular because of underreporting of concussion and the lack of widespread surveillance in youth sports.1 As we improve on the recognition and diagnosis of concussions, it is expected that the number of diagnosed concussions will increase. Interestingly, although concussions as a whole are more commonly associated with males, studies have shown that across similar sports, females have a higher incidence of concussion.3 The possible explanations for this include weaker neck muscles and a smaller head mass in females, and that males may be prone to underreport their symptoms for fear of being removed from competition.1 In boys, the sports most likely to to cause concussion are football and hockey, whereas for girls the sports are soccer and basketball.3
Immediate symptoms of mild TBI include headache, nausea/vomiting, decreased motor coordination, dizziness, blurred vision/diplopia, and tinnitus. Fatigue, sleep changes, behavioral/mood changes, confusion, difficulty with memory, concentration, and attention can present later in the progression of concussion if early symptoms are not detected. Symptoms of concussion are usually present immediately after injury but may be delayed up to 72 hours after the initial event.4 Recovery is usually fairly quick, with most children recovering within 1 week to 10 days.4 Those with prolonged headaches, fatigue, fogginess, previous concussions, or those presenting with more than three symptoms are at risk for delayed recovery. Common signs of concussion include loss of consciousness, loss of balance or lack of motor coordination, disorientation or confusion, amnesia, visible facial injury, and a blank or vacant look.5
A thorough physical examination is an essential component to any evaluation of concussion. Particular areas of emphasis include a mental status examination, a careful cranial nerve examination, balance testing, and standard strength, reflex, and coordination testing.6 Any focal neurological findings may suggest other causes and may warrant further evaluation, including neuroimaging. Physical examination findings that may indicate concussion include impaired vision, slow or purposeful movements on the finger-to-nose test, cranial nerve deficits, and vestibular abnormalities including saccades and spontaneous or gaze-holding nystagmus.7
Currently, management is complicated due to the difficulty in diagnosing concussions. There is no clear constellation of symptoms that immediately lends itself to a clinical diagnosis, and the symptoms of concussion are nonspecific and are often subtle. The traditional means of evaluating concussion focused on whether the patient lost consciousness or had amnesia. However, studies have shown that those factors do not accurately reflect the severity or the time to recovery of a concussion and are not helpful for management purposes.4
The most common means of evaluating recovery and return to play are tools such as the Sport Concussion Assessment Tool 3 (SCAT3) or the ChildSCAT3. The ChildSCAT3 is a standardized tool designed for medical professionals to evaluate children for concussion using a series of questionnaires, cognitive tests, physical examination findings, and comparing symptoms from the patient's perspective and an adult's perspective. It also serves as a guideline for physicians to provide advice to families in the event of a concussion. Two essential elements in the management of any concussion include cognitive and physical rest, as activity has been shown to intensify concussion symptoms and may even delay recovery.8 Cognitive rest may include a temporary removal from school activities, reduced workloads in school, or allowing more time for a child to take tests.1 Coordination between school faculty and the family is essential to establish the student's true ability after the concussion symptoms resolve. Children, in particular, are managed conservatively, often with longer return-to-play times. Once the child's symptoms have resolved, a graded return-to-play plan of action is implemented. Neuropsychological testing is often indicated for those at risk of prolonged recovery.
Neuroimaging is not typically indicated with concussions. Indications for neuroimaging with a concussion include severe headache, focal neurological signs or symptoms, slurred speech, poor orientation to either person, place, or time, significant drowsiness, significant irritability, and loss of consciousness for longer than 30 seconds.1 The New Orleans criteria state that a computed tomography scan is warranted in trauma if there is severe headache; vomiting; deficits in short-term memory; physical evidence of contusions, abrasions, or lacerations; deformities or signs of fracture above the clavicles; or seizure.6
The main reason concussions are such a source of concern is their potential for devastating long-term consequences. Although most children's concussion symptoms resolve within 7 to 10 days, there are a number of sequelae that physicians and families need to be aware of once the diagnosis has been established.
One of the most common sequelae of concussions is postconcussive syndrome (PCS). PCS is defined as a concussion in which symptoms do not resolve after 7 to 10 days.9 It is important to understand that PCS is not a prolonged concussion—it is an entirely separate entity. Like concussions, diagnosing PCS is a challenge due to its varying and vague clinical features. The most common symptoms of PCS include headache, dizziness, nausea, memory disturbance, confusion, fatigue, depression, sleep issues, difficulty concentrating, and persistent mental fogginess. Typical diagnostic testing includes neuroimaging and neuropsychological evaluation, although there are no established diagnostic criteria for PCS. Much of the diagnosis is made based on individualized clinical judgement. Because there is no specific treatment for PCS, most clinicians tend to treat it symptomatically.10 Persistent symptoms often lead to missed school and a lower quality of life.11 Fortunately, many patients with PCS tend to recover within 1 month and roughly 90% recover by 3 months; those who do not recover can have persistent symptoms for up to 1 year or longer in some cases.11
A more worrisome consequence of concussion is a phenomenon known as second impact syndrome, which is defined as a devastating neurological injury secondary to massive cerebral edema in those who sustain a second concussion before completely recovering from an initial concussion.12 Although this complication is rare, its consequences are severe enough that those who suffer a concussion, especially children, are often placed on strict individualized return-to-play recommendations to avoid it. Whereas most children have their symptoms resolve by 1 week, studies have shown that children, in particular, take longer to fully recover compared to adult or college athletes.1 This has resulted in a more conservative approach to deciding when children can return to play.1 A 2013 review article found that although certain risk factors can elevate a child's risk for initial concussion, there are insufficient data to evaluate risk factors for second impact syndrome.13 Although second impact syndrome remains somewhat of an unknown entity, it has been clearly demonstrated in numerous studies that children are at the highest risk for this condition.1 In fact, all reported cases of this condition are in athletes younger than age 20 years, and catastrophic football head injuries are 3 times more likely in high school players compared to college players.1
Perhaps the most worrisome complication of pediatric concussions is chronic traumatic encephalopathy (CTE). CTE has become known due to increasing rates of dementia among NFL players with a history of multiple concussions.14 CTE was first recognized in the world of boxing, where it was historically referred to as “dementia pugilistica.”15 CTE is defined as a progressive tauopathy that occurs as a consequence of repetitive mild TBIs. There is a typical symptomology associated with CTE. Usually patients with CTE experience headache with associated loss of attention and concentration, which then progresses to a stage of violent behavior and short-term memory loss.16 Interestingly, this study has shown that the tauopathy associated with CTE is also associated with other neurodegenerative disorders such as motor neuron disease, Alzheimer's disease, and Lewy body dementia; and that these occasionally coexist with CTE. Although a single concussion does not necessarily increase a child's risk for developing CTE, recent thinking has evolved to suggest that children or adults who sustain multiple concussions or head blows over time tend to be at the greatest risk.
As discussed earlier, concussions can have significant long-term consequences; therefore, concussion prevention becomes paramount. Minimizing high-risk situations for concussions as well as enforcing strict guidelines on the management of a concussion may be the best chance to reduce concussions and their sequelae. The best prevention strategy we have is to educate parents, teachers, and the general public on signs, symptoms, and risk factors for concussion. A 2017 study examined concussion trends before and after youth sports organizations passed laws about TBIs.17 The authors found that there was a significant increase in the rate of concussion reporting immediately after these laws were passed; however, the rate of reporting recurrent concussions decreased in the years after the laws were passed.17 This finding is significant in that these laws are encouraging coaches, families, and patients themselves to identify and report concussions, which is often the most difficult aspect of treating and preventing concussion sequelae.
Interestingly, although equipment such as helmets and mouth guards have been shown to reduce catastrophic head injuries, facial injuries, and dental injuries, equipment has not been shown to prevent concussions.1,18 In a survey of 229 high school football players, 15.3% reported sustaining a concussion during the current football season; of those, 47.3% reported their injury.19 The most commonly cited reasons for underreporting included the player not thinking the injury was serious enough to be reported, not wanting to be taken out of the game, and lack of awareness of probable concussion.19 A study found that although educational programs are associated with increased recognition of concussions and their severity, they have not necessarily been able to show changes in behavior and attitudes regarding concussion.11 Although education is an essential first step in concussion prevention, we need more research on methods that will reduce or prevent concussions from occurring.
Because of their significant overlap with other conditions, as well as their potential sequelae, it is important to properly recognize concussions when they happen. Neuropsychological evaluation and the ChildSCAT3 are mainstays of evaluation, although these are not the sole means of diagnosing pediatric concussions. In most cases, the signs and symptoms of concussion tend to resolve in 7 to 10 days with proper physical and cognitive rest, although there are exceptions. Return-to-play decisions are made on an individual basis, although children who are currently symptomatic or who experienced a concussion earlier that day should not return to play. Currently, education is vital to improve community-wide recognition and awareness of concussions. Although the long-term effects of pediatric concussions are currently being investigated, further research is needed to improve management and prevent sequelae.
- Halstead ME, Walter KDCouncil on Sports Medicine and Fitness. American Academy of Pediatrics. Clinical report—sport-related concussion in children and adolescents. Pediatrics. 2010;126(3):597–615. doi:. doi:10.1542/peds.2010-2005 [CrossRef]
- Veliz P, McCabe SE, Eckner JT, Schulenberg JE. Prevalence of concussion among US adolescents and correlated factors. JAMA. 2017;318(12):1180–1182. doi:. doi:10.1001/jama.2017.9087 [CrossRef]
- Marar M, McIlvain NM, Fields SK, Comstock RD. Epidemiology of concussions among United States high school athletes in 20 sports. Am J Sports Med. 2012;40(4):747–755. doi:. doi:10.1177/0363546511435626 [CrossRef]
- Scorza KA, Raleigh MF, O'Connor FG. Current concepts in concussion: evaluation and management. Am Fam Physician. 2012;85(2):123–132.
- [No authors listed.]Child SCAT3. Br J Sports Med. 2013;47(5):263.
- Stillman A, Alexander M, Mannix R, Madigan N, Pascual-Leone A, Meehan WP. Concussion: evaluation and management. Cleve Clin J Med. 2017;84(8):623–630. doi:. doi:10.3949/ccjm.84a.16013 [CrossRef]
- Matuszak JM, McVige J, McPherson J, Willer B, Leddy J. A practical concussion physical examination toolbox. Sports Health. 2016;8(3):260–269. doi:. doi:10.1177/1941738116641394 [CrossRef]
- Sarmiento K, Waltzman D, Lumba-Brown A, Yeates KO, Putukian M, Herring S. CDC guideline on mild traumatic brain injury in children: important practice takeaways for sports medicine providers. Clin J Sport Med. 2018. [Epub ahead of print]. doi:. doi:10.1097/JSM.0000000000000704 [CrossRef]
- Bazarian JJ, Wong T, Harris M, Leahey N, Mookerjee S, Dombovy M. Epidemiology and predictors of post-concussive syndrome after minor head injury in an emergency population. Brain Inj.1999;13(3):173–189. doi:10.1080/026990599121692 [CrossRef]
- Evans RW, Evans RI, Sharp MJ. The physician survey on the post-concussion and whiplash syndromes. Headache. 1994;34(5):268–274. doi:10.1111/j.1526-4610.1994.hed3405268.x [CrossRef]
- Zemek RL, Farion KJ, Sampson M, McGahern C. Prognosticators of persistent symptoms following pediatric concussion: a systematic review. JAMA Pediatr. 2013;167(3):259–265. doi:. doi:10.1001/2013.jamapediatrics.216 [CrossRef]
- Saunders RL, Harbaugh RE. The second impact in catastrophic contact-sports head trauma. JAMA. 1984;252(4):538–539. doi:10.1001/jama.1984.03350040068030 [CrossRef]
- Giza CC, Kutcher JS, Ashwal S, et al. 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. 2013;80(24):2250–2257. doi:. doi:10.1212/WNL.0b013e31828d57dd [CrossRef]
- Omalu BI, DeKosky ST, Hamilton RL, et al. Chronic traumatic encephalopathy in a National Football League player: part II. Neurosurgery. 2006;59(5):1086–1092; discussion 1092–1093. doi:. doi:10.1227/01.NEU.0000245601.69451.27 [CrossRef]
- Smith DH, Johnson VE, Stewart W. Chronic neuropathologies of single and repetitive TBI: substrates of dementia?Nat Rev Neurol. 2013;9(4):211–221. doi:. doi:10.1038/nrneurol.2013.29 [CrossRef]
- McKee AC, Stern RA, Nowinski CJ, et al. The spectrum of disease in chronic traumatic encephalopathy. Brain. 2013;136(Pt 1):43–64. doi:. doi:10.1093/brain/aws307 [CrossRef]
- Yang J, Comstock RD, Yi H, Harvey HH, Xun P. New and recurrent concussions in high-school athletes before and after traumatic brain injury laws, 2005–2016. Am J Public Health. 2017;107(12):1916–1922. doi:. doi:10.2105/AJPH.2017.304056 [CrossRef]
- Rivara FP, Graham R. Sports-related concussions in youth: report from the Institute of Medicine and National Research Council. JAMA. 2014;311(3):239–240. doi:. doi:10.1001/jama.2013.282985 [CrossRef]
- McCrea M, Hammeke T, Olsen G, Leo P, Guskiewicz K. Unreported concussion in high school football players: implications for prevention. Clin J Sport Med. 2004;14(1):13–17. doi:10.1097/00042752-200401000-00003 [CrossRef]