Study Links Menstrual Cycle, Concussion Outcomes in Women

Nov. 13, 2013

What part of your head was hit and how hard? Did you pass out? When was your last period?

Monthly menstrual cycleAsking about menstruation may be surprising, but new research shows that a woman’s monthly cycle plays an important role in how well she bounces back after a concussion.

For years, coaches and doctors have noticed gender differences in recovery; women have more symptoms and take longer to recuperate than men.  A study by concussion expert Jeffrey Bazarian, M.D., M.P.H. suggests that a sudden drop in the hormone progesterone, which is known to have a calming effect on the brain and on mood, is a big reason for the discrepancy.

Researchers believe that women hit in the head during the two weeks leading up to their period, when progesterone is highest, experience a steep decline. This drop, or withdrawal, causes women to feel worse and experience lingering symptoms such as headaches and nausea.  In contrast, women injured during the two weeks directly after their period, when progesterone is already low, don’t experience a dramatic drop and have a better recovery. Similarly, men, who have low pre-injury levels of progesterone, would not be affected by a change in the hormone.     

Bazarian’s study of 144 women ages 18 to 60 who experienced a head hit showed that this hypothesis is right on target. If confirmed, the findings could help doctors identify patients who might need more aggressive monitoring or treatment. It would also allow doctors to counsel women that they’re more – or less – likely to feel poorly because of their menstrual phase.

Read more about the study and watch a video here