Abstract:
BACKGROUND: Multiple concussions have been associated with prolonged symptoms, recovery time, and risk for future concussions. However, very few studies have examined the effect of multiple concussions on neurocognitive performance and the recently revised symptom clusters using a large database. PURPOSE: To examine concussed athletes with a history of 0, 1, 2, or >/=3 concussions on neurocognitive performance and the recently revised symptom clusters. STUDY DESIGN: Cohort study (prognosis); Level of evidence, 2. METHODS: The independent variables were concussion group (0, 1, 2, and >/=3 concussions) and time (baseline, 3 days, and 8 days). The dependent variables were neurocognitive test scores as measured by the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) neurocognitive test battery (verbal and visual memory, processing speed, and reaction time) and 4 concussion symptom clusters (migraine-cognitive-fatigue, affective, somatic, and sleep). All concussed athletes (n = 596) were administered the ImPACT test at a mean 2.67 +/- 1.98 and 7.95 +/- 4.46 days after injury. A series of 4 (concussion group) x 3 (time) repeated-measures analyses of covariance (age = covariate) were performed on ImPACT composite scores and symptom clusters. RESULTS: Concussed athletes with >/=3 concussions were still impaired 8 days after a concussion compared with baseline scores on verbal memory (P < .001), reaction time (P < .001), and migraine-cognitive-fatigue symptoms (P < .001). There were no significant findings on the remaining dependent variables. CONCLUSION: Concussed athletes with a history of >/=3 concussions take longer to recover than athletes with 1 or no previous concussion. Future research should concentrate on validating the new symptom clusters on multiple concussed athletes, examining longer recovery times (ie, >8 days) among athletes with multiple concussions.