Persistent, Long-term Cerebral White Matter Changes after Sports-Related Repetitive Head Impacts | Bazarian, Zhu, Zhong, Janirgo, Rozen, Roberts, Javien, Merchant-Borna, Abar, Blackman

Jeffrey J. Bazarian, Tong Zhu, Jianhui Zhong, Damir Janigro, Eric Rozen, Andrew Roberts, Hannah Javien, Kian Merchant-Borna, Beau Abar, Eric G. Blackman; Persistent, Long-term Cerebral White Matter Changes after Sports-Related Repetitive Head Impacts; In PLoS One; 2014-04-16; 12 pages; landing.

Abstract

Introduction:

Repetitive head impacts (RHI) sustained in contact sports are thought to be necessary for the long-term development of chronic traumatic encephalopathy (CTE). Our objectives were to: 1) characterize the magnitude and persistence of RHI-induced white matter (WM) changes; 2) determine their relationship to kinematic measures of RHI; and 3) explore their clinical relevance.

Methods:

Prospective, observational study of 10 Division III college football players and 5 non-athlete controls during the 2011-12 season. All subjects underwent diffusion tensor imaging (DTI), physiologic, cognitive, and balance testing at pre-season (Time 1), post-season (Time 2), and after 6-months of no-contact rest (Time 3). Head impact measures were recorded using helmet-mounted accelerometers. The percentage of whole-brain WM voxels with significant changes in fractional anisotropy (FA) and mean diffusivity (MD) from Time 1 to 2, and Time 1 to 3 was determined for each subject and correlated to head impacts and clinical measures.

Results:

Total head impacts for the season ranged from 431–1,850. No athlete suffered a clinically evident concussion. Compared to controls, athletes experienced greater changes in FA and MD from Time 1 to 2 as well as Time 1 to 3; most differences at Time 2 persisted to Time 3. Among athletes, the percentage of voxels with decreased FA from Time 1 to 2 was positively correlated with several helmet impact measures. The persistence of WM changes from Time 1 to 3 was also associated with changes in serum ApoA1 and S100B autoantibodies. WM changes were not consistently associated with cognition or balance.

Conclusions:

A single football season of RHIs without clinically-evident concussion resulted in WM changes that correlated with multiple helmet impact measures and persisted following 6 months of no-contact rest. This lack of WM recovery could potentially contribute to cumulative WM changes with subsequent RHI exposures.

Mentions

  • Cognitive testing is based on some software package
    • Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT)
    • Collins MW, Iverson GL, Lovell MR, McKeag DB, Norwig J, et al. (2003) On-field predictors of neuropsychological and symptom deficit following sports-related concussion. Clinical Journal of Sport Medicine 13: 222–229.

Previously

Hits to the Head Don’t Differ With Age, Research Indicates | NYT

Ken Belson; Hits to the Head Don’t Differ With Age, Research Indicates; In The New York Times (NYT); 2013-09-24.

Mentions

  • Based on a press release covering research “to be released” 2013-09-25; uncited.
  • Hook: <quote>Football players as young as 7 sustain hits to the head comparable in magnitude to those absorbed by high school and adult players, and most of the hits are sustained in practices, not games, according to research to be released Wednesday.</quote>
  • Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences
    • annual Biomedical Engineering Society conference
  • Professor Stefan Duma
    • “runs” the School of Biomedical Engineering and Sciences
    • “oversaw” the youth football studies.
  • Shape of the fieldwork
    • N=120 players
    • Virginia and North Carolina
    • ages 7 to 18
    • across two seasons
    • Each subject wore six accelerometers,
    • Followups with magnetoencephalography (MEG) scans for sum (not all).
  • Four studies
    1. <quote> 19 boys ages 7 and 8 were found to have absorbed 3,061 hits to the head during the 2011 and 2012 seasons, with 60 percent of those hits coming in practice. The players sustained an average of 9 hits per practice and 11 in games, which are less frequent. Although none of the boys received a diagnosed concussion, they absorbed 11 hits of 80g of force, or greater, a level that represents a higher risk of concussion.</quote>
    2. <quote>three teams of players from 9 to 12 for one season. Nearly 12,000 hits were recorded, or an average of 240 per player. Again, players absorbed more hits during practice, and at higher acceleration rates than younger players.</quote>
    3. not summarized
    4. not summarized
  • Responses & color (“had not seen the study” but …)
    • Dr. Vernon Williams, a neurologist, at the Sports Concussion Institute.
    • Jon Butler, the executive director of Pop Warner

Principal

Background

Consequences of Repeated Blood-Brain Barrier Disruption in Football Players | Marchi, Bazarian, Puvenna, Janigro, Ghosh, Zhong, Zhu, Blackman, Stewart, Ellis, Butler, Janigro

Nicola Marchi, Jeffrey J. Bazarian, Vikram Puvenna, Mattia Janigro, Chaitali Ghosh, Jianhui Zhong, Tong Zhu, Eric Blackman, Desiree Stewart, Jasmina Ellis, Robert Butler, Damir Janigro. Consequences of Repeated Blood-Brain Barrier Disruption in Football Players; In PLoS ONE; 2013; 8 (3): e56805 DOI: 10.1371/journal.pone.0056805

Abstract

The acknowledgement of risks for traumatic brain injury in American football players has prompted studies for sideline concussion diagnosis and testing for neurological deficits. While concussions are recognized etiological factors for a spectrum of neurological sequelae, the consequences of sub-concussive events are unclear. We tested the hypothesis that blood-brain barrier disruption (BBBD) and the accompanying surge of the astrocytic protein S100B in blood may cause an immune response associated with production of auto-antibodies. We also wished to determine whether these events result in disrupted white matter on diffusion tensor imaging (DT) scans. Players from three college football teams were enrolled (total of 67 volunteers). None of the players experienced a concussion. Blood samples were collected before and after games (n = 57); the number of head hits in all players was monitored by movie review and post-game interviews. S100B serum levels and auto-antibodies against S100B were measured and correlated by direct and reverse immunoassays (n = 15 players; 5 games). A subset of players underwent DTI scans pre- and post-season and after a 6-month interval (n = 10). Cognitive and functional assessments were also performed. After a game, transient BBB damage measured by serum S100B was detected only in players experiencing the greatest number of sub-concussive head hits. Elevated levels of auto-antibodies against S100B were elevated only after repeated sub-concussive events characterized by BBBD. Serum levels of S100B auto-antibodies also predicted persistence of MRI-DTI abnormalities which in turn correlated with cognitive changes. Even in the absence of concussion, football players may experience repeated BBBD and serum surges of the potential auto-antigen S100B. The correlation of serum S100B, auto-antibodies and DTI changes support a link between repeated BBBD and future risk for cognitive changes.

Promotions

Via: backfill

Head Impact Exposure in Youth Football: Elementary School Ages 9–12 Years and the Effect of Practice Structure | Cobb, Urban, Davenport, Rowson, Duma, Maldhan, Whitlow, Powers, Stitzel

Bryan R. Cobb, Jillian E. Urban, Elizabeth M. Davenport, Steven Rowson, Stefan M. Duma, Joseph A. Maldjian, Christopher T. Whitlow, Alexander K. Powers, Joel D. Stitzel; Head Impact Exposure in Youth Football: Elementary School Ages 9–12 Years and the Effect of Practice Structure; In Annals of Biomedical Engineering; 2013-07; landing.

Abstract

Head impact exposure in youth football has not been well-documented, despite children under the age of 14 accounting for 70% of all football players in the United States. The objective of this study was to quantify the head impact exposure of youth football players, age 9–12, for all practices and games over the course of single season. A total of 50 players (age = 11.0 ± 1.1 years) on three teams were equipped with helmet mounted accelerometer arrays, which monitored each impact players sustained during practices and games. During the season, 11,978 impacts were recorded for this age group. Players averaged 240 ± 147 impacts for the season with linear and rotational 95th percentile magnitudes of 43 ± 7 g and 2034 ± 361 rad/s2. Overall, practice and game sessions involved similar impact frequencies and magnitudes. One of the three teams however, had substantially fewer impacts per practice and lower 95th percentile magnitudes in practices due to a concerted effort to limit contact in practices. The same team also participated in fewer practices, further reducing the number of impacts each player experienced in practice. Head impact exposures in games showed no statistical difference. While the acceleration magnitudes among 9–12 year old players tended to be lower than those reported for older players, some recorded high magnitude impacts were similar to those seen at the high school and college level. Head impact exposure in youth football may be appreciably reduced by limiting contact in practices. Further research is required to assess whether such a reduction in head impact exposure will result in a reduction in concussion incidence.

Promotions

  • Ingrid Wickelgren; Limit Youth Football Practice Hits for Brain Health; In Scientific American; 2013-08-13; an audio podcast, with transcript.
    Teaser: Changes in youth football practices cut total hits to the head in half, whereas leaving game situations unaffected.

Via: backfill

The War on Football: Saving America’s Game | Daniel Flynn

Daniel J. Flynn; The War on Football: Saving America’s Game; Regnery; 2013-08-19; 256 pages; kindle: $15.

Promotions

Biography

Background

Previously

Daniel Flynn;

Youth Football Trick Play “another five yards” “hey we have the wrong ball”

Some Dude; Driscoll Middle School Trick Play; YouTube; 2010-11-07; 0:27.

Point: No, the ball does not have to be snapped through the center’s legs.

We train against this play every year. And we’ve used this play in the past. “Hey, we have the wrong ball” is the script to start it. It’s potent about once a year.

Promotions

References

MC10 CheckLight

Isaiah Kacyvenski modeling the CheckLight

Via: Engadget; More photos here

References

Who & What

  • Reebok Promotion; not in wide trials, contact MC10
  • CheckLight goes on sale “sometime in the first half of this year” (2013)
  • Isaiah Kacyvenski
    • mc10′s Director of Licensing and Business
    • ex-NFL (player)

Promotions