Exploring brain activation patterns in asymptomatic athletes with and without a history of two or more concussions

The long-term effects of multiple concussions in athletes are unclear. Functional magnetic resonance imaging (fMRI) studies have previously reported compensatory brain activation patterns and brain activation (i.e., engagement) differences in symptomatic athletes with a history of multiple concussions. These fMR1 findings are in absence of any neurocognitive impairment. No fMRI study has examined brain activation patterns in athletes with a history of concussion who are asymptomatic. Objective. The current study evaluated neurocognitive performance and brain activation patterns in asymptomatic athletes with and without a history of two or more concussions. Design. Paired case-control Subjects. Fourteen athletes with a history of two or more concussions were matched (age, sex) to 14 athletes with no history of concussion. Measurements. A neurocognitive test battery (Trail-Making Test Form A and B, Symbol Digit Modalities Test, and ImPACT); N-back Working Memory Task; Functional MRI. Results. Similar performance on the Trail Making Test Form A and B, Symbol Digit Modalities Test, and ImPACT were observed in both groups. The history of concussion group was less accurate than controls on the low (p =.01), moderate (p =.04), and high (p =.02) working memory load. No compensatory brain activation patterns were observed between groups and these common brain regions used to perform the task were used to the same degree during low, moderate, and high working memory demands. Conclusions. Following the resolution of symptoms, a history of two or more concussions is not associated with reduced neurocognitive performance or compensatory brain activation patterns.