21 November 2013

Concussions in 2013: A Brief Overview

While sports such as football, hockey, and soccer bear the brunt of most of the concerns and outrage over player concussions, baseball does have its share of the injury, in spite of its reputation as a non contact sport. In particular, catcher concussions appear to be on the rise in recent years; however, they are not limited to just those who wear the tools of ignorance, as the injuries to Tampa Bay Rays pitcher Alex Cobb and Baltimore Orioles second baseman Alexi Casilla this past season can attest. Despite the plethora of statistics in the game, the publicly available data detailing the incidence of concussions and even head injuries in general is scant, with most of it dedicated to catcher concussions. When data from collegiate and youth baseball circles are included, we still find that catastrophic head injuries are rare, but that concussive injuries arising from contact with another player, ball, bat, ground, or base are the most common of head and face injuries sustained on the playing field.

Part of a long list of maladies whose long term effects remain poorly understood in the neurological world, a concussion is defined as a complex process involving the brain secondary to trauma; this trauma can be a direct blow to the head or neck or something that is transmitted to the head from elsewhere in the body. As a result, a rapid onset of impaired neurologic function occurs, sometimes with a loss of consciousness, but often without impaired consciousness. Symptomatically, a person who has sustained a concussion can suffer from deficits in emotional, cognitive, and physical function that will typically resolve in a short period of time, on the order of seven to ten days; while not as common, concussive symptoms can persist for months or even remain permanently. For a more detailed description of what is commonly encountered symptom-wise by those felled by a concussion, John Sickels has a fantastic account of his own struggles with concussive symptoms that you can find here, with the caveat that the symptoms he describes are not exhaustive. A list of the more frequently encountered symptoms at presentation of a concussion are provided below:

Signs and symptoms of a concussion, courtesy of cdc.gov.

A systematic approach is taken when evaluating a player who is believed to have suffered a concussion, with a medical professional on hand to witness the injury ideal in order for a rapid response to be undertaken. Initial assessments are comprised of the basic ABCs of medical emergencies -- airway, breathing, and circulatory processes and fitness being evaluated. If a player is not in any sort of immediate distress related to their breathing or blood circulation, then evaluations to determine if they have lost consciousness or otherwise compromised neurologically are begun, with particular attention paid to the potential for spinal injury. Once cleared, the focus is then turned to getting the player off of the field in order to perform a thorough evaluation and use of an assessment tool to acquire data to evaluate the concussion, such as memory assessments. Questions related to a player's ability to orient themselves to place and time are older and more widely known methods of evaluation, but have been found to be unreliable compared to memory testing. There are multiple forms of memory tests, but recent changes to MLB policies related to concussive injuries included the formal adoption of the SCAT2 -- Sport Concussion Assessment Tool, version 2 -- which assesses a player's current symptoms in relation to their symptom severity while also focusing on physical and cognitive function post-injury. With SCAT2 results, medical staff can better determine the proper disposition plans for a player and whether more rigorous evaluations and interventions are warranted for management and treatment of the concussion.

2013 saw 20 concussions suffered by 19 players, up from 13 suffered in 2012. As expected, catchers dominated the data, accounting for 58% of the players and 60% of the 450 games lost due to concussion:

Player Team Games Lost Position Career Concussions*
Wilkin Ramirez Twins 69 LF 1
David Ross** Red Sox 68 C 3
John Jaso Athletics 60 C 1
Alex Cobb Rays 51 P 1
Joe Mauer Twins 39 C 1
Max Stassi Astros 30 C 1
Carlos Corporan Astros 19 C 1
Austin Romine Yankees 17 C 2
Alex Avila Tigers 16 C 1
Justin Maxwell Astros 12 OF 1
Domonic Brown Phillies 11 OF 1
Placido Polanco Marlins 10 3B 2
Ryan Doumit Twins 8 C 6
Yorvit Torrealba Rockies 8 C 1
Stephen Drew Red Sox 7 SS 1
Trevor Plouffe Twins 7 3B 1
Salvador Perez Royals 7 C 1
Alexi Casilla Orioles 6 2B 1
Didi Gregorius Diamondbacks 5 SS 1
* information courtesy of baseballprospectus.com; includes MLB and MILB data
** Ross' 69 games lost to concussion are from two concussions suffered in 2013

Along with the catcher leanings, we also see a few repeat offenders, with four of the 19 players of 2013 having previously suffered a concussion in either MLB or MILB play, with Minnesota Twins receiver Ryan Doumit suffering a shocking six concussions as a professional.

Let's now briefly discuss the effects of the concussion on our concussed players. In the following graphs, we will look at pre and post concussion data for those players who sustained a concussion during the season and returned to play afterwards. For this exercise, we have 12 players' data, with the remaining eight players sustaining concussions that ended their 2013 season:

First, position players and the difference in OPS pre and post concussion:

For this chart, we find that five players performed worse post-concussion, with Boston Red Sox catcher David Ross being an interesting case study, given his suffering two concussions last year.

Since we do have a pitcher in our data, this next chart describes pre and post injury RE24 differences, with negative values meaning that the player performed worse (per RE24) after returning from concussion:

Again, we don't see a drastic difference in the number of positive/negative performances after concussion, but we do see that the effects of the injury were significant to the production of Twins' Trevor Plouffe and Philadelphia Phillies' Domonic Brown, with two catchers -- Salvador Perez and Alex Avila -- actually playing better post injury. Why this trend is seen is no clear and additional data would be necessary to parse out whether this 'improvement' is significant.

...and last, the number of games played pre and post injury for each player to reference when looking at the OPS and RE24 data:

Much has been done in the last couple of years to better evaluate and treat concussions in baseball; in spite of these interventions, we find not only an increase in the number of concussions suffered, but tangible evidence of the effects the injury can have on the play of those afflicted. While there still remains much to be learned and researched with respect to the long term effects of concussions on players, the data as presented shows that while the raw number of injuries sustained in baseball is not extravagant as compared to other sports, the need for increased awareness and vigilance of concussions is warranted.

All data courtesy of Baseball-Reference.com unless otherwise noted.

Reference: Dines, JS, Altchek, DW, Andrews, JR, ElAttrache, NS, Wilk, KE, Yocum, LA. (2012) Sports Medicine of Baseball: Philadelphia, PA.

1 comment:

Ann Engelland, M.D. said...

SCAT 2 has been replaced by SCAT3. Hope they catch up in Baseball before Spring.
Ann Engelland, MD
author of
It's All in Your Head: Everyone's Guide to Managing Concussions