Philip Schatz

Prolonged effects of concussion in high school athletes.

OBJECTIVE:To identify enduring prolonged neuropsychological effects of cerebral concussion in high school youth athletes. METHODS:High school athletes (n = 223) underwent baseline neuropsychological evaluation between 1999 and 2000, assigned to independent groups on the basis of concussion history: athletes with no concussion history or present medical and/or neuropsychological complaints (n = 82), symptom-free athletes who experienced one (n = 56) or two or more (n = 45) concussions (not in the prior 6 mo), and those who experienced a concussion 1 week before testing (n = 40). Main outcome measures included a structured clinical interview, demographic form, symptom checklist, the Repeatable Battery for the Assessment of Neuropsychological Status, and the Trail Making Tests A and B. Analyses of variance were used to determine between-group differences. RESULTS:Athletes with recent concussions performed significantly worse on measures of attention and concentration than youth athletes with no concussion history. Symptom-free athletes with a history of two or more concussions performed similar on testing to youth athletes who had just experienced a recent concussion. Similarly, cumulative academic grade point averages were significantly lower not only for youth athletes with two or more previous concussion groups, but for youth athletes who experienced recent concussions, suggesting that athletes with lower grade point averages may be more prone to concussion. CONCLUSION:There seem to be subtle yet significant prolonged neuropsychological effects in youth athletes with a history of two or more previous concussions.

Long-Term Test-Retest Reliability of Baseline Cognitive Assessments Using ImPACT

Background Computer-based assessment programs are commonly used to document baseline cognitive performance for comparison with postconcussion testing. There are currently no guidelines for how often baseline assessments should be updated, and no data documenting the test-retest stability of baseline measures over relevant time periods. Purpose To establish long-term test-retest reliability of baseline assessments using ImPACT, and to compare various statistical methods for establishing test-retest reliability. Study Design Case series; Level of evidence, 4. Methods Participants were 95 collegiate varsity athletes completing baseline cognitive testing at 2 time periods, approximately 2 years apart. No participant sustained a concussion between assessments. All athletes completed the ImPACT test battery; dependent measures were the composite scores and total symptom scale score. Results Intraclass correlation coefficient estimates for visual memory (.65), processing speed (.74), and reaction time (.68) composite scores reflected stability over the 2-year period, with greater variability in verbal memory (.46) and symptom scale (.43) scores. Using reliable change indices and regression-based methods, only a small percentage of participants’ scores showed “reliable” or “significant” change on the composite scores (0%-6%), or symptom scale scores (5%-10%). Conclusion The current results suggest that college athletes’ cognitive performance at baseline remains considerably stable over a 2-year period. These data help establish the effects of longer, clinically pragmatic testing intervals on test-retest reliability. Clinical Implications The current results suggest that stretching the time between baseline assessments from 1 to 2 years may have little effect on the clinical management of concussions in collegiate athletes. These results should not be generalized to collegiate football players, who were not included in this sample. Youth athletes (high school and younger) should continue to receive annually updated baseline assessments until prospective study of the stability of baseline assessments for this younger age group can be completed.

Sex differences in baseline neuropsychological function and concussion symptoms of collegiate athletes

Objective: To investigate sex differences in baseline neuropsychological function and concussion symptoms between male and female collegiate athletes. Methods: A post-test only design was used to examine baseline neuropsychological test scores and concussion symptoms. A total of 1209 NCAA Division I collegiate athletes from five northeastern universities in the USA completed a baseline ImPACT test. ImPACT, a computerised neuropsychological test battery, was administered during an athlete’s pre-season. Results: Female athletes performed significantly better than male athletes on baseline verbal memory scores (p = 0.001), while male athletes performed significantly better than female athletes on baseline visual memory scores (p = 0.001). Female athletes endorsed a significant number of mild baseline symptoms as compared to male athletes. Conclusions: Male and female athletes exhibit differences on baseline neuropsychological test performance and concussion symptoms.

Efficacy of Immediate and Delayed Cognitive and Physical Rest for Treatment of Sports-Related Concussion

OBJECTIVES To evaluate the efficacy of cognitive and physical rest for the treatment of concussion. STUDY DESIGN High school and collegiate athletes (N = 49) underwent post-concussion evaluations between April 2010 and September 2011 and were prescribed at least 1 week of cognitive and physical rest. Participants were assigned to groups on the basis of the time elapsed between sustaining a concussion and the onset of rest (1-7 days, 8-30 days, 31+ days). Main outcome measures included Concussion Symptom Scale ratings and scores on the 4 composite indices of the Immediate Post-Concussion Assessment and Cognitive Testing measure, both before and following rest. Mixed-factorial design ANOVA were used to compare changes on the dependent measures within and between groups. RESULTS Participants showed significantly improved performance on Immediate Post-Concussion Assessment and Cognitive Testing and decreased symptom reporting following prescribed cognitive and physical rest (P < .001), regardless of the time between concussion and onset of rest (P = .44). CONCLUSION These preliminary data suggest that a period of cognitive and physical rest may be a useful means of treating concussion-related symptoms, whether applied soon after a concussion or weeks to months later.

One-Year Test-Retest Reliability of the Online Version of ImPACT in High School Athletes

Background: The ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) neurocognitive testing battery is a popular assessment tool used for concussion management. The stability of the baseline neurocognitive assessment is important for accurate comparisons between postconcussion and baseline neurocognitive performance. Psychometric properties of the recently released online version of ImPACT have yet to be established; therefore, research evaluating the reliability of this measure is warranted. Purpose: The authors investigated the 1-year test-retest reliability of the ImPACT online version in a sample of high school athletes. Study Design: Case series; Level of evidence, 4 Methods: A total of 369 varsity high school athletes completed 2 mandatory preseason baseline cognitive assessments approximately 1 year apart as required by their respective athletics program. No diagnosed concussion occurred between assessments. Results: Intraclass correlation coefficients (ICCs) for ImPACT online indicated that motor processing speed (.85) was the most stable composite score, followed by reaction time (.76), visual memory (.70), and verbal memory (.62). Unbiased estimates of reliability were consistent with ICCs: motor processing speed (.85), reaction time (.76), visual memory (.71), and verbal memory (.62). Conclusion: The online ImPACT baseline is a stable measure of neurocognitive performance across a 1-year time period for high school athletes. These reliability data for online ImPACT are higher than the 2-year ICCs previously reported from the desktop version. Clinical Relevance: It is recommended that the ImPACT baseline assessment (both desktop and online) continue to be updated every 2 years. The online version of ImPACT appears to be a stable measure of neurocognitive performance over a 1-year period, and systematic evaluation of its stability over a 2-year period is warranted.

Enduring effects of concussion in youth athletes

The purpose of this study was to explore the mild, enduring effects of concussion in otherwise healthy youth athletes. Reported history of concussion and cognitive functioning was examined in an initial sample of 35 youth athletes, 21 of whom were considered healthy volunteers (No Recent Concussion within the past 6 months) with no identified medical or neuropsychological difficulties related to concussion. The remaining 14 volunteers had each sustained a concussion within 1 week of testing (Recent Concussion). Significant differences in performances on a general cognitive measure, and specifically in the area of attention, were found as a function of number of concussions reported by the No Recent Concussion athletes. Furthermore, on some of the measures, No Recent Concussion athletes with a history of two or more concussions appeared to resemble Recent Concussion athletes more so than No Recent Concussion athletes with a history of one or no concussion. The importance of assessment of youth concussion and the use of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) for this purpose are discussed.

Applications of computer-based neuropsychological assessment

Objectives:To present current applications of computer-based neuropsychological assessment, including the assessment of sports-related concussion, symptom validity testing, and the remote administration of tests through the Internet. Problem areas:If computer-based assessment benefits are to become popularized, a few issues will need to be addressed: the development of psychometric data based on comparisons with long-standing empirically sound test measures; additional validation of measures by parties not involved in their commercial development; increased focus on ecological validity; exploration of the usefulness of remote data storage and automated posting to databases; and improved documentation of specific computer hardware and software used in experimental methods. Conclusions:Beyond ease of administration and data collection, computer-based assessment offers benefits over paper-and-pencil measures in the form of millisecond timing accuracy, reliable and randomized presentation of stimuli over multiple trials and repeat administrations, and unobtrusive measurement of cognitive skills and response times during all aspects of the assessment process.

Sensitivity and Specificity of the Online Version of ImPACT in High School and Collegiate Athletes

Background: The utility of postconcussion neurocognitive testing versus symptom data has been debated. The sensitivity of the desktop version of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) tool has been documented, but psychometric properties of the recently released online version of ImPACT have yet to be fully established. Purpose: To document the sensitivity of the online ImPACT version in samples of (1) symptomatic concussed (high school and collegiate) athletes, and (2) asymptomatic concussed (high school and collegiate) athletes suspected of hiding their concussions. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 81 athletes observed to sustain a concussion by a certified athletic trainer or team physician, a finding that was confirmed with reported postconcussion symptoms, completed the ImPACT test within 3 days of injury. Data were compared with an independent sample of 81 athletes who completed preseason baseline cognitive assessments using ImPACT and who were matched (with concussed athletes) on the basis of sex, age, sport, concussion history, and absence of attention deficit hyperactivity disorder and learning disability. An independent group of 37 athletes who were also observed to sustain a concussion completed ImPACT within 3 days of injury. These athletes reported no postconcussion symptoms but were noted for suspected invalid response patterns on ImPACT (Impulse Control index >30 and Verbal Memory index <69%). The subscale data from the assessments (excluding those contributing to the aforementioned indices) were compared with a matched sample of 37 athletes who completed preseason baseline cognitive assessments in ImPACT (using the same criteria described above). Results: Data from the ImPACT online version yielded 91.4% sensitivity and 69.1% specificity. For asymptomatic athletes suspected of hiding their concussion, data from ImPACT yielded 94.6% sensitivity and 97.3% specificity. Conclusion: The online version of the ImPACT tool is a valid measure of neurocognitive performance at the acute stages of concussion, with high levels of sensitivity and specificity, even when athletes appear to be denying postconcussion symptoms.

Removal from play after concussion and recovery time

OBJECTIVE: Despite increases in education and awareness, many athletes continue to play with signs and symptoms of a sport-related concussion (SRC). The impact that continuing to play has on recovery is unknown. This study compared recovery time and related outcomes between athletes who were immediately removed from play and athletes who continued to play with an SRC. METHODS: A prospective, repeated measures design was used to compare neurocognitive performance, symptoms, and recovery time between 35 athletes (mean ± SD age, 15.61 ± 1.65 years) immediately removed after an SRC (REMOVED group) compared with 34 athletes (mean ± SD age, 15.35 ± 1.73 years) who continued to play (PLAYED group) with SRC. Neurocognitive and symptom data were obtained at baseline and at 1 to 7 days and 8 to 30 days after an SRC. RESULTS: The PLAYED group took longer to recover than the REMOVED group (44.4 ± 36.0 vs 22.0 ± 18.7 days; P = .003) and were 8.80 times more likely to demonstrate protracted recovery (≥21 days) (P < .001). Removal from play status was associated with the greatest risk of protracted recovery (adjusted odds ratio, 14.27; P = .001) compared with other predictors (eg, sex). The PLAYED group exhibited significantly worse neurocognitive and greater symptoms than the REMOVED group. CONCLUSIONS: SRC recovery time may be reduced if athletes are removed from participation. Immediate removal from play is the first step in mitigating prolonged SRC recovery, and these data support current consensus statements and management guidelines.

Individual and Combined Effects of LD and ADHD on Computerized Neurocognitive Concussion Test Performance: Evidence for Separate Norms

Decreased neurocognitive performance in individuals with self-reported attention deficit hyperactivity disorder (ADHD) and learning disability (LD) is well documented in the neuropsychological research literature. Previous studies employing paper-and-pencil neurocognitive assessments report lower performance in individuals with ADHD and LD. The purpose of the current study was to examine the influence of a self-reported diagnosis of LD, ADHD, and combined LD/ADHD on baseline computerized neurocognitive testing (CNT) used for the concussion assessment. Results revealed athletes with a self-reported diagnosis of LD, ADHD, and/or combined LD/ADHD demonstrated lower performance on baseline CNT and reported larger numbers of symptoms than did control athletes without these diagnoses. These findings provide evidence for the development of separate normative data for athletes with LD, ADHD, and LD/ADHD diagnoses on CNT batteries commonly used for concussion management.