The American Academy of Neurology

Classification for Cerebral Concussions

[from: "AAN Practice Parameter: The Management of Concussions in Sports (Summary Statement). Report of the Quality Standards Subcommittee." Neurology 48:581-585 (1997).]


The Athletic Injury Monitoring System project of ExRA has adopted the recently released American Academy of Neurology classification of cerebral concussions. This classification system, based on a background paper written by James P. Kelly, MD and Jay H. Rosenberg, MD ("The Diagnosis and Management of Concussion in Sports," Neurology 48:575-580, 1997) and on sports concussion guidelines published by the Colorado Medical Society, is the result of a major effort to at long last standardize the classification of cerebral concussions in sports. It currently has the endorsement of most of the major relevant professional organizations, including NATA. The AAN classification is as follows:


- Transient confusion

- No loss of consciousness

- 'Bell rung' or 'dinged'

- Concussion symptoms or mental status abnormalities on examination resolve in less than fifteen minutes.

Grade 2

- Transient confusion

- No loss of consciousness

- Concussion symptoms or mental status abnormalities on examination resolve in more than fifteen minutes.

Grade 3

- Any loss of consciousness, brief (seconds) or prolonged (minutes).

Suggested management for each of these grades: Grade 1 - Remove from participation; examine immediately and every five minutes for development of mental status abnormalities or post-concussive symptoms at rest and with exertion; may return to activity if mental status abnormalities or post-concussive symptoms clear within 15 minutes. A second Grade 1 concussion in the same day eliminates the player from participation that day, and may return only if asymptomatic for one week at rest and with exercise. Grade 2 - Remove from participation and disallow return that day; examine on-site frequently for signs of evolving intracranial pathology; examination by trained person the next day; physician should perform neuro exam to clear for participation after having been asymptomatic for one full week at rest and with exertion; CT or MRI if headache or other associated symptoms worsen or persist longer than one week. With a second Grade 2 concussion, return to contact play should be deferred until athlete has at least two weeks symptom-free at rest and with exertion; termination of season mandatory if any abnormality on CT or MRI consistent with intracranial pathology. Grade 3 - Transport immediately to nearest emergency department (with C-spine immobilization if indicated); neurological status assessed daily until all symptoms stabilized or resolved; withheld from contact sports until asymptomatic at rest and with exertion for a minimum of one week following a brief (seconds) Grade 3 concussion, a minimum of two weeks following a prolonged (minutes) Grade 3 concussion. An athlete who suffers a second Grade 3 concussion should be withheld from contact sports for a minimum of one asymptomatic month.

For the purposes of this study, in order to capture more detailed data on milder football head injuries, AIMS includes a "Grade 0" classification (derived from Nelson [Phys Sportsmed 12(3):103-107, 1984]), which is not a part of the AAN classification system. In the "Grade 0" classification, the athlete's head is struck or moved rapidly, but the athlete is not stunned or dazed initially; however, he subsequently complains of headache and difficulty in concentrating. "Grade 0" would not likely be noted by the medical staff unless the athlete complained of headache in the day or two following the incident.