header photo

Traumatic brain injuries (TBI) cover a wide range of injuries to the brain. A concussion may be considered a mild traumatic brain injury, whereas more severe forms may include injuries such as brain bleeds. TBI's resultant from sport have been estimated by the National Head Injury Association to account for around 18% of head injuries in the USA.

Severity of TBI's is rated on a three point scale. Mild TBI's are characterised by a Glasgow Coma Scale (GCS) rating of 13-15 with post traumatic amnesic symptoms (memory loss) of none to less than one day, with a loss of consciousness of anywhere between 0-30 minutes. Moderate TBI's are characterised by a GCS score of 9-12, between 1 and 7 days of post traumatic amnesia symptoms and  30 minutes - 24 hours of loss of consciousness. Severe TBI's are characterised by  GCS scores  of 3-8 with post traumatic symptoms lasting for seven days or more



Severity of traumatic brain injury[13]
Mild 13–15<1
Moderate 9–12>1 to <7
>30 min to
<24 hours
Severe 3–8>7 days>24

Brain injuries can be classified into mild, moderate, and severe categories.[12] The Glasgow Coma Scale (GCS), the most commonly used system for classifying TBI severity, grades a person's level of consciousness on a scale of 3–15 based on verbal, motor, and eye-opening reactions to stimuli.[14] In general, it is agreed that a TBI with a GCS of 13 or above is mild, 9–12 is moderate, and 8 or below is severe.[3][8][15] Similar systems exist for young children.[8] However, the GCS grading system has limited ability to predict outcomes. Because of this, other classification systems such as the one shown in the table are also used to help determine severity. A current model developed by the Department of Defense and Department of Veterans Affairs uses all three criteria of GCS after resuscitation, duration of post-traumatic amnesia (PTA), and loss of consciousness (LOC).[13] It also has been proposed to use changes that are visible on neuroimaging, such as swelling, focal lesions, or diffuse injury as method of classification.[2] Grading scales also exist to classify the severity of mild TBI, commonly called concussion; these use duration of LOC, PTA, and other concussion symptoms.[16]