ImPACT Test: How It's Used To Determine Concussion Recovery
Editor’s Note: Yesterday, Eagles quarterback Michael Vick failed his second concussion test of the week, meaning he has not been cleared to return to football activities. Robert Franks, D.O., takes a closer look at the testing used to make such determinations.
As concussion remains at the forefront of sports health with two prominent Eagles players continuing to be treated for symptoms, it has not been uncommon to hear about reports of them being tested. Often I am asked, what is this test and how does it work? More importantly, how does it help a physician to make the decision to return an athlete to play?
The testing of which we are speaking is used to gauge the cognitive part of the concussion, or the part that deals with how the brain is functioning. There are two ways to do this. One is formal neuropsychological testing. This is still considered the ‘gold standard’ when testing a patient’s cognition and is done by administering several cognitive tests over several hours by a trained neuropsychologist.
Obviously, this is time consuming and not every concussed athlete reaches the severity of concussion where it is necessary to perform these tests with every incident. However, those athletes with a more severe concussion or those who are recovering slower than anticipated or are showing signs of worsening are often tested in this manner.
Most athletes, however, are tested a second way—a computerized neurocognitive test. There are several computer testing batteries used in practice today. The most common is ImPACT, or Immediate Post-Concussion Assessment and Cognitive Testing. Several others do exist such as CogSport, HeadMinder, and CNS Vital Signs. The best ways to administer these examinations are to perform the baseline test before an athlete is concussed, and then administer a post-injury test once the athlete has been injured. The two are then compared to see deficiencies between pre- and post-concussive cognitive function. Using ImPACT as an example, if a baseline is not available, the athlete is compared to their sex and age matched peers to determine in what percentile their score falls.
Again, using ImPACT as an example, the test asks for demographics on the patient and a history of both present and past concussions. It also asks for a symptom score reported by the athlete across 22 different concussive symptoms. The bulk of the test then tests the athlete’s verbal memory, visual memory, visual motor speed, and reaction time through 6 different modules. These numbers are then reviewed by the physician and can be used to track recovery or lack thereof.
An impulse control score under a certain number is used to validate the test. These numbers are given to the physician both numerically and graphically. Athletes do not have to get the exact baseline numbers they scored before a concussion, but must score within a certain range.
Physicians use these numbers to assist in return to play decisions. An athlete is considered recovered cognitively once their scores return to baseline. Neurocognitive testing is one part of the total return to play decision. The athlete must also be symptom free, on no medications, and go through normal daily activities for 24-48 hours without symptoms before they can begin a return to play protocol and ultimately return to their sport.