Table 1.

Definitions of concussion or MHI

Canadian Academy of Sport and Exercise Medicine, 2010“A form of head injury characterized by any alteration in cerebral function and caused by a direct or indirect (rotation) force transmitted to the head. It results in one or more of the following acute signs or symptoms: a brief loss of consciousness, light-headedness, vertigo, cognitive and memory dysfunction, tinnitus, blurred vision, difficulty concentrating, amnesia, headache, nausea, vomiting, photophobia or a balance disturbance. Delayed signs and symptoms may also include sleep irregularities, fatigue, personality changes, and inability to perform usual daily activities, depression or lethargy”4
SCAT3, from the 4th International Conference on Concussion, 2012A concussion is a disturbance in brain function caused by a direct or indirect force to the head. It results in various nonspecific signs and symptoms and most often does not involve loss of consciousness. Concussion should be suspected in the presence of any 1 or more of the following:
  • symptoms (eg, headache),

  • physical signs (eg, unsteadiness),

  • impaired brain function (eg, confusion), or

  • abnormal behaviour (eg, change in personality)4,5

American Academy of Neurology, 2013Concussion is a trauma-induced alteration in mental status that might or might not involve loss of consciousness. Confusion and amnesia are the hallmarks of concussion. The confusional episode and amnesia might occur immediately after the blow to the head or several minutes later. Close observation and assessment of the athlete over some period of time is necessary to determine whether evolving neuropathologic change associated with concussion will lead to a confusional state or to the development of memory dysfunction3
  • MHI—mild head injury, SCAT3—Sport Concussion Assessment Tool, version 3.