Concussion: Symptoms, Signs, Measurement, Forces in Concussion, and Management

1. Concussion: Symptoms, Signs, Measurement, Forces in Concussion, and Management Roger E. Thomas, MD, Ph.D, CCFP, FCFP, MRCGP Professor of Family Medicine, Faculty of Medicine, University of Calgary, Canada

2. OUTLINE • Definition of concussion • Symptoms and signs of concussion • Incidence • Initial assessment • Measurement: SCAT2/3 (Sports Concussion Assessment Tool) • Numbers and force of impacts in sports • Therapy for concussion

3. Definition: A form of head injury characterized by any alteration in cerebral function and caused by a direct or indirect (rotation) force transmitted to the head Canadian Academy of Sport and exercise Medicine. 2010 Acute signs or symptoms: • Brief loss of consciousness • Light-headedness • Vertigo, tinnitus, blurred vision, photophobia • Cognitive and memory dysfunction, difficulty concentrating, amnesia • Headache, nausea, vomiting • Balance disturbance Delaney J, Frankovich R. Discussion Paper. Head Injuries and Concussions in soccer. Canadian Academy of Sport and Exercise Medicine. 2010.

4. Canadian Academy of Sport and exercise Medicine. 2010 Delayed signs and symptoms: • Sleep irregularities • Fatigue • Personality changes • Inability to perform usual daily activities • Depression or lethargy

6. Incidence • 1/3 of all mild head injuries in US occur in 5-19 year olds • For children > 1 year trauma is main cause of death, and head trauma is leading cause of disability and death • In high schoolers 9% of athletic injuries involve mild head injury

7. Improvement in symptoms • Symptoms of 80% to 90% of cases appear to improve in 7 to 10 days but the long-term effects of cumulative concussions become apparent • 24.5% of 13 to 21 year olds still having disabling symptoms at one month • 5.9% remain symptomatic after six months • Symptoms can persist > one year • Symptoms of repeated concussions can last a lifetime

8. Comprehensive initial assessment • Symptoms • Details of the mechanism of injury • The time line of symptoms • Aggravating factors • Rule out child abuse

9. Physical Exam Full Physical exam, focused on Head • Signs of trauma • Lacerations and abrasions • Skull fractures (depression, discontinuity) • Basilar skull fracture • Hemotympanum • drainage of fluid or blood from the nose or ears • Battle’s sign (bleeding behind the ear)

10. MEASURING CONCUSSIONSystematic review of all SCAT2 and 3 tests by Thomas, Alves, Magalhães and Vaska • Searched 18 databases, 9 grey literature resources searched for SCAT2/3 data; 9,150 articles identified • 21 studies with data • 16 SCAT2 studies with partial/complete data (4,087 athletes) • 5 SCAT3 studies (891 athletes) • 1,067 females; 3,831 males; 80 gender not stated

11. Systematic review of all SCAT2 and 3 tests by Thomas, Alves, Magalhães and Vaska • Only 1 study reported SCAT data for a professional league (Finnish ice hockey players) • Minimal data on elementary students • No data on adult non-collegiate athletes • Concussion: Only 2 studies report both baseline and post-concussion scores and 9 report partial scores but data are too limited to provide weighted average scores • Unwitnessed concussions: A study of rugby players during 62 games noted 52 concussions (44/1000match hours) with 8 witnessed concussions but 44 unwitnessed concussions identified post-match by the King-Devick test

12. Weighted mean SCAT2 scores by age group (21 studies)

13. Perfect scores may not be attained because of age differences in ability to repeat digits and months of the year backwards

14. Preseason baseline SCAT2 scores 1134 High School Arizona athletes

15. Instructions for the Balance Error Exam (also printed at end of the SCAT3) 3 stance tests timed over 20 seconds: • all without shoes, socks and trousers rolled above ankle so you can observe balance • all hands on hips, eyes closed • Double leg stance. Feet together. • Single leg stance. Stand on non-dominant foot, with dominant leg 30 degrees hip flexion, 45 degrees knee flexion • Tandem stance: heel-to-toe, non-dominant foot behind

16. SCAT3 Balance exam: scoring errors Take off one point for each error during each 20 second test (max errors = 10 for each test) • Lifted hands off iliac crest • Opened eyes • Step, stumble or fall • Moved hip into > 30 degrees abduction • Lifted forefoot or heel • Remained out of test position > 5 seconds

17. SCAT3 balance tests: Tandem gait • Walk heel-toe along 38 mm wide tape for 3 meters then return • 4 trials and choose best time (should complete in 14 seconds) • Fail test if step off the line, or separate heel and toe, or grab an object for support Finger-Nose • Starting position: sit on chair, shoulder flexed to 90 degrees, elbow and fingers extended • Now touch nose and return to starting position 5 x • Score 1 point for 5 correct repetitions in < 4 seconds

18. Systematic review of all SCAT2 and 3 tests by Thomas, Alves, Magalhães and Vaska • Only 1 study reported SCAT data for a professional league (Finnish ice hockey players) • Minimal data on elementary students • No data on adult non-collegiate athletes • Concussion: Only 2 studies report both baseline and post-concussion scores and 9 report partial scores but data are too limited to provide weighted average scores • Unwitnessed concussions: A study of rugby players during 62 games noted 52 concussions (44/1000 match hours) with 8 witnessed concussions but 44 unwitnessed concussions identified post-match by the King-Devick test

19. Summary: Amount of data • Generalisability of results highest for a study of Finnish professional male ice hockey which assessed most players in the league • Generalisability lowest for studies of individual schools or studies including many sports. • SCAT component average scores were homogeneous between samples • Considerable heterogeneity within samples. • No strong differences between genders.

20. Summary: problems collecting data on concussions No uniformity across sports: • In pre-season SCAT testing to obtain baseline scores • Numbers of observers to increase the likelihood of detecting concussions during play • Using King-Devick tests to detect unwitnessed concussions. Urgently need: • Systematic adoption of continuous follow-up assessments including complete SCAT and King-Devick testing in all age ranges of amateur and professional sports • Follow them if concussed until fully recovered.

21. Summary: Comprehensive use of SCAT 3 with medical examinations and neuropsychological testing Minimum Clinically Important Differences in SCAT scores: • have not been defined • would need to be based on careful assessments by several assessors with minimal intra- and inter-observer variability • detailed follow-up of athletes to determine full recovery and appropriate return to play. Until these problems have been solved the SCAT should be used cautiously for clinical and return-to-play decision processes and also need: • extensive medical examination • quantitative neuropsychological testing

22. Initial Management • Allow player/child to sleep, checked regularly for clinical deterioration • Avoid medications that affect evaluation of cognition (e.g. meclizine, benzodiazepines), mask symptoms (e.g. anti-emetics) or facilitate bleeding (e.g. ASA, NSAIDs) • Avoid participation in sports/physical activities. Make this clear to parents, coaches, trainers and teachers • Gradual return to mental and physical activities • Regular assessments

23. Initial Management: Rest and no intense mental activities: • Reading • Computers • Videogame • Puzzles, Sudokus • Texting, TV • Schoolwork

24. HOW MANY SPORTS INJURIES ARE THERE? • US National Electronic Injury Surveillance System 2001-12 • 3.42 million emergency department visits for sports- and recreation-related trumatic brain injury • 70% ages 0-19 • Males: bicycling, American football, basketball • Females: bicycling, playgound, horseback riding

25. Boxing: US National Electronic Injury Surveillance System (NEISS) from a sample of 100 hospitals 1990-2008 • Extrapolated to US population: 165,502 injuries • Rate of boxing participation computed using Superstudy of Sports Participation database. • Injuries: fractures (27.5%), soft tissue (26%), sprains/strains (22%), lacerations (8.8%), concussion (5.1%), dislocations (3.7%) • Injury rate males 13.3/1000, females 8.9/1000; • 12-17 years 14/1000, 18-24 years 16.4/1000, 25-34 years 13.6/1000 • Concussions as % of injuries: age 12-17 8.9%, 18-24 8.1%, 25-34 8.5% • 36.8% of all injuries occurred hitting or missing punching bag

29. Measuring impacts in soccer Collegiate athletes head the ball 2.8-8.5 times/game and > 500 times/season Summary of 18 studies of heading soccer balls: • higher accelerations of head if low head/neck mass • lower accelerations if align head and torso and follow through with head • Heading a ball: • 28.7g head acceleration if ball 6psi (pounds/square inch pressure) and 15m/s speed • 50.7g if ball at 8 psi and 22.4 m/s (Caccese 2016)

30. Number of impacts: American Football • 22 high school football players wore helmets with 6 accelerometers • Head impacts: median 9/practice (range 2-22), 12/game (range 6-18), 252/season (306 for those who participated in ≥ 66% of sessions) • Maximum for an individual player was 54 for a practice, 50 for a game and 880 for a season. • Team head impacts: 6183/season (61% in the 27 practices, 33% in the 9 games and 6% in pre-game warm-ups) • Average linear acceleration: 25.5g (range 10,175.9g) • Average rotational acceleration: 1691.8 rad/s2 (range 7.1, 12,322.5)

31. Number of impacts: American Football Total head accelerations received by 20 University of Virginia American football players/player/season • Average number of head impacts (> 10g) = 974 (maximum 2277) • Average cumulative Peak Linear Acceleration = 29,233g (maximum 76,296g) • Average cumulative Peak Rotational Acceleration = 5,857,749 rad/s2 (maximum 16,174,965 rad/s2) (Reynolds 2015)

32. Mixed Martial Arts

34. How many concussions are there? The more detailed the data collection the higher the rate 1% of high school athletes, Minneapolis/St Paul, Minnesota. [trainers entered concussion details in Reporting Information Online system of the Nationwide Children’s Hospital of Columbus, Ohio] • 3% of athletes at two Canadian universities (2.58% females, 3.39% males) • Boxing: post-fight medical examinations of all 550 boxers and 1181 mixed martial artists (MMA) in Edmonton, Canada, 2000-2013 • 10.4% of boxers and 8.3% of MMA had concussions • 7.1% of boxers and 4.2% MMA loss of consciousness • Boxers average 26 and MMA 20 days post-bout medical suspensions

35. How many concussions? The more detailed the data collection the higher the rate Motocross motor bike racers: 48% of 139 motocross under 18 concussed/ racing season (range 1-5 concussions) (average age 12 years) • 61% continued racing the same day and 24% the entire season • 33% had concussions from multiple sources other than motocross

36. Specific activities within sports cause the highest percentage of concussions in that sport: • Soccer: heading ball (40.5%), goaltending (20.5%), receiving a pass (10.5%) • American Football: running play offense/defence (55.4%), passing play offence/defence (16.3%) • Wrestling: takedown (42.8%) and sparring (21.9%) • Basketball: rebounding (30.5%) and chasing a loose ball (26%); and • Baseball/softball: batting (50.6%)

37. Multiple cellular changes occur during a concussion • efflux of potassium and influx of sodium • increase in intra-axonal calcium which triggers calpain-mediated proteolysis of the cytoskeletal proteins • glutamate release leading to increased glucose consumption • acidosis and cerebral edema • microtubule disassembly impairing axonal transport • swelling of axons and disconnection at the site of injury (usually deep gyri at the white and grey matter interfaces) biomarker research incudes: • NFL (found in large calibre myelinated axons which project to the spinal cord and deep brain regions • tau proteins (found in non-myelinated axons of cortical interneurons)

38. Second Impact Syndrome Can occur after a concussion if further blows to the head result in: • loss of autoregulation of the cerebral circulation • massive brain edema

39. What forces are received during daily activities? Head accelerations from 7 impacts in daily life • Each tested by 10-20 subjects who wore triaxial head accelerometers and 2 bite block accelerometers • soccer ball impact to forehead (5-11.5 cms/sec) • self-imposed hand strike to forehead • vigorous head shaking • plopping down in chair • jumping off step (30-90 cms) • seated drop onto buttocks 5-10cm drop) • vertical drop while seated supine in chair 5-10cms

40. Head accelerations from daily activities

41. Head accelerations received by soccer players • 16 Collegiate soccer players headed wearing mouthpiece with three accelerometers, soccer machine accelerated balls (8 pounds/square inch pressure): to 30, 40 or 60 mph

42. Head accelerations received by American Football players • Reconstruction in laboratory of 31 of the 182 concussions in US National Football league 1996-2001

43. At what forces do concussions occur? • Concussions tend to occur above linear accelerations ≥ 50 g • Rotational accelerations are more important in the combination of rotational and linear accelerations in causing concussions • Concussions occur all the way down to rotational accelerations < 1000 radians/sec2

44. Effects of concussions? 66 US Major League Baseball players who sustained a concussion 2007- 2013 were identified through league disabled-list records Compared to 68 players on paternity or bereavement leave same period Concussed players 2 weeks after return lower performance (p<.05): • batting average .235 vs .266 • on-base percentage .294 vs .326 • slugging percentage .361 vs .423 • onbase plus slugging .650 vs .749

45. Methods of reducing head injuries • Training to avoid contact (Taekwondo) • Rules to outlaw dangerous manoevres (Mixed Martial Arts) • Training to avoid dangerous manoevres • Training to block dangerous manoevres • In pair sports, pair opponents of similar weight, training and match success (Boxing) • Shorter matches (Taekwondo 3 bouts of 3-5 minutes vs. boxing 14 bouts) • Train coaches and referees to enforce rules • Remove dangerous players • Better protective gear

46. Athletes still receive major impacts wearing boxing and Taekwondo helmets (Hybrid III Crash Test Dummy head and neck hit at 8±0.3 m/s)

47. 2 layers of foam on helmets reduce head accelerations • Helmets with HIT system accelerometers • In laboratory 10 hits on each of 9 helmets from 0 layers polyolefin foam to 2 layers of foam on both helmet and impacting helmet

48. Conclusions: numbers of concussions • There are large numbers of impacts in contact sports per player and season • American football, ice hockey, soccer, boxing, martial arts, wrestling motocross have the highest concussion rates • There are far more unobserved and undocumented than observed and documented impacts and concussions in sports

49. Conclusions: effects of concussions on tissues • Shearing of interneuronal connections is an important cause in concussions and occurs more by rotational than linear head accelerations • Forces sufficient to cause concussions also show damage to animal, cadaver and operation specimens • Cumulative effect of subclinical impacts is not known • Rules to avoid injuries and enforcement of rules reduces injuries and concussions • 2 layers of padding on helmets reduces linear and rotational impacts by 30%

50. What therapy can we offer?Systematic review of therapy for mild brain injury/concussion. Thomas RE, Alves J, Magalhães R, Vaska M