I've never had a concussion. I probably get my "bell rung" or get "dinged" once every game or other game. I've never told a trainer because it doesn't really cause problems, it's just a short little bang. It's pounded in your head that you can play though anyting. I just suck it up most of the time. You just have to suck it up if you want to play." - former college football player

"Nobody in football should be called a genius. A genius is a guy like Norman Einstein." -Football commentator and former player Joe Theismann

• at least a temporary alteration in consciousness
• or loss of consciousness of less than 20 minutes
• GCS 13-15
• no findings on neuroimaging

Post-Concussion Syndrome (PCS)

• Ruff's "Miserable Minority"

  The term 'Miserable Minority' refers to those mild traumatic brain injury (MTBI) patients in whom recovery differs from what is typically expected [1]. In a three- centre study a representative sample of MTBI cases consecutively admitted to the emergency room was evaluated. Most of these individuals experienced initial physical, cognitive and emotional dysfunction yet, after 1-3 months, most return to functioning within the normal ranges compared to controls [2]. In other studies [3,4], similar trends of recovery were evident, indicating that a single uncomplicated MTBI does not, as a rule, result in poor outcome with permanent functional disability. However, a relatively small subset of MTBI patients present with complaints that persist more than 12 months following the trauma. The term 'Miserable Minority' includes this subset, but in itself does not imply that the problems of these patients are necessarily brain-based. Instead, it can represent one or more of the following factors: (1) neurogenic; (2) psychogenic; (3) co-morbid medical complications (i.e. neck injury, vestibular problems); or (4) financial gain.

• Lowry study

Summary and Agreement Statement of the 2nd. International Conference on Concussion in Sport, Prague 2004. (Re-state definition from Vienna Conference) "Sports concussion is defined as a complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces". Several common features that incorporate clinical, pathological, and biomechanical injury constructs that may be used in defining the nature of a concussive head injury include the following.

1. Concussion may be caused by a direct blow to the head, face, neck, or elsewhere on the body with an "impulsive" force transmitted to the head.
2. Concussion typically results in the rapid onset of short lived impairment of neurological function that resolves spontaneously.
3. Concussion may result in neuropathological changes, but the acute clinical symptoms largely reflect a functional disturbance rather than structural injury.
4. Concussion results in a graded set of clinical syndromes that may or may not involve loss of consciousness. Resolution of the clinical and cognitive symptoms typically follows a sequential course.
5. Concussion is typically associated with grossly normal structural neuroimaging studies.

Issues in Concussion:

• Pathophysiological basis: no experimental model that accurately reflects a sporting concussion injury
• Grading scales: abandon in favor of combined measures to indivually guide return to play... symptoms must clear, neurological exam return to normal, cognitive function returns to baseline.
• Loss of Consciousness: associate with early deficits but not imply severity... presence of LOC does not classify concusison as "complex"
• Amnesia: PTA as a surrogate measure of severity... nature, burden, and duration of post-concussion symptoms may be more important than presence or duration of PTA alone. Retrograde amnesia varies with time of measurement and is poorly reflective of injury severity
• Paediatric injury: children 5-18 should not return to play until symptom free. Children need "cognitive rest" to limit exertion with ADLs and limit scholastic activities while symptomatic. Cognitive assessment is problematic due to cognitive maturation and comparisons with own baseline
• Pre-participation physical examination: review concussion history, protective equipment, conduct baseline cognitive assessment.
• SCAT Card

Return to Play:
Most injuries will be simple concussions, and such injuries recover spontaneously over several days... it is expected that an athlete will proceed rapidly through the stepwise return to play strategy.

During this period of recovery in the first few days, physical and cognitive rest is required. Activities that require concentration and attention may exacerbate the symptoms and as a result delay recovery.

The return to play after a concussion follows a stepwise process:

1. No activity, complete rest. Once asymptomatic, proceed to level 2.
2. Light aerobic exercise such as walking or stationary cycling, no resistance training.
3. Sport specific exerciseÑfor example, skating in hockey, running in soccer; progressive addition of resistance training at steps 3 or 4.
4. Non-contact training drills.
5. Full contact training after medical clearance.
6. Game play.