Post-Concussion Assessment Research Articles

Data from an emerging UK sports concussion clinic; should athlete assessment be sports-specific?

ObjectiveTo provide an overview of the Cambridge Sports Concussion Clinic; to investigate trends in patients’ neurocognition utilising assessment with the Immediate Post-concussion Assessment and Cognitive Test (ImPACT) as stratified by sport.BackgroundProfessional sporting litigation in the USA has brought to the fore the issue of sports concussion. Despite this, UK outpatient management remains in its infancy, with less than five centres offering specialised post-injury review. This poster presents data from the Cambridge Sports Concussion Clinic (CSCC), comparing ImPACT assessments across motorsport and rugby.Design/MethodsThe data is a retrospective analysis of a prospectively maintained database cohort, in which demographic, clinical and neurocognitive data are archived. The submission includes CSCC patients who attended Addenbrooke’s Hospital, Cambridge for clinical review June 2017-March 2019, who were diagnosed with concussion and completed an ImPACT assessment.Results36 post-injury reviews were completed across 19 clinical encounters with patients aged 15yrs+. 47% of athletes were injured during motorsport (saloon car, rally, motocross and single seater racing), 47% in rugby and 5% during equestrian activity. The majority were professional (47%) or competed in collegiate (21%) or high school (21%) competition with 1–13 years at their current sporting level (mean4.2 +/−SD 4.2 years). Only 22% of 18 patients were concussion-naïve prior to their current injury, with a range of 0–4 physician-confirmed diagnoses (1.7 +/− 1.3). Comparison of motorsport drivers versus rugby athletes reveals trends towards lower scores in ImPACT memory composite values (verbal F 0.57, t −1.4, p 0.15; memory F 2.1, t −0.9, p 0.37) and improved reaction time (F 3.3, t 1.8, p 0.08) with significant differences in visual motor speed (F 0.90, t−4.1, p < 0.001).ConclusionsPreliminary cross-sport analyses indicate that motorsport competitors have worse composite memory scores, better reaction times and significantly altered visual motor speed. These early data provide support for sports-specific approaches.

Estimated Age of First Exposure to Contact Sports Is Not Associated with Greater Symptoms or Worse Cognitive Functioning in Male U.S. Service Academy Athletes.

This study examined the association between estimated age of first exposure (eAFE) to contact sport participation and neurocognitive performance and symptom ratings in U.S. service academy National Collegiate Athletic Association (NCAA) athletes. Male cadets (N = 891), who participate in lacrosse (n = 211), wrestling (n = 170), ice hockey (n = 81), soccer (n = 119), rugby (n = 10), or non-contact sports (n = 298), completed the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test before the season. Generalized linear modeling was used to predict each neurocognitive domain score and total symptom severity score. Predictor variables were entered in the following order: group (contact vs. non-contact); eAFE (eAFE <12 years vs. eAFE ≥12 years); group-by-eAFE; and covariates for learning accommodation status, concussion history, and age. The group-by-eAFE interaction was not significant for any of the ImPACT composite scores (Verbal Memory, Wald χ2 = 0.073, p = 0.788; Visual Memory, Wald χ2 = 2.71, p = 0.100; Visual Motor Speed, Wald χ2 = 0.078, p = 0.780; Reaction Time, Wald χ2 = 0.003, p = 0.955; Symptom Severity, Wald χ2 = 2.87, p = 0.090). Learning accommodation history was associated with lower scores on Visual Motor Speed (χ2 = 6.19, p = 0.013, B = -2.97). Older age was associated with faster reaction time (χ2 = 4.40, p = 0.036, B = -0.006) and lesser symptom severity (χ2 = 5.55, p = 0.019, B = -0.068). No other parameters were significant. We observed no association between eAFE, contact sport participation, neurocognitive functioning, or subjectively experienced symptoms in this cohort. Earlier eAFE to contact sport participation is not related to worse neurocognitive performance or greater subjectively experienced symptoms in male U.S. service academy NCAA athletes.

The Natural History of Postconcussion Recovery Among High School Athletes.

Evaluate postconcussive symptom reporting and recovery. Public high school. Unmatched controls (n = 760); students who sustained a sports-related concussion (n = 77); matched controls (gender, grade, sport) (n = 77). Prospective longitudinal cohort study. Immediate Postconcussion Assessment and Cognitive Testing. At baseline, athletes who went on to sustain concussions were more likely than unmatched controls to be younger (P = .02), male (P = .001), and participate in different sports (P < .0001) such as football (concussed = 52%, unmatched controls = 20%). Differences were also noted regarding a previous history of concussion (P = .045; concussed athletes = 26%; unmatched control athletes = 16%) and lifetime number of concussions (P = .05). At baseline, those whose sustained concussions during the study period were more likely than matched controls to report numbness (P = .01) and concentration problems (P = .01) and more likely than unmatched controls to report dizziness (P = .02), sensitivity to light (P = .01), sensitivity to noise (P = .002), and numbness (P = .02). However, when data were reanalyzed and those with a previous history of concussion were removed, differences between those who sustained concussions during the study period and matched controls were no longer significant; when compared to unmatched controls, sensitivity to light (P = .01) and vision problems (P = .04) remained significant. Among those who sustained concussions, median time to recovery was 6 days (95% confidence interval: 4-9), and 71 out of 77 (92%) recovered by the fourth postinjury evaluation (median: 20 days postinjury). Course and time frame of recovery were variable. Data also suggest that a previous history of concussion may be contributing to baseline symptom reporting and highlight the potential enduring impact of history of concussion on sensorimotor function. However, further research as to whether preinjury measures of sensorimotor function may increase understanding regarding concussion risk is warranted.

Confirmatory factor analysis of two computerized neuropsychological test batteries: Immediate post-concussion assessment and cognitive test (ImPACT) and C3 logix

ABSTRACTIntroduction: Tests of memory and speed of cognitive and motor responses have been the primary foci in sports-related concussion assessment. This study sought to assess the construct validity of neuropsychological tests within C3 Logix.Method: Results of both baseline C3 Logix and the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) computerized tests from 86 Division I collegiate athletes were submitted to a two-factor confirmatory analysis using structural equation modeling. The two factors of Speed and Memory have been confirmed in previous studies of ImPACT.Results: Results confirmed the two-factor model of ImPACT, whereas C3 Logix did not conform to a pure two-factor model. Instead, along with additional error terms, a cross-loading was required between Speed and Memory factors in order to obtain the best model fit (χ2 = 22.91, p= 0.12, CFI = 0.94, TLI = .90, RMSEA = 0.07 (90% CI [0.00, 0.13], SRMR = .06)): all factor loadings exceeded 0.30.Conclusions: The final model suggested C3 Logix employs three pure indicators of Speed and one indicator of both Speed and Memory. The lack of a pure indicator of Memory in C3 Logix raises a concern about its specificity and ultimately, its sensitivity to a sports-related concussion.

Self-Reported History of Seizure, Baseline Neurocognitive Performance, and Symptoms Reported in High School Athletes

Abstract Purpose To examine whether a self-reported history of seizure is associated with differences in baseline neurocognitive performance and total reported symptoms. Methods Data was derived from a de-identified Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) database of high school athletes in Florida. After inclusion and exclusion criteria were applied, athletes were separated into groups dependent on self-reported history of seizure. 260 athletes (Mage=15.49, SD=1.26; 57.1% male) reported a history of seizure, and 260 athletes were randomly selected from those with no such history (Mage=15.64, SD=1.22; 61.1% male). Results ANOVA (alpha=.05) revealed significant differences between groups on the visual memory composite (F[1,559]=4.915, p=.027) and total symptom score (F[1,559]=28.596, p&lt;.001) at baseline. Athletes with a self-reported history of seizure performed significantly worse than athletes without on visual memory and reported significantly higher total symptom scores. No significant between-group differences were found on the other composites of ImPACT. Conclusion The association between seizure history and decreased neurocognitive performance has been documented in the neuropsychological literature, and may be explained by differences at a microstructural level such as differences in white matter integrity (Yassine et al., 2018). While these microstructural differences have implications on cognitive functioning and symptomatology, the present study surprisingly found comparable scores between athletes with a history of seizure and those without. Previous researchers published similar findings; however, differences were observed on the visual-motor speed composite of ImPACT (Zalneraitis et al., 2017). The inconsistencies and small effect sizes in the present literature highlight the need for investigators to determine the clinical significance of these results in concussion evaluations.

Test-Retest Reliability of ImPACT Across a Two-Year Interval in Collegiate Athletes

Abstract Purpose To examine the two-year test-retest reliability of Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) in a sample of collegiate athletes. Methods A total of 163 college athletes (63.8% female) completed two pre-season baseline assessments two years apart as mandated by their athletic programs. Participants completed the first baseline prior to their first year of competition (M age=18.38, M edu=12.13). Individuals with baselines flagged as invalid by ImPACT were excluded. No diagnosed concussions occurred between baseline assessments. Results Pearson r correlations for ImPACT composite scores between assessments ranged from .32 to .70. Paired samples t-tests indicated significant differences between verbal memory (t(162)=-4.61, p&lt;.001, MD=-3.6) and visual-motor speed (t(162)=-4.10, p&lt;.001, MD=-1.5) at time 1 and time 2. Intraclass correlation coefficients (ICCs) with a “two-way mixed” model and “consistency” type indicated higher reliability for all composite scores. Visual-motor speed (mean ICC=.83; .76–.87 95% confidence interval [CI]) was the most reliable composite score, followed by visual memory (.66; 95% CI .53-.75), impulse control (.62; 95% CI .48–.72), verbal memory (.58; 95% CI .43–.69), and reaction time (.49; 95% CI .30-.62). The total symptom score showed moderate reliability (.63; 95% CI .50–.73). Conclusion Overall, ImPACT composite and total symptom scores appear to maintain relative long-term stability in a collegiate sample across a two-year period. ImPACT composite scores showed moderate to good reliability, and total symptom scores showed moderate reliability. Results of this study corroborate previous research indicating moderately stable ImPACT scores across a 2-year test-retest period in collegiate athletes (Schatz, 2010).

Etiology and Clinical Presentation of Concussion: An Age- and Sex-matched Case Series

Abstract Purpose Differential patterns of clinical presentation in concussion have been explored previously based on etiology (e.g., sport vs. non-sport) and may be affected by biomechanical, pathophysiological, and psychological factors. The purpose of the study was to compare neurocognitive performance and symptom presentation across different etiologies in concussed patients. Methods 36 concussion patients, 12 slip-and-fall (SNF) were age- and sex-matched with motor vehicle accident (MVA) and sport-related concussions (SRC) (20.3±1.5 years; 4 males; 8 females per group). They were evaluated ≤ 2 weeks (7.2±3.7 days) after their injury. Patients completed medical history, an Immediate Post-Concussion Assessment and Cognitive Test (ImPACT), and Post-Concussion Symptom Scale (PCSS) at initial visit. Descriptive statistics, a series of Kruskal-Wallis H Tests, χ² tests and one-way ANOVAs were performed using SPSS 24. Results The three groups exhibited no differences in verbal memory (p=0.11), visual memory (p=0.10), visual motor speed (p=0.19), or reaction time (p=0.19) composites. There were no differences in symptom severity (p=0.69) or symptom count (p=0.99) or the cognitive-migraine-fatigue (p=0.69), somatic (p=0.26), affective (p=0.92), or sleep (p=0.73) symptom clusters. Comorbidities (i.e., learning disorder, previous concussion, migraine, seizure, psychological condition, or motion sickness) were not significantly different across groups. Conclusion No significant differences were found on ImPACT or PCSS across etiologies. When controlling for comorbidities and demographic variables, these groups appear similar at the initial evaluation. Future research will focus on practice patterns and clinical outcomes.

Preliminary Examinations of Concussion in Older Adults

Abstract Purpose This study sought to investigate whether concussion in older adults improves through evaluating their performance on the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) and Vestibular/Ocular-Motor Screen (VOMS) across visits and to describe and better characterize concussion in this at-risk population. Methods We conducted a retrospective review of medical records for 69 older adult patients (40 females, 29 males) that presented to a concussion specialty clinic. Participants averaged 64.71 (SD=4.1) years in age and presented within 6-998 days of injury (SD=170.9). Demographics and clinical data were recorded at intake through last appointment. Descriptive analysis, including frequencies, means, and standard deviations were performed as well as paired T-test to compare mean scores for first and last visit. Statistical significance was determined by two-sided p-values &lt;.05. Results Twenty out of 69 participants (29%) reported a previous concussion. Concussion symptom severity scores at participants’ first clinic visit averaged 56.19 (SD=26.56) compare with 39.51 (SD=25.53) at their final clinic visit. When comparing ImPACT data, all scores improved comparatively from Visit 1 to Last Visit (P values =0.000-0.014); all VOMS total scores improved as well (P =0.00-0.047). The most frequent primary profile among participants was Vestibular (31.9%). Conclusion Older adults diagnosed with concussion showed improvement on ImPACT scores and their symptom severity scores decreased. The most frequent primary concussion profile at initial visit was Vestibular. Further research with this at-risk population is needed.

Age of First Exposure to Contact Sports and Neurocognitive Performance in U.S. Service Academy Athletes

Abstract Purpose To examine the association between estimated age of first exposure (eAFE) to contact sports and neurocognitive performance and symptom ratings in collegiate U.S. Military Service Academy athletes. We hypothesized that contact-sports participation before the age of 12 would not be associated with worse neuropsychological test performance or greater symptom reporting. Methods Male cadets (N=891) who participated in contact sports [i.e., in lacrosse (n=211), wrestling (n=170), ice hockey (n=81), soccer (n=119), rugby (n=10)], or non-contact sports (n=298), completed the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test before the season. Generalized linear modeling was used to predict each cognitive domain score and the symptom severity score. Predictor variables were entered in the following order: group (contact vs. non-contact), eAFE (eAFE&lt;12 vs. eAFE≥12), group-by-eAFE, and covariates for learning accommodation status, concussion history, and age. Results The group-by-eAFE interaction was not significant for any of the ImPACT composite scores (Verbal Memory, Wald Χ2=.073, p=.788; Visual Memory, Wald Χ2=2.71, p=.100; Visual Motor Speed, Wald Χ2=.078, p=.780; Reaction Time, Wald Χ2=.003, p=.955; Symptom Severity, Wald Χ2=2.87, p=.090). Learning accommodation history was associated with lower scores on Visual Motor Speed (Χ2=6.19, p=.013, B=-2.97). Older age was associated with faster reaction time (Χ2=4.40, p=.036, B=-.006) and lesser symptom severity (Χ2=5.55, p=.019, B=-.068). No other parameters were significant. Conclusion We observed no association between eAFE, contact-sport participation, cognitive functioning, or subjectively-experienced symptoms in this cohort. Earlier eAFE to RHI is not related to worse neurocognitive performance or greater subjectively-experienced symptoms in collegiate student-athletes enrolled in military academies.

SCAT Symptom Recall Bias in Concussed Athletes

Abstract Purpose The assessment of concussed athletes uses standardized tools like the Sport Concussion Assessment Tool (SCAT). The purpose of this study was to evaluate whether concussed athletes accurately recalled baseline functioning. Methods A retrospective cohort analysis of University football student-athletes from 2014-16 seasons was conducted. Forty-six student-athletes (M=19.7, SD=1.8) who suffered a concussion during the competitive season underwent a post-concussion assessment with a sports medicine physician within 24 hours of injury. Assessments included use of the symptom report from The SCAT3. Athletes were asked to recall their pre-injury baseline functioning. Results Of the 46 athletes who underwent assessments, 22 reported having at least 1 symptom (M=1.4, SD=2.0) at baseline evaluations. Yet at the initial medical evaluation, only 10 of these athletes correctly recalled having symptoms prior to injury, and none of them accurately reported their total symptom report. Paired t-tests revealed significant differences between an athletes predicted recall of the number of symptoms (M=0.7, SD=1.2) and total symptom scores (M=2.1, SD=3.4) conditions; t(45)=-3.28, p=.002, d=0.48. Conclusion Having accurate information for diagnosing concussions is important during concussion medical evaluations. Many clinicians depend on an athlete’s subjective reporting of symptom change. Our results indicate that an athlete’s accuracy of pre-injury functioning is poor, consistent with what has been termed “the good old days bias.” The findings suggest having baseline assessments can be helpful and clinicians may need to carefully understand an athletes pre-morbid functioning.

Exposure to Serial Post-Concussion Neurocognitive Testing Does not Affect Future “Updated” Baseline Neurocognitive Performance in Adolescent Athletes

Abstract Purpose We investigated a dose response for serial post-concussion neurocognitive testing exposure on updated post-concussion baseline testing performance. Methods Athletes (13-18 yrs) that completed two, valid baseline neurocognitive testing (ImPACT) sessions approximately 1-3 years apart participated in this study. A sub-sample of athletes that sustained a SRC between baseline sessions were categorized into dose-response groups based on the number of serial, post-concussion neurocognitive tests completed following SRC: ONE (n=76), TWO (n=99), and THREE OR MORE (n=111). Athletes that did not sustain a SRC comprised the ZERO group (n=289). Change scores between the first to the second baseline were calculated for the ImPACT Composite and Symptom Scores and compared between the dose-response groups and controls with 5 ANOVAs, with a Bonferroni-corrected p-value of (p&lt;.01). Baseline testing was administered using ImPACT stimuli within the “Baseline” administration, and all post-concussion ImPACT testing was administered using alternate-form associated with that specific post-injury assessment (Post-Injury1, Post-Injury2, etc). Results ANOVAs revealed no effect of number of post-concussion assessments (0, 1, 2, or 3+) on magnitude of the change between first and final baselines, for Verbal Memory (p=.08), Visual Memory (p=.96), Visual Motor Speed (p=.47), Reaction Time (p=.91), or Total Symptom Scores (p=.86). Conclusion Repeated exposure to neurocognitive testing has revealed improvements in Visual Motor Speed among normal controls, across test-retest intervals of 1-month, 1-year, and 2-years. However, in this study, exposure to post-concussion, serial neurocognitive testing had no effect on future performance on post-concussion baseline neurocognitive testing.

Influence of Pre-Morbid Migraine History on Baseline Vestibular/Ocular Motor Screening and King-Devick Test Performance

Abstract Purpose To examine the effects of premorbid migraine history on baseline Vestibular/Ocular Motor Screening (VOMS) and King-Devick (KD) test performance in youth athletes. Methods This study implemented a cross-sectional design and was conducted at a series of youth sport venues in a designated research area. Youth athletes between the ages of 8 and 14 years with a diagnosed history of migraine headaches (n=28) and match controls (n=28) were administered a baseline VOMS and KD test. Between-group comparisons for provocation scores on the VOMS (smooth pursuit, saccades, convergence, vestibular-ocular reflex [VOR], and visual motion sensitivity [VMS]), Near-point of convergence [NPC] average distance (cm), and KD time (seconds) were conducted. Results Individuals diagnosed with migraine headaches reported greater VOMS scores compared to match controls on smooth pursuit (0.43±1.1 vs. 0.00±0.0; p=.02), convergence (0.46±1.2 vs. 0.04±0.1; p=.04), horizontal VOR (0.89±1.4 vs. 0.07±0.2; p&lt;.001), vertical VOR (0.61±1.1 vs. 0.11±0.3; p=.04), and VMS (0.86±1.5 vs. 0.04±0.1; p=.01). Differences were also observed on the KD test with worse times in the diagnosed migraine group (54.33±11.8s) compared to match controls (47.17±8.9s; p=.02). No differences were reported on NPC distance between the migraine (2.22±3.1cm) and control group (0.83±1.2; p=.06). Conclusion Youth athletes with diagnosed migraine history reported higher baseline VOMS scores and worse KD time compared to match controls, further illustrating the influence of premorbid migraine headaches as a risk factor for elevated baseline concussion assessment. Special consideration may be warranted for post-concussion assessment in athletes with diagnosed migraine headaches.

A-02 Baseline Symptom Reporting Scores Vary Between International and Domestic Athletes as Measured by SCAT-5 and ImPACT

Abstract Objective Prior research has not evaluated symptom-reporting differences between international and domestic athletes for baseline concussion symptoms. Since universities enroll both, it is important to consider differences for interpretation of post-trauma assessments. This study compared symptom endorsements between international and domestic athletes utilizing the Sport Concussion Assessment Tool-5th Edition (SCAT5) and Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). Method 622 domestic collegiate athletes, aged 17-25 years (M = 19.29, SD = 1.44; 65% male), and 167 international collegiate athletes, aged 17-24 (M = 20.27, SD = 1.61; 62% male) were administered the SCAT5 and ImPACT. All symptoms were compared. Results International participants (M = 3.46; SD = 3.99) reported significantly more symptoms, U = 42561, p &lt; 0.001 (Mann-Whitney U Test), on the SCAT5 compared to domestic participants (M = 2.43; SD = 3.20), and at a greater severity, U = 43404, p = 0.001, among international participants (M = 5.04; SD = 7.27) compared to domestic participants (M = 3.70; SD = 5.54). Of the 22 SCAT5 symptoms, 9 were endorsed more frequently by international students. International participants (M = 4.95; SD = 7.57) also reported significantly more symptoms, U = 43514, p = 0.001, on the ImPACT compared to domestic participants (M = 3.18; SD = 5.35). Of the 22 ImPACT symptoms, 12 were endorsed more frequently by international students and 2 by domestic. Conclusions International athletes report significantly more symptoms and at a greater severity on ImPACT and SCAT5 compared to domestic athletes. Differences did not appear related to travel and fatigue such as sensitivity to light and noise, difficulty concentrating, and feeling more emotional. Over 20,000 international student-athletes are enrolled in the NCAA, it is important to note differences observed in symptom reporting for appropriate baseline evaluation (NCAA, 2019).

The Influence of Atypical Sleep Before Baseline Concussion Testing

Abstract Objective To examine the role of an atypical night of sleep prior to baseline neuropsychological testing on symptom reporting and cognitive functioning in student-athletes. Method 182 (M = 138, F = 44) athletes were assessed on neuropsychological battery at baseline. Athletes were categorized as sleeping a typical amount (within 1.5 hours, N = 128) or less (&gt; 1.5 hours less, N = 54) the night prior to baseline. The Cognitive Health Questionnaire (CHQ) assessed typical levels of sleep and the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) assessed hours of sleep the night before. Independent samples t-tests compared the two groups on the following outcome measures: affective, somatic, sleep, and cognitive post-concussion symptom scale (PCSS) clusters, headache, Beck-Depression Inventory-Fast Screen (BDI-FS), and composites of memory and attention/processing speed. Results Athletes getting less sleep than typical the night before a baseline assessment reported significantly more depression symptoms on the BDI-FS (p &lt; .001) and significantly more symptoms on all PCSS symptoms scales: affective (p &lt; .001), cognitive (p &lt; .001), physical (p &lt; .001), and sleep (p = .001). A trend in the same direction was present for headache (p = .06). The groups did not significantly differ on performance on either composite of cognitive functioning (p &gt; .05). Conclusions Sleeping less than the typical amount the night before a baseline assessment results in self-reported higher levels of depression symptoms across all domains of the PCSS.

Multivariate Base Rates of Low Scores and Reliable Decline on ImPACT in Healthy Collegiate Athletes Using CARE Consortium Norms.

To describe multivariate base rates (MBRs) of low scores and reliable change (decline) scores on Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) in college athletes at baseline, as well as to assess MBR differences among demographic and medical history subpopulations. Data were reported on 15,909 participants (46.5% female) from the NCAA/DoD CARE Consortium. MBRs of ImPACT composite scores were derived using published CARE normative data and reliability metrics. MBRs of sex-corrected low scores were reported at <25th percentile (Low Average), <10th percentile (Borderline), and ≤2nd percentile (Impaired). MBRs of reliable decline scores were reported at the 75%, 90%, 95%, and 99% confidence intervals. We analyzed subgroups by sex, race, attention-deficit/hyperactivity disorder and/or learning disability (ADHD/LD), anxiety/depression, and concussion history using chi-square analyses. Base rates of low scores and reliable decline scores on individual composites approximated the normative distribution. Athletes obtained ≥1 low score with frequencies of 63.4% (Low Average), 32.0% (Borderline), and 9.1% (Impaired). Athletes obtained ≥1 reliable decline score with frequencies of 66.8%, 32.2%, 18%, and 3.8%, respectively. Comparatively few athletes had low scores or reliable decline on ≥2 composite scores. Black/African American athletes and athletes with ADHD/LD had higher rates of low scores, while greater concussion history was associated with lower MBRs (p < .01). MBRs of reliable decline were not associated with demographic or medical factors. Clinical interpretation of low scores and reliable decline on ImPACT depends on the strictness of the low score cutoff, the reliable change criterion, and the number of scores exceeding these cutoffs. Race and ADHD influence the frequency of low scores at all cutoffs cross-sectionally.

Clinical Utility of Oculomotor and Electrophysiological Measures in Identifying Concussion History.

To examine whether oculomotor and electrophysiological measures improve the clinical performance of the typical concussion protocol for classifying collegiate athletes with a history of concussion. Cross-sectional. University Athletic Medicine and Research Facility. Forty-five varsity collegiate athletes. Collegiate varsity athletes with or without a history of a diagnosed concussion. Multivariate receiver operating curve and area under the curve (AUC) analyses tested the clinical performance of the typical concussion protocol (symptoms, postural control, neuropsychological abilities). We examined differences in clinical performance between this protocol and after adding reflexive saccade and event-related potential (ERP) indices. Hypotheses were formed after data collection. Significant AUCs were demonstrated for the typical concussion protocol (model 1: AUC = 0.75, P = 0.007), after adding reflexive saccade eye excursion gain (model 2: AUC = 0.80, P = 0.001), and ERPs (model 3: AUC = 0.79, P = 0.002). The AUC for reflexive saccades and ERPs was significant (model 4: AUC = 0.70, P = 0.030). Model 2's increased clinical performance compared with model 1 was nonsignificant, χ(2) = 1.871, P = 0.171. All 4 models demonstrated adequate sensitivity and specificity for classifying athletes with a previous concussion. Adding reflexive saccades and ERPs did not significantly increase clinical performance of the typical concussion protocol. Future research should determine the clinical utility of saccades and ERPs for acute postconcussion assessments.

Assessing Postconcussive Reaction Time Using Transport-Based Morphometry of Diffusion Tensor Images.

Cognitive deficits are among the most commonly reported post-concussive symptoms, yet the underlying microstructural injury is poorly understood. Our aim was to discover white matter injury underlying reaction time in mild traumatic brain injury DTI by applying transport-based morphometry. In this retrospective study, we performed DTI on 64 postconcussive patients (10-28 years of age; 69% male, 31% female) between January 2006 and March 2013. We measured the reaction time percentile by using Immediate Post-Concussion Assessment and Cognitive Testing. Using the 3D transport-based morphometry technique we developed, we mined fractional anisotropy maps to extract the common microstructural injury associated with reaction time percentile in an automated manner. Permutation testing established statistical significance of the extracted injuries. We visualized the physical substrate responsible for reaction time through inverse transport-based morphometry transformation. The direction in the transport space most correlated with reaction time was significant after correcting for covariates of age, sex, and time from injury (Pearson r = 0.44, P < .01). Inverting the computed direction using transport-based morphometry illustrates physical shifts in fractional anisotropy in the corpus callosum (increase) and within the optic radiations, corticospinal tracts, and anterior thalamic radiations (decrease) with declining reaction time. The observed shifts are consistent with biologic pathways underlying the visual-spatial interpretation and response-selection aspects of reaction time. Transport-based morphometry discovers complex white matter injury underlying postconcussive reaction time in an automated manner. The potential influences of edema and axonal loss are visualized in the visual-spatial interpretation and response-selection pathways. Transport-based morphometry can bridge the gap between brain microstructure and function in diseases in which the structural basis is unknown.

Changes in Fixational Eye Movements following Concussion

Concussions can affect smooth pursuit, saccadic, and vergence eye movements. Fixational eye movements (FEMs) - the small, involuntary motion of the eye that occurs while focusing on a target - are affected by Alzheimer’s, Parkinson’s, and mild cognitive impairment. However, little is known about changes in FEMs following concussion. PURPOSE: To compare FEMs in concussed patients to controls using a retinal image-based eye tracking device. METHODS: Participants included 50 patients with a concussion and 39 age- and gender-matched controls aged 13-27 years. FEMs were measured with a tracking scanning laser ophthalmoscope (TSLO) that tracks retinal image motion at 480 Hz with accuracy of ~0.2 arcmin. Eye traces were analyzed offline to compute microsaccadic amplitude, peak velocity, and peak acceleration. Fixational spread, using bivariate contour ellipse area (BCEA), intersaccadic intervals, blink rate, and total blink time were also analyzed. Concussed patients completed the Vestibular Oculomotor Screening (VOMS), Post-concussion Symptom Scale (PCSS), and Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) for comparison with FEMs. RESULTS: Microsaccades were larger (amplitude – controls: 0.397° SD 0.32, concussion: 0.597° SD: 0.45; p <0.001) and faster (peak velocity: control: 27.9°/sec SD: 22.2; concussion: 39.7°/sec SD: 30.3; p<0.001; peak acceleration: control: 6.27°/sec2 SD: 9.29; concussion: 9.47°/sec2 SD: 14.1) in concussed participants. Although concussed patients and controls made equal numbers of microsaccades during a 30 sec recording, concussion patients had a greater proportion of larger, faster microsaccades - with 19% more microsaccades at amplitudes greater than 0.75° and 22% more microsaccades ≥30°/sec. The BCEA was 221% larger in concussed patients (0.56°) compared to controls (0.26°). CONCLUSIONS: These findings support changes in FEMs following concussion as measured using retinal image-based eye tracking. Microsaccades in concussed patients were larger in amplitude, peak velocity, and peak acceleration compared to controls. Specifically, fixation is less precise, with a larger spread (i.e., increased BCEA). Retinal imaging and eye-tracking of FEMs may be useful in identifying and monitoring recovery following concussion.

Administering Computerized Neurocognitive Testing Does Not Increase Symptoms Following Sport-Related Concussion

Computerized neurocognitive testing (CNT) is an important component for the management of sport-related concussion (SRC). The cognitive demands required to complete CNT may exacerbate SRC symptoms. PURPOSE: To prospectively examine changes in post-concussion symptom reporting after completing CNT. METHODS: One hundred forty-five athletes (15.72 ± 1.78 years) with a medically diagnosed SRC completed the Post-Concussion Symptom Scale (PCSS) before and after completing a CNT (e.g., The Immediate Post-Concussion Assessment and Cognitive Testing: ImPACT). Changes in total PCSS symptoms and symptom clusters (somatic, affective, and cognitive-migraine-fatigue) were examined with a series of paired samples t-tests. Participants were also assigned to groups based on the time elapsed from injury until their first clinical visit: 0-7, 8-14, and 15-21 days. A series of 3 (time since injury group) X 2 time (pre, post) analysis of variance were performed on symptom totals and clusters. Statistical significance was set at a Bonferroni-corrected p < .01. RESULTS: There were no significant differences in total (t (145) = -.69, p = .49), somatic, (t (145) = -1.02, p = .31), or cognitive-migraine-fatigue symptoms (t (145) = -1.75, p = .08) before and after CNT. There was a significant difference for affective symptoms (t (145) = 2.51, p = .01). Affective symptoms were significantly higher before CNT (M = 2.19, SD = 3.15) compared to after CNT (M = 1.80, SD = 2.89). There were no between-subjects or within-subjects main effects for total, somatic, affective, or cognitive-migraine-fatigue symptom clusters (p > .05). There were also no significant group x time interactions for total symptoms (Wilks λ =.99, F [1, 142] = 0.20, p = .40, η2 = .01), somatic, (Wilks λ =1.00, F [2, 142] = .30, p =.74, η2 = .004), affective (Wilks λ =.99, F [2, 142] = 0.89, p =.43, η2 = .01), or cognitive-migraine-fatigue symptom clusters (Wilks λ =.99, F [2, 141] = 0.41, p =.67, η2 = .01). CONCLUSIONS: The administration of CNT during recovery from SRC does not increase concussion symptoms. Sports medicine professionals should administer CNT to concussed athletes even when symptomatic, to more accurately identify neurocognitive impairment, which will help determine targeted treatment options.

Preliminary normative study of ImPACT® in Finnish professional male ice hockey players

Assessment of cognition is an important part of concussion management. The common paradigm of baseline and postinjury evaluations is recommended but due to the often lacking baseline data, reliable normative values are needed. The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®) battery is a widely used method of cognitive assessment offering several language options. There are few comparative studies between language groups on this test battery. ImPACT was administered at baseline to 184 Finnish male Professional Ice Hockey league players. The performance of the Finnish sample differed from previously published English and Czech language samples on the Visual Motor Speed and Reaction Time composites with medium effect-sizes (d = 0.38–0.52). Age, but not education or prior concussions, was associated with ImPACT performance. ImPACT performance is not uniform across language and culture groups and the findings highlight the need for language-specific norms. Finnish reference values for ImPACT for ages <20, 20–26, and >26 are presented. A similar approach is encouraged for other languages.