What is baseline testing for a concussion?

By: Mark Halstead, MD
Washington University Orthopedics

With so much attention these days to concussions in sports, I think it is helpful to explain what exactly baseline testing is all about as I find there is much confusion over what it actually does. The term baseline testing is also often not used correctly in the media so I hope to clarify some of that as well.

A baseline test can be one of several tests currently available to assess someone after they have had a concussion to either help determine if someone has had a concussion or to help determine if they have recovered from their injury to return to play. 

Several examples of sideline baseline tests include the SCAT3 (Sport Concussion Assessment Tool, 3rd edition), the King-Devick test, SAC (Standardized Assessment of Concussion), and BESS (Balance Error Scoring System) just to name a few of the more commonly utilized tests.

The SCAT3 actually incorporates the SAC and the BESS into its testing protocol. The goal is to test someone with one or more of these tests preseason and then to test them after a suspected concussion has occurred. If someone performs worse after a suspected concussion than they did on their baseline test, that increases the likelihood significantly that the person being tested did sustain a concussion.

Example of SCAT3 test which is freely downloadable to any individual free of charge

There are versions of the SCAT3 for athletes over the age of 12 and also a Child SCAT3 for those from 5-12 years of age. Unfortunately at this time, the Child SCAT3 has not had many of the components included validated for use in this age group and assumptions were made by the group who created these modified tests that these would be able to be applied to this age group. Research still needs the be conducted on the reliability of assessing for concussion with the use of these tests in athletes under the age of 12. For the SCAT3 that is used over the age of 12, the majority of the test components have been extensively researched although no published standard exists for determining, with absolute certainty, as to how poor one needs to perform to truly be diagnosed with a concussion.

The King-Devick test is another test that may be used to assess for a concussion on the sidelines. It is a test that requires the athlete to read through three cards with numbers printed on them in a left to right fashion. The test is timed and is recommended to be conducted as a pre-season assessment and then potentially be used when assessing for a concussion. Originally developed as a screening test for reading difficulties in children, it was first shown to have some application for screening for concussions in boxers and MMA fighters in a study published in 2011 in the journal Neurology by Galetta, et al. Since then several other studies have been published evaluating its use. To date, limited studies have been published in the use of this test in athletes middle school age and below and for those that have been published, in this blog authors' opinion, have had some questionable methods and conclusions made regarding the use of this test. While this test may have some utility in the evaluation of concussions in athletes, more research needs to be conducted to ensure other factors do not effect performance on the test. This test is not available for free and the company does charge for the materials, whether they be in hand test booklets or handheld tablet version of the test.

Example of the King-Devick Test

Finally, the tests that probably are recognized most commonly by the public as a baseline test are the computerized neuropsychological tests such as ImPACT, Concussion Vital Signs, ANAM (primarily a military assessment), to name a few. These tests are conducted as a preseason assessment for an athlete and take about 20-25 minutes to complete. If an athlete sustains a concussion, these are tests that are primarily designed more to determine the recovery after an injury rather than being a tool to diagnose a concussion. Different providers, schools and clinics may have different protocols for the use of these tests following an injury. Dr. Halstead will use them once an athlete is very minimally symptomatic or symptom free to see if the athlete, on a post injury test, has returned to their baseline performance. Dr. Halstead does not typically use these types of tests in athletes who have not had a previous baseline assessment. 

Example of one test in the ImPACT test battery

Unfortunately, some consider these computerized tests as the 'gold standard' for concussion assessment. These tests are just one tool in the management of a concussion and concussions can be managed without their use. These tests also have an annual cost to the schools or organizations who are administering the tests. Test results are ideally interpreted by a physician or neuropsychologist who are trained in the interpretation of these results. They should not be interpreted by the coach or parent and these are not considered a 'red light/green light' type of test as far as returning an athlete to play following a concussion. 

Currently, the majority of these computerized tests are valid for use in athletes as young as 12. They must be repeated annually until the 10th grade due to increasing scores as a child gets older. Performance on these tests has been found to be affected by ADHD (Attention Deficit Disorder), depression, prior night's sleep, prior computer use, administration at home as opposed to controlled testing environment and race. You cannot "fail" a baseline test, but very poor test performance may be considered an invalid test and an athlete may be asked to repeat their baseline assessment. The test afterwards is not called a 'baseline' but actually a post injury test, which is often described incorrectly in the media. Again, an athlete cannot 'fail' a post-injury test but if they do not perform as well as they did on their baseline, and athlete is described as having 'not returned to their baseline.'

Dr. Halstead is the director of the Washington University Sports Concussion Clinic. He currently oversees the concussion programs for 8 local high schools, Washington University and the St Louis Rams. He also acts as the primary concussion consultant for the St Louis Blues. He is the lead author on two American Academy of Pediatrics statements about concussions entitled "Sport-Related Concussions in Children and Adolescents" and "Returning to Learning following Concussion."

If you would like your child evaluated following their sport-related concussion by the Washington University Concussion Clinic, please call 314-514-3500. Dr. Halstead also performs in office baseline assessments on individual athletes over the age of 12 who may be involved with teams that do not have a concussion program already in place.