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) 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" 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, 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, in her 2012 book, Ahead of the Game: The Parents' Guide To Youth Sports Concussion.

"Also," writes Dr. Moser, "neurocognitive testing should not be confused with sideline testing, 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.

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, 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.