Impaired Judgment: Gender and Traumatic Brain Injury
Stories of former football players grappling with memory loss and depression, developing degenerative brain disease, or even taking their own lives have become increasingly commonplace over the last decade. While these stories occasionally gained traction beyond the sports pages, Will Smith's 2015 movie Concussion galvanized the public awareness of traumatic brain injury and athletes. The movie chronicles a researcher's discovery of chronic traumatic encephalopathy (CTE) in football players, thereby cementing the association between football and traumatic brain injuries in public discourse. Mainstream media coverage has taken its cue accordingly, highlighting studies of CTE in the autopsied brains of deceased football players. These tragedies have brought concussions and CTE to the forefront of public awareness. Sadly, we now realize that this devastation isn’t limited to players at the professional level. Traumatic brain injuries have been linked to the suicides of college football players and even athletes at the high school level.
Football players at all ages are taking steps to minimize the potential for brain trauma. However, these more visible stories of football players suffering from TBI shape the public health approach to the diagnosis, treatment, and prevention of TBI. Because football players have become the face of TBI and CTE, discussions and studies of brain injury are focused on identifying TBI and CTE in football playing populations, which means women are in the minority.
Fortunately, athletes in other sports are speaking up, just as studies are acknowledging discrepancies between genders in presentation and treatment of traumatic brain injury. Indeed, it has been demonstrated that women experience more symptoms of brain injury, including nausea, sensitivity to light, fatigue, and poor sleep, and with greater severity and duration. There is increasing evidence there are different injury patterns — both in terms of symptoms and structural changes to the brain — between men and women players in volleyball, soccer, and ice hockey.
Studies show that women may be biologically more vulnerable to TBI. Generally speaking, women have weaker neck muscles, which could lead to more dramatic movement after an impact to a head. However, while we’ve moved past the days of having our medical issues dismissed as hysteria, it remains that women's medical concerns are not taken seriously. When women do report concussion symptoms or abnormalities, their concerns are disregarded and minimized. The inherent biases in a field dominated by men and the gender imbalance in the medical practice adds has created a fundamental lack of understanding of how to diagnose and treat concussions in women. In the case of traumatic brain injury and concussion, the focus has has been on men. Even prophylactic methods may not be providing adequate protection in a manner beneficial to women — protective equipment is designed for men, not women.
The problem goes far beyond preventing, diagnosing, and treating TBI. The lack of understanding of how trauma uniquely affects women’s brains begins not on the playing field and the doctor’s office but long before in the laboratory.
The search is on for methods of prevention and mitigation of TBI as well as methods of diagnosing brain injury before symptoms manifest. The goal is to develop a single diagnostic tool that can be used on the playing field, but this may not be adequate. Without knowing whether or not men and women exhibit the same changes in the same biomarkers to the same degree, how can we use the same test on men and women?
Measuring and detecting any changes in biomarkers in an injured subject is an attractive diagnostic modality, with the potential for rapid, minimally invasive testing. Two potential biomarkers for mild TBI have been identified: GFAP, found in the astroglial skeleton in both white and gray brain matter, and UCH-L1, a neuronal brain injury biomarker found in neurons. Both GFAP and UCH-L1 are detectable less than an hour after a mild TBI event. But in this particular study, the data set is normalized so as to not take gender into account. While that may be helpful in achieving a one-size-fits-all diagnostic test, it fails to acknowledge that men and women may express these biomarkers in different levels or at different times post injury; or, they may express different biomarkers altogether. This gender gap has perpetuated throughout laboratory research over the years.
Historically, male mice have been favored for use in laboratory research, but with the NIH’s initiative to address sexual dimorphism in animal studies beginning in 2014, there has been increasing research looking at both male and female mice. In a study of the inflammatory response in both male and female mice after TBI, researchers found that the immune response in male mice occurred as quickly as one day, but the response in female mice took up to seven days. Measuring these inflammatory biomarkers a day or two after an injury could have markedly different results for men and women, as women may not have quantifiable levels for several days. Fortunately, more general studies of TBI are expanding awareness of brain trauma beyond the football player population and are enrolling more women. Just as men playing football shape the interest and public awareness of brain injuries, men overseeing laboratory funding and research shape the research around brain injuries.
Football has brought attention to the devastation caused by traumatic brain injuries, but the men playing football are not the only athletes at risk. Men have exerted an undue influence over the world of sports, and they have steered scientific research based on their own biases. Athletes have a long history of breaking barriers and bringing social issues to light, particularly when it comes to gender diversity. Perhaps athletes can bring attention not only to the high level of competitive play in women’s sports, but to the need for studying brain injuries in women.
Ultimately, the study of traumatic brain injury in women is a concern beyond sports. This isn’t just a question of keeping athletes safe, but of women’s health and how we approach the research behind women’s health issues.
References and Resources
Peter Keating, “Why does it seem like nobody cares about female concussions?”, ESPN The Magazine, July 15, 2017
Carrie Arnold, “Concussions in women”, The Lancet Neurology,13, no. 2 (2014): 136-137
Cecilia Davis-Hayes, et al. “Sex-specific Outcomes and Predictors of Concussion Recovery”, Journal of the American Academy of Orthopaedic Surgeons, 25, no. 12 (2017): 818–828
Diane Hoffman and Anita J. Tarzian, “The Girl Who Cried Pain: A Bias Against Women in the Treatment of Pain” Journal of Law, Medicine & Ethics, 29 (2001): 13-27
Sonia Villapol, et al. “Sexual dimorphism in the inflammatory response to traumatic brain injury”, Glia, 65, no. 9 (2017): 1423-1438