Concussion Definition

A concussion is a traumatic brain injury that causes changes in how the brain functions, leading to signs and symptoms that can emerge immediately or in the hours or days after the injury. It is possible for symptoms to take up to 7 days to appear.

Concussion signs and symptoms can be physical (for example, headache, dizziness), cognitive (for example, difficulty concentrating or remembering), emotional/behavioural (for example, depression, irritability) and/or related to sleep (for example, drowsiness, difficulty falling asleep).

Concussions may be caused by a jarring impact to the head, face, neck or body, with an impulsive force transmitted to the head, that causes the brain to move rapidly within the skull1,2
(for a visual description of how a concussion occurs, consult cdn.hockeycanada.ca/hockey-canada/Hockey-Programs/Safety/Concussion/Infographic/english.html).

Concussions can occur even if there has been no loss of consciousness, (in fact most concussions occur without a loss of consciousness)3.

Concussions cannot normally be seen on X-rays, standard CT scans or MRIs4.

A concussion is typically expected to result in symptoms lasting 1-4 weeks in children and youth (18 years or under), but in some cases symptoms may be prolonged5,6.

1 Parachute. (2018). Concussion guide for teachers. Toronto: Parachute

2 McCrory et al. (2017). Consensus statement on concussion in sport—the 5th international conference on concussion in sport held in Berlin, October 2016. British Journal of Sports Medicine, 51 (11), 838–847. doi: 10.1136/bjsports-2017-097699

3 Parachute. (2017). Canadian Guideline on Concussion in Sportem> (p. 29). Toronto: Parachute

4 Parachute. (2017). Canadian Guideline on Concussion in Sportem> (p. 29). Toronto: Parachute

5 Parachute. (2017). Canadian Guideline on Concussion in Sport (p. 8, 30). Toronto: Parachute

6 Parachute. (2017). McCrory et al. (2017). Consensus statement on concussion in sport—the 5th international conference on concussion in sport held in Berlin, October 2016. British Journal of Sports Medicine, 51 (11), 838–847. doi: 10.1136/bjsports-2017-097699