Bret Stetka, MD; Andrew N. Wilner, MD


April 17, 2013

In This Article

Suspected Concussion

The Basics

Instruct inexperienced LHCPs in the use of standardized assessment tool

Use standardized assessment tools

Ensure communication between sideline LHCPs and clinical LHCPs

Obtain baseline scores

Remove the athlete from play

No return to play without clearance by an LHCP

Don't perform imaging to diagnose SRC

Do perform imaging to rule out serious TBI

The Bottom Line

Inexperienced LHCPs should be instructed by LHCPs who have concussion experience in the appropriate use of "standardized validated sideline assessment tools." Sideline LHCPs should initially apply assessment tools and relay findings to appropriate clinical LHCPs. Obtaining baseline assessment scores to have on hand is recommended to facilitate more accurate postinjury scores.

The next recommendation was a source of some confusion at the AAN 2013 press conference. The guidelines state that "any athlete suspected of having sustained a concussion" should be immediately removed from play to minimize the risk for further injury. There has long been an idea that a "second hit" in close proximity to a previous head injury may result in cumulative injury beyond the sum of the 2 single hits (in other words, 2 + 2 = 5 in terms of brain injury), but this hypothesis has not been proven in athletes.

There is also accumulating evidence that repeated mild head injury, particularly concussion, may result in chronic traumatic encephalopathy (CTE). However, research on CTE is still in its early phase, and the role of repeated concussions in the development of CTE requires better definition.

Because this is an evidence-based guideline, the above concerns regarding repetitive head injury are not the basis for the recommendation for removing the athlete from play. That recommendation is based on robust epidemiologic evidence that people who experience a single concussion are more likely to experience another one compared with people who never had one (6 class I studies[2,3,4,5,6,7] and 1 class II study[8]). Furthermore, that risk is particularly increased in the 10 days after the first concussion (2 class I studies[9,10]). Because of this strong evidence that a single concussion predisposes to a second one, the guideline advises that players exit the game and not return until symptoms resolve.

The reason for this increased risk for a second injury is unknown. The most likely hypothesis is that impaired cognition or physical reflexes due to the first concussion increase the player's susceptibility to injury.

The AAN guideline insists that players who experience symptoms suggestive of concussion, such as blurry or double vision, confusion, dizziness, headache, nausea, memory loss, or other cognitive or behavioral problems, must have full resolution of their symptoms (off medication) and approval for return to play by an LHCP. This approach would seem to allow players who had transient symptoms after a mild head injury to return to play if they felt better on the sidelines and had no discernible neurologic deficit. When asked about this, Dr. Kutcher explained that the player could not return to play that day if a concussion had been diagnosed, even if symptoms had cleared. This recommendation is echoed by the American Medical Society for Sports Medicine position statement, which clearly prohibits same-day return to play for an athlete diagnosed with a concussion.[11]

A potential loophole for return to play is for the player who sustains a concussion, but denies symptoms and has no objective findings on examination. This player might be hiding symptoms, but in the absence of any neurologic findings would be able to return to play because no diagnosis of concussion was made.

A second situation not addressed by the guidelines, and pointed out by some reporters attending the press conference, is the player who has a head injury but whose concussive symptoms don't appear until after the game. This player would have been allowed to resume play, potentially putting him or her at risk for a second head injury. Because the diagnosis of concussion requires symptoms or signs, in both of these scenarios the players could return to play, even after witnessed collisions involving their heads. Although concussion symptoms may take hours to days to manifest, most concussive symptoms appear within minutes to hours, according to Dr. Kutcher.

Less open to interpretation are the AAN's recommendations for neuroimaging in athletes with a suspected concussion. They state that CT is not appropriate in diagnosing SRC, because SRC is a clinical diagnosis that does not depend on radiologic findings. However, CT can be obtained to rule out more severe TBI, including intracranial hemorrhage in cases of suspected concussion and loss of consciousness, posttraumatic amnesia, focal neurologic deficits, persistently altered mental status, potential skull fracture, or signs of clinical deterioration.