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Medline ® Abstract for Reference 15

of 'Sideline evaluation of concussion'

Cumulative effects of concussion in high school athletes.
Collins MW, Lovell MR, Iverson GL, Cantu RC, Maroon JC, Field M
Neurosurgery. 2002;51(5):1175.
OBJECTIVE: A common assumption in sports medicine is that a history of concussion is predictive of a lower threshold for, as well as a worse outcome after, subsequent concussive injury. The current study was conducted to investigate the relationship between concussion history in high school athletes and the on-field presentation of symptoms after subsequent concussion.
METHODS: One hundred seventy-three athletes who experienced sports-related concussion composed the initial study group. Binary groups were subsequently created on the basis of concussion history. Sixty athletes with no concussion history were compared with 28 athletes with a history of three or more concussions. The groups were compared in terms of the on-field presentation of symptoms after an in-study concussion. Dependent variables included the postinjury presence of loss of consciousness, anterograde amnesia, retrograde amnesia, and confusion.
RESULTS: Athletes with three or more prior concussions were more likely to experience on-field positive loss of consciousness (chi(2) = 8.0, P = 0.005), anterograde amnesia (chi(2) = 5.5, P = 0.019), and confusion (chi(2) = 5.1, P = 0.024) after a subsequent cerebral concussion. An odds ratio revealed that athletes with a history of three concussions were 9.3 times more likely than athletes with no history of concussion to demonstrate three to four abnormal on-field markers of concussion severity.
CONCLUSION: This study is the first to suggest a cumulative effect of concussion in high school athletes. A more severe on-field presentation of concussion markers is evidenced in high school athletes with a pronounced history of concussion. This study's findings highlight the need for more long-term outcome studies in high school athletes who sustain sports-related concussions.
Department of Orthopaedic Surgery, Sports Medicine Concussion Program, University of Pittsburgh Medical Center, 3200 S. Water Street, Pittsburgh, PA 15203, USA. collinsmw@msx.upmc.edu