Double Concussions and Cognitive Dysfunction: A Population Study of Young Men

摘要

Aims: To determine whether double concussions can result in longer-lasting cognitive dysfunctioning than a single concussion and/or whether cognitive dysfunction is a greater risk factor for double concussions than for a single concussion. Method: Through a national hospitalisation database, 2753 men were found who, at ages between infancy and early adulthood, had, on two separate occasions, been briefly hospitalised after a concussion. This cohort was compared with a previously obtained and comparable sample of men who had suffered a single concussion. From Draft Board records a dichotomised index was obtained indicating whether or not they had performed at or above a cut-off total score on a cognitive screening test involving four timed subtests, below cut-off being considered as dysfunctional. Findings: For all age groups, double concussions were associated with higher rates of cognitive dysfunction than single concussions. This was especially true where the concussion(s] had occurred after cognitive testing [odds ratio = 2.53, 95% confidence interval (Cl) = 1.92-3.36]. Where double concussions had occurred before cognitive testing but after age 12, cognitive dysfunction was more prevalent when the interval between concussions was less than 1 month than at longer intervals (odds ratio = 3.91, 95%CI = 1.14-13.34). It is concluded that cognitive dysfunction in young men is a risk factor for repeat concussions; at the same time cognitive dysfunction can also be a long-term consequence of two concussions occurring in close temporal proximity.