Women athletes are twice as likely to get concussed than men and the symptoms are more severe, but with studies focused mainly on men, is concussion being underestimated in women?

Few events, like roller derby, are as fast and furious. The hour-long game unfolds in two-minute frenetic intervals as two teams sprint in an anti-clockwise direction around an oval track.

– team has a “jammer” to pass four “blockers” opponents and score points for each enemy they chase.

Blockers can block the path with their chest, or with a swift nudge of their upper legs or upper arms moves opponents off course. Jammers “juke” – a lateral dummy motion – and “whip” – where a member of the team catches his hand and moves it forward in front of the pack.

Supporters are drawn to the competition’s violent drama but accidents are frequent as you would expect any contact sport.

Jessica had just moved from France to the USA when she took part in her first roller derby event. “I just fell in love with it from that very first session,” she says. She started competing, eventually leading Team France in World Cup 2011, and even met through the game with her father.

Jessica had been playing blocker for a club in the Bay Area, California in the summer of 2016. She was standing in front of the jammer of the opposition and just as she turned to test her spot, an opposing blocker collided with her at high speed.

As the forearm of the blocker struck her chin’s right side, Jessica felt an intense pain on her skull’s opposite side, then fell to the floor. She also understands that the unexpected jerking motion of her head caused her brain to ricochet inside the skull –leading to sharp pain and a severe concussion.

She was not receiving immediate medical attention. Having previously suffered a concussion, her doctor’s advice was to take it easy for a couple of weeks before returning to play. And it had appeared to work well.

Nevertheless, this time she had started with insomnia and a sensation of mind constriction – a feeling of distress, she notes, like a “hole” on the brain – no matter how much she slept. Concentration was often extremely difficult for any length of time, and she was prone to the bright light on monitor and television windows, so she would have to wear sunglasses at work.

She also encountered mysterious changes in her mood; she would sometimes have to go to work and cry in her vehicle. “Nothing would have prompted this,” she says. “And I wasn’t someone who wept very much, so it was extremely alarming for me to have such bursts of tears suddenly come from nowhere.”

It has now been three years since her accident, but Jessica has not yet fully recovered from those symptoms. “I haven’t given up hope, but it’s not like there’s a clear path to being better at this point or a clear timeline of when that would be.”

Will Jessica be at a greater risk of coughing simply because of her sex? Compelling recent evidence indicates this is a possible possibility, with a growing understanding that male and female brains can react very differently to injuries.

It follows a growing concern for concussion, which is partially caused by high-profile incidents in sports such as soccer, American football, rugby, and boxing.

The neurological feature of concussion is changed as a result of a hit, impact, or jolt to the brain. The vigorous head movement causes a momentary release of multiple neurotransmitters that throw out of balance the functioning of the brain. It can also cause the neuronal tissue to expand and reduce blood flow to the brain – and glucose and oxygen along with it – killing our gasoline nerve cells.

Immediate symptoms include looking at stars, feeling dizzy and confused or completely losing consciousness. Some patients still recover from post-concussion syndrome with a range of residual effects including fatigue, vomiting, dizziness and mental confusion long after the event. This might last weeks, months, or even years. Several studies suggest that a concussion may also be caused by an increased risk of suicidal thinking and there are fears that repetitive accidents can result in long-term damage and degeneration of the brain.

The potential long-term effect of concussion is now well established and has prompted many sports organizations to change their rules and practices to reduce the risk of injury. Yet there is a poor understanding of the potentially higher risks of female participants and the possible need for differential diagnosis and treatment, particularly among health care workers. “At no time when I was talking to doctors they ever discussed any potential difference [ emerging ] from being a woman,” Jessica says.

Nevertheless, recent research suggests that female athletes in any given sport are not only more likely to sustain a concussion; they do appear to have more severe symptoms and take longer to recover.

Katherine Snedaker, director of the Pink Concussions, a non-profit campaign group, claims that many such as Jessica are “invisible people” with an “invisible injury” – and that means they may fail to get the care they need.

Researchers and activists like Snedaker, by shedding light on these inequalities and acknowledging their roots, hope to improve the condition of all women dealing with the lasting and sometimes crippling effects that may result from a single blow to the head.