University of Michigan researchers have reported that a simple test that measures reaction time can help detect and diagnose concussion in athletes.

In the study, athletes were tested once at the beginning of their sport season—they had to catch a weighted cylinder dropped by their coach. Their reaction time was measured. Then, if one of those athletes received a concussion during the season, there reaction time was measured again several days after the injury.

The researchers discovered that athletes with concussion had a 15% longer reaction time. This demonstrates that concussion carries effects that linger even after the initial headache and dizziness go away. And it dovetails with recent suggestions we reported that athletes with concussion should remain sidelined for  at least three months. Such a simple test…and yet, if it is adopted by high school and college coaches, it may help save the brains of our young athletes.