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

McCrea, M. Guskiewicz, K. Randolph, C. Barr, W. Hammeke, T. Marshall, S. Powell, M. Woo Ahn, K. Wang, Y. Kelly, J. J Int Neuropsychol Soc (2012), 18, 1–12.
The authors of this 10-year prospective-cohort study sought to build upon the growing body of evidence in post-concussion management by following high school and college athletes to determine the typical clinical course of concussion recovery, the frequency of athletes who do not follow the typical recovery course, and what risk factors may be associated with prolonged recovery time. Over 18,000 player seasons were monitored, with 345 high school and 225 collegiate athletes (total n = 570) sustaining a concussion. Among the athletes with a concussion (3.1% of cohort sample) 88.9% were male and American football accounted for 80.7% of concussions, followed by soccer, lacrosse, and ice hockey. The authors also observed a demographically-matched control group of 166 non-concussed high school (63.3%) and college (36.7%) athletes. Both groups were administered the same baseline and post-injury testing protocol which included testing with the Graded Symptom Checklist (GSC), Balance Error Scoring System (BESS), Standardized Assessment of Concussion (SAC), and a neuropsychological test battery. After assessment 513 (90%) concussed athletes were classified as typical recovery (TR) with symptoms returning to baseline by seven days post-concussion. Fifty seven (10%) athletes with concussions were stratified as prolonged recovery (PR). The TR group was then compared to the PR group at 1 to 2 days, 1 week, and 45 or 90 days post-injury. Both groups were also compared to the non-concussed control group. The TR and PR groups had different cognitive functioning (SAC) scores until day 7 but not at day 45/90 post-injury. In contrast, the TR and PR groups only had different balance (BESS) scores one day post-injury. Compared to the control group, the TR group had more symptoms until day 7, impaired cognitive functioning until day 3, and less balance only at the first day post-injury. Finally, unconsciousness at time of injury, posttraumatic or retrograde amnesia, and greater symptom severity (> 20 points from baseline on the GSC) within the first 24 hours of injury were significantly associated with PR. Furthermore, athletes withheld longer from competition and allowed a symptom-free waiting period had lower the risks of PR.

This study is significant because it is one of the first prospective studies that followed a large sample of athletes over a long period of time. This study reinforces on a larger scale, data that previously showed approximately 90% of athletes on the high school and college level who sustain a concussion functionally recover within seven to fourteen days. This study also shows new risk factors that predict PR not seen in previous research. These results can help clinicians better predict which athletes may experience a prolonged recovery. Additionally, the use of multi-dimensional assessment tools such as the BESS, GSC and SAC, as used in this study, can potentially help clinicians discriminate between athletes who will fall in the typical versus the prolonged recovery pattern. Finally, these findings emphasize the importance of complete brain rest as the main component of post-concussion symptom recovery. The authors showed that the longer an athlete was withheld from competition, the less risk the athlete had for PR. Future prospective studies will hopefully explore concussions sustained in sports other than football and the effects of gender on concussion recovery. What is the typical length of recovery for athletes who sustain concussion under your care? Have you developed any sort of feel for symptoms that may be predictors of PR in your clinical practice?

Written By: Stephen Stache, MD
Reviewed By: Marc Harwood, MD and
Stephen Thomas

Related Readings:

On-field predictors of neuropsychological and symptom deficit following sports-related concussion.
The relation between post concussion symptoms and neurocognitive performance in concussed athletes

McCrea M, Guskiewicz K, Randolph C, Barr WB, Hammeke TA, Marshall SW, Powell MR, Woo Ahn K, Wang Y, & Kelly JP (2012). Incidence, Clinical Course, and Predictors of Prolonged Recovery Time Following Sport-Related Concussion in High School and College Athletes. Journal of the International Neuropsychological Society : JINS, 1-12 PMID: 23058235