Baseline and Post-Injury Neuropsychological Testing Valuable Tool in Concussion Management Says Dr. Robert Cantu

Several recent studies have demonstrated the value of neuropsychological testing in evaluating the cognitive effects of and recovery from sport-related concussions. Such testing has become increasingly popular in recent years, so much so that it is now, according to the 2004 Prague consensus statement, a "cornerstone" of concussion evaluation, at least for "complex" concussions (e.g. those where athletes suffer persistent post-concussion symptoms, experience concussive convulsions or prolonged loss of consciousness or have suffered repeated concussions over time or with progressively less impact force).

Baseline pre-injury and post-injury testing is now commonplace at the professional and collegiate level and has become more and more common at the high school level as well (although the cost, either conventional or computerized, is a factor in how widely such testing can be implemented at the high school level).

Pen-and-paper tests

Standard pencil and paper neuropsychological tests (see box) have proven useful for identifying cognitive deficits resulting from concussions, and have been available to sports medicine clinicians for several years. These 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 results from pre-season baseline testing for comparison to post-injury results.

Because most states require advance training and licensing to purchase and use neuropsychological tests, and they are copyright protected, the NATA's 2004 Position Statement 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. These requirements are, unfortunately, likely to restrict how widely testing can be implemented at the high school level and in rural areas where access to neuropsychologists for consultation is likely to be limited.

Computerized Neuropsychological Tests

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

1. 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;
2. CogState developed by CogState Ltd of Victoria, Australia; and
3. Concussion Resolution Index (CRI) developed by HeadMinder, Inc. of New York, NY; and
4. Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) developed at the University of Pittsburgh Medical Center.

Computerized tests have three significant advantages over more traditional pen and paper neuropsychological tests:

• They take less time (more traditional pen and paper neuropsychological tests usually take an hour or more to administer)
• They are easier to administer, as they do not need to be administered by a neuropsychologist.
• They allow for infinite variety in the test questions that alleviate the practice or learning effects seen with more traditional neuropsychological test batteries.

Widespread use of such tests faces many of the same challenges as with use of pen-and-paper tests, including:

• Questions regarding test reliability;
• Validity, sensitivity, and specificity in peer-reviewed literature;
• Required user training and qualifications;
• The necessary role of the licensed psychologist for clinical interpretation of test results;
• Hardware and software issues inherent to computerized testing; and
• User costs.

Debate about test timing

The point or points at which post-injury neuropsychological testing should occur has been the subject of debate.

There are two main approaches.

• After symptoms clear. Some clinicians incorporate testing only after the injured players reports that his or symptoms are completely gone. Because all experts agree that an athlete should not return to play while symptomatic, serial testing is thus unnecessary, burdensome and costly to the athlete and medical staff and also introduces practice effects that may render interpretation of subsequent tests more unreliable. This is the view taken in the Summary and Agreement Statement of the 2nd International Conference on Concussion in Sport held in Prague in 2004.
• Testing at fixed time intervals. Some clinicians incorporate neuropsychological testing at fixed time points (e.g. postinjury day 1, day 7, etc.) until the test results return to normal, pre-injury (e.g. baseline) levels and the players is asymptomatic. While appropriate in a research setting, it is unnecessary in a clinical setting when the player is still reporting symptoms.

Regardless of which approach is taken, return to play decisions should be based on all clinical information, including the player's medical history (i.e. history of prior concussions, severity, whether subsequent concussions occur with less impact force; recovery time).