Currently, the Glasgow Coma Scale (GCS) is a numerical scale widely used clinically to assess coma and impaired consciousness. Persons with GCS scores of 3 to 8 are classified with a severe TBI, those with scores of 9 to 12 are classified with moderate TBI, and those with scores of 13 to 15 are classified with mild TBI. Other classification systems include the Abbreviated Injury Scale (AIS), Trauma Score, and the Abbreviated Trauma Score.
Concussion grading scales include the Cantu guidelines. Three grades are described, with grade I an injury associated with no loss of consciousness and less than 30 minutes of post-traumatic amnesia. This is the most common type of concussion by this guideline. In grade II the patient loses consciousness for less than 5 minutes or experiences amnesia for between 30 minutes and 24 hours. In grade III, the patient loses consciousness longer than 5 minutes and amnesia lasting longer than 24 hours. The patient may also exhibit signs or symptoms lasting over 1 week. More than one grade III concussion during a professional or collegiate athlete’s career may lead to recommendation that the player cease playing the sport.
A computerized concussion evaluation system was more recently developed call ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) that has been implemented by many sports teams. ImPACT is a 20-minute test that assists the clinician in making decision regarding the extent of the concussion injury and when the player can return to the sport activity. It measures attention span, working memory, sustained and selective attention time, response variability, non-verbal problem solving, and reaction time.
A biologic measure for TBI and concussions is not currently available, and the Iron Horse brain injury assay would be the first such biologic biomarker for neuronal injury that occurs after TBI or concussion.