A simple blood test may soon be used to determine if footballers can return to the field after suffering a concussion.

The test could also help other athletes, car-crash victims and soldiers know when it is safe to return to work or play.

Underlying brain damage can often last for at least a month after trauma to the head, and currently there is no sophisticated way to measure when a concussed player should take up their sport again.

But researchers are trying to take the guess work out of the situation, conducting a study involving the Melbourne University Blacks Football Club.

Footballer Scott Myers lay unconscious for about four minutes when he was knocked out by sling tackle. He has no memory of the event.

“To not remember the incident and then be able to go back and watch it on TV is a bit scary,” he said.

“The next thing I remember is being in the change rooms after the game and couldn’t remember anything, couldn’t remember how I got to the ground.”

The risk of concussion is ever-present at Mr Myers’s club.

“We’ve got four teams at Uni Blacks and I’d say we’d have around nine or 10 concussions a year — generally in the senior team, the two senior teams, where it’s probably a bit more physical and faster,” he said.

Repeated concussions linked to Alzheimer’s

This trial involving the footballers will take a year and is running parallel to similar research on rodents that has been presented at the Australasian Neuroscience Society’s annual scientific meeting.

Mice that received multiple head injuries in a short time span recorded longer deficits over a month in cognition.

Matt Ballin of the Wests Tigers – benched after leaving the field for a concussion test in round 11 of the NRL. Photo: AAP/Dan Himbrechts

Professor Terry O’Brien from Melbourne University’s Department of Medicine said the study’s findings showing when the brain is no longer vulnerable will aid the creation of a blood test.

“We’ve done MRI and blood tests and psychological tests at the beginning of the season on all the senior players,” he said.

“In a blood test you can look at markers of brain injury and inflammation in particular — they go up after a concussion.”

At the same time, researchers are looking to see if the drug sodium selenate — currently being tested in Alzheimer’s patients — could one day be used to reduce brain damage.

Professor O’Brien said there are many risks for athletes returning to play before they are ready.

“We know that patients who’ve had repeated concussions have an increased risk of developing Alzheimer’s disease as well as other serious neurodegenerative diseases.

“A major component of what we think causes that is a protein called tau, which in its abnormal state gets deposited into the brain and is toxic to the brain.”

NFL defensive player of the year Luke Kuechly being taken off the field after a head knock – he was one of five Carolina Panthers players under the NFL concussion protocol this season. Photo: AP/Bob Leverone

Mr Myers said he was excited about the prospect of a blood test that could deliver certainty about a player’s health.

“Sports in Australia are heading in the right direction, and for some people that’s probably going to mean missing more weeks of work or football, or whatever else it is.

“For others, it might mean they get back quicker than what they’d expected.

“But I think if [the researchers] can prove that is when you should be going back, then I think that’s a great thing.”

This clinical trial could take two or three years to complete.

– ABC