Effect of concussion on clinically measured reaction time in 9 NCAA division I collegiate athletes: a preliminary study.

OBJECTIVES To evaluate the effect of concussion on clinically measured reaction time (RT(clin)) and in comparison to a computerized reaction time measure (RT(comp)). DESIGN Prospective, repeated measures observational study. SETTING Athletic training clinic at a National Collegiate Athletic Association (NCAA) Division I university. PARTICIPANTS Data are reported for 9 collegiate athletes with acute concussion who were part of a larger cohort of 209 athletes recruited from the university's football, women's soccer, and wrestling teams before the start of their respective athletic seasons. METHODS Baseline RT(clin) and RT(comp) were measured during preparticipation physical examinations. RT(clin) measured the time required to catch a suspended vertical shaft by hand closure after its release by the examiner. RT(comp) was derived from the simple RT component of the CogState-Sport computerized neurocognitive test battery. Athletes who subsequently sustained a physician-diagnosed concussion underwent repeated RT(clin) and RT(comp) testing within 72 hours of injury. A Wilcoxon signed rank test was used to compare baseline and after-injury RTs. MAIN OUTCOME MEASUREMENTS After-injury changes in RT(clin) and RT(comp) were calculated with respect to each athlete's own preseason baseline value. RESULTS After-injury RT(clin) was prolonged in 8 of the 9 athletes with concussions, whereas RT(comp) was prolonged in 5 of the 9 athletes with concussions. The mean (standard deviation) RT(clin) increased from 193 ± 21 ms to 219 ± 31 ms (P = .050), and mean RT(comp) increased from 247 ± 75 to 462 ± 120 ms (P = .214). CONCLUSIONS We concluded that RT(clin) appears to be sensitive to the known prolongation of RT after concussion and compares favorably with an accepted computerized RT measure. This study supports the potential utility of RT(clin) as part of a multifaceted concussion assessment battery.