Sex Differences in Cerebral Blood Flow Associated with a History of Concussion

Growing evidence suggests that a history of sport concussion may lead to long-term changes in brain physiology, with cerebral blood flow (CBF) being particularly sensitive to injury. However, it is unknown whether these changes are sex specific. The goal of this study was to evaluate sex differences in CBF of asymptomatic athletes, with and without a history of concussion (HOC) using arterial spin labeling (ASL). Scans were acquired for 122 athletes, including those without HOC (33 male, 33 female) and those with HOC (28 male, 28 female). Males with HOC had lower CBF bilaterally than males without HOC, seen predominantly in the temporal lobes. In contrast, females with HOC showed no significant differences relative to females without HOC, although they had significantly higher variability in temporal CBF values compared with males with HOC. Additional analyses within the HOC groups found that females with multiple concussion had lower CBF posteriorly compared with those with a single concussion, whereas males showed no significant effects. This study provides the first evidence of sex differences in CBF associated with HOC.