The impact of concussion on brain adaptation: the use of prism glasses as a novel diagnostic tool

Objective To evaluate brain adaptation following concussion. Do youth with a history of previous or acute concussion require more ball throws to land on or near a target, when wearing prism glasses (bend light to the left by 15˚), than youth with none? Design Cross-sectional study. Setting Sport Injury Prevention Research Centre, Alberta, Canada. Participants Ice hockey players: 21 with acute concussion [(17 males), mean age 13.8 (95% CI: 13.4, 14.2), median number of days since concussion 4 (range 2–11)], 40 reporting previous concussion(s) [(33 males), mean age 13.4 (95% CI: 13.1, 13.7), median number of days since last concussion 620 (range 90–1560)], and 40 with no concussion history [(36 males), mean age 12.9 (95% CI: 12.5, 13.2)]. Independent variable Lifetime concussion history (yes/no) or acute concussion (<10 days). Dependent variable Number of throws for brain adaptation. Main results A significant concussion effect was identified across groups [F(2,98)=26.17, p<0.001]. Post-hoc analyses showed a difference in the number of throws in players with no concussion history versus players reporting previous concussions [−4.700 (95% CI: −8.44, −0.96)] and acute concussions [−13.440 (95% CI: −17.89, −8.99)], as well as between previous history versus acute concussion groups [−8.740 (95% CI: −13.19, −4.29)]. Conclusions Concussion history and acute concussion appears to negatively impact brain plasticity in youth. They do not adapt as well as individuals with no concussion history. Our results support the use of a prism adaptation paradigm for identifying/quantifying short and long-term neurologic impairments in youth following concussion. Competing interests None.