Concussion Monthly Select- October 2019

Concussion Monthly Select- October 2019


Doug Van Pelt, PhD


Below are 5 highlighted recently published concussion research articles with a brief summary and takeaway points.

Cannabis, alcohol and cigarette use during the acute post-concussion period.

Lawrence DW, Foster E, Comper P, Langer L, Hutchison MG, Chandra T, Bayley M

Brain Inj. 2019 Oct 17:1-10

  • Summary: This study wanted to determine whether cannabis, alcohol and cigarette use after a concussion influenced recovery. Study participants were recruited from the emergency department and were included in the study if they came to the emergency department within 7 days of their concussion. There were 307 concussions among 127 males (41%) and the average age of participants was 34. Most concussions were due to “a flying object” (28%), “sport or exercise” (25%), or “transportation (walking or cycling)” (21%). Prior to concussion 24% used cannabis, 52% used alcohol, and 20% used cigarettes regularly. In the month after the concussion, 14% used cannabis, 41% used alcohol, and 20% used cigarettes regularly. Despite substance use being common, cannabis, alcohol, or cigarette use was not associated with concussion recovery time.
  • Takeaway: Cannabis, alcohol, and cigarette use does not appear to influence concussion recovery within four weeks of injury. 

King-Devick Test Reliability in National Collegiate Athletic Association Athletes: A National Collegiate Athletic Association-Department of Defense Concussion Assessment, Research and Education Report.

Breedlove KM, Ortega JD, Kaminski TW, Harmon KG, Schmidt JD, Kontos AP, Clugston JR, Chrisman SP, McCrea M, McAllister TW, Broglio SP, Buckley TA

J Athl Train. 2019 Oct 16.

  • Summary: It is common for athletic trainers to perform a baseline assessment on their intercollegiate athletes so that if a suspected concussion occurs, the athletic trainer can compare an individual’s scores. Therefore, knowing the reliability, or how stable, a test is can greatly inform clinical judgment. The King-Devick test is a rapid number reading test to evaluate vestibulo-ocular changes post-concussion. The King-Devick instructions require two trials to be completed in order to establish a baseline, however, it is unknown how necessary the second trial is. Therefore, researchers evaluated the test-retest reliability of the King-Devick test to determine how stable scores were across trials and years. Additionally, they also tested whether it mattered if the King-Devick test was completed using physical cards or on a tablet. A total of 3248 athletes (55% male) completed the King-Devick test and a subset of 833 athletes (60% male) completed the King-Devick test during two serial baseline assessments, one in Year 1 and one in Year 2. Across the two trials, there was good reliability, but there is a small learning effect where 77% of athletes improved their King-Devick time by an average of 2.4 seconds. A similar improvement was observed among athletes year to year with a 2-second improvement in year 2 compared to year 1. Notably, 27% of athletes had slower King-Devick times in year 2 compared to Year 1. Overall, it did not matter whether the King-Devick test was completed via cards or tablet.
  • Takeaway: The results reinforce the need to conduct two trials to establish a baseline on the King-Devick. Additionally, since 27% “failed” the King-Devick test in Year 2 the King-Devick test should only be used as part of a multifaceted concussion assessment and not a diagnostic test itself. 

Improving Concussion Reporting across NCAA Divisions Using a Theory-Based, Data-Driven, Multimedia Concussion Education Intervention

Schmidt JD, Weber ML, Suggs DW, Bierema L, Miller LS, Reifsteck F, Courson R, Hoff R, Dill K, Dunham J

J Neurotrauma. 2019 Oct 9.

  • Summary: Up to 40-50% of athletes say they did not report a concussion. Rapidly reporting a concussion can decrease recovery time and prevent secondary brain trauma. Thus, finding a way to increase athletes’ reporting behavior could drastically improve athlete health and safety. Schmidt and colleagues developed a video-based intervention to improve athlete reporting behaviors. The videos were tailored to contact sport levels and included a first-person perspective of an injury scenario, symptom identification, and questions, along with a simulated concussion scenario. Athletes from Division I, II, and III colleges/universities participated in the study. Concussion reporting intentions increased for the intervention group, but there was no improvement in concussion reporting behaviors. Additionally, athletes in the intervention group reported greater self-efficacy, knowledge, and attitudes regarding concussion. 
  • Takeaway: The multimedia intervention improved the intentions of athletes to report concussions, but did not actually change reporting behaviors. It is reassuring the intervention was able to improve the culture surrounding concussion reporting. 
  • Note: To demo the concussion education module or to use it clinically for concussion education purposes, please contact Dr. Julianne Schmidt at

Duration of American football play and chronic traumatic encephalopathy.

Mez J, Daneshvar DH, Abdolmohammadi B, Chua AS, Alosco ML, Kiernan PT, Evers L, Marshall L, Martin BM, Palmisano JN, Nowinski CJ, Mahar I, Cherry JD, Alvarez VE, Dwyer B, Huber BR, Stein TD, Goldstein LE, Katz DI, Cantu RC, Au R, Kowall NW, Stern RA, McClean MD, Weuve J, Tripodis Y, McKee AC

Ann Neurol. 2019 Oct 7

  • Summary: Brains of 266 American football players were examined from the VA-BU and Framingham Heart Study brain banks. The objective of the study was to determine whether players who played American football for longer were more likely to have chronic traumatic encephalopathy (CTE) and to greater severity. Overall, longer football duration was associated with greater odds of having CTE. For each year of playing football, the odds of CTE increases by 30%. Furthermore, among those with CTE, playing football for longer was associated with more severe CTE.
  • Takeaway: There appears to be a dose-response relationship between years of playing football and the likelihood of CTE. 

Mapping brain recovery after concussion: From acute injury to 1 year after medical clearance.

Churchill NW, Hutchison MG, Graham SJ, Schweizer TA

Neurology. 2019 Oct 16

  • Summary: Concussion symptoms are transient, typically recovering within four weeks of injury. However, symptoms indirectly measure the underlying brain injury and dysfunction. The current study used advanced MRI techniques to measure brain functional connectivity, white matter integrity, neuroinflammation, and cerebral blood flow in the brain one year after return to play (RTP). The study assessed 24 university athletes with a concussion and 122 control athletes without a concussion. Concussed athletes under when MRI scans within 6 days of concussion, medical clearance for RTP, and one-year post-RTP.  In the acute phase of an injury, from concussion to RTP, there were increased in functional connectivity, decreased white matter integrity, increased cerebral blood flow, and increased markers of neuroinflammation. At one year post-RTP, there were persistent decreases in cerebral blood flow in increases in markers of neuroinflammation. 
  • Takeaway: This study indicates that the brain might still be recovering one year after an athlete is cleared for return to play.  

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