TORONTO - An online test that measures brain function -- including memory, spatial recognition and thinking speed -- is giving doctors a comparison point to decide if and when a young athlete can safely return to play after a concussion.

The ImPACT test is already being used to get a baseline neurocognitive score for professional hockey, football, baseball and soccer players, but it's increasingly being tapped by amateur leagues with players in their teens or younger.

Licensed to sports teams and leagues in Canada by Critical Medicine Research Group, the test can be taken by a young athlete under adult supervision anywhere there is Internet access, said John Chehade, the company's director of sales and marketing.

"The athlete can go home with a parent and sit down at the computer after school," Chehade said Tuesday from London, Ont. "The parent can watch the athlete take the test, make sure there's no siblings in the background distracting them, the TV's not on (and) there's no loud music."

The online test, which takes about 25 minutes to complete, begins with a medical history, including whether the subject has experienced such neurological symptoms as dizziness, drowsiness, irritability, sadness or difficulties with concentration.

Moving from one cognitive challenge to the next, the test requires full concentration as the subject's memory and mental agility are put through their paces.

One section, called the Smart Test, provides a lengthy list of simple words, which the test subject is then asked to recall.

Another section shows 12 drawings -- arrow-tipped lines formed into various shapes and configured right or left, up or down -- which the test subject must then correctly identify. Another test using a complex grid of Xs and Os, some highlighted within the pattern, also assesses recall ability.

Finally, the subject must click on a series of coloured shapes that appear on the screen as another way to test thinking, reaction speed and recognition skills.

Once completed, the results are stored in a secure central computer that can only be accessed by physicians trained in evaluating the test scores, should the athlete require followup testing after a head trauma, said Chehade.

"So now that we've established a baseline test of how that (individual's) brain processes information, that athlete goes out into their sport of play," he said. "If they suffer a concussion or there's a suspected head injury, we're going to send them to one of the sports medicine physicians trained in interpreting the data.

"And only when the athlete comes into the clinic can they access the data."

Chehade said the company doesn't sell only the test, which costs $25 per person, but also provides free training in its interpretation to sports medicine doctors, team trainers and other health professionals involved with a particular team or league.

Dr. Richard Goudie, a sports medicine specialist in Barrie, Ont., who includes ImPACT when assessing an athlete's recovery after a concussion, said the test allows him to compare the patient's current neurocognitive status with earlier baseline results.

"The trick has always been asking them how do they feel and looking at a post-concussion symptom scale," Goudie said.

"Gradually, when they feel completely normal, some concussed individuals still have a delay before neurocognitive function returns to normal," he said. "And that's where the major impact of the ImPACT test comes in, because we can then tell somebody you feel great but you're not ready yet because we know that brain function hasn't returned to what it was before the injury."

Goudie said while doctors consider the test an important tool, it is only one of many they use in judging a patient's progress.

"Now some players, unfortunately, and a lot of people look at this as a green light-red light. It is not. It is still a part of a package of physical examination, history-taking, assessing the risk of the injury to return (to play), and also being very conservative about returning them slowly and safely.

"So having a normal neurocognitive test doesn't mean you're good to go, as we have to look at the individual as a whole and look at everything that can be considered a concussive symptom. And sometimes it can be very subtle."