• A broadly-accepted, standard definition of concussion, also known as mild traumatic brain injury (MTBI), does not exist and is still a work in progress. 

• Historically, the diagnosis of concussion has been based upon the presence of three findings:  (1) Loss of consciousness (usually for less than 30 seconds), (2) post-traumatic amnesia (usually for less than 24 hours), and (3) a Glascow Coma Scale score of 13 to 15.                  

• Today, many experts question whether loss of consciousness is inherently associated with concussion, but rather that any change in consciousness, such as that related to amnesia, suffices.  

• Patients with the following symptoms should be screened, typically with head CT, for more serious injury:  loss of/deteriorating consciousness, persistent headache, dizziness, vomiting, disorientation/confusion, seizure, and unequal pupil size.

• Treatment of concussion consists of monitoring and rest.  Symptoms usually spontaneously resolve within 3 weeks, but may persist for up to around 3 months.

References

• Borg J, Holm L, Cassidy JD, et al. (2004). "Diagnostic procedures in mild traumatic brain injury: Results of the WHO collaborating centre task force on mild traumatic brain injury". Journal of Rehabilitation Medicine 36 (Supplement 43): 61–75.
• http://en.wikipedia.org/wiki/Concussion#cite_note-BorgHolm04-50