Demystifying Sport Concussion Baseline Testing
Five common myths; what you need to know about these tests gaining notoriety..
Posted December 8, 2015
Finally concussions, and Dr. Bennet Omalu’s battle to uncover the risks of repetitive head trauma, are getting the attention they deserve. The movie Concussion starring Will Smith will undoubtably generate more questions than answers about what we, as a society, should know and do about sport-related concussion.
One important tool becoming more prominent, yet also highly misunderstood, is the use of “baseline” testing. Here is a brief explanation of the tool, along with five common myths and misconceptions about baseline testing.
Baseline testing is a measurement of the performance of an athlete’s nervous system function taken before the season starts for the purpose of concussion management. The baseline scores provide a reference for comparison for athletes should a concussion injury be suspected. The results of this testing are often used by a healthcare provider as an objective assessment of the extent of such an injury, and whether the effects of the injury persist during recovery. This is relevant to the readiness of the athlete to return to normal activity and gameplay. Using baseline testing in a potentially-concussed athlete is much like using a thermometer to determine if there is a fever in a patient who is ill. The healthcare practitioner uses the information to help determine if an infection is present, and to track recovery. Knowing what the patient's usual temperature when he is healthy makes the measure much more useful.
The baseline test measures several nervous system functions including balance, oculomotor-motor function, and cognitive performance. Typically, baseline tests are administered via a computerized program with a tutorial like this. Computerized assessments have several benefits including standardization, ease of administration, objective measurement of accuracy and reaction time with millisecond precision, and the ability to provide rapid statistical analysis and comparisons to baseline performance.
Myth #1: The baseline test diagnoses concussion.
False. There is no substitute for the expert opinion of a healthcare provider who has been trained to evaluate concussion injury in making a diagnosis. Medical science has brought to bear the full force of technology to assess the effects of trauma to the brain, including quantitative EEG, fMRI, PET scans, SPECT scans and biomarkers, yet we still do not have a definitive test for concussion injury. Ultimately, the diagnosis rests on the healthcare provider's shoulders.
Myth #2: Baseline testing is just another form of neuropsychological testing.
False. Neuropsychological tests are typically used to determine the psychological or cognitive status of an individual in comparison to a normative database. Clinically, they are usually administered for the first time after illness or injury. A distinct difference with baseline testing is that the test is administered before injury so that the injured athlete's cognitive performance is compared to his own pre-injury performance rather than a normative population.
Myth #3: Baseline tests are sensitive and specific to concussion injury.
False. Like any tool, the use and interpretation of these tests must be taken in context. Sensitivity refers to how often a test will pick up a condition when the condition is truly present. Statisticians refer to the "false negative" rate or "Type 2 error" of the test. The fact is that there are many situations in which a cognitive performance test will not be sensitive to concussion injury even though one is present. Every concussion is different. One person may have headache, another dizziness, another mood and sleep problems, and yet another nausea and light sensitivity, and all of these people may perform normally on their cognitive performance test and it has nothing to do with the test itself.
Specificity refers to how often a test may say there is a concussion, when one is not present. This is the "false positive" or "Type 1" error. Similarly, many factors may adversely influence performance on cognitive performance tests that are not related to concussion injury. Drug and alcohol use, effort, sleep deprivation (unrelated to concussion), even having a full bladder can negatively affect performance on these tests resulting in a false positive result that have nothing to do with the test. These are the reasons that baseline tests are not diagnostic of concussion and cannot replace the assessment of a qualified healthcare professional.
Myth #4: "All my athletes have completed their baseline tests, my concussion management program is complete.”
False. A troubling, and common misconception is that baseline testing constitutes a complete concussion management program. Baseline testing is but one small part of a comprehensive and complete program. A complete program must have an effective concussion awareness educational component, a sideline detection and reporting tool, and guided recovery protocols. These recovery protocols should include not only to return-to-play guidance but also return-to-normal academic activity for student athletes. This program may also integrate balance and oculomotor testing. Such a program should be fully integrated and leverage information technology to facilitate communication amongst the complex community that surrounds the athlete. This includes notification alerts to parents, athletic trainers, and other healthcare providers caring for the athlete and centralized data management which integrates the most important people involved in the athlete's care.
Myth #5: Baseline, and post-injury, testing must be used in every case of sport-related concussion.
False. Guidelines provided by many respected organizations, including the 4th International Conference on Concussion in Sport, state that post-injury cognitive testing is not needed to manage most cases of sport concussion. It can be extremely useful in many cases, and there is no way to predict which cases are the ones where it will be needed. Future research may help us identify those cases, such as athletes with a history of past concussions, or a history of cognitive impairments such as attention deficit disorder or learning disabilities. Then algorithms may be developed to streamline the pre-season assessment process. Until then, best practice is to get a baseline assessment on all athletes.
Recent searches for the "Holy Grail" of baseline testing have focused on finding the ideal balance between a quick and easily administered test and one that adequately describes the condition of the potentially injured athlete. Tests of oculomotor function are available that can be administered very quickly, but the trade off is that all they provide is simply an index of oculomotor performance. The test result tells nothing about the clinical presentation of the athlete. Is there headache? Vertigo? Cognitive impairment? Impaired balance?
Ultimately, the best practice for baseline testing includes a more comprehensive approach that is also compliant with state, medical requirements.
Neurologist Harry Kerasidis, M.D. specializes in sports concussions. He co-founded XLNTbrain LLC after 25 years studying the the brain and treating thousands of concussion injuries. Today, numerous sports leagues, state high school athletic associations and various urgent care clinics are using his protocols. Dr. Kerasidis authored, “Concussionology: Redefining Sports Concussion Management For All Levels” September 2015, Author House.
Have a question for Dr. Kerasidis? Please add a Comment, and Like "XLNTbrain Sport" on Facebook, Follow @XLNTbraindoctor on Twitter.