Football and Traumatic Head Injuries; Research and Clinical Implications

Transcription

1 Football and Traumatic Head Injuries; Research and Clinical Implications AAO Convocation March 23rd, 2014 P. Gunnar Brolinson, DO, FAOASM, FAAFP, FACOFP Professor and Discipline Chair, Sports Medicine Director, Primary Care Sports Med Fellowship Team Physician, Virginia Tech Team Physician, US Ski Team Stefan Duma, PhD Steve Rowson PhD Virginia Tech Wake Forest School of Biomedical Engineering

2 Funding and Disclaimer DOT: National Highway Traffic Safety Administration Toyota Central Research and Development Labs, Inc NIH: R01HD I do not have any relevant financial relationships to be discussed, directly or indirectly, referred to or illustrated with or without recognition within this presentation.

3 Congratulations! 13 ACC Players in Super Bowl Kam Chancellor, Virginia Tech

4 No health topic in recent memory has captured the public s attention as much as the debate on sports related traumatic brain injury. The deal calls for the NFL to pay $765 million to fund medical exams, concussion-related compensation, medical research for retired NFL players and their families, and litigation expenses, according to a court document filed in U.S. District Court in Philadelphia.

5 Presentation Outline Part 1: STAR Helmet Rating Update Review Data and Validation Studies Adding Rotational Acceleration Part 2: Brain Strain During Impact Part 3: Head Impact Sensor Evaluation Accuracy and Exposure Comparisons Part 4: Clinical Implications and Challenges Questions and Discussion

6 HIT System Helmet Instrumentation Two parallel systems during past 10 years 6DOF Device (VT) 6 Accelerometers mounted normal to the skull 3 Linear and Resultant Rotational Accelerations $1,000/helmet Validated by NFL, others 12 Accelerometers mounted tangential to the skull 3 Linear and 3 Rotational Accelerations (6DOF) $10,000/helmet Validates HIT System

7 Teams Using the HIT System Total Number of Impacts Collected at Virginia Tech Cumulative HITS Data Collection 200, , , , , ,000 80,000 60,000 40,000 20, Virginia Tech 195,000+ impacts recorded at Virginia Tech 2,000,000+ impacts recorded at all institutions Virginia Tech North Carolina Oklahoma Virginia Tech North Carolina Oklahoma Dartmouth Arizona State Virginia Tech North Carolina Oklahoma Dartmouth Arizona State Indiana Illinois Virginia Tech North Carolina Oklahoma Dartmouth Brown Indiana Minnesota Virginia Tech North Carolina Oklahoma Dartmouth Brown Indiana Virginia Tech North Carolina Oklahoma Dartmouth Brown Indiana Virginia Tech North Carolina Oklahoma Dartmouth Brown Indiana Wake Forest Virginia Tech North Carolina Oklahoma Dartmouth Brown Indiana Wake Forest Virginia Tech North Carolina Oklahoma Dartmouth Brown Indiana 1 High School 5 High Schools 5 High Schools 2 High Schools 3 High Schools 4 High Schools 4 High Schools 4 High Schools 4 High Schools 1 Youth Team 5 Youth Teams

8 STAR Rating System for Football Helmets (Rowson and Duma, 2011) STAR: Summation of Tests for the Analysis of Risk STAR 4 L 1 6 H 1 E h R a Combines true impact exposure with an unbiased risk analysis using real world biomechanical data to assess helmet safety for consumers.

9 Helmet Comparison: Top Impact from 60 inch Drop Height Severity Index NOCSAE Pass / Fail Threshold Adams A2000 Riddell 360 VS Adams A2000 Riddell Peak Acceleration (g) Adams A2000 Riddell 360

10 Probability of MTBI Consider Two Helmets 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Which helmet would you choose? Helmet B Helmet A For Identical Impacts: Helmet A 90 g 1% risk of concussion Helmet B 200 g 59% risk of concussion Linear Acceleration (g)

11 Journal of Neurosurgery 2014 Data compiled from 8 collegiate football teams 1833 players over 6 years Exposure controlled Clinical Evidence

12 Journal of Neurosurgery 2014 Riddell Revolution reduces risk of concussion by 53.9% compared to Riddell VSR4 (p=0.03) (STAR Equation predicts 54.2% reduction)

13 Institute of Medicine Committee on Sports-Related Concussions in Youth The National Academies Press 2013 The STAR system is theoretically grounded and represents an intriguing approach to how the injury mitigation properties of a helmet could be assessed. The STAR system is based on sound principles Adding rotational acceleration and youth specific data would increase widespread application of the STAR system

14 NFL Developed a Poster from the Virginia Tech Helmet Ratings Posted in all 32 Locker Rooms

15 Rotational Acceleration Comparison Concussion DAI NFL Volunteer DAI

16 True Positive Rate Rotational Acceleration (rad/s/s) True Positive Rate Combined Linear and Rotational Risk Risk Contours 1% 90% 75% 50% 25% 10% 5% Volunteer Data ROC Curves AUC = HITS Data 63,011 Impacts 244 Concussions False False Positiv Positiv e Rate Rate 2000 Risk = Linear Acceleration (g) e ( a a (Rowson and Duma, ABME, 2013) AUC = NFL Data 58 Impacts 25 Concussions False False Positiv Positiv e Rate Rate

17 Pneumatic Linear Impactor 14 kg Impacting Ram Piston Solenoid Valve Hybrid III Head 5DOF Linear Slide Table Pressure Vessel

18 Implications of Helmet Fit Upper skull is very similar between headforms Hybrid III NOCSAE Substantial differences are noted in: Nape of neck Chin Jaw Differences can have profound effect on helmet fit

19 NOCSAE Headform Modifications 1. Removed material to better position the neck 2. Developed custom neck mount 3. Instrumented with 6DOF sensor package NOCSAE head customized to mount on Hybrid III 50 th percentile male neck

20 Presentation Outline Part 1: STAR Helmet Rating Update Review Data and Validation Studies Adding Rotational Acceleration Part 2: Brain Strain During Impact Part 3: Head Impact Sensor Evaluation Accuracy and Exposure Comparisons Questions and Discussion

21 Experimental Concussion Research Cadaver Data Animal Data NFL Data Volunteer Data 1954 Ford funds WSU 1961 Gurdjian, Lissner origin of WSTC 1966 Gadd: GSI or SI (General Motors) 1971 Versace: HIC (Ford) 1997 Mertz: scaling 2007 Hardy: brain strain and pressure As linear acceleration increases, risk of injury increases. As linear and rotational acceleration increase, brain pressure and motion increase Over 200 Primate tests performed in six sets from Ommaya, Hirsch first primate tests More recent analysis: 1985 Ommaya:4500r/s2 concussion 1992 Margulies,Thibault DAI at 16,000 r/s Arbogast, and Margulies: properties 2003 Gennarelli: concussion values 2009 Davidsson: DAI As linear and rotational accelerations increase, brain injury in primates increases Mid-90s to present: extensive research utilizing dummy reconstructions and other evaluations 2003: Pellman, Viano HIII reconstructions 2003: King, analysis of tests with model Linear and rotational accelerations are significantly correlated to concussion risk 2003 Present, instrumented high school and college football players Linear and rotational accelerations are significantly correlated to concussion risk

22 In Situ Brain Strain 1. Effect of linear and rotational acceleration 2. Effect of helmet on brain strain Hardy et al (2007)

23 Specimen Preparation Neutral Density Targets Cranial Pressure Transducer 3 mm 5 mm

24 Head Impact Testing High-speed bi-planar x-ray Riddell VSR4 Helmet Hardy et al (2007)

25 IS-Z (mm) Example Motion Patterns PA-X (mm) C2 25 C

26 Hardy et al (2007) In Situ Brain Strain Findings Strain measures follow looping pattern Avg. maximum brain excursion 7 mm Peak principal strain 0.09 (9%) and peak shear strain 0.09 (9%) Helmet reduces accelerations

27 Presentation Outline Part 1: STAR Helmet Rating Update Review Data and Validation Studies Adding Rotational Acceleration Part 2: Brain Strain During Impact Part 3: Head Impact Sensor Evaluation Accuracy and Exposure Comparisons

28 New Sensors New Opportunities X2 Patch MC10 CheckLight Triax Riddell Insite

29 Careful of Comparisons Published studies ~10/14g threshold If higher trigger, 20g or 30g, exposure data will be very different

30 Sensor Validation Studies: Acceleration Correlation

31 Sensor Validation Studies: Impact Detection

32 X2 Patch New Sensors New Questions Linear and/or Rotational Acceleration Validation, Methods, Publication MC10 CheckLight Private or Public Data Triax Visible player lights Sideline trainer/coach alert Riddell Insite

33 Accuracy Measures Systematic Error and Random Error Presented as Average +/- stdev, Absolute, RMS Accuracy Example 10 % Absolute Error (RMS Error) 20 g 18 g g 54 g g 60 g 90 g g 100g

34 Presentation Outline Part 1: STAR Helmet Rating Update Review Data and Validation Studies Adding Rotational Acceleration Part 2: Brain Strain During Impact Part 3: Head Impact Sensor Evaluation Accuracy and Exposure Comparisons Part 4: Clinical implications and Challenges Questions and Discussion

35 Schneider KJ, Iverson GL, Emery CA, et al. The effects of rest and treatment following sport-related concussion: a systematic review of the literature. Br J Sports Med. 2013;47: Review of all of the evidence based scientific literature related to athletes with multiple concussions and return to play There isn t any Studies of management of concussion were so poor So what do we do? Rely on Expert Opinion based on clinical practice, the relevant available medical and scientific literature and currently available diagnostic testing.

36 53% of concussions are unreported (McCrea et al. 2004)

37 MTBI Event The Next Play

38 Another Example MTBI Event

39 Another Example MTBI Event Peak G = 139 G Clinically diagnosed concussion

40 Return To Play Return-to-play decisions must be made with the risks of possible symptom exacerbation and prolongation of recovery, subsequent concussion, or catastrophic injury in mind McCrory, P, et al. Clin J Sport Med 2009;19: A Review of Return to Play Issues and Sports-Related Concussion Doolan, Brolinson, et al Annals of Biomedical Engineering, Vol. 40, No. 1, January 2012 pp

41 RTP Other Considerations Age discussed above generally more conservative with younger athletes Must rely more on input from parents and coaches Social Pressure Teammates, coaches and parents Multiple Concussions No specific number has been established to mandate season ending injury or retirement. Worrisome group Decreased time between concussions More prolonged recovery from each subsequent concussion Concussions resulting from progressively decreased biomechanical forces Persistent Headache Must differentiate post concussive from cervicogenic or cranial dysfunction Consider PT/OMT to address cervical and upper thoracic dysfunction With these last two groups may need to consider full neuropsych evaluation as well as other diagnostic testing as indicated

42 Risk of Recurrence Significantly increased risk of sustaining a concussion when an athlete is still recovering from a previous concussive injury A second impact, often of less or even minimal force, then produces signs and symptoms that are severe enough to be observed directly In extreme cases, it is likely that this same scenario produces the second impact syndrome Guskiewicz et al. showed that high school football players who suffered a concussion were three times more likely to sustain a second concussion during the same season Delaney, et al. showed that athletes who experienced concussion with a loss of consciousness were six times more likely to sustain another concussion than those who had been concussed but never lost consciousness Guskiewicz K, et al. Am. J. Sports Med. 2000; 28: Delaney J,et al. Clin. J. Sport Med. 2000; 10:9-14

43 Post Concussion Syndrome A function of the length of symptom persistence 3 months duration of 3 or more symptoms Of retired NFL players who were diagnosed with post-concussion related depression, 87% continued to have lifelong symptoms Medications that address symptoms may be considered in the treatment of PCS Dosing should begin low and titrated upward slowly Jotwani, V et al. Curr. Sports Med. Rep.; 2010; 9 (1): Halsted, M and K Walter. Pediatrics, 2010; 126 (3):

44 Placebo-Controlled Trial of Amantadine for Severe Traumatic Brain Injury; Gianco et al; N Engl J Med 2012; 366: March 1, 2012DOI: /NEJMoa Summary of Gunnar s clinical treatment Pearls for PCS Remember that dx and tx is a team event Psychologists, neurologists, PM&R, PT s and ATC s can all be involved You are treating symptoms Evaluate and treat cranial, cervical and thoracic somatic dysfuntion For mild insomnia with head/neck pain Flexeril 10mg at hs Elavil 10-25mg at hs For headache NSAIDs Topamax 25-50mg BID For depression with diffuse body pain Effexor and Cymbalta (SNRI s) Tricyclics SSRI s don t seem to work well For fogginess Omega 3 supplements Antioxidants Alpha Lipoic Acid 100mg QD B Complex Amantadine mg BID Remember to include physical therapy and neurocognitive rehab as appropriate In general avoid narcotics

45 Clinical Considerations for Athletes with Multiple Concussions To date, no specific number of concussions has been established to mandate season ending injury or retirement. Experts understand that repetitive concussions can be associated with significant and prolonged neurocognitive deficits decreased time between concussions increased recovery time concussions resulting from decreased biomechanical forces Clinicians may wish to consider a full neuropsychological evaluation and the use of advanced diagnostics and imaging techniques in these athletes. A Review of Return to Play Issues and Sports-Related Concussion Doolan, Brolinson, et al Annals of Biomedical Engineering, Vol. 40, No. 1, January 2012 pp

46 Clinical Considerations for Athletes with Multiple Concussions When to remove an athlete from the competitive season or recommend permanent retirement from competition? Must be managed in on individualized basis and multiple factors taken into account Utilize the sports medicine team and appropriate diagnostic modalities One opinion is no opinion The current literature is unclear and contradictory regarding specific therapeutic approaches. Sports clinicians are left to develop an approach to management of concussion that is based on currently available best practices that have little scientific evidence to support them. P.G. Brolinson; management of sport related concussion review and commentary; Clin J Sport Med Journal Club issue 24(1) -Jan 2014.

47 Clinical Considerations for Athletes with Multiple Concussions Remove for Season Prolonged post concussive symptoms 3 simple concussions in a single season 2 or more complex concussions in a single season decreased academic and athletic performance clinically relevant imaging abnormality. Career Ending Pathologic abnormality such as Chiari malformation Intracranial hemorrhage Clinically relevant imaging abnormality Diminished academic performance or cognitive abilities Persistent prolonged post-concussion syndrome Decreased threshold for concussion 3 or more complex concussions during career Persistent neuropsychiatic symptoms A Review of Return to Play Issues and Sports-Related Concussion Doolan, Brolinson, et al Annals of Biomedical Engineering, Vol. 40, No. 1, January 2012 pp

48 What about repetitive sub concussive impacts? Millions of individuals have played contact sports for many years without obvious functionally significant adverse effects, and without developing progressive neurodegenerative disorders. Nevertheless, we are concerned that repetitive head impacts may have an adverse effect on some athletes. It is reasonable to speculate that individual differences such as polymorphisms in genes modulating response to neurotrauma39 (e.g., APOE, BDNF, ANKK1) or other host factors may play a role it is tempting to hypothesize that risk of chronic traumatic encephalopathy or other long term effects of contact sports may represent a gene environment interaction between repetitive mild neurotrauma and genetic vulnerability to heightened injury response or attenuated neural repair. McAllister TW, Flashman LA, Maerlender AC, Greenwald RM, Beckwith JG, Tosteson TD, Crisco JJ, Brolinson PG, Duma SM, Duhaime AC, Grove MR and Turco JH. Cognitive Effects of One Season of Head Impacts in a Cohort of Collegiate Contact Sport. Neuro May 29;78(22):

49 What is Chronic Traumatic Encephalopathy??? A progressive neurodegenerative syndrome Dementia Pugilistica Punch Drunk Syndrome Accumulation of Tau Protein in neurologic tissue Genetically determined? Head trauma triggered? Over-production vs Inadequate Clearance? Presents clinically after a prolonged latent period A composite syndrome of mood disorders associated neuropshychiatric and cognitive impairments Definitive diagnosis is by direct tissue analysis post mortem Brain tissue from 18-year-old multi-sport athlete BU Center for the Study of Traumatic Encephalopathy

50 What is Post Traumatic Encephalopathy? A clinicopathologic syndrome that follows focal or diffuse brain trauma Associated with gross or microspcopic destruction of brain tissue Lacerations, contusions, hemorrhages, etc Not neurodegenerative and not progressive Can co-exist with CTE

51 HS Football and Risk of Neurodegenerative Disease To assess whether high school football played between 1946 and 1956, when headgear was less protective than today, was associated with development of neurodegenerative diseases later in life. Compared 438 FB players to 140 non FB players from HS in Rochester, MN High school students who played American football from 1946 to 1956 did not have an increased risk of later developing dementia, PD, or ALS compared with non football-playing high school males, despite poorer equipment and less regard for concussions compared with today and no rules prohibiting head-first tackling (spearing). These results should be somewhat reassuring to high school players from 50 years ago, they should give no reassurance to today s players. High School Football and Risk of Neurodegeneration: A Community-Based Study; Savica, Parisi et al; Mayo Clin Proc. 2012;87(4):

52 Legislating Risk Former British prime minister Harold Macmillan said, "To be alive at all involves some risk." Yet, some lawmakers on this side of the Atlantic want to remove all risks for high school athletes through restrictive legislation, with concussions being the flavor of the month. The Federal Government has also gotten involved in the concussion debate and the Government Accountability Office (GAO) published its report on the testimony given before the committee on education and labor of the House of Representatives on May 20 th Erik Simpson and Brent Crane Posted 04/26/ :21:41 PM USA Today Texas (2007), Washington and Oregon (2009) passed the first concussionspecific laws addressing scholastic sports. Washington s law was named after Zackery Lystedt, a teenager who in 2006 sustained a serious brain injury while playing football. One problem with this legislation are the costs of implementing such a program which would include athletic trainers present at all practices and games as well as physician coverage for games.

53 Legislating Risk Since Sates and DC have enacted youth sports TBI laws aimed at increasing awareness or reducing risk of repeat injury or both. These laws represent a uniform but not scientifically proven consensus about the minimum time a young athlete should refrain from reentering contact sports activities. Also exhibit divergence regarding the health care professional best qualified to make the RTP decision. Existing youth TBI laws are not designed to reduce initial TBIs. Continued research and evaluation of existing laws will be needed to develop a more comprehensive risk reduction program. Harvey, H; American Journal of Public Health: May 16, 2013

54 NCAA Institutions shall have a concussion management plan on file such that a student-athlete who exhibits signs, symptoms or behaviors consistent with a concussion shall be removed from practice or competition and evaluated by an athletics healthcare provider with experience in the evaluation and management of concussion. Student-athletes diagnosed with a concussion shall not return to activity for the remainder of that day. Medical clearance shall be determined by the team physician or their designee according to the concussion management plan. In addition, student-athletes must sign a statement in which they accept the responsibility for reporting their injuries and illnesses to the institutional medical staff, including signs and symptoms of concussions. During the review and signing process student-athletes should be presented with educational material on concussions. -- NCAA Memorandum April,

55 Thoughts on Rules Changes, Technique and The Game "I sent those plays to make that statement," Carroll said. "Let's demonstrate that guys like that are turning the corner and do get it. That message should go throughout pro football, throughout college football and down to the young kids playing so they can see the game can be played differently."

56 Thoughts on Rules Changes, Technique and The Game "There's still the warrior mentality of the players, which we can relate to," Carroll said. "But through proper education and awareness, the way they play is shifting. It's clear our game is not the same as it was, but it's still OK. It's fine. "And guys like [Seahawks safety] Kam Chancellor can be as physical and tough as anybody in football and still make the right decisions on hitting guys to keep the game safe. I would have never thought I would be saying this; I see the game different now."

57 Multiple Concussions and Future Diagnostic Considerations Biomarkers term often used to refer to a protein measured in blood whose concentration reflects the severity or presence of some disease state. Troponin is a biomarker used to diagnose acute myocardial infarction (AMI) in Emergency Rooms Advanced Imaging fmri and DTI Improved point of care diagnostics and technology Head acceleration sensing systems

58 58 Banyan Biomarker Panel for TBI GFAP UCH-L1 GFAP dimer Glial Fibrillary Acidic Protein Structural protein of the intermediate filament of Astroglia 50 kda Highly enriched in the nervous system. 1% of total brain protein Ubiquitin Carboxyl-Terminal Esterase L1 Small compact 24 kda protein Expressed at a high level in neurons 5% of total brain protein

59 59 Mild and moderate TBI study (GFAP) Elevated Levels of Serum Glial Fibrillary Acidic Protein Breakdown Products in Mild and Moderate Traumatic Brain Injury Are Associated With Intracranial Lesions and Neurosurgical Intervention SUMMARY: Annals of Emergency Medicine May 29, 2011 GFAP-BDP is detectable in serum within an hour of injury It is associated with measures of injury severity, including the GCS score, CT lesions, and neurosurgical intervention. Further study is required to validate these findings before clinical application.

60 60 Mild and moderate TBI Study (UCHL-1) Serum levels of UCHL-1 distinguishes mild and moderate traumatic brain injury from trauma controls and is associated with lesions on computed tomography. SUMMARY: UCHL-1 was detected in the serum of mild and moderate TBI (MMTBI) patients within an hour of injury Journal of Neurotrauma July, 2011

61 Biomarkers Swedish researchers say they have devised a blood test that could better diagnose sportsrelated brain injuries and prevent American football, rugby and ice hockey players returning to the field in danger. Zetterberg's team examined all the players in the Swedish Hockey League and found that between September and December of the 2012/2013 season alone, 35 of 288 players had had a concussion. In three cases, it was so severe that the player was knocked unconscious. The results were compared with the pre-season samples from two full teams, and the scientists found that having raised levels of a nerve cell protein called tau in the blood was a marker of concussion.

62 Angular Acceleration (rad/s 2 ) Linear Acceleration (g) Example 1: 58 g, 2011 rad/s x y z resultant Time (ms) x y z resultant Time (ms) SIMon says: CSDM predicts 3% probability of concussion

63 Angular Acceleration (rad/s 2 ) Linear Acceleration (g) Example 2: 83 g, 9922 rad/s x y z resultant Time (ms) x x y z resultant Time (ms) SIMon says: CSDM predicts 14% probability of concussion

64 Concussion Incidence Minimization Rule Changes 3 Strategies: Most Effective Proper Technique Reduce exposure to head impact Rule changes and enforcement Proper technique Improved diagnostic capabilities + Better Equipment Reduce concussion risk for remaining head impacts Improve helmet design Fewest Concussions

65 Summary Data suggest that female athletes may have a higher incidence of concussion and experience more severe concussive symptoms We are just now beginning to research and understand risk and clinical implications for concussion in youth sports The presence of preexisting mood or learning disorders can confound pre-injury baseline testing as well as concussion diagnosis and management Multiple concussions are associated with increased risk of: Mood disorders (anxiety and depression) Cognitive dysfunction Migraine headache and concussion have similar presentations Athletes who have migraines also may be at a higher risk of being concussed but not know if this is a cause and effect relationship The genetics of concussion remain a mystery, and the role of factors such as the ApoE promoter gene are being investigated Brain Biomarkers and Advanced Imaging Technologies are an emerging area of research for enhancing our clinical diagnostic capability There are some data to suggest that concussion risk may increase as an athlete fatigues or if he or she continues to participate in the sport after sustaining an initial mild traumatic injury Regarding helmets more padding is more better!

66 All Data and Reports Online

67 We choose to do these things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win. John F. Kennedy