Long-term test-retest reliability of baseline cognitive assessments using ImPACT

The effect of preinjury sleep difficulties on neurocognitive impairment and symptoms after sport-related concussion

BACKGROUND

Researchers have reported that sleep duration is positively related to baseline neurocognitive performance. However, researchers have yet to examine the effect of preinjury sleep difficulties on postconcussion impairments.

PURPOSE

To compare neurocognitive impairment and symptoms of athletes with preinjury sleep difficulties to those without after a sport-related concussion (SRC).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The sample included 348 adolescent and adult athletes (age, mean ± SD, 17.43 ± 2.34 years) with a diagnosed SRC. The sample was divided into 2 groups: (1) 34 (10%) participants with preinjury sleep difficulties (sleeping less as well as having trouble falling asleep; SLEEP SX) and (2) 231 (66%) participants without preinjury sleep difficulties (CONTROL). The remaining 84 (24%) participants with minimal sleep difficulties (1 symptom) were excluded. Participants completed the Immediate Postconcussion Assessment and Cognitive Test (ImPACT) and Postconcussion Symptom Scale (PCSS) at baseline and 3 postinjury intervals (2, 5-7, and 10-14 days after injury). A series of repeated-measures analyses of covariance with Bonferroni correction, controlling for baseline non-sleep-related symptoms, were conducted to compare postinjury neurocognitive performance between groups. Follow-up exploratory t tests examined between-group differences at each time interval. A series of analyses of variance were used to examine total PCSS score, sleep-related, and non-sleep-related symptoms across time intervals between groups.

RESULTS

Groups differed significantly in PCSS scores across postinjury intervals for reaction time (P < .001), with the preinjury SLEEP SX group performing worse than controls at 5-7 days (mean ± SD, 0.70 ± 0.32 [SLEEP SX], 0.60 ± 0.14 [CONTROL]) and 10-14 days (0.61 ± 0.17 [SLEEP SX]; 0.57 ± 0.10 [CONTROL]) after injury. Groups also differed significantly on verbal memory performance (P = .04), with the SLEEP SX (68.21 ± 18.64) group performing worse than the CONTROL group (76.76 ± 14.50) 2 days after injury. The SLEEP SX group reported higher total symptom (P = .02) and sleep-related symptom (P = .02) scores across postinjury time intervals.

CONCLUSION

Preinjury sleep difficulties may exacerbate neurocognitive impairment and symptoms after concussion. The findings may help clinicians identify athletes who are at risk for worse impairments after a concussion due to preinjury sleep difficulties.

Neurocognitive responses to a single session of static squats with whole body vibration

The purpose of this study was to determine if the head accelerations using a common whole body vibration (WBV) exercise protocol acutely reduced neurocognition in healthy subjects. Second, we investigated differential responses to WBV plates with 2 different delivery mechanisms: vertical and rotational vibrations. Twelve healthy subjects (N = 12) volunteered and completed a baseline (BASE) neurocognitive assessment: the Immediate Postconcussion Assessment and Cognitive Test (ImPACT). Subjects then participated in 3 randomized exercise sessions separated by no more than 2 weeks. The exercise sessions consisted of five 2-minute sets of static hip-width stance squats, with the knees positioned at a 45° angle of flexion. The squats were performed with no vibration (control [CON]), with a vertically vibrating plate (vertical vibration [VV]), and with a rotational vibrating plate (rotational vibration [RV]) set to 30 Hz with 4 mm of peak-to-peak displacement. The ImPACT assessments were completed immediately after each exercise session and the composite score for 5 cognitive domains was analyzed: verbal memory, visual memory, visual motor speed, reaction time, and impulse control. Verbal memory scores were unaffected by exercise with or without vibration (p = 0.40). Likewise, visual memory was not different (p = 0.14) after CON, VV, or RV. Significant differences were detected for visual motor speed (p = 0.006); VV was elevated compared with BASE (p = 0.01). There were no significant differences (p = 0.26) in reaction time or impulse control (p = 0.16) after exercise with or without vibration. In healthy individuals, 10 minutes of 30 Hz, 4-mm peak-to-peak displacement vibration exposure with a 45° angle of knee flexion did not negatively affect neurocognition.

A potential biomarker in sports-related concussion: brain functional connectivity alteration of the default-mode network measured with longitudinal resting-state fMRI over thirty days

Current diagnosis and monitoring of sports-related concussion rely on clinical signs and symptoms, and balance, vestibular, and neuropsychological examinations. Conventional brain imaging often does not reveal abnormalities. We sought to assess if the longitudinal change of functional and structural connectivity of the default-mode network (DMN) can serve as a potential biomarker. Eight concussed Division I collegiate football student-athletes in season (one participated twice) and 11 control subjects participated in this study. ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) was administered over the course of recovery. High-resolution three dimensional T1-weighted, T2*-weighted diffusion-tensor images and resting-state functional magnetic resonance imaging (rs-fMRI) scans were collected from each subject within 24 h, 7±1 d and 30±1 d after concussion. Both network based and whole-brain based functional correlation analyses on DMN were performed. ImPACT findings demonstrated significant cognitive impairment across multiple categories and a significant increase of symptom severity on Day 1 following a concussion but full recovery by 6.0±2.4 d. While the structural connectivity within DMN and gross anatomy appeared unchanged, a significantly reduced functional connectivity within DMN from Day 1 to Day 7 was found in the concussed group in this small pilot study. This reduction was seen in eight of our nine concussion cases. Compared with the control group, there appears a general trend of increased DMN functional connectivity on Day 1, a significant drop on Day 7, and partial recovery on Day 30. The results of this pilot study suggest that the functional connectivity of DMN measured with longitudinal rs-fMRI can serve as a potential biomarker to monitor the dynamically changing brain function after sports-related concussion, even in patients who have shown clinical improvement.

Effects of youth football on selected clinical measures of neurologic function: a pilot study

We assessed 10 youth football players (13.4 ± 0.7 y) immediately before and after their season to explore the effects of football participation on selected clinical measures of neurologic function. Postseason postural stability in a closed-eye condition was improved compared to preseason (P = .017). Neurocognitive testing with the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery revealed that reaction time was significantly faster at postseason (P = .015). There were no significant preseason versus postseason differences in verbal memory (P = .507), visual memory (P = .750), or visual motor speed (P = .087). Oculomotor performance assessed by the King-Devick test was moderately to significantly improved (P = .047-.115). A 12-week season of youth football did not impair the postural stability, neurocognitive function, or oculomotor performance measures of the players evaluated. Though encouraging, continued and more comprehensive investigations of this at-risk population are warranted.

Advanced topics in neuropsychological assessment following sport-related concussion

OBJECTIVE

This study examined seven topics relating to neuropsychological assessment following sport-related concussion: (i) traditional vs. computerized tests; (ii) the value of baseline, pre-season testing; (iii) invalid baseline scores and poor effort; (iv) when to assess following injury; (v) the reliability of neuropsychological tests; (vi) reliable change methodology; and (vii) new methods for identifying cognitive impairment.

MAIN RESULTS

Baseline testing can be helpful for quantifying cognitive deficits following injury and for assessing recovery. At present, however, there is insufficient evidence to conclude that having baseline test results is clearly superior to not having baseline test results. Although invalid baseline test performance can be detected in some athletes, validity indicators cannot determine the extent to which the results were due to deliberately poor performance, confusion or misunderstanding regarding some aspect of the test, distractions in group testing environments or some combination of factors. When interpreting baseline and post-injury data, sophisticated psychometric methods (e.g. reliable change, multivariate base rates) are available to assist with more accurate identification of cognitive impairment and the serial monitoring of recovery.

CONCLUSIONS

The value of neuropsychological assessment in the management of sport-related concussion has a strong empirical foundation. Additional research is needed, however, to refine its use.

Baseline Neurocognitive Performance in Professional Lacrosse Athletes

Background:

Concussions have become a major public health concern for both youth and professional athletes. The long-term consequences of concussion can be debilitating or even life threatening. To reduce these concerns, baseline neurocognitive performance can aid decision making in postconcussion recovery and return to play for athletes sustaining concussions. To date, these data are not available for lacrosse athletes.

Purpose:

To present baseline neurocognitive performance for Major League Lacrosse (MLL) players and to determine differences between athletes with and without a history of concussion.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A retrospective review was conducted of Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) scores from MLL players who completed baseline testing from June 2010 to June 2011. Inclusion required a valid baseline test and no history of concussion in the 3 months prior to testing. Means ± standard deviations were computed for all demographic variables and ImPACT composite scores including visual and verbal memory, reaction time, and visual motor processing speed. Independent-samples t tests were used to determine differences between athletes with and without a history of concussion.

Results:

Valid baseline ImPACT testing was available for 235 MLL athletes (mean age, 25.1 ± 3.0 years). Forty percent of MLL athletes (n = 94) reported a history of concussion, with 14% of those (n = 13) reporting a history of 3 or more previous concussions. There were no differences on any demographic variables between MLL athletes with and without a history of concussion. MLL athletes with a history of concussion had lower ImPACT composite scores than those without a history of concussion, although only the verbal memory composite was found to be statistically significant (MLL with concussion, 83.2 ± 10.8 vs MLL without concussion, 86.9 ± 9.5; P = .007).

Conclusion:

This study establishes baseline ImPACT scores for MLL and demonstrates that athletes with a history of concussion have poorer neurocognitive performance compared with MLL athletes without a history of concussion.

Clinical Relevance:

These data can serve as normative values for subsequent testing following concussion to assess neurocognitive recovery.

Comparing post-concussive neurocognitive test data to normative data presents risks for under-classifying "above average" athletes

We compared classification accuracy of post-concussion test data against baseline and normative data, accounting for baseline level of performance. Athletes (N = 250) completed baseline and post-concussion ImPACT assessments, within 7 days of concussion (verified by sports medicine professionals and self-reported symptoms). Athletes were classified as "below average," "average," or "above average" at baseline. Change from baseline was calculated using reliable change indices (RCIs) and regression-based measures (RBz), and comparison to normative data was achieved using z-scores. Normative comparisons identified fewer symptomatic, concussed athletes than RCIs and RBz. Both RCIs and RBz consistently identified "impairment" at 1 and 1.5 SD, regardless of baseline level, whereas normative comparisons identified 46-48% fewer athletes performing "above average" at baseline using a cut-off of 1 SD and 36-38% fewer using a cut-off of 1.5 SD. The use of normative comparisons may differentially classify concussed, symptomatic athletes who are outside the "average" range at baseline.

Examination of the Test-Retest Reliability of a Computerized Neurocognitive Test Battery

BACKGROUND

Test-retest reliability is a critical issue in the utility of computer-based neurocognitive assessment paradigms employing baseline and postconcussion tests. Researchers have reported low test-retest reliability for the Immediate Post Concussion Assessment and Cognitive Testing (ImPACT) across an interval of 45 and 50 days.

PURPOSE

To re-examine the test-retest reliability of the ImPACT between baseline, 45 days, and 50 days.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Eighty-five physically active college students (51 male, 34 female) volunteered for this study. Participants completed the ImPACT as well as a 15-item memory test at baseline, 45 days, and 50 days. Intraclass correlation coefficients (ICCs) were calculated for ImPACT composite scores, and change scores were calculated using reliable change indices (RCIs) and regression-based methods (RBMs) at 80% and 95% confidence intervals (CIs).

RESULTS

The respective ICCs for baseline to day 45, day 45 to day 50, baseline to day 50, and overall were as follows: verbal memory (0.76, 0.69, 0.65, and 0.78), visual memory (0.72, 0.66, 0.60, and 0.74), visual motor (processing) speed (0.87, 0.88, 0.85, and 0.91), and reaction time (0.67, 0.81, 0.71, and 0.80). All ICCs exceeded the threshold value of 0.60 for acceptable test-retest reliability. All cases fell well within the 80% CI for both the RCI and RBM, while 1% to 5% of cases fell outside the 95% CI for the RCI and 1% for the RBM.

CONCLUSION

Results suggest that the ImPACT is a reliable neurocognitive test battery at 45 and 50 days after the baseline assessment. The current findings agree with those of other reliability studies that have reported acceptable ICCs across 30-day to 1-year testing intervals, and they support the utility of the ImPACT for the multidisciplinary approach to concussion management.

CLINICAL RELEVANCE

This study suggests that the computerized neurocognitive test battery, ImPACT, is a reliable test for postconcussion serial assessments. However, when managing concussed athletes, the ImPACT should not be used as a stand-alone measure.

Effect of education and language on baseline concussion screening tests in professional baseball players

OBJECTIVE

The purpose of the present study was to investigate the possible effects of sociocultural influences, specifically pertaining to language and education, on baseline neuropsychological concussion testing as obtained via immediate postconcussion assessment and cognitive testing (ImPACT) of players from a professional baseball team.

DESIGN

A retrospective chart review.

SETTING

Baseline testing of a professional baseball organization.

PARTICIPANTS

Four hundred five professional baseball players.

INDEPENDENT VARIABLES

Age, languages spoken, hometown country location (United States/Canada vs overseas), and years of education.

MAIN OUTCOME MEASURES

The 5 ImPACT composite scores (verbal memory, visual memory, visual motor speed, reaction time, impulse control) and ImPACT total symptom score from the initial baseline testing.

RESULTS

The result of t tests revealed significant differences (P < 0.05) when comparing native English to native Spanish speakers in many scores. Even when corrected for education, the significant differences (P < 0.05) remained in some scores.

CONCLUSIONS

Sociocultural differences may result in differences in computer-based neuropsychological testing scores.

Baseline evaluation in youth ice hockey players: comparing methods for documenting prior concussions and attention or learning disorders

STUDY DESIGN

Cross-sectional.

OBJECTIVE

To examine differences in concussion history and attention or learning disorders reported by elite youth ice hockey players, using a questionnaire that allows parental input compared to a clinic-based test battery that does not.

BACKGROUND

A history of previous concussion and the presence of attention or learning disorders can affect concussion-management decisions; however, youth athletes may not accurately report their medical history because they may not know or recall important details.

METHODS

The sample included 714 Bantam (ages 12-14 years) and Midget (ages 15-17 years) ice hockey players (601 male, 113 female) from the most elite divisions of play (AA and AAA). Players completed a take-home preseason questionnaire (PSQ) with the input of a parent/guardian, and also independently completed the baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) at the beginning of the 2011-2012 hockey season.

RESULTS

In 21.1% (95% confidence interval: 18.1%, 24.1%) of cases, there was disagreement between the PSQ and ImPACT in the number of previous concussions reported. Among those who reported an attention disorder on the PSQ, 85.7% also reported an attention disorder on the ImPACT. Only 9.5% of those who reported a learning disorder on the PSQ also reported a learning disorder on the ImPACT.

CONCLUSION

In 1 of 5 players, reported concussion history differed between the PSQ and ImPACT, and there was substantial disagreement between instruments for those reporting learning disorders. The method of obtaining medical history may, therefore, affect baseline and postconcussion evaluations.

Relationship between concussion history and neurocognitive test performance in National Football League draft picks

BACKGROUND

There are limited empirical data available regarding the relationship between concussion history and neurocognitive functioning in active National Football League (NFL) players in general and NFL draft picks in particular. Potential NFL draft picks undergo 2 neurocognitive tests at the National Invitational Camp (Scouting Combine) every year: the Wonderlic and, since 2011, the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT). After conclusion of the combine and before the draft, NFL teams invite potential draft picks to their headquarters for individual visits where further assessment may occur.

PURPOSE

To examine the relationship between concussion history and neurocognitive performance (ImPACT and Wonderlic) in a sample of elite NFL draft picks.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Over 7 years, 226 potential draft picks were invited to visit a specific NFL team's headquarters after the combine. The athletes were divided into 3 groups based on self-reported concussion history: no prior concussions, 1 prior concussion, and 2 or more prior concussions. Neurocognitive measures of interest included Wonderlic scores (provided by the NFL team) and ImPACT composite scores (administered either at the combine or during a visit to the team headquarters). The relationship between concussion history and neurocognitive scores was assessed, as were the relationships among the 2 neurocognitive tests.

RESULTS

Concussion history had no relationship to neurocognitive performance on either the Wonderlic or ImPACT.

CONCLUSION

Concussion history did not affect performance on either neurocognitive test, suggesting that for this cohort, a history of concussion may not have adverse effects on neurocognitive functioning as measured by these 2 tests. This study reveals no correlation between concussion history and neurocognitive test scores (ImPACT, Wonderlic) in soon-to-be active NFL athletes.

National Athletic Trainers' Association position statement: management of sport concussion

OBJECTIVE

To provide athletic trainers, physicians, and other health care professionals with best-practice guidelines for the management of sport-related concussions.

BACKGROUND

An estimated 3.8 million concussions occur each year in the United States as a result of sport and physical activity. Athletic trainers are commonly the first medical providers available onsite to identify and evaluate these injuries.

RECOMMENDATIONS

The recommendations for concussion management provided here are based on the most current research and divided into sections on education and prevention, documentation and legal aspects, evaluation and return to play, and other considerations.

Baseline neurocognitive testing in sports-related concussions: the importance of a prior night's sleep

BACKGROUND

The management of sports-related concussions (SRCs) utilizes serial neurocognitive assessments and self-reported symptom inventories to assess recovery and safety for return to play (RTP). Because postconcussive RTP goals include symptom resolution and a return to neurocognitive baseline levels, clinical decisions rest in part on understanding modifiers of this baseline. Several studies have reported age and sex to influence baseline neurocognitive performance, but few have assessed the potential effect of sleep. We chose to investigate the effect of reported sleep duration on baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) performance and the number of patient-reported symptoms.

HYPOTHESIS

We hypothesized that athletes receiving less sleep before baseline testing would perform worse on neurocognitive metrics and report more symptoms.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

We retrospectively reviewed 3686 nonconcussed athletes (2371 male, 1315 female; 3305 high school, 381 college) with baseline symptom and ImPACT neurocognitive scores. Patients were stratified into 3 groups based on self-reported sleep duration the night before testing: (1) short, <7 hours; (2) intermediate, 7-9 hours; and (3) long, ≥9 hours. A multivariate analysis of covariance (MANCOVA) with an α level of .05 was used to assess the influence of sleep duration on baseline ImPACT performance. A univariate ANCOVA was performed to investigate the influence of sleep on total self-reported symptoms.

RESULTS

When controlling for age and sex as covariates, the MANCOVA revealed significant group differences on ImPACT reaction time, verbal memory, and visual memory scores but not visual-motor (processing) speed scores. An ANCOVA also revealed significant group differences in total reported symptoms. For baseline symptoms and ImPACT scores, subsequent pairwise comparisons revealed these associations to be most significant when comparing the short and intermediate sleep groups.

CONCLUSION

Our results indicate that athletes sleeping fewer than 7 hours before baseline testing perform worse on 3 of 4 ImPACT scores and report more symptoms. Because SRC management and RTP decisions hinge on the comparison with a reliable baseline evaluation, clinicians should consider sleep duration before baseline neurocognitive testing as a potential factor in the assessment of athletes' recovery.

Administration and environment considerations in computer-based sports-concussion assessment

Computer-based testing has become a vital tool for the assessment of sport-related concussion (SRC). An increasing number of papers have been published on this topic, focusing on subjects such as the purpose and validity of baseline testing, the performance of special populations on computer-based tests, the psychometric properties of different computerized neurocognitive tools, and considerations for valid and reliable administration of these tools. The current paper describes several considerations regarding computerized test design, input and output devices, and testing environment that should be described explicitly when administering computer-based cognitive testing, regardless of whether the assessment is used for clinical or research purposes. The paper also reviews the conclusions of recent literature (2007-2013) using computer-based testing for the assessment of SRC, with special attention to the methods used in these studies. We also present an appendix checklist for clinicians and researchers that may be helpful in ensuring proper attention to factors that could influence the reliability and validity of computer-based cognitive testing. We believe that explicit attention to these technological factors may lead to the development of standards for the development and implementation of computer-based tests. Such standards have the potential to enhance the accuracy and utility of computer-based tests in SRC.

Concussion symptoms and neurocognitive performance of high school and college athletes who incur multiple concussions

BACKGROUND

Multiple concussions have been associated with prolonged symptoms, recovery time, and risk for future concussions. However, very few studies have examined the effect of multiple concussions on neurocognitive performance and the recently revised symptom clusters using a large database.

PURPOSE

To examine concussed athletes with a history of 0, 1, 2, or ≥3 concussions on neurocognitive performance and the recently revised symptom clusters.

STUDY DESIGN

Cohort study (prognosis); Level of evidence, 2.

METHODS

The independent variables were concussion group (0, 1, 2, and ≥3 concussions) and time (baseline, 3 days, and 8 days). The dependent variables were neurocognitive test scores as measured by the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) neurocognitive test battery (verbal and visual memory, processing speed, and reaction time) and 4 concussion symptom clusters (migraine-cognitive-fatigue, affective, somatic, and sleep). All concussed athletes (n = 596) were administered the ImPACT test at a mean 2.67 ± 1.98 and 7.95 ± 4.46 days after injury. A series of 4 (concussion group) × 3 (time) repeated-measures analyses of covariance (age = covariate) were performed on ImPACT composite scores and symptom clusters.

RESULTS

Concussed athletes with ≥3 concussions were still impaired 8 days after a concussion compared with baseline scores on verbal memory (P < .001), reaction time (P < .001), and migraine-cognitive-fatigue symptoms (P < .001). There were no significant findings on the remaining dependent variables.

CONCLUSION

Concussed athletes with a history of ≥3 concussions take longer to recover than athletes with 1 or no previous concussion. Future research should concentrate on validating the new symptom clusters on multiple concussed athletes, examining longer recovery times (ie, >8 days) among athletes with multiple concussions.

Invalid performance and the ImPACT in national collegiate athletic association division I football players

CONTEXT

Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is a computerized cognitive test battery commonly used for concussion evaluation. An important aspect of these procedures is baseline testing, but researchers have suggested that many users do not use validity indices to ensure adequate effort during testing. No one has examined the prevalence of invalid performance for college football players.

OBJECTIVE

To examine the prevalence of invalid scores on ImPACT testing.

DESIGN

Cross-sectional study.

SETTING

National Collegiate Athletic Association Division I university.

PATIENTS OR OTHER PARTICIPANTS

A total of 159 athletes (age = 20.3 ± 1.41 years; range = 17.8-23.7 years) from a Division I collegiate football team participated.

INTERVENTION(S)

An informational intervention regarding the importance of concussion testing to promote safety was administered before testing for the most recent season.

MAIN OUTCOME MEASURE(S)

We examined preseason ImPACT testing data across a 3-year period (total assessments = 269). Based on invalid and sandbagging indices denoted by the ImPACT manual, protocols were examined to indicate how many invalid indices each athlete had.

RESULTS

A total of 27.9% (n = 75) of assessments were suggestive of invalid scores, with 4.1% (n = 11) suggesting invalid responding only, 17.5% (n = 47) indicating "sandbagging" only, and 6.3% (n = 17) showing both invalid and sandbagging responding. The informational intervention did not reduce the prevalence of invalid responding.

CONCLUSIONS

These findings highlight the need for further information about the ImPACT validity indices and whether they truly reflect poor effort. Future work is needed to identify practices to reliably target and reduce invalid responding.

Neurocognitive test performance and symptom reporting in cheerleaders with concussions

OBJECTIVE

To evaluate neurocognitive test results and symptom reporting after sports-related concussion in a group of female cheerleaders.

STUDY DESIGN

Junior and senior high school female cheerleaders (n = 138) underwent preparticipation baseline testing and repeated the ImPACT (Immediate Postconcussion Assessment and Cognitive Testing) evaluation within 7 days of concussive injury (range, 0-7 days; mean, 3.9 days). Postinjury neurocognitive and symptom scores were compared with preinjury (baseline) scores. "Abnormal" test performance was determined statistically using Reliable Change Index scores and self-reported symptoms. Main outcome variables included the composite scores indices from the ImPACT test, as well as symptoms reported by participants. Preinjury baseline and postinjury test results were compared using MANOVA.

RESULTS

As a group, cheerleaders with concussion evaluated within 7 days of injury performed poorly on the ImPACT test battery relative to their own baseline (F = 6.5; P = .00). In addition, 61% of the cheerleaders with concussions reported an increase in symptoms compared with baseline. The groups did not differ significantly by position on the squad (F = 0.37; P = .96). Of the group of cheerleaders who did not report increased symptoms at the time of postinjury evaluation, 37% had at least 1 abnormal ImPACT composite score result, suggesting some residual cognitive decline compared with baseline.

CONCLUSION

The diagnosis and management of concussion in cheerleaders should not consist solely of self-reported symptoms. Neurocognitive test results represent an important component of the evaluation process and may identify athletes with residual neurocognitive deficits who report being clinically asymptomatic.

Baseline neurocognitive scores in athletes with attention deficit-spectrum disorders and/or learning disability

OBJECT

Up to 16% of children in the US between the ages of 3 and 17 years have either attention deficit-spectrum disorder or a learning disability (LD). Sports-related concussions among youth athletes represent a significant public health concern, and neurocognitive testing is a method to evaluate the severity of cognitive impairment and recovery after a sports-related concussion. The goal of this study was to assess baseline neurocognitive differences between athletes with attention deficit hyperactivity disorder (ADHD) and/or LD versus those with neither disorder and to establish normative data for these special populations.

METHODS

Between August 2007 and March 2012, 6636 young athletes underwent baseline neurocognitive testing performed using the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery. Of these participants, 90 had self-reported LD only, 262 had self-reported ADHD only, and 55 reported both. Those with ADHD and/or LD were matched with 407 participants with no history of ADHD or LD by age, sex, and number of prior concussions. The mean scores and SDs were calculated for each group to obtain normative values. A pairwise comparison between each diagnostic group was done to assess whether LD and/or ADHD diagnostic status predicted participants' baseline neurocognitive scores.

RESULTS

Participants with ADHD had significantly lower verbal memory, visual memory, and visual motor processing speed scores, along with significantly higher reaction time, impulse control, and symptom scores compared with those without LD or ADHD. Participants with LD had similar results, with significantly lower verbal memory, visual memory, and visual motor processing speed scores, higher reaction time and symptom score, but did not differ in their impulse control score compared with those without LD or ADHD. Participants with both LD and ADHD had a significantly lower visual motor speed score and a significantly higher reaction time and symptom score than those without LD or ADHD, but did not differ with regard to the other composite scores.

CONCLUSIONS

Athletes with ADHD and/or LD have lower baseline ImPACT neurocognitive scores compared with athletes without ADHD and LD. Preliminary normative neurocognitive data for these special populations are provided.

Subjective, but not objective, lingering effects of multiple past concussions in adolescents

The existing literature on lingering effects from concussions in children and adolescents is limited and mixed, and there are no clear answers for patients, clinicians, researchers, or policy makers. The purpose of this study was to examine whether there are lingering effects of past concussions in adolescent athletes. Participants in this study included 643 competitive Bantam and Midget hockey players (most elite 20% by division of play) between 13 and 17 years of age (mean age=15.5, SD=1.2). Concussion history at baseline assessment was retrospectively documented using a pre-season questionnaire (PSQ), which was completed at home by parents and players in advance of baseline testing. Players with English as a second language, self-reported attention or learning disorders, a concussion within 6 months of baseline, or suspected invalid test profiles were excluded from these analyses. Demographically adjusted standard scores for the five composites/domains and raw symptom ratings from the brief Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) computerized battery were analyzed. Adolescent athletes with one or two or more prior concussions did not have significantly worse neurocognitive functioning on ImPACT than did those with no previous concussions. There were significantly more symptoms reported in those with two or more prior concussions than in those with no or one prior concussion. Adolescents with multiple previous concussions had higher levels of baseline symptoms, but there were not group differences in neurocognitive functioning using this brief computerized battery.

Test-retest reliability of four computerized neurocognitive assessment tools in an active duty military population

Computerized neurocognitive assessment tools (NCATs) are increasingly used for baseline and post-concussion assessments. To date, NCATs have not demonstrated strong test-retest reliabilities. Most studies have used non-military populations and different methodologies, complicating the determination of the utility of NCATs in military populations. The test-retest reliability of four NCATs (Automated Neuropsychological Assessment Metrics 4 [ANAM4], CNS-Vital Signs, CogState, and Immediate Post-Concussion Assessment and Cognitive Test [ImPACT]) was investigated in a healthy active duty military sample. Four hundred and nineteen Service Members were randomly assigned to take one NCAT and 215 returned after approximately 30 days for retest. Participants deemed to have inadequate effort during one or both testing sessions, according to the NCATs scoring algorithms, were removed from analyses. Each NCAT had at least one reliability score (intraclass correlation) in the "adequate" range (.70-.79), only ImPACT had one score considered "high" (.80-.89), and no scores met "very high" criteria (.90-.99). However, overall test-retest reliabilities in four NCATs in a military sample are consistent with reliabilities reported in the literature and are lower than desired for clinical decision-making.

ImPact test-retest reliability: reliably unreliable?

CONTEXT

Computerized neuropsychological testing is commonly used in the assessment and management of sport-related concussion. Even though computerized testing is widespread, psychometric evidence for test-retest reliability is somewhat limited. Additional evidence for test-retest reliability is needed to optimize clinical decision making after concussion.

OBJECTIVE

To document test-retest reliability for a commercially available computerized neuropsychological test battery (ImPACT) using 2 different clinically relevant time intervals.

DESIGN

Cross-sectional study.

SETTING

Two research laboratories.

PATIENTS OR OTHER PARTICIPANTS

Group 1 (n = 46) consisted of 25 men and 21 women (age = 22.4 ± 1.89 years). Group 2 (n = 45) consisted of 17 men and 28 women (age = 20.9 ± 1.72 years).

INTERVENTION(S)

Both groups completed ImPACT forms 1, 2, and 3, which were delivered sequentially either at 1-week intervals (group 1) or at baseline, day 45, and day 50 (group 2). Group 2 also completed the Green Word Memory Test (WMT) as a measure of effort.

MAIN OUTCOME MEASURES

Intraclass correlation coefficients (ICCs) were calculated for the composite scores of ImPACT between time points. Repeated-measures analysis of variance was used to evaluate changes in ImPACT and WMT results over time.

RESULTS

The ICC values for group 1 ranged from 0.26 to 0.88 for the 4 ImPACT composite scores. The ICC values for group 2 ranged from 0.37 to 0.76. In group 1, ImPACT classified 37.0% and 46.0% of healthy participants as impaired at time points 2 and 3, respectively. In group 2, ImPACT classified 22.2% and 28.9% of healthy participants as impaired at time points 2 and 3, respectively.

CONCLUSIONS

We found variable test-retest reliability for ImPACT metrics. Visual motor speed and reaction time demonstrated greater reliability than verbal and visual memory. Our current data support a multifaceted approach to concussion assessment using clinical examinations, symptom reports, cognitive testing, and balance assessment.

Between-seasons test-retest reliability of clinically measured reaction time in National Collegiate Athletic Association Division I athletes

CONTEXT

Reaction time is typically impaired after concussion. A clinical test of reaction time (RT(clin)) that does not require a computer to administer may be a valuable tool to assist in concussion diagnosis and management.

OBJECTIVE

To determine the test-retest reliability of RTclinmeasured over successive seasons in competitive collegiate athletes and to compare these results with a computerized measure of reaction time (RT(comp)).

DESIGN

Case series with repeated measures.

SETTING

Preparticipation physical examinations for the football, women's soccer, and wrestling teams at a single university.

PATIENTS OR OTHER PARTICIPANTS

102 National Collegiate Athletic Association Division I athletes.

INTERVENTION(S)

The RT(clin) was measured using a measuring stick embedded in a weighted rubber disk that was released and caught as quickly as possible. The RT(comp) was measured using the simple reaction time component of CogState Sport.

MAIN OUTCOME MEASURE(S)

Data were collected at 2 time points, 1 season apart, during preparticipation physical examinations. Outcomes were mean simple RT(clin) and RT(comp).

RESULTS

The intraclass correlation coefficient estimates from season 1 to season 2 were 0.645 for RT(clin) (n = 102, entire sample) and 0.512 for RT(comp) (n = 62 athletes who had 2 consecutive valid baseline CogState Sport test sessions).

CONCLUSIONS

The test-retest reliability of RT(clin) over consecutive seasons compared favorably with that of a concurrently tested computerized measure of reaction time and with literature-based estimates of computerized reaction time measures. This finding supports the potential use of RT(clin) as part of a multifaceted concussion assessment battery. Further prospective study is warranted.

Prevalence of invalid computerized baseline neurocognitive test results in high school and collegiate athletes

CONTEXT

Limited data are available regarding the prevalence and nature of invalid computerized baseline neurocognitive test data.

OBJECTIVE

To identify the prevalence of invalid baselines on the desktop and online versions of ImPACT and to document the utility of correcting for left-right (L-R) confusion on the desktop version of ImPACT.

DESIGN

Cross-sectional study of independent samples of high school (HS) and collegiate athletes who completed the desktop or online versions of ImPACT. Participants or Other Participants: A total of 3769 HS (desktop = 1617, online = 2152) and 2130 collegiate (desktop = 742, online = 1388) athletes completed preseason baseline assessments.

MAIN OUTCOME MEASURE(S)

Prevalence of = ImPACT validity indicators, with correction for L-R confusion (reversing left and right mouse-click responses) on the desktop version, by test version and group. Chi-square analyses were conducted for sex and attentional or learning disorders.

RESULTS

At least 1 invalid indicator was present on 11.9% (desktop) versus 6.3% (online) of the HS baselines and 10.2% (desktop) versus 4.1% (online) of collegiate baselines; correcting for L-R confusion (desktop) decreased this overall prevalence to 8.4% (HS) and 7.5% (collegiate). Online Impulse Control scores alone yielded 0.4% (HS) and 0.9% (collegiate) invalid baselines, compared with 9.0% (HS) and 5.4% (collegiate) on the desktop version; correcting for L-R confusion (desktop) decreased the prevalence of invalid Impulse Control scores to 5.4% (HS) and 2.6% (collegiate). Male athletes and HS athletes with attention deficit or learning disorders who took the online version were more likely to have at least 1 invalid indicator. Utility of additional invalidity indicators is reported.

CONCLUSIONS

The online ImPACT version appeared to yield fewer invalid baseline results than did the desktop version. Identification of L-R confusion reduces the prevalence of invalid baselines (desktop only) and the potency of Impulse Control as a validity indicator. We advise test administrators to be vigilant in identifying invalid baseline results as part of routine concussion management and prevention programs.

The relationship among neurocognitive performances and biopsychosocial characteristics of elite National Football League draft picks: an exploratory investigation

Sports neuropsychology has emerged as a specialty area within the field of clinical neuropsychology. The role of the sports neuropsychologist, rooted in baseline and post-concussion testing, has evolved to include other clinical domains, including the clinical assessment of potential draft picks. There is no published information on the neurocognitive characteristics of these draft picks. We sought to determine whether elite NFL draft picks differed from NFL roster athletes on neurocognitive (ImPACT) and biopsychosocial characteristics, and given that no published data exists for this population, adopted null hypotheses. Null hypotheses were rejected for two of the four ImPACT scores, as elite draft picks scored higher on measures of visual motor speed and reaction time than roster NFL athletes. Subtle but distinct neurocognitive differences are noted when comparing elite NFL draft picks with norms from a cumulative roster of a single NFL team.

The management of sport-related concussion: considerations for male and female athletes

Sport-related concussion continues to be a centerpiece of attention in the field of sports medicine. The benefit to using neurocognitive testing when managing concussion will be documented in this review. In addition to providing critical objective information on the neurocognitive status of the concussed athlete, research data will be provided on the pre- and post-concussion neurocognitive profiles of concussed male and female athletes. Specifically, an overview of research will be presented on the epidemiology of male and female concussion rates, as well as concussion outcomes including symptoms and cognitive function post-injury. Finally, a clinician's perspective on managing sports-related concussion will be presented focusing on three factors regarding sex differences: risk factors, clinical presentation, and management.

Response to acute concussive injury in soccer players: is gender a modifying factor?

OBJECT

Several studies have suggested a gender difference in response to sports-related concussion (SRC). The Concussion in Sport group did not include gender as a modifying factor in SRC, concluding that the evidence at that point was equivocal. In the present study the authors endeavored to assess acute neurocognitive and symptom responses to an SRC in equivalent cohorts of male and female soccer players. The authors hypothesized that female athletes would experience greater levels of acute symptoms and neurocognitive impairment than males.

METHODS

Baseline symptom and neurocognitive scores were determined in 40 male and 40 female soccer players by using the Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) scale prior to any SRC. After sustaining an SRC, each athlete completed postconcussion ImPACT tests and was carefully matched on a wide array of biopsychosocial variables. Baseline symptom and neurocognitive test scores were compared, and their acute symptoms and neurocognitive responses to concussive injury were assessed.

RESULTS

Specific a priori hypotheses about differences between males and females at baseline and at postconcussion measurements of verbal and visual memory ImPACT scores were evaluated according to simple main effects of the gender variable and according to baseline-to-postconcussion main effect and interaction of 2 × 2 split-plot ANOVA. Neither the interaction nor the main effects nor the simple main effects for either ImPACT variable were found to be statistically significant. Exploratory ANOVAs applied to the remaining ImPACT variables of visualmotor speed, reaction time, impulse control, and symptom total scores revealed only a single statistically significant baseline-to-postconcussion main effect for the symptom total.

CONCLUSIONS

The results failed to replicate prior findings of gender-specific baseline neurocognitive differences in verbal and visual memory. The findings also indicated no differential gender-based acute response to concussion (symptoms or neurocognitive scores) among high school soccer players. The implications of these findings for the inclusion of gender as a modifying factor in this tightly matched cohort are addressed. Potential explanations for the null findings are discussed.

The Human-Computer Interface in Computer-Based Concussion Assessment

Recent progress in technology has allowed for the development and validation of computer-based adaptations of existing pencil-and-paper neuropsychological measures and comprehensive cognitive test batteries. These computer-based assessments are frequently implemented in the field of clinical sports psychology to evaluate athletes’ functioning postconcussion. These tests provide practical and psychometric advantages over their pencil-and-paper counterparts in this setting; however, these tests also provide clinicians with unique challenges absent in paper-and-pencil testing. The purpose of this article is to present advantages and disadvantages of computer-based testing, generally, as well as considerations for the use of computer-based assessments for the evaluation of concussion among athletes. Furthermore, the paper provides suggestions for further development of computerized assessment of sports concussion given the limitations of the current technology.

Neuropsychological evaluation and management of sport-related concussion

PURPOSE OF REVIEW

Sport-related concussion (SRC) is common in children and adolescents. Although symptoms are typically self-limiting and short-lived, some individuals suffer persistent negative outcomes. The risk of repeat injury and prolonged recovery can be reduced by accurate diagnosis and management. In the absence of reported symptoms, neuropsychological assessment has been identified as objective means of determining dysfunction following concussion. Most research to date has focused on adult populations. This review summarizes the literature regarding neuropsychological evaluation of SRC in the pediatric athlete.

RECENT FINDINGS

As with adult populations, neuropsychological evaluation of children and adolescents diagnosed with SRC has documented skills and abilities that are particularly sensitive to head injury. Difficulties with attention and concentration, speed of information processing, and memory are commonly reported in the literature. There is also some evidence to suggest that younger children are particularly vulnerable to neurologic insult and are at greater risk for secondary consequences. Although such findings argue for more conservative management, the availability of diagnostic tools, including computerized neurocognitive assessment batteries, is limited.

SUMMARY

The neuropsychological impact of SRC on functioning is well established. Because documented deficits have the potential to interfere with critical aspects of normal development in children and adolescents, accurate diagnosis and management of SRC are especially important. Despite some limitations, there is good evidence to support the use of neuropsychological assessment to inform treatments and return-to-play decision making.

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.

Recovery from sports-related concussion: Days to return to neurocognitive baseline in adolescents versus young adults

BACKGROUND

Sports-related concussions (SRC) among high school and collegiate athletes represent a significant public health concern. The Concussion in Sport Group (CIS) recommended greater caution regarding return to play with children and adolescents. We hypothesized that younger athletes would take longer to return to neurocognitive baseline than older athletes after a SRC.

METHODS

Two hundred adolescent and young adult athletes who suffered a SRC were included in our clinical research cohort. Of the total participants, 100 were assigned to the 13-16 year age group and 100 to the 18-22 year age group and were matched on the number of prior concussions. Each participant completed baseline and postconcussion neurocognitive testing using the Immediate Post-Concussion assessment and Cognitive Testing (ImPACT) test battery. Return to baseline was defined operationally as post-concussion neurocognitive and symptom scores being equivalent to baseline using reliable change index (RCI) criteria. For each group, the average number of days to return to cognitive and symptom baseline were calculated. Independent sample t-tests were used to compare the mean number of days to return to baseline.

RESULTS

Significant differences were found for days to return to baseline between 13-16 year olds and 18-22 year olds in three out of four neurocognitive measures and on the total symptom score. The average number of days to return to baseline was greater for 13-16 year olds than for 18-22 year olds on the following variables: Verbal memory (7.2 vs. 4.7, P = 0.001), visual memory (7.1 vs. 4.7, P = 0.002), reaction time (7.2 vs. 5.1 P = 0.01), and postconcussion symptom scale (8.1 vs. 6.1, P = 0.026). In both groups, greater than 90% of athletes returned to neurocognitive and symptom baseline within 1 month.

CONCLUSIONS

Our results in this clinical research study show that in SRC, athletes 13-16 years old take longer to return to their neurocognitive and symptom baselines than athletes 18-22 years old.