Girls don't appear to be worse off after sports-related concussion than boys, either in terms of concussion symptoms or on neurocognitive tests measuring reaction time and visual memory, a new study finds. 
The only significant gender-related difference the study identified was that female high school soccer players reported a greater number of post-concussion symptoms, although their total symptom score, when the symptoms were ranked on a 6-point scale for severity, were not statistically different from those of the male athletes.
In a tightly controlled study matching 40 male and 40 female concussed high school soccer players, researchers at Vanderbilt University Medical Center and the Vanderbilt Sports Concussion Center were unable to replicate the findings of previous studies [4,5] of mixed groups of athletes from a variety of sports which had reported that girls did worse on neurocognitive testing of visual memory (both at baseline and post-concussion) and experienced more individual concussion symptoms.
"We were somewhat surprised and were not sure what to expect in such a tightly controlled population," said Scott Zuckerman, a neurosurgery resident who led the study.
Implications for treatment
The finding shed additional light on the role of gender in the treatment of sports-related concussion, which despite being an active area of research, is an issue that remains "somewhat murky," said Zuckerman.
The Consensus Statement on Concussion in Sport issued by the 3rd International Conference on Concussion in Sport  held in Zurich in November 2008 "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."
A 2012 study in the American Journal of Sports Medicine  nevertheless recommended that gender be considered by clinicians when interpreting the results of symptom reports, neurocognitive testing, and postural stability (i.e. balance) assessments (e.g. BESS) following concussion.
Zuckerman and his colleagues at Vanderbilt, however, cautioned against interpreting their results as indicating 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 supported the interim position taken by the Zurich consensus statement: that gender may be a risk factor for injury and/or influence injury severity.
"When we see any child after concussion, we don't want to make snap decisions based on gender. Gender may not be as big a modifying factor [in treatment] as previously thought," Zuckerman 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 [3,4,5], agreed that caution was warranted, as it is "still early to make any definitive claims on gender differences."
Whether experts convening in Zurich in November 2012 for the Fourth International Conference on Concussion in Sport will be able to reach a consensus on the relationship between gender and concussion remains to be seen. A consensus statement is expected by spring 2013.
[Update: The Consensus Statement on Concussion in Sport issued by the 4th International Conference on Concussion in Sport  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."
Takeaway for parents
Covassin says the biggest thing parents and athletes should take away from these studies is that "regardless of [whether] females take longer to recover than male athletes, they need to understand that females will incur concussions. I think there are parents out there who still believe only football and ice hockey athletes get concussions and their female volleyball or basketball daughter will not get a concussion."
Parents and coaches and primary physicians should all know the definitions of concussion, the signs of continued post-concussion syndrome, the guidelines for return to normal activity and the signs that should keep an athlete out of play for an entire season or longer," advises Dr. Jean Ogborn, a pediatric emergency medicine specialist at Johns Hopkins Children's Center, in an interview with ABC News.
"What is very important [to remember is] that concussions can occur in girls' sports with significant frequency, and that girls and their parents need to be aware that these injuries must be carefully managed to prevent permanent damage," Ogborn says.
1. 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).
2. McCrory P, Meeuwisse W, Johnston K, Dvorak J, Aubry M, Molloy M. et al. Consensus Statement on Concussion in Sport: the 3rd International Conference on Concussion in Sport held in Zurich, November 2008. Br J Sports Med 2009; 43(Suppl. 1):i76-i90.
3. 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;20(10); published on April 26, 2012 at doi:10.117703654651244454
4. Covassin T, Schatz P, Swanik C. Sex differences in neuropsychological function and post-concussion symptoms of concussed collegiate athletes. Neurosurgery 2007:61:345-351.
5. 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.
6. 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.
Addtional source: Vanderbilt University.
Posted October 16, 2012; updated April 10, 2014