BOSTON (CBS) - A new study finds that examining a patient's saliva may reveal whether they have had a concussion.

When someone hits their head, you often have to rely on self-reported symptoms or cognitive tests to determine if they suffered a concussion. But researchers at Penn State College of Medicine say they may have a non-invasive, unbiased solution.

Using data on 500 participants, they found they could identify those with a concussion with some accuracy by looking at the characteristics of tiny strands of genetic material in their saliva.

They hope a so-called "spit test" could one day be used as a quick and reliable screening tool for concussions.