Background Consensus guidelines for managing sport-related concussion in adults are being implemented in Europe, but for adolescents they are still limited. While cognitive function in adults is relatively stable over time, cognition in adolescence continues to develop. Changes in adolescents’ cognitive performance have been reported to be of comparable magnitude to impairments observed on cognitive post-injury assessment in adults. Maturational improvement between baseline and post-concussion assessment may compensate any injury related cognitive impairment in adolescents, and can lead to misdiagnosis if not taken into account. The aim was to study the effect of age on cognitive performance in the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) in Finnish adolescent ice hockey players.

Methods The ImPACT test was administered to 1311 Finnish ice hockey players at baseline for the season 2015–2016, mean age 16.31 years (standard deviation 1.79, median 16 y, range 12–21 y). Players were divided in seven equal sized groups (12–14, 15, 16, 17, 18, 19, and 20–21 years olds) and cognitive test results were compared between groups.

Results There was a statistically significant difference in cognitive test performance between age groups (Wilks’ Lambda p < 0.001). The effect appeared in all composite scores, but especially in Visual Motor Speed and Reaction Time the four first age groups showed a significant yearly change.

Conclusions Age-specific national test norms and concussion assessment guidelines are needed. Longitudinal data would enable a more reliable comparison.