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 Medicine36 (Supplement 43): 61–75.
