energy). A woman’s menstrual cycle may
also directly impact recovery—one 2014
study of 144 women reported brain injuries
during certain phases of the cycle might
take longer to heal, which researchers think
might be due to a sudden drop in levels of
progesterone, a female sex hormone. And
other research suggests menstrual pat-
terns, which are often associated with
headaches and other symptoms of discom-
fort, might also affect self-reports both be-
fore and after concussions.
Across the sexes, concussion is common
in contact sports such as soccer and hockey,
where heads bang and helmets clash. And,
over the years, the public has become more
aware of the serious health effects associat-
ed with repeated blows to the head. The Na-
tional Football League has publicly acknowl-
edged the link between its sport and degen-
erative brain disorders such as chronic
traumatic encephalopathy. Such head inju-
ries are also prevalent in amateur and recre-
ational athletics. In a study recently pub-
lished in the Journal of the American Medical
Association, for example, researchers found
that in a sample of 13,088 U.S. teens, around
20 percent reported at least one diagnosed
concussion in 2016. Among those who had
participated in a contact sport recreational-
ly, such as football or wrestling, the preva-
lence was 31.5 percent.
Overall, this latest study adds to a grow-
ing body of literature that shows girls have
a higher incidence of concussions than
boys and might also experience more per-
sistent symptoms, says Robert Cantu, a
neurosurgeon and professor at Boston Uni-
versity who did not take part in the new re-
search. “This is one of the most robust stud-
ies in terms of the numbers of people in-
volved,” he says, confirming “girls take
longer to recover.”
Yet some concussion experts caution
this latest work has some limitations. Ma-
yumi Prins, who studies traumatic brain in-
jury in children at the University of Cali-
fornia, Los Angeles, points out that where-as Neidecker’s findings are consistent with
what others have reported, a key consider-
ation is that the authors relied on the ath-
letes’ self-reports to determine their con-
ditions at baseline (before the injury hap-
pened)—measures physicians typically use
to determine whether a concussion has re-
solved. “Self-reporting or parental report-
ing is often fraught with errors,” Prins says.
More generally, there is also evidence of
gender differences in symptom reporting
across concussion studies. For example, a
study published earlier this year in the Jour-
nal of Athletic Training found that although
high schoolers of both sexes were equally
knowledgeable about concussion symp-
toms, girls were more likely to disclose
sports-related injuries to authority figures
such as a medical professional or coach.“This is one of the most robust studies in
terms of the numbers of people involved,” he
says, confirming “girls take longer to recover.”