Concussion Defined

Statue of a Roman boxer
Courtesy ThinkStock: Andrew Dimock

"" is derived from the Latin word concussus, to shake violently. Concussion is a complicated injury that can present in a variety of ways. We are striving for, but have yet to achieve, a complete neurological and neurobehavioral understanding of concussion.

Module 2 Content

Forces that Produce Concussions

Confusion about Concussions

	CONCUSSION IN SPORTS Definitions and Position Statements
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Overview

The definitions gathered here have basic commonalities:

A concussion is a brain injury that is transient — its effect is of relatively short duration.

A concussion affects the functioning of the brain.

This might create the impression that a concussion is a "mild" injury, not worthy of much concern. However, concussion makes the brain vulnerable to further injury with serious, long-term consequences.

Although the concussion itself may be minor, the greatest risk comes afterward, depending on how the injury is managed. You can’t prevent a concussion, but by managing a first concussion with rest and time to recover, you can prevent subsequent concussions and the serious risks they entail.

The American Society for Sports Medicine defines concussion as:

A traumatically induced transient disturbance of brain function.

Caused by a complex pathophysiological process.
- Concussions are a subset of mild traumatic brain injuries (mTBIs).
- All Concussions are mTBIs, but not all mTBIs are concussions.

Harmon, KG et al. Br J Sports med 2013; 47:15-26
Position Paper

The American Academy of Neurology defines concussion as:

A clinical syndrome of biomechanically-induced alteration of brain function.
Typically affects memory and orientation.

May involve loss of consciousness.

Giza C, Kutcher J, et al. Neurology, 2013; 10.1212/WNL.0b013e31828d57dd.
Position Paper

The 4^th International Conference on Concussion in Sport held in Zurich defined concussion as:

A complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces.

Concussion may be caused by a direct blow to the head, face, or neck or elsewhere on the body with an "impulsive" force transmitted to the head.

Typically results in the rapid onset of short lived impairment of neurological functioning that resolves spontaneously.

No abnormality on standard structural neuroimaging studies.

Results in a graded set of clinical syndromes that may or may not involve the loss of consciousness. While the resolution of symptoms typically follows a sequential course, symptoms may be prolonged in some cases.

Zurich Statement 2013

The National Athletic Trainers Association Position Statement 2014 chose to use the American Academy of Neurology’s definition of concussion — a “trauma-induced alteration in mental status that may or may not involve loss of consciousness.”

NATA explained:

This definition was selected based on its broad application by medical organizations and widespread use within the literature.... Notably absent from the literature and consistent with previous recommendations were the terms ding, getting one’s bell rung, clearing the cobwebs, and other such phrases . . . These colloquial terms are antiquated, minimize injury severity, and should not be used to refer to concussion or mild traumatic brain injury.

Position Paper