Female soccer players and soccer players who have had a previous concussion recuperate differently from males or players without a history of concussion, new research1 released at the 2008 American Orthopaedic Society for Sports Medicine Annual Meeting showed.
The study found that prior history of concussion and gender account for significant differences in test results following the injury. Because of these differences, the authors urge physicians and coaches to take an individualized approach to treating concussion patients.
"The results of this study suggest that physicians should not be taking a one-size-fits-all approach to treating concussions," said co-author Alexis Chiang Colvin, MD, Sports Medicine Fellow for the Department of Orthopaedics at the University of Pittsburgh Medical Center. "Our study shows that patients with a history of a previous concussion perform worse than patients without a previous history on neurocognitive tests taken after they sustain a concussion. Furthermore, females perform worse than males on post-concussion testing, as well."
The authors chose to examine concussion recovery patterns in soccer players due to the popularity of the sport among both genders. Also, it is a non-helmeted sport with identical rules for all participation levels for both genders. In the United States, there are between 1 and 4 million estimated sports-related concussions each year. The most common causes of concussion in soccer include head-to-head contact, head contact with other body parts and head-to-ground contact.
A concussion is an injury to the brain that results in temporary loss of normal brain function, usually caused by a blow to the head. Concussions can affect memory, judgment, reflexes, speech, balance and coordination.
Researchers studied 234 soccer players (61 percent female, 39 percent male) ranging in age from 8 to 24 years old, who were given neuropsychological tests that measured attention, memory, processing speed and reaction time after their concussion. The results of the tests were analyzed to see if there were group differences in performance between male and female participants and those with a previous history of concussion.
The study found that females performed significantly worse than males on tests of reaction time. Females were also significantly more symptomatic than males. Additionally, there was a trend, although not significant, towards females testing poorly regarding verbal memory and processing speed when compared to males.
Soccer players with a history of concussion performed significantly worse on verbal memory testing after another concussion, the study found.
"There's a theory that males typically have a stronger neck and torso that can handle forces better," said Dr. Colvin. "But when we accounted for Body Mass Index in this study, we still found a difference between males and females. Therefore, there are differences in recovery between genders that cannot simply be attributed to size difference. More studies are needed to determine the reason for differences in recovery between males and females."
The new research was consistent with the results of an earlier study which found that girls took much longer than boys for post-concussion signs and symptoms to clear and to return to play.
More recent research finds no gender differences
The 2011 study found no difference in the number of symptoms reported between male and female athletes, no difference in the time symptoms took to resolve (most reported resolution of their symptoms within 3 days of injury) or in the time it took for girls and boys to return to play (median time for RTP was 3 to 6 days). The one difference: girls reported symptoms more subtle and easily missed or attributed to causes other than concussion than those of boys.
Most significantly, in the 2012 study, researchers at Vanderbilt University Medical Center and the Vanderbilt Sports Concussion Center, studying tightly matched, homogeneous groups of 40 male and 40 female concussed soccer players, found no gender differences in symptoms at baseline (pre-concussion) or in the first week after concussion, and were unable to replicate the findings of previous studies of mixed groups of athletes from a variety of sports, including the one authored by Dr. Colvin,1 which had reported small but significant gender differences, both at baseline in terms of symptoms and neurocognitive test scores (girls reported more headaches, fatigue, sleep difficulties, irritability, sadness, nervousness, feeling more emotional, feeling slowed down, and difficulty concentrating4 and on verbal memory tasks, while males perform better on tests of visual memory5, 6) and post-concussion (girls reporting a higher number of symptoms1,7 and performing more poorly on neurocognitive testing (significantly slower reaction times).1,7
The only significant gender-related difference identified by the Vanderbilt researchers was that female high school soccer players reported a greater number of post-concussion symptoms. The trend in the research, however, is to focus on total symptom score, not differences in individual symptoms, said Tracey Covassin PhD., ATC, an Associate Professor and Undergraduate Athletic Training Program Director at Michigan State University, and author of three studies on the subject.4,5,9
The reason, said the Vanderbilt researchers, may have been due to the fact that prior studies, including the Colvin study1, "have not routinely and consistently controlled for the potentially confounding variables of age, years of education, specific sport, number of prior concussions, time of testing postinjury, medical history, and other biopsychological moderating variables (for example, medical history, presence of ADHD and/or learning disability and so on)."
Gender: a factor in concussion management?
The Consensus Statement on Concussion in Sport issued by the 4th International Conference on Concussion in Sport9 held in Zurich in November 2012 "accepted that gender may be a risk factor for injury and/or influence injury severity" but did not list female gender as a possible modifier in the management of concussions because there was no "unanimous agreement that the current published research evidence is conclusive enough."
A literature review10 issued with the Zurich consensus statement noted that, while the data suggested that in sports that use the same rules (soccer11 and basketball12), the reported incidence of concussion is greater in females than their male counterparts, concussion risks between genders were not significant in lacrosse, softball/baseball or gymnastics.12 The study cited five studies1,4,7,11,13,14 to support its finding that "there apppear to be differences in how women experience concussive symptoms as well as how long symptoms persist compared with men."
A 2012 study9 recommends that gender be considered by clinicians when interpreting the results of symptom reports, neurocognitive testing, and postural instability assessments (e.g. BESS) following concussion, and the authors of the 2012 Vanderbilt study3 cautioned against interpreting their results as indicating either that there is no gender-based difference in acute response (symptoms or neurocognitive scores) to concussive injury in high school athletes, or that gender should always be considered a modifying factor in managing a concussion. Instead, they were supported the interim position taken by the Zurich consensus statement:8 that gender may be a risk factor for injury and/or influence injury severity.
1. The study discussed in this article was ultimately published in the American Journal of Sports Medicine: Colvin AC, Mullen J, Lovell MR, West RV, Collins MW, Groh M. The Role of Concussion History and Gender in Recovery from Soccer-Related Concussion. Am. J. Sports Med 2009;37(9):1699-1704.
2. Frommer L, Gurka K, Cross K, Ingersoll C, Comstock R.D., Saliba S. Sex Differences in Concussion Symptoms of High School Athletes. J Ath Train 2011; 46(1):000-000.
3. Zuckerman SL, Solomon GS, Forbes JA, Haase RF, Sills AK, Lovell MR. Response to acute concussive injury in soccer players: is gender a modifying factor? J Neurosurg: Pediatrics 2012; DOI:10.3171/2012.8.PEDS12139 (published online ahead of print October 2, 2012)(accessed October 15, 2012).
4. Covassin T, Swanik CB, Sachs M, Kendrick Z, Schatz P, Zillmer E, et. al. Sex differences in basesline neuropsychological function and concussion symptoms of concussed collegiate athletes. Br J Sports Med 2006;40:923-927.
5. Covassin T, Schatz P, Swanik C. Sex differences in neuropsychological function and post-concussion symptoms of concussed collegiate athletes. Neurosurgery 2007:61:345-351.
6. Weiss E, Kemmler G, Deisenhammer E, Fleischhacker W, Delazer M. Sex differences in cognitive functions. Pers Individ Dif 2003;35:863-875.
7. Broshek DK, Kaushik T, Freeman JR, Erlanger D, Webbe F, Barth JT. Sex differences in outcome following sports-related concussion. J Neurosurg 2005;102:856-863.
8. McCrory P, et al. Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012. Br J Sports Med 2013; 47:250-258.
9. Covassin T, Elbin R, Harris W, Parker T, Kontos A. The Role of Age and Sex in Symptoms, Neurocognitive Performance, and Postural Stability in Athletes After Concussion. Am J Sports Med 2012;40(6):1303-1312.
10. Makdissi M, Davis G, Jordan B, Patricios J, Purcell L, Putakian M. Revisiting the modifers: how should the evaluation and management of acute concussions differ in specific groups. Br J Sports Med 2013;47:314-320.
11. Gessel L, Fields S, Collins C, et al. Concussions among United States high school and collegiate athletes. J Athl Train 2007;42:495-503.
12. Covassin T, Swanik C, Sachs M. Sex differences and the incidence of concussions among college athletes. J Athl Train 2003;38:238-244.
13. Dick R. Is there a gender difference in concussion incidence and outcomes? Br J Sports Med 2009;43:146-150.
14. Kutcher J, Eckner J. At-risk populations in sports-related concussin. Curr Sports Med Rep 2010;9:16-20.
Most recently updated May 5, 2013