		Concussion grades and management recommendations
Guideline	Frequency*	1	2	3
Cantu⁵	Second concussion	Athlete may return to play in two weeks if asymptomatic for one week.	Athlete may not return to play for at least one month; athlete may then return to play if asymptomatic for one week	Terminate season.
Cantu⁵	Third concussion	Terminate season.	Terminate season.
Colorado Medical Society⁶	Second concussion	Athlete may return to play if asymptomatic for one week.	Athlete may return to play if asymptomatic for one month.	Terminate season.
Colorado Medical Society⁶	Third concussion	Terminate season.	Terminate season.
American Academy of Neurology⁷	Second concussion	Athlete may return to play if asymptomatic for one week.	Athlete may return to play if asymptomatic for two weeks.	Athlete may return to play if asymptomatic for one month or longer.
American Academy of Neurology⁷	Third concussion	No recommendation	No recommendation	No recommendation