The most recent concussion consensus statements ^[1,7,15] recommend neuropsychological (NP) testing in making return to play decisions after concussion, and formal baseline NP screening of athletes in all organized sports in which there is a high risk of concussion (e.g. football, hockey, lacrosse, soccer, basketball), regardless of the age or level of performance. ^[1,7]

Baseline pre-injury and post-injury neuropsychological or neurocognitive testing is now commonplace at the professional and collegiate level, and has become more and more common at the high school level as well, with a recent study showing computerized neuropsychological testing being used to assess fully 41.2% of concussions at schools with at least one athletic trainer on staff in the 2009-2010 year, ^[2] an increase of 15.5% from the 25.7% of concussions in which such testing was used in assessing concussions during the 2008-2009 school year. ^[3]  

In the absence of NP and other (e.g. balance assessment [1]) testing, the Zurich consensus statement ^[1] recommends a more conservative approach to return to play approach, especially for children and adolescents.

Assessment of cognitive function 

A baseline neurocognitive exam measures an athlete's cognitive function (e.g. his ability to think) before the season, generating a score to serve as a reference point (a "baseline" [2] in the vernacular of concussion management) against which to compare scores on tests performed after a young athlete sustains a head injury in practice or game play.

The results of the baseline are also helpful in identifying pre-existing conditions that may affect post-concussion test scores and that have little or nothing to do with head trauma, such as migraine headaches, attention deficit disorder (ADD), attention deficit hyperactivity disorder (ADHD), depression, anxiety disorders, and panic attacks, all of which can significantly skew test results, and have recently prompted calls for the development of separate normative data for athletes with learning disabilities (LD), ADHD, and LD/ADHD diagnosis on computerized neurocognitive test batteries. ^{[15, 17]}

A neurocognitive test, as the name suggests, is just that: a test of cognitive function.  It does not measure other critical brain functions that can be adversely affected by head trauma, such as balance and vision [3], which is why expert groups ^[1] recommend a "multifaceted approach to concussion management that emphasizes the use of objective assessment tools aimed at capturing the spectrum of clinical signs and symptoms, cognitive dysfunction, and physical deficits ... that are more sensitive to the injury than using any one component alone." ^[18,19] 

As Dr. Robert Cantu explains in his 2012 book, Concussions and Our Kids, ^[15] it "takes more than one type of test to compile a comprehensive baseline," because neurocognitive tests measure the thinking and reasoning parts of the brain (medial temporal lobe and front lobe), but concussions "also may cause trauma to the calcarine cortex, which is in the back of the brain and controls vision, and the cerebellum, at the top of the neck, where balance and coordination are measured. ImPACT [Immediate Post-Concussion Assessment and Cognitive Testing] and other cognitive testing wouldn't establish a baseline or reveal deficits in these areas of the brain [so] more and different evaluations are needed."

Neither diagnostic or for sideline use

"What's [also] important to understand at the outset is that neurocognitive testing is not diagnostic, meaning that it cannot be used to definitively determine if a concussion has occurred, and it shouldn't be the only tool that doctors use to determine when an athlete may return to play," writes MomsTEAM expert sport concussion neuropsychologist Rosemarie Scolaro Moser, PhD [4], in her 2012 book, Ahead of the Game: The Parents' Guide To Youth Sports Concussion. [5]

"Also," writes Dr. Moser, "neurocognitive testing should not be confused with sideline testing [6], which is performed immediately after an injury is sustained, in order to determine how oriented the athlete is, and to document his or her immediate symptoms [7].

Nor should neurocognitive testing be confused with or used in place of an initial medical assessment.  If you think your child has sustained a concussion, he or she should be immediately removed from play and referred for evaluation by a physician to rule out a more serious (or potentially life-threatening) injury [8], such as a skull fracture or brain hemorrhage.

Paper and pencil tests

Standard paper and pencil neuropsychological tests (see box) have proven useful for identifying cognitive deficits resulting from concussions, and have been available to sports medicine clinicians for a number of years.

The tests are designed to assess various domains of cognitive functioning such as:

• short-term memory
• working memory
• attention
• concentration
• visual spatial capacity
• information processing speed, and 
• reaction time. 

The tests assist clinicians in quantifying the severity of the injury and eliminating some of the guesswork. The key to a successful testing program is having valid results from pre-season baseline testing for comparison to post-injury results.

 

Common Neuropsychological Tests Used in Sport Concussion Assessment [4]
Neuropsychological Test	Cognitive Domain
Controlled Oral Word Association	Verbal Fluency
Hopkins Verbal Learning Test	Verbal learning, immediate and delayed memory
Trail Making: Parts A and B	Visual scanning, attention, information processing speed, psychomotor speed
Wechsler Letter Number Sequencing Test	Verbal working memory
Wechsler Digit Span: Digits Forward and Digits Backward	Attention, concentration
Symbol Digit Modalities Test	Psychomotor speed, attention, concentration
Paced Auditory Serial Addition Test	Attention, concentration
Stroop Color Word Test	Attention, information processing speed

Computerized neuropsychological tests

More recently, computer generated neuropsychological test programs have been developed and are currently being validated in the sports setting. They include:

1. Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) developed at the University of Pittsburgh Medical Center;
2. Computerized Cognitive Assessment Tool (CCAT) marketed in North America by Axon Sports and developed by CogState of Victoria, Australia;
3. Concussion Resolution Index (CRI) developed by HeadMinder, Inc. of New York, NY;
4. Automated Neuropsychological Assessment Metrics (ANAM) system: a PC Windows-based test protocol developed by the National Rehabilitation Hospital Assistive Technology and Neuroscience Center in Washington, DC (Editor's note: a joint investigation by National Public Radio and Pro Publica, which aired on NPR's "All Things Considered" on November 28, 2011 [9], severely questioned the reliability of this program, which was developed and is primarily used by the military); ^[9]and
5.  Concussion Vital Signs, [10] a web-based neurocognitive assessment platform developed by CNS Vital Signs and marketed by Pearson, which provides a brief, web-based neurocognitive baseline and post-injury testing solution, a self-reported history, mobile-deployed sideline assessment, and a post-concussion symptom checklist.

Advantages

Computerized tests have four significant advantages:

• Rapid scoring: tests take less time (more traditional pen and paper neuropsychological tests usually take an hour or more to administer)
• Ease of administration: the tests do not need to be administered by a neuropsychologist (although a neuropsychologist, ideally, should supervise the testing program and test interpretation).
• Increased test-retest reliability.  Some tests allow for infinite variety in the test questions that alleviate the practice or learning effects seen with more traditional neuropsychological test batteries.
• Greater accessibility: The computerized test batteries are accessible to a wide range of clinicians, including athletic trainers [11].

One recent study suggests that the tests may also help clinicians predict, when combined with an athlete's scores on the Post-Concussion Symptom Scale [7] in the first 2 to 3 days post-injury, whether a concussion will require protracted recovery (more than 14 days),^[7] although the study have been criticized  for using only post-injury test results without comparison to pre-injury baseline test results, and as lacking in practical value in the care of individual athletes which, current concussion management guidelines [12] say, requires individualized assessment and treatment.

Neuropsychologists should administer and interpret test results 

Because most states require advance training and licensing to purchase and use NP tests, and they are copyright protected, the National Athletic Training Association's 2004 Position Statement ^[4] recommends that a licensed psychologist, preferably board-certified in clinical neuropsychology or with clinical experience in evaluating sport-related concussions, oversee and supervise the testing.

The Zurich consensus statement ^[1] echoes that position ("Neuropsychologists are in the best position to interpret NP tests by virtue of their background and training."). 

The Centers for Disease Control's FAQs about Baseline Testing ^[10] states that, ideally, and where possible, a neuropsychologist should interpret the computerized or paper-pencil neuropsychological test components of a baseline exam.  As for who should administer baseline tests, the CDC is even more emphatic, stating flatly that "baseline tests should only be conducted by a trained health care professional."

Use of computerized tests on rise 

A study published in 2011 [13] ^[2] analyzing data collected on concussions suffered in nine high school sports during the 2009-2010 school year, reported that in schools with at least one athletic trainer on staff, computerized neuropsychological testing was used to assess 41.2% of concussions, up from 25.7% of concussions for the 2008-2009 school year,^[3] although it found that, when the return to play decision was made by a physician, the athlete was more likely to undergo comptuerized neuropsychological testing than if the decision was made by an ATC (52.6% versus 35.7%). 

A 2010 study^[3] found that injured athletes evaluated with such tests were less likely to return to play on the same day as their injury, and also less likely to return to play within a week of injury than those who were not tested using such diagnostic tool. 

The authors speculated that one possible explanation for such finding was that, despite reporting resolutions of their symptoms [7], the athletes still had subtle deficits in their neurocognitive function (memory, concentration, processing speed, reasoning), which the tests picked up. 

They said the results provided "further evidence [of] the benefit of neuropsychological testing in the management of sport-related concussion" as shown in several previous studies.

Limitations

More widespread use of computerized tests faces many of the same challenges as with use of pen-and-paper tests, including:

• Questions regarding test reliability: As a 2010 clinical report issued by the American Academy of Pediatrics noted,"one critique of the computerized tests is that the vast majority of studies have been conducted by the developers of the tests themselves, which raises some concern for bias, because some independent study results have suggested slightly less reliable results." ^[4] A 2011 study, noting the rapid rise in usage of computerized neuropsychological testing for the management of concussions in sports in the high school setting, urged that "future research focus" on their use; ^[3] 
  • As noted above, the ANAM test recently came under severe criticism in an NPR/Pro Publica investigation of computerized neuropsychological testing by the U.S. military, particularly the Army. ^[9]
  • Test-retest reliability in two recent studies of the ImPACT test was lower than previously reported,^[11,19] and up to 20% to 40% of athletes who were not concussed were found to have impairments on one of the test's five cognitive measures (false positives),^[11-13]  while another found that 17% of concussed athletes did not have any detectable cognitive abnormalities (false negatives).^[14]
• Validity, sensitivity, and specificity in peer-reviewed literature; ^[2,6]
• Required user training and qualifications (a licensed psychologist is needed to interpret results of the most widely used test);
• Hardware and software issues inherent to computerized testing; and 
• User costs.^[3]

Children and adolescents: different rules

The Zurich consensus statement recognizes that in the "NP testing may be used to assist RTP decisions and is typically performed when an athlete is clinically asymptomatic," but that "NP assessment may add important information in the early stages following injury," and that there "may be particular situations where testing is performed early to assist in determining aspects of management, for example, return to school in a pediatric athlete."   

Thus, for children and adolescents, different testing rules may apply:

• Testing while symptomatic.  In contrast to adults and athletes in their late teens, NP testing may be performed while the young athlete is still symptomatic in order to assist in school and home management;^[1,7]  young athletes need to limit exertion in day-to-day activities and scholastic and other cognitive stressors [14] (e.g. text messaging, video-games, etc.) while symptomatic ("cognitive rest"), which in some cases may require restricting school attendance and extracurricular activities to avoid making symptoms worse.^[1] Clinical evaluation of such athletes for concussion may also need to include both patient and parent input [15], as well as teacher and school input, where appropriate. If an athlete is suffering from post-concussion symptoms over several months (post-concussion syndrome [16]) or has had multiple concussions [17], formal assessment by a neuropsychologist may be helpful, specifically to identify areas for which the athlete may need academic accommodations [18].  MomsTEAM's expert sport concussion neuropsychologist Rosemarie Scolaro Moser, PhD [4], believes that the first post-concussion test should be performed relatively soon following an injury - within a day or two is fine, whatever is convenient - provided the athlete has been medically evaluated, and then retested no sooner than one week later.  She warns, however, against over-testing.  "Just as sending a concussed athlete back to school too soon can tax an overly tired brain [hence the need for cognitive rest], sub[jecting] a concussed athlete to repeated neurocognitive tests can tire him out, too."
• Adjusted for age and maturity level. Whatever cognitive testing is performed, it must be sensitive to the fact that athletes younger than their late teens are not only growing physically, but cognitively at a rapid rate, which may limit the value of  test results when comparing them to either the athlete's own, earlier baseline performance or to what is considered "normal" among his peer population. Note: different rules will apply for children below age 10, because such children report different symptoms - thus requiring a different, age-appropriate symptom checklist [19] as an assessment component.^[1,20]  There is currently no established, validated computerized neuropsychological test for the grade school athlete, although a computerized test for use in the athletes younger than 12 years is currently being developed.
• Repeated annually or every two years.  The Centers for Disease Control ^[10] recommends that most components of baseline tests (such as balance assessment [1], and the presence of any concussion symptoms [7]) be repeated annually to establish a valid test result to which post-concussion results can be compared, and that baseline computerized or paper-pencil neuropsychological tests be repeated every two years.  The CDC notes that more frequent neuropsychological testing may be needed if an athlete has a history of concussions [17] or if the athlete has a medical condition that could effect results of the test."  Dr. Moser agrees. "This kind of repetitive baseline testing," Moser writes in her excellent 2012 book, Ahead of the Game: A Parents'  Guide To Youth Sports Concussion [5], "can not only anticipate maturational growth spurts, but it can also take into account mild concussions that might have gone unnoticed or undiagnosed, as well as cumulative deficits from a series of subconcussive blows [20] (blows that aren't strong enough to trigger immediate symptoms, but that may cause problems over time)."

The bottom line, says Dr. Moser, is that neurocognitive "testing is not perfect, nor should it be the only tool used in monitoring recovery from concussions or in making return-to-playdecisions.  [It] is one tool of many and, despite its inherant flaws, it is valuable and generally considered preferable to not testing at all."

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1. P. McCrory et. al, Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012. Br J Sports Med 2013;47;250-258. 

2. Meehan WP, d'Hemecourt P, Collins C, Comstock RD, Assessment and Management of Sport-Related Concussions in United States High Schools.  Am. J. Sports Med. 2011;20(10)(published online on October 3, 2011 ahead of print) as dol:10.1177/0363546511423503 (accessed October 3, 2011). 

3. Meehan W, d'Hemecourt P, Comstock D. High School Concussions in the 2008-2009 Academic Year: Mechanism, Symptoms, and Management. Am. J. Sports. Med. 2010;38(12):2405-2409 (accessed December 2, 2010 at http://ajs.sagepub.com/content/38/12/2405.abstract?etoc [21]).

4.  National Athletic Trainers’ Association Position Statement: Management of Sport-Related Concussion. Journal of Athletic Training 2004;39(3):280–297 [22]

5. Halstead, M, Walter, K. Clinical Report - Sport-Related Concussion in Children and Adolescents.  Pediatrics. 2010;126(3):597-615.

6. Lau BC, Collins MW, Lovell MR. Sensitivity and Specificity of Subacute Computerized Neurocognitive Testing and Symptoms Evaluation in Predicting Outcomes After Sports-Related Concussion.  Am. J. Sports Med. 2011;20(10).

7. Broglio SP, Ferrara MS, Macciocchi SN, Baumgartner TA. Test-Retest Reliability of Computerized Concussion Assessment Programs. J. Athl. Tr. 2007; 42(4):509-514.

8. Herring S, Cantu R, Guskiewicz K, Putakian M, Kibler W.B.  Concussion (Mild Traumatic Brain Injury) and the Team Physician: A Consensus Tatement - 2011 Update.  Am J Sp Med. 2011: DOI:10.1249/Mss.ob013e3182342e64.

9. Zwerdling D, Sapien J, Miller TC.  Military's Brain-Testing Program A Debacle [9] (http://www.npr.org/2011/11/28/142662840/militarys-brain-testing-program-... [9])(accessed November 30, 2011).

10. Centers for Disease Control and Prevention.  FAQs about Baseline Testing among Young Athletes (http://www.cdc.gov/concussion/pdf/baseline_testing_FAQs-a.pdf [23])(accessed April 16, 2012)

11. Randolph C. Baseline neuropsychological testing in managing sport-related concussion: does it modify risk? Curr Sports Med Rep. 2011;10:21-26.

12. Broglio SP, Ferrara MS, Macciocchi SN, et. al. Test-retest reliability of computerized concussion assessment programs.  J Athl Train. 2007;42:509-14.

13. Van Kampen DA, Lovell MR, Pardini JE, et. al. The "value added" of neurocognitive testing after sports-related concussion. Am J Sports Med. 2006;34:1630-5.

14. Collie A, Makdissi M, Maruff P, Bennell K. McCrory P. Cognition in the days following concussion: comparison of symptomatic versus asymptomatic athletes. J Neurol Neurosurg Psychiatry 2006;77:241-5.

15. Cantu R, Hyman M. Concussions and Our Kids (Houghton Mifflin Harcourt 2012). 

16. Giza C, Kutcher J, Ashwal S, et al. Summary of evidence-based guideline update: Evaluation and management of concussion in sports: Report of the guideline Development Subcommittee of the American Academy of Neurology. Neurology 2013;DOI:10.1212/WNL.0b013e31828d57dd (published online ahead of print March 18, 2013). 

17. Elbin R, Kontos A, Kegel N, Johnson E, Burkhart S, Schatz P.  Individual and Combined Effects of LD and ADHD on Computerized Neurocognitive Concussion Test Performance: Evidence for Separate Norms.  Arch Clin Neuropsychol 2013;DOI:10.1093/arclin/act024 (published online ahead of print April 21, 2013). 

18. Guskiewicz K, et al. Evidence-based approach to revising the SCAT2: introducing the SCAT 3. Br J Sports Med 2013;47:289-293. 

19. Resch J, et al. ImPact Test-Retest Reliability: Reliably Unreliable? J Athl Tr. 2013;48(3):000-000 doi: 10.4085/1062-6050-48.3.09 (ePub in advance of print)

20. Child SCAT3. Br J Sports Med 2013;47:263. 

Most recently revised and updated August 13, 2013