Journal of the International Neuropsychological Society

Research Articles

Incidence, Clinical Course, and Predictors of Prolonged Recovery Time Following Sport-Related Concussion in High School and College Athletes

Michael McCreaa1 c1, Kevin Guskiewicza2a3a4, Christopher Randolpha5, William B. Barra6, Thomas A. Hammekea7, Stephen W. Marshalla3a4a8, Matthew R. Powella9, Kwang Woo Ahna10, Yanzhi Wanga10 and James P. Kellya11

a1 Departments of Neurosurgery and Neurology, Medical College of Wisconsin, Milwaukee, Wisconsin

a2 Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina

a3 Department of Orthopedics; University of North Carolina at Chapel Hill, Chapel Hill, North Carolina

a4 Injury Prevention Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina

a5 Department of Neurology, Loyola University Medical School, Maywood, Illinois

a6 Departments of Neurology and Psychiatry, New York University School of Medicine, New York, New York

a7 Department of Psychiatry and Behavioral Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin

a8 Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina

a9 Department of Neuropsychology, Marshfield Clinic – Minocqua Center, Minocqua, Wisconsin

a10 Division of Biostatistics, Medical College of Wisconsin, Milwaukee, Wisconsin

a11 U.S. Department of Defense, National Intrepid Center of Excellence, Bethesda, Maryland


Sport-related concussion (SRC) is typically followed by clinical recovery within days, but reports of prolonged symptoms are common. We investigated the incidence of prolonged recovery in a large cohort (n = 18,531) of athlete seasons over a 10-year period. A total of 570 athletes with concussion (3.1%) and 166 controls who underwent pre-injury baseline assessments of symptoms, neurocognitive functioning and balance were re-assessed immediately, 3 hr, and 1, 2, 3, 5, 7, and 45 or 90 days after concussion. Concussed athletes were stratified into typical (within 7 days) or prolonged (> 7 days) recovery groups based on symptom recovery time. Ten percent of athletes (n = 57) had a prolonged symptom recovery, which was also associated with lengthier recovery on neurocognitive testing (p < .001). At 45–90 days post-injury, the prolonged recovery group reported elevated symptoms, without deficits on cognitive or balance testing. Prolonged recovery was associated with unconsciousness [odds ratio (OR), 4.15; 95% confidence interval (CI) 2.12–8.15], posttraumatic amnesia (OR, 1.81; 95% CI, 1.00–3.28), and more severe acute symptoms (p < .0001). These results suggest that a small percentage of athletes may experience symptoms and functional impairments beyond the typical window of recovery after SRC, and that prolonged recovery is associated with acute indicators of more severe injury. (JINS, 2012, 18, 1–12)

(Received September 21 2011)

(Revised June 07 2012)

(Accepted June 07 2012)


  • Brain injury;
  • Concussion;
  • Neuropsychological tests;
  • Sport injuries;
  • Neurological disorders;
  • Closed head injury


c1 Correspondence and reprint requests to: Michael McCrea, Department of Neurosurgery, Medical College of Wisconsin, 9200 W. Wisconsin Avenue, Milwaukee, WI 53226. E-mail: