This article is courtesy of my colleague Lara Janitens PT at Honsberger Physiotherapy.
Although on average, research shows that males participate more often in sports than females, the number of female participants has been increasing quickly over the past decade. Recent data has started to show that females have a higher incidence rate of sport-related concussions than their male counterparts. This has opened up the door to research and questions including, ‘are females more prone to concussions’ and, ‘do females respond differently to a concussion than males’. Research into the consequences of concussions has skyrocketed in the past decade, but the potential for gender differences is a more recent trend that it is being investigated. Part of the difficulty with investigating concussions, is that it is necessary for their occurrence to be accurately reported. One theory of why female concussion rates are higher is that females typically are better at reporting their symptoms than males, and are less likely to deny presence of symptoms than males.
Recent research is beginning to investigate the potential link between hormone levels and their effects on concussions. Levels of estrogen and progesterone have been linked with inflammatory reactions in the body, and have the potential to cause and/or prevent damage in the brain after traumatic brain injury (TBI). After a concussion, past research has shown that sudden drops in the sex hormones, estrogen & progesterone, may occur. This has effect has been linked with poorer outcomes in patients. Some data supports the neuroprotective effects of the progesterone on its own, and it is the sudden drop that can occur after a concussion that can put females specifically at higher risk for complications post injury. A 2013 study followed woman from the time of their concussion up until one month after. The study concluded that women who sustained concussions during the two weeks leading up to their menses, were more likely to report headache and dizziness along with a general poorer perception of their overall health status. Those who sustained the concussion in the two weeks following their period, and those on birth-control pills seemed to fare better post concussion. The theory is that women post period have lower levels of progesterone in their bodies already, thus post concussion, less of a drop in these hormones occurs, and is more tolerable to the body. In addition, those on birth control pills have a constant supply of synthetic progesterone, thus even with a concussion, they will not experience a drop in their levels. Those however who sustain a concussion leading up their period have a much higher level of progesterone in their bodies, thus a sudden unexpected drop causes more substantial negative effects.
Another group of studies has begun to look at neck muscle strength as a risk factor in concussions. Preliminary research has suggested that weaker neck muscles might in fact make an individual more likely to sustain a concussion. Typically, it is believe that females have weaker neck muscles, thus further making them more susceptible to sustaining a concussion. This creates the necessity for further research to look at the protective effects of neck strengthening exercises, particularly in the female population, to determine if this could lower the incidence of concussions.
Studies have also started to compare symptom severity and types of symptoms, and how they differ across sexes. Currently, the evidence is conflicting amongst studies. A 2011 study, which looked at data across 100 high schools in the United States, suggested that although symptom resolution time and return-to-play timelines were similar, the types of symptoms reported between sexes after a concussion were different. The study concluded that males were more likely to report cognitive symptoms (amnesia, confusion, disorientation etc), yet neuro-behavioural and somatic symptoms (drowsiness, sensitivity to noise etc) were more common amongst females. A 2013 study investigated specifically differences in neuro-cognitive performance between male and female soccer players post concussion. This study was able to conclude that females in fact performed worse 8 days post concussion on the neuro-cognitive tests they conducted and reported more symptoms at this same marker than male counterparts. They also found that memory, migraines and reports of affected sleep were more prominent in females. The difference between this and previous studies, is that body mass index was adjusted for when the data was interpreted.
The above information has highlighted a few interesting points that might be worthwhile when dealing with female athletes and concussions. Firstly, are females in fact at higher risk for concussions due to such factors as neck muscle strength, as well as the hormonal fluctuations they experience compared to male athletes. This might raise the question whether questions about menstrual cycle might be a valuable screening tool when concussions are sustained, or whether it is necessary to start strengthening neck musculature until research disproves the necessity for it. In addition, the above addresses the need to screen carefully for concussion symptoms, as some of the symptoms research shows to be more prevalent in females, could often be overlooked due to the fact that such characteristics might be more common in non-concussed females as a whole. Regardless, it is clear that the window for further research is wide open, as there are a lot of gaps present in our knowledge at this time.
Efan Gonsalves PT 