Investigating baseline neurocognitive performance between male and female athletes with a history of multiple concussion.

OBJECTIVE The purpose of this study was to examine, using a dose-response model, sex differences in computerised neurocognitive performance among athletes with a history of multiple concussions. DESIGN Retrospective with randomly selected concussion cases from four levels/numbers of previous concussion. SETTING Multicentre analysis of NCAA student-athletes. PARTICIPANTS Subjects included a total of 100 male and 88 female NCAA athletes. INTERVENTION Sex and four mutually exclusive groups of self-reported concussion history: (1) no history of concussion, (2) one previous concussion, (3) two previous concussions, (4) three or more previous concussions. MAIN OUTCOME MEASUREMENTS Neurocognitive performance as measured by a computerised neurocognitive test battery (Immediate Postconcussion Assessment Cognitive Testing (ImPACT)). RESULTS A dose-response gradient was found for two or more previous concussions and decreased neurocognitive performance. Females with a history of two and three or more concussions performed better than males with a history of two (p=0.001) and three or more concussions (p=0.012) on verbal memory. Females performed better than males with a history of three or more concussions (p=0.021) on visual memory. Finally, there was a significant difference for sex on both motor processing speed and reaction-time composite scores. Specifically, males performed worse than females on both processing speed (p=0.029) and reaction time (p=0.04). CONCLUSION The current study provided partial support for a dose-response model of concussion and neurocognitive performance decrements beginning at two or more previous concussions. Sex differences should be considered when examining the effects of concussion history on computerised neurocognitive performance.