Elk Grove Village, ILâ(ENEWSPF)âJanuary 6, 2014. After a concussion, adolescents who engaged in the highest levels of cognitive activity took the longest to fully recover from their symptoms, according to a study in the February 2014 Pediatrics. The study, âEffect of Cognitive Activity Level on Duration of Post-Concussion Symptoms,â published online Jan. 6, tracked 335 people ages 8 to 23 who visited a sports concussion clinic between October 2009 and July 2011 after suffering a concussion.
