Preseason Symptom Reporting and Cognition in Middle School Athletes with Past Concussions

This study examined the association between past concussions and current preseason symptom reporting and cognitive performance in 9,257 youth ages 11–13. Participants completed neurocognitive testing prior to participating in a school sports between 2009 and 2019. We stratified the sample by gender and number of prior concussions and assessed group differences on the Post-Concussion Symptom Scale total score and the ImPACT cognitive composite scores. Those with≥2 prior concussions reported more symptoms than those with 0 concussions (d=0.43–0.46). Multiple regressions examining the contribution of concussion history and developmental/health history to symptom reporting showed the most significant predictors of symptoms scores were (in descending order): treatment for a psychiatric condition, treatment for headaches, history of learning disability (in boys only), history of attention-deficit/hyperactivity disorder, and age. Concussion history was the weakest statistically significant predictor in boys and not significant in girls. Cognitively, boys with 1 prior concussion had worse speed those with 0 concussions (d=0.11), and girls with≥2 prior concussions had worse verbal/visual memory than girls with 0 concussions (ds=0.38–0.39). In summary, youth with≥2 prior concussions reported more symptoms than those with no concussions. Boys with multiple concussions performed similarly on cognitive testing, while girls had worse memory scores.

Specialist Referral and Outcomes in Adolescent Athletes With Prior Concussion History

ObjectiveTo examine specialist referral patterns and clinical outcomes in adolescents with differing levels of prior concussion history.BackgroundLimited evidence exists on healthcare utilization and outcomes in concussed adolescent athletes with and without a history of prior concussion.Design/MethodsData were prospectively collected from participants aged 12–18 diagnosed with a sport-related concussion and documented prior concussion history between August 2015-March 2020. Participants were separated into 3 groups: 0, 1, and 2 + prior concussions. Demographics, medical history, specialist referrals, and clinical outcome variables obtained at 3-months post-concussion were analyzed.ResultsOne thousand one hundred ninety-seven participants were included: 114 (10.4%) had 2+, 213 (19.4%) had 1, and 770 (70.2%) had 0 prior concussions. There was no difference in sex or time to presentation. A small difference was found across age (15.3 ± 1.6 vs 14.9 ± 1.6 vs 14.5 ± 1.6 years, p < 0.001). Significant differences were also observed between groups in self-reported history of psychological disorders (14.9 vs 15 vs 8.4%, p = 0.01) and headaches/migraines (25.4 vs 20.2 vs 15.5%, p = 0.02). Significant differences between the groups were found in specialist referrals, with more referrals made in the 2 + group to physical therapy (39.6 vs 28.2 vs 23.4%, p = 0.001), neuropsychology (17.1 vs 5.3 vs 7.5%, p = 0.001), and neurology (8.9 vs 2.9 vs 2.2%, p = 0.001). Fewer participants in the 2 + group recovered in = 30 days (53.6 vs 65.6 vs 68.5%, p = 0.04) and reported lower rates of return to activity at 3-months post-concussion (67.9 vs 85.9 vs 87.6%, p < 0.001). No differences were seen in symptom severity, PHQ-8, or GAD-7 scores. All reported as 2 + vs 1 vs 0.ConclusionsConcussed adolescent athletes with a history of 2 or more prior concussions had a higher rate of specialist referrals, were less likely to have returned to prior level of play/activity 3 months following injury, and were less likely to have resolution of symptoms in 30 days or less.

Concussion Assessment Across Several Clinical Batteries: Identifying the Components That Best Discriminate Injured Adolescents From Controls

ObjectiveTo identify which sub-components of 4 clinical assessments optimize concussion diagnosis.BackgroundMultiple assessments are part of the clinical toolbox for diagnosing concussions in youth, including the Post-Concussion Symptom Inventory (PCSI), the visio-vestibular exam (VVE), the King-Devick (KD) assessment, and the Sport Concussion Assessment Tool (SCAT-5). Most of these assessments have sub-components that likely overlap in aspects of brain function they assess. Discerning the combination of sub-components that best discriminate concussed adolescents (cases) from uninjured controls would streamline concussion assessment.Design/MethodsParticipants, 12–18 years, were prospectively enrolled from August 1, 2017 to April 29, 2020 Controls (n = 189, 53% female) were recruited from a suburban high school with PCSI, VVE, KD and SCAT-5 assessments associated with their sport seasons. Cases (n = 213, 52% female) were recruited from a specialty care concussion program, with the same assessments performed ≤28 days from injury. We implemented a forward-selection sparse principal component (PC) regression procedure to group sub-components into interpretable PCs and identify the PCs best able to discriminate cases from controls while accounting for age, sex, and concussion history.ResultsThe AUC of the baseline model with age, sex, and concussion history was 62%. The PC that combined all 5 sub-components of PCSI and SCAT-5 symptom count and symptom severity provided the largest AUC increase (+10.6%) relative to baseline. Other PC factors representing (1) KD completion time, (2) Errors in BESS tandem and double-leg stances, and (C) horizontal/vertical saccades and vestibular-ocular reflex also improved model AUC relative to baseline by 5.6%, 4.7%, and 4.5%, respectively. In contrast, the SCAT5 immediate recall test and right/left monocular accommodation did little to uniquely contribute to discrimination (<1% gain in AUC). Overall, the best model included 5 PCs (AUC = 77%).ConclusionsThese data show overlapping features of clinical batteries, with symptoms providing the strongest discrimination, but unique features obtained from neurocognitive, vision, and vestibular testing.

The Effect of Sex, Sport Participation, and Concussion History on Baseline Concussion Balance Test Performance in Division-I Collegiate Athletes

ObjectiveExplore the effect of baseline characteristics such as sex, sport, and concussion history on the Concussion Balance Test (COBALT) performance in collegiate athletes.BackgroundThe COBALT is a recently developed clinical balance assessment specifically for athletic populations following concussion. The task conditions of the COBALT are designed to challenge sensory integration and reweighting processing underlying postural control. It has been documented that balance performance is influenced by factors such as sex and sport in collegiate athletes.Design/MethodsOne-hundred twenty seven collegiate athletes (77 male, 50 female; age: 19.81 ± 1.39; height: 68.77 ± 5.57 in; mass: 80.98 ± 26.15 kg), who participated in Division-I football, soccer, or cheerleading were included. Participants completed the 4 baseline conditions (Condition 3, 4, 7, 8) of the COBALT. Condition 3 (C3) included a side-to-side headshake with eyes closed. For Condition 4 (C4) the participant stood with hands clasped, elbows extended, and thumbs up while rotating their trunk side-to-side, visually focusing on their thumbs. Conditions 7 (C7) and 8 (C8) repeated C3 and C4 on a foam surface. Two 20-second trials of each condition were completed on a forceplate and the mean angular sway velocity (°/s) were calculated and number of errors were counted. ANOVAs and ANCOVAs were used to assess the potential effects on COBALT performance.ResultsThere were no significant differences in postural sway for any COBALT condition based on sex (p > 0.05). Females demonstrated more errors than males on C7 (p < 0.001). Cheerleaders had more balance errors compared to football athletes for C3 and C7 (p < 0.05) and soccer athletes for C7 (p < 0.05). Concussion history did not have an effect on COBALT performance (p > 0.05).ConclusionsUnderstanding factors that may influence COBALT performance at baseline may enhance concussion evaluation in collegiate athletes with suspected balance deficits following concussion. While concussion history had no effect, sex and sports participation may influence performance and should be considered when interpreting COBALT results post-concussion.

Cumulative Concussion and Odds of Stroke in Former National Football League Players

Background and Purpose: Postmortem and experimental studies indicate a potential association between repeated concussions and stroke risk in older contact sport athletes. We examined the relationship between concussion and stroke history in former National Football League players aged ≥50 years. Methods: Former professional football players aged ≥50 years who played ≥1 year in the National Football League were enrolled in the cross-sectional study. Indirect standardization was used to calculate overall and decade-specific standardized prevalence ratios. Logistic regression using Firth’s bias reduction method examined the association between lifetime concussion history 0 (n=119; 12.2%), 1 to 2 (n=152; 15.5%), 3 to 5 (n=242; 24.7%), 6 to 9 (201; 20.5%), and 10+(n=265; 27.1%) and stroke. Adjusted odds ratios for stroke were calculated for concussion history groups, age, and coronary artery disease and/or myocardial infarction. Results: The 979 participants who met inclusion criteria had a mean age of 65.0±9.0 years (range, 50–99). The prevalence of stroke was 3.4% (n=33), significantly lower than expected based on rates of stroke in US men aged 50 and over (standardized prevalence ratio=0.56, Z= −4.56, P <0.001). Greater odds of stroke history were associated with concussion history (10+ versus 0, adjusted odds ratio [95% CI]=5.51 [1.61–28.95]), cardiovascular disease (adjusted odds ratio [95% CI]=2.24 [1.01–4.77]), and age (1-year-increase adjusted odds ratio [95% CI]=1.07 [1.02–1.11]). Conclusions: The prevalence of stroke among former National Football League players aged ≥50 years was lower than the general population, with significantly increased risk among those with 10 or more prior concussions. Findings add to the evidence suggesting that traumatic brain injuries are associated with increased risk of stroke. Clinically, management of cardio- and cerebrovascular health may be pertinent to those with a history of multiple prior concussions.

Concussion Among Children in the United States General Population: Incidence and Risk Factors

The objective of this study was to examine the incidence of concussion and risk factors for sustaining concussion among children from the United States general population. This prospective cohort study used data from the Adolescent Brain Cognitive Development (ABCD) Study®. Children were recruited from schools across the US, sampled to reflect the sociodemographic variation of the US population. The current sample includes 11,013 children aged 9 to 10 years old (47.6% girls; 65.5% White) who were prospectively followed for an average of 1 year (mean = 367.9 days, SD = 40.8, range 249–601). The primary outcome was caregiver-reported concussion during a 1 year follow-up period. Logistic regression was used to determine which potential clinical, health history, and behavioral characteristics (assessed at baseline) were prospectively associated with concussion. In the 1 year follow-up period between ages 10 and 11, 1 in 100 children (n = 123, 1.1%) sustained a concussion. In univariate models, three baseline predictors (ADHD, prior concussion, and accident proneness) were significantly associated with sustaining a concussion. In a multivariate model, controlling for all other predictors, only prior concussion remained significantly associated with the occurrence of a concussion during the observation period (Odds Ratio = 5.49, 95% CI: 3.40–8.87). The most robust and only independent prospective predictor of sustaining a concussion was history of a prior concussion. History of concussion is associated with 5.5 times greater odds of sustaining concussion between ages 10 and 11 among children from the general US population.

The Pupillary Light Reflex as a Biomarker of Concussion

The size of our pupils changes continuously in response to variations in ambient light levels, a process known as the pupillary light reflex (PLR). The PLR is not a simple reflex as its function is modulated by cognitive brain function and any long-term changes in brain function secondary to injury should cause a change in the parameters of the PLR. We performed a retrospective clinical review of the PLR of our patients using the BrightLamp Reflex iPhone app. The PLR variables of latency, maximum pupil diameter (MaxPD), minimum pupil diameter (MinPD), maximum constriction velocity (MCV), and the 75% recovery time (75% PRT) were associated with significant differences between subjects who had suffered a concussion and those that had not. There were also significant differences in PLR metrics over the life span and between genders and those subjects with and without symptoms. The differences in PLR metrics are modulated not only by concussion history but also by gender and whether or not the person has symptoms associated with a head injury. A concussive injury to the brain is associated with changes in the PLR that persist over the life span, representing biomarkers that might be used in clinical diagnosis, treatment, and decision making.

Longitudinal trajectory of depression symptom severity and the influence of concussion history and physical function over a 19-year period among former National Football League (NFL) players: an NFL-LONG Study

ObjectiveThis study investigated the longitudinal course of depressive symptom severity over 19 years in former American football players and the influence of concussion history, contact sport participation and physical function on observed trajectories.MethodsFormer American football players completed a general health questionnaire involving demographic information, medical/psychiatric history, concussion/football history and validated measures of depression and physical function at three time points (2001, 2010 and 2019). Parallel process latent growth curve modelling tested associations between concussion history, years of football participation, and overall and change in physical function on the overall level and trajectory of depressive symptoms.ResultsAmong the 333 participants (mean(SD) age, 48.95 (9.37) at enrolment), there was a statistically significant, but small increase in depressive symptom severity from 2001 (48.34 (7.75)) to 2019 (49.77 (9.52)), slope=0.079 (SE=0.11), p=0.007. Those with greater concussion history endorsed greater overall depressive symptom severity, B=1.38 (SE=0.33), p<0.001. Concussion history, B<0.001 (SE=0.02), p=0.997 and years of participation, B<0.001 (SE=0.01), p=0.980, were not associated with rate of change (slope factor) over 19 years. Greater decline in physical function, B=−0.71 (SE=0.16), p<0.001, was predictive of a faster growth rate (ie, steeper increase) of depression symptom endorsement over time.ConclusionsConcussion history, not years of participation, was associated with greater depressive symptom severity. Neither factor was predictive of changes over a 19-year period. Decline in physical function was a significant predictor of a steeper trajectory of increased depressive symptoms, independent of concussion effects. This represents one viable target for preventative intervention to mitigate long-term neuropsychiatric difficulties associated with concussion across subsequent decades of life.

Sex-Related Differences in Visuomotor Skill Recovery Following Concussion in Working-Aged Adults

Background: The ability to perform visually-guided motor tasks requires the transformation of visual information into programmed motor outputs. When the guiding visual information does not align spatially with the motor output, the brain processes rules to integrate somatosensory information into an appropriate motor response. Performance on such rule-based, “cognitive-motor integration” tasks is affected in concussion. Here, we investigate the relationship between visuomotor skill performance, concussion history, and sex during the course of a post-concussion management program. Methods: A total of 43 participants, divided into 3 groups based on their concussion history, completed a recovery program over the course of 4 weeks. Prior to, mid-way, and following the program, all participants were tested on their visuomotor skills. Results: We observed an overall change in visuomotor behaviour in all groups, as participants completed the tasks faster and more accurately. Specifically, we observed significant visuomotor skill improvement between the first and final sessions in participants with a concussion history compared to no-concussion-history controls. Notably, we observed a stronger recovery of these skills in females. Conclusions: Our findings indicate that (1) concussion impairs visuomotor skill performance, (2) the performance of complex, rule-based tasks can be improved over the course of a recovery program, and (3) stronger recovery in females suggests sex-related differences in the brain networks controlling skilled performance, and the effect of injury on these networks.